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MONTHLY REVIEW—Part 1

Published by the American Electroplaters Society

Publication and Editorial Office, 3040 Diversey Ave., Chicago

VOL. XVI   JULY, 1929   No. 7

Note: This month has 2 parts. Click here for PART 2.


EDITORIAL

Our Seventeenth Annual Convention has come and gone, and has added to the history of our society, both from standard of educational program and the social end of the convention, not forgetting plant visitation part of the program. Nowhere we may hold a convention holds so much in store for the observer who avails himself of the visits to plants as Detroit, and these committee men did themselves proud in their endeavors to assist visitors to see as much as the time would permit.

Did you know that 23 out of 24 papers read were read by chemists or chemically trained men and this in itself was highly commendable, and it is a sure omen that our society is keeping in progress with the time and demand of employers for more intelligent methods of plating control and research.

Of course it is hoped that we may not become to highly technical all at once and lose the interest of the member who is slowly but surely grasping the mechanics of chemistry in high schools and vocational schools of United States and Canada, or we may lose the interest of that part of our group of fellows who are always furnishing commercial efficiency that is necessary to further success of our education. I believe that our convention committees will do well to try and hold this matter in mind and greater interest in our future conventions will result.


THE EDITOR’S MEMOIRS

As the editor of your Review for past three fiscal years, I address you ”I” rather than the editorial ”We”, for just this once, because this is a personal message.

I wish to thank every member of the American Electroplaters Society and the many associate members and subscribers to our Research Fund, for the timely aid and advice offered me during my different terms of office in your society—as Vice-President, Secretary-Treasurer, President and Editor—and assure you that it has been the privilege of a lifetime to associate with you and to serve you for another year.

As you all know, I was born long ago (I refuse to say when). My parents passed out of the picture when I was quite young, leaving me to support a family at age of 16 years. This was first imposition that was thrust upon me and, no doubt, is responsible for my dislike of large families and work.

Some children grow up, some are brought up, and many are dragged up by hard knocks and experiences, and summarizing my experiences, I guess I was in the class of dragged ups.

And although I feel that I passed the dangerous age of a growing kid, I am still hoping that I can fulfill my desire to keep the many associations and friendships formed while in service of A. E. S. and live to see the further progress of this great society.

F. J. Hanlon


QUESTION BOX

*Philadelphia Branch Annual Sov-Book.
Conducted by Mr. Geo. B. Hogaboom, Past President A. E. S., Philadelphia 1929 Annual Meeting


MR. GEORGE B. HOGABOOM: Members of the Philadelphia Branch and Guests: I am a little bit surprised at Dr. Graham renigging and putting the time over on me, but inasmuch as the surprise was real (I happened to be with him at the time he received the program and I know that what he says is perfectly correct, that he did not have the opportunity of preparing anything) it is our misfortune.

When Mr. Gehling spoke to me and asked me if it would be possible to say something at this meeting, I consented, and later, in thinking over meetings that had been held, it occurred to me that probably a Question Box would be more in line than a set speech. We have heard two very excellent speeches, one by Mr. Beaver and the other by Mr. Proctor, and they are very good. We need those; we need that work of investigation; we need the investigations to carry us along. But sometimes it is well to stop and think what has been done, to mull it over, and then to begin to ask questions. And it has been found in a number of the meetings that those present are kind of hesitant in asking questions other than those which bear upon the subject in hand. So, if you have a general, open question box, why, then any question is in order.

I had the privilege of speaking a week ago last night at the Bridgeport Branch, and tried the same thing, a Question Box, with more success, and it was very pleasing to note the large number of people that turned out. And for two hours straight, there was a continuous bombardment of questions. And what was the lest part of it, and what pleased me more than anything else and made me feel it was worthwhile was that those in the audience took part and answered backward and forward. So that I would ask that same thing this afternoon, if the questions are asked, that those in the audience that have some answer on that question do not hesitate a moment, but give your views.

It must not be assumed, it cannot be assumed, that every question that comes up, a speaker can answer. That would be an impossibility. But you can give a general indication, and it is quite probable that there is someone in the audience that has enough experience in that line, in which the question is asked, to answer the question. So will you please do that ?

Now I am going to take the privilege, if I may, of asking the first question. I think that is the speaker’s privilege, and the question that I would like to ask need not be answered if you don’t wish to but still I would like to ask it; and that is what causes nickel to peel when chromium plated, and how are you going to stop it? (Laughter.)

MR. CHARLES PROCTOR: I think Dr. Blum answered that question some time ago, when he said there is one thing chromium can teach us, to put a good nickel deposit upon the basic surface, and then chromium would not peel off. Of course, it isn’t always in the cleaning. We sometimes go back at cleaning and think it is the fault of the cleaning. But I think it is right there in the nickel solution.

MR. HOGABOOM: Well, we will discuss that fully a little later on, and I may take issue with that statement.
Now, let us go along to general things and come to that afterwards. Has anybody a question?

MR. ALBERT HIRSCH: Could one add too much sodium perborate to a nickel solution?

DR. BLUM: I think Mr. Proctor probably has some information on that.

MR. PROCTOR: I think too much can be added. Too much of anything can be added.

MR. HOGABOOM: What would be the harmful effect of an increase?

MR. PROCTOR: It seems to me the effects are the reverse, when you have too much. When you add sodium perborate you have to acidate that sodium perborate, irrespective of the amount of it you use, to the acidity of your nickel solution. If you stat putting it in your solution, it acts the same as any other alkali would act, and you get a reverse action of your solution. But when they put the correct amount in there, not only put it when it is absolutely needed, then, of course, sodium perborate does do the work—but I believe you can add too much. In fact, I have added too much myself, and got reverse results

MR. HIRSCH: Will sodium perborate positively stop pitting?

MR. HOGABOOM: I don’t think that question can be answered by ”yes” or ”no.” You know that is one of those questions like a man that has said every question can be answered by ”yes” or ”no,” and a fellow asked him if he had stopped beating his wife. If he says ”no,” it means he has been beating her, and if he says ”yes,” it means the same thing. You can’t answer ”yes” or ”no” to every question. Pitting is not the result of any one thing, and, therefore, one thing will not correct pitting. Pitting can be from several causes. It can be from an excess of acid. It can be from probably organic matter in the solution. It can be from a high copper content in the solution. It can be that if you will clean work in a solution or in an alkali that has highly insoluble material in it, such as sodium aluminum silicate, and that adheres to the work, and that is not put through an acid so as to remove it; it is not thoroughly removed. That will cause pitting.

Pitting is of two, kinds. If you will examine them under a microscope you will see that immediately. I am sorry we haven’t a blackboard. A meeting without a blackboard is like a piece of steak without salt, almost. If you will examine pitting under a microscope, you will find if it is gas pitting, that the deposit will be like this:

DRAWS DIAGRAM

and there will be the bubble of gas in the centre. But the deposit will always come down, slope toward the pit. If it comes from some material on the work, for example, like sodium aluminum of silicate, the plate will try to bridge across that and it will slope up over the top, and then, if you wash that out and examine it, it will look like the crater of a volcano.

DRAWS DIAGRAM.

I have some excellent micrographs of both classes of pitting— so that when you say pitting, you are using a general term that cannot be specified as it can be stopped by any one thing.

Now another cause of pitting, and I was very much interested in this pitting—it was brand new to me, only a few weeks ago; it was in the latter part of September. And that was plating on aluminum, where you nickel plate on aluminum, according to Mr. Harold Work’s process. The percolators were made from aluminum. I had never in all my life seen such an elegant example of pitting The whole article was one mass of pits. The whole trouble was low current density. Contrary to everything that would be expected, it was low current density. And in all probability what happened was—I may be wrong, I will ask Dr. Blum or Dr. Graham, or somebody to correct me if I am in error—but in all probability what happened was the nickel which was on there was so porous that it went on there like lace, and it was probably an electrolytic action that was setup between the nickel and the aluminum and caused a gassing which resulted in a pit. Now the example of it was this: There were twelve percolators put in a nickel solution, and the current density amounted to about two amperes per square foot. Beautiful pitting. The percolators were taken out, and three were put in, because the carrying capacity of the wire was not sufficient to carry enough current so you could get about eight or ten amperes per square foot. So they took out enough wok to carry eight or ten amperes per square foot, ran the work for forty-five minutes, and not a solitary pit could be found. That was operated all day Sunday (I work on Sunday once in a while— not in Philadelphia, though; there is nothing open in Philadelphia on Sunday; it is dead)—we operated it all day Sunday and all day Monday, and later, one of our service men went down to that same plant and stayed there for ten days, and the thing was operated at ten amperes per square foot, and not a pit.

So, when you say pitting, it is your local problem, and you must try several remedies before overcoming it.

MR. ALBERT HIRSCH: I realize that. What I have reference to starts at the bottom of the rack—only the ones on the bottom are pitted, and I have used sodium perborate in various ways.

MR. HOGABOOM: I have cleared up pitting by cleaning anodes. I think dirty anodes is one of the greatest contributory causes toward pitting. It may be this. I have spoken for a long time upon the voltage that is used. I realize that in those days I didn’t know what I was talking about. I should have said ”anode current density,” and now we will talk anode current density, and that is something that should be written on, because you have to have anode current density the same as your cathode current density. If you have a relation of your anode to your cathode so you can get anode current density so that you can get a cathode current density that will give you probably what you wish at a pressure of 1.8 volts, you get a very good nickel, without gassing, and without pitting. If you were to plate cast iron shears (Mr. Clark will bear me out) and you would want to grind those shears and sharpen them after they were nickel plated, you would not run over 1.8 or 2.0 volts at the outside, pressure. That is, you would ‘have your anode current density so that you could get that. If you will do that, then you can grind and you can sharpen and not lose a shear. If’ you use more than that, say 3.0 or 3.5 or 4.0 volts, unless you are well protected, you get both pitting and peeling.

Now if you have an anode that is coated over, like the lower purity anodes, or solutions that are not run correctly, you get a polarization, that is, you get a blocking up of your current. When you get a blocking up of your current, and you want a certain number of amperes on your rheostat, you jack up your current. When you jack up your current, you increase that pressure. When you increase the pressure, it may be that you take and get a decomposition of solution. We watched, on the plating of metal; we watched for a small, brown spot that would appear on nickel plated work. The moment that brown spot appeared, we knew that within 24 hours we would have pitting. If we stopped at the first indication of that brown spot, cleaned our anodes, didn’t change the solution at all, we wouldn’t have any pitting.’ Then we could get our current density at a pressure that wasn’t above the decomposition voltage of the solution.

Now, anode current density. If you have a square foot of anode and a square foot of cathode in a nickel solution, for example, and that anode is clean, you can get five amperes per square foot, for example, we will say at 1.8 volts pressure. You have got, then, five amperes anode current density and five amperes cathode current density. You change the anode area so you have only a half of a square foot of anode area, and maintain one square foot of cathode area. You want five amperes per square foot on your cathode. You have got to have ten amperes on your anode. Now if you get that at 1.8 volts, when you have five amperes current density at your anode, you don’t get it when you have to have ten. You have got to increase your pressure to get that across. When you increase your pressure and get that, then something happens in the solution.

Now on the opposite side, suppose you take a cathode current density of five amperes per square foot on a square foot of surface, and have two square feet of anode, then all you require is 2/ amperes on your anode per square foot. Then, instead of 1.8 volts, you may have to go down to 1.3, or even a lower voltage, to take and get that across. Now that may be a condition in which you do not get good anode corrosion, that your metal won’t go into solution. In experimental work that I did on silver, back several years ago, I did that and gave a talk before the Platers’ Society— I think it was in 1909, and I called it pressure, not knowing the term, ”anode current density,” at that time. When I had one-half volt pressure on my anode, that is, keeping my cathode area constant, and wanting five amperes per square foot, when I increased my anode area so I could get that five amperes per square foot on my cathode at half a volt pressure in a run of twenty-four hours a day, seven days in the week, I did not get any metal into my solution from my anodes. My metal constantly decreased. My anodes looked like galvanized iron. When I used a pressure of 1 volt, I got an upkeep of my solution. Mesle probably will take issue with me—we will ask Mesle in a moment because this is question box time. But that was my experience, that when we dropped to three volts, we got a black coating on the anode, and the meter immediately began to go down, because the anode was polarized. Had you said polarization to me, that day, I would have thought you were talking about the North Pole or the South Pole; but you get anode polarization. It is blocked off. That block would completely cover the anode, fall off, and then the ampere needle would return. Correcting that wasn’t a very easy job. It was analyzed and found to be silver peroxide, and silver peroxide is not as soluble in the cyanide solution as when it would go in from a clean anode—that is when the silver would go in from a clean anode, so that you there got a disintegration of your anode.

And so anode current density, in my opinion, plays a very important part, both in the upkeep of the metal in the solution, and the nature of the corrosion of the anode, and in all probability an effect upon the solution which in turn will affect the character of the deposit.

MR. F. C. MESLE (Oneida Community): I think that my experience in general is in accord with what you have said, Mr. Hogaboom.

MR. HOGABOOM: For the first time we agree.

MR. MESLE: We do agree, once in awhile. Just one thought that did occur to me. That is that sometimes, for instance, the position of anode to cathode will really give you a higher anode current density at certain parts of the anode than you think you have because maybe here is the anode (shows) and the cathode is down there (shows) and you will judge that your anode current density is at a certain point, when in reality most of the current is flowing from the lower third of the anode, and that; of course, causes the same trouble.

MR. HOGABOOM: Mr. Mesle, at the Hartford meeting of the Platers’ Society, and later at Toronto, brought out one of the most important things there is in electroplating of recent times. The more I have thought over it, the more I admire his work, and the more appreciative I am of being able to listen to him. Carrying along what he has stated there, about the anode, he talked about cathode current density, and that is one of the misleading things, and why some fellows are misled by measuring with the micrometer and saying they are plating a thousandth of an inch of nickel in an hour. There is local cathode current density. You have here, for example, a piece of work, and Mesle found that in a spoon, for example, if this happens to be the bowl of a spoon (shows)—he may have outside here, on the outside edge, as high a local current density or current concentration there as 30 amperes per square foot. In the centre, he may not have over 4 or 5 amperes per square foot; but the total current density over the whole article would be 15 amperes per square foot, and you would say, ”I am using 15 amperes per square foot,” but where is that 15 amperes per square foot? You don’t know, Now along comes a fellow and he uses a micrometer, he takes the edge, here, and he has got here, not fifteen amperes per square foot, but over here at the edge he has got probably what Mesle found, twice that, 30 amperes per square foot. Then he measures that and says, ”I am using so many amperes and I get such a thickness, therefore, I am depositing a thousandth of an inch in an hour.” He is wrong. This thing of distribution of current, as Mesle found, is very interesting, and it explains a great number of things, which I didn’t understand myself before Mesle brought that out. I had a general opinion of it on account of some work on distribution of deposit of paper that I read in the Indianapolis Convention several years ago, but Mesle had the right thing; he gave the right definition of having local current densities or current concentrations at different points.

Now comes this point: If Mesle could get on the edge of the spoon a silver deposit that would be where it is perfectly O. K. for burnishing, at that edge, then it stands to reason that if you could get that all over that spoon, the same current density, then you could use 30 amperes per square foot all over the spoon. See what that would mean? We are plating today, five amperes per square foot average in the general plating shops. Mesle is doing better, by controlling it. That is six times faster than we can do today, if we learn how to distribute our current all over the surface so we get a uniformity, and that is what you want to consider when you are doing plating, that you are not getting the anode current density which your ammeter is indicating, all over your surface; you are getting local current densities.

MR. LEROY BEAVER: May I ask a question? The answer to it probably deserves a great deal of research on the part of the American Electro-Platers’ Society. This is the problem. In the United States we have several hundred manufacturers of valves, and among their line they have what we call a ball seat, or a ball check valve. Now these balls used in some of the valves are chrome steel, sometimes they use brass, sometimes bronze, sometimes monel metal, and lately they have been using stainless steel. There isn’t a week goes by that I don’t find in my mail a letter from one of these valve manufacturers asking, ”Can you supply us with chromium plated steel balls?” We find a bronze ball is not satisfactory due to the solutions carried through the pipes to which the valves are attached. Live steam affects an ordinary chrome ball. Monel metal is subject to disintegration; stainless steel, unless it is highly polished, isn’t stainless. If the American ElectroPlaters’ Society, or some members of it, can work out some way to chromium plate a steel ball in such a way that the pounding of the ball on the seat will not break the chromium off, it is a question of thousands of dollars’ worth of plating business waiting for them to take hold of. I have asked, recently, nine different platers in Philadelphia, and they have said, without exception, it can’t be done.

MR. HOGABOOM: You have brought up a very interesting point, Mr. Beaver, and one that I think the Electro-Platers’ Society should take cognizance of, because a large number of manufacturers that would be directly benefited, financially benefited by such a research are asking their platers to do it and are not contributing anything towards research themselves. It would be far better if they would contribute money or get a fund and establish a research fellowship, if they would take, and some of them have spent thousands of dollars,—take a portion of that money and support a fellowship at the Bureau of Standards it would probably solve that problem for them.

MR. BEAVER: The problem is one that should be solved, because new concerns who are making valves are coming, into the field all the time and asking: ”What can you do for us in the way of chromium plating?”

MR HOGABOOM: The question you want answered is how to wire a ball ?

MR. BEAVER: I will tell you how we do it. I took a piece of half-inch pipe, used as a mandrel, and wrapped around that a coil of copper wire. I took that coil of wire off, and dropped down inside of it a half-inch steel ball, and on top of that ball a half inch glass marble, and then another ball, alternating balls, and marbles until I had this coil full. Then I took it over to Harry Farland and said, ”Harry, here is something I want you to chromium plate.” He looked at me and used the customary platers’ language to me, telling me it couldn’t be done. I said, ”Harry, will you try it, anyhow?” He said, ”all right, we will give it a shot of acid copper and finish that with nickel, and then stick it in the chromium and see what happens.” What happened was the ball came out chromium plated.

Then, everyone has been telling me how hard chromium is to polish, the only thing you could use is a green rouge or something like that. I took one of these balls, and on the carpet in the floor of my office I rubbed it back and forth a dozen times, using considerable pressure, and got a beautiful polish. How do you account for that?

MR. HOGABOOM: Chromium is not difficult to polish. It can be steel ball burnished, providing the chromium is put on in a certain way. You, of course, must realize that you can get everything from a soft chromium deposit to a glass hard chromium - deposit by regulating the current density and the temperature.

MR. BEAVER: I don’t know what sort of an operation it was, or what the solution was, or anything; all I know is that the balls we polished have that peculiar bluish cast to them. But that is a way to do it; but it seems to me to be too intricate and involves too much intermediate handling. But I do feel satisfied that if there is an answer to that question, if some solution can be found of it, it is going to mean an awful lot of work for electro-platers all over the country, and you can get an idea when I tell you that a 5/8” steel ball satisfactory for valve requirements can be gotten from any of the foremost ball manufacturers at $16.00 a thousand, but if you want a stainless steel ball, in the equivalent of ” size, you will pay $78.00 There is a terrific lee-way in it that the plater could charge a fee for his plating work on these balls that would substantially compensate him for the work, because if it is true that chromium is more resistant to many corroding agents than other metals at present use, there is no reason it shouldn’t be applied to this particular use. It is one of those problems where a fellow says it can’t be done, but it is going to be done; it is just a question who will do it first.

DR. A. K. GRAHAM: There is a member of the Bridgeport Branch (some of you know him) Mr. Seifert. Mr. Seifert had a steel ball he chromium plated, and he used a magnet to hold the thing in solution and change the position of the ball in order to chromium plate it where it was touching the contact. Now I am merely giving you what one of your men has already done. There is no reason why you should have to operate an individual magnet for each ball you put in, but a ball can be held in the solution that way, and changing the position of the ball where it is being plated. Now’ if you have to have protection on a steel ball, in some of those applications the balls could be given a cyanide copper or brass deposit, and then treated that way, because the steel in there would act as a core and still could be used. It is only a suggestion, but it happens to have been done.

DR. WM. BLUM: It works. Graham beat me to it. We have done that, just in a purely experimental way. We wanted to make some tests of the friction coefficient of friction on some ball bearings. They wanted them chromium plated. We did it. I won’t say as to whether it can be don at least how practically it could be done, or how expensive it would be to do it, but we used a magnet for it just as Graham has said, put two or three of those on a magnet, a plain magnet or electro-magnet, and every few minutes just rolled them around there so as to, get a different point of contact, and the deposits were fairly bright. Of course, they were probably not quite uniform.

The question struck me (which is more important than that) —how many platers have’ ever used a magnetic rack for plating? It is one of those things which you think of, that comes into your mind every once in a while. It was in mine for years, until this problem of these balls for chromium plating came up, and I never went to the trouble of trying it. And it worked. Now I can see possibilities’ in that, not only for chromium plating steel balls, but for other things where you may be able to use a magnet for a rack, in that way being able to plate articles where it is not feasible to attach wires to them—not necessarily steel balls, but other articles. While we haven’t made any research or anything of the sort to find out whether it was commercially practicable, I can say with certainty you can plate steel balls if you hold them with a magnet and change the position occasionally.

MR. PROCTOR: I would like to say a word in favor of the use of the magnet. If any of you gentlemen go to Indianapolis, go to the Climax Machinery Company some time and see’ our friend, Mr. Hennessey. They are using magnets, four rows of magnets. They use horseshoe magnets and put them on a square cathode bar, and use it on articles that they can’t frame up easily, like a ball. The tank is about six feet long. The man goes along putting the articles on the magnets, and the whole thing is put in the tank. The product is cleaned in the solution. They go down and he puts another row on. When that comes up, he has rubber gloves on, and he takes them off the magnets. That shows the possibility of the use of magnets in plating many articles. I saw screws plated that way. They had a basket for catching any screws that might fall down. They were plating screws that way, and some of them were nearly as good as those screws I showed you this afternoon, but, of course, you get, once in a while, a place where the deposit doesn’t go in. But it shows the possibilities of using a magnet in chromium plating.

MR. HOGABOOM: I think the Question Box has been justified by bringing up a new point like that. Now in a general meeting, probably that point would have been brought up. Now we have learned something. Next question.

MR. PHILIP SIEVERING: Will you give a description of different dynamos used in chromium plating? 3 and 4 wire system?

MR. HOGABOOM: In generators, we have a disadvantage in that, but I will accept the challenge, although as an engineer, I dislike very much to recommend any specific generator. But in my opinion, the four-wire system is the only generator to use for chromium plating, for this reason. If you have a three-wire system generator, you could get twelve volts between the two out side poles, you could get six volts between the neutral and either of the outside poles. If you have, for example, a 2,000 amperes, 12-volt generator, between the outside poles you could get 1,000 amperes at 12 volts; on either pole, on either commutator,—you can get six volts at 1,000 amperes.

Suppose you are called upon to do chromium plating below six volts. You only can put your field rheostat down so you could get from the 12 volts probably down to 6 volts, and then you have got to take and use a tank rheostat to bring it below 6 volts, or else use one leg of your line, that is, one armature. If you plate on the one armature, then you get an unbalanced field and get a sparkling.

Now with the four-wire system, you can get the three-wire system, that is, you can get your 12 volts at your 1,000 amperes, but if you connect your two positives and two negatives by another switch, then you get two wires and you can get your full 2,000 at 6 volts. That gives you, then, a range from 2 volts (because on your field rheostat you can get down to 2 volts on a 6-volt generator. Then you can get 12 volts by turning it the other way, so you have got a complete range there of from 2 to 12 volts. Then, any good generator will stand a 25 per cent overload for a certain length of time, and that will give you 15 volts if it is necessary. So you have got a complete range, on a four-wire system, from 2 to 15 volts, which you cannot get in any other way.

Now, what voltage should you use for chromium plating? A great deal depends upon your solution. Mr. Sievering and a number of others are using 4, 4/2 and 5 volts. They are using below 6 volts’ Others are using 7, 8 and 9, and I have actually seen 12 volts being used on chromium plating. That is a question of solution.

I would like to make just one more statement, and I don’t want to be misunderstood as criticizing anyone. It is just about the effect of iron in solution. The way that iron will go mostly into solution will be through an anode of either using a steel anode or through a steel tank, or through using a thorough chromium anode. Some experiments were made, and you can duplicate them. Take a little glass battery jar, put in it hot water, and say you have four inches distance between the anode and the cathode, and you take an anode area and cathode area of equal size. You get in a solution that has no iron in it, you can get at four inches square, at 5 volts, 13 amperes. Put iron in that solution, and it doesn’t require much before your amperage is only 33/2, at 5 volts. Iron has a distinct property of increasing the resistivity of the solution, so that you have to use more pressure, and those that are being successful—I will not say that you cannot get successful plating by having iron in your solution; you can get successful plating by having iron in the solution, but the amount of pressure, the amount of juice that you are using and your cost, is considerably more than one without iron. In a problem which came to my attention, plating 2,000 bumper bar sets every eight hours, which meant four bumper bars, that is, two front bumper bars and four bumperettes, and plating not 20,000, but 2,000 a day for a whole year, with 300 working days a year, 2,000 a day, is quite a few bumpers and not one piece was lost but they had iron in their solution and they were getting 1900 amperes upon that amount of bumper bars with 12 volts. They changed the solution, using a solution free from iron, and the same load, and they got 150 amperes more, that is, 2,050 amperes, at 64 volts. That shows the effect of iron in the solution. They did get good plate with iron, absolutely good plate, but look at the cost of their power.

MR. CHARLES PROCTOR: I might answer and say that nevertheless, if you go into the Middle West I think you will find that iron is being used quite extensively in the solution. And they don’t have to use 12 volts to plate chromium, or 9 or 8 or 7, because they can use less than 6.

MR. HOGABOOM: Iron, added as a chemical, precipitates. Iron will go into solution from an oxide. The only way to get iron in a chromium solution is to use an iron anode and run it in like you do in a porous cup. That is the way you will get iron in a chromium solution.

I might say this, that taking again the privilege of speaking not as an engineer, or not as a representative of any house, but chromium plating is being done on a full automatic machine. One of the largest radiator shell companies, one of the largest automobile companies, are going to have a brass radiator shell on their automobile, which was exhibited for the first time yesterday in New York City. That radiator shell is buffed on an automatic buffing machine, hung on a rack, cleaned, nickel plated, bright nickel plated, and chromium plated, and comes out ready to put on the car, 320 radiator shells an hour,—full automatic. There is another installation where the bumper bars are going to be plated full automatic. Gears are being plated in chromium solution, full automatic, and that means that you just take the work and hang it on a rack with all its dirt and everything, and it goes through nickel and goes around through the whole thing and comes out without the hands touching it. The pieces work in, and out, and chromium plating is being successfully done on full automatic, and with loose contacts, not positive contacts, not soldered contacts, just merely hang it on racks. So chromium is going along all right.

MR. CLARK: I had some experience with chromium, and, taking two solutions, one with iron and one without iron, I believe the one with iron is more to be adapted to articles that are perfectly flat, while for anything with a background another solution should be used.

Here is an article made of steel (shows) and I plated those with the iron solution. I found out they wouldn’t plate in the crevices, those three crevices in there. I put them through the copper sulphate test, and immediately the copper showed me that there was no chromium on there. We had other articles which were flat, and they covered thoroughly. I put them through the copper sulphate test, and there was no copper at all. And I had to use another solution for this type of article, which you can see right here is plated in deep crevices, in all three corners, and has been through the acid copper dip. I believe a flat surface can be plated with the iron solution.

MR. HOGABOOM: Another point about the .chromium solution I think would be of interest is that it isn’t always necessary to have an anode shaped to the cathode as has generally been done. In this full automatic on radiator shells, the shells are run lengthwise through the solution—there is an anode on either side just exactly as in your nickel bath, and the wide ‘radiator shell and the bottom—it is plated upside down, and plates under the bottom, plates on the side, and there are just the anodes on the sides, and you don’t have to take and put a special anode around it or anything. It plates right straight across. I think we have all been afraid of chromium, that is the trouble.

DR. A. K. GRAHAM: I wanted to comment on Mr. Clark’s remark. It points out something that we know. In a solution that builds up in chromic salts, where your chromic acid content accumulates, the resistance of your solution increases, and consequently you have to use higher voltage for higher current density. The work of the Bureau of Standards has shown the resistance is one factor which influences throwing power. If you are plating a flat surface, there is not much difficulty in throwing; it is just current distribution over a flat surface. If the surface is recessed, then you are concerned with throwing power, and the solution which has higher throwing power would give you, in general better covering of a recessed surface. The similarity between chromium, chromic acid, chromic salt, and iron salt, is that they all increase the resistance of your solution, and they can be considered alike, and n that way would have the same effect.

MR. ROCKY MASSACOTTE: I was going to ask if your solutions are automatically agitated in any way.

MR. HOGABOOM: Convex current from the heat is quite sufficient to agitate it. There is no agitation whatever in the chromium solution.

MR. MASSACOTTE: I did a copper kettle, a water-kettle, in chromium, and I had an awful tine to convince the wife the inside was all right because the chromium got in it, and I said the agitation did that, and the inside was like tin, almost plated.

MR. CHARLES PROCTOR: That tank you have reference to, of course I am very familiar with the name of that plant. Did you say they are chromium plating direct on the brass?

MR. HOGABOOM: Nickel plated and chromium plated.

MR. PROCTOR: When I was in that vicinity a few days ago, they apparently were having trouble. They were copper plating the brass first before putting on the chromium.

MR. HOGABOOM: Was that due to trouble?

MR. PROCTOR: I don’t know anything about the trouble.

MR. HOGABOOM: You said it was due to trouble.

MR. PROCTOR: I said they said there was trouble in the plant and they were copper plating the brass first.

MR. HOGABOOM: That is generally the way some people observe things; they only observe half and only tell half the story. The thing is to tell the whole story, and then you are not misunderstood. It has been known for a long time, there has been plenty of work published—Ollard has published some in England, and there has been some published in this country—the two Grant Brothers published some very excellent papers upon it, and found that where brass is directly chromium plated that there is a tendency—now not on all brass, because remember a thing that looks like brass may not be brass; brass is an alloy of copper and zinc, and when you say brass you must designate what alloy it is. Scovill Manufacturing Co., manufacture brass in 100 different alloys So that when you say brass, be sure you know what alloy is being used. Common high brass containing 65 per cent copper and 35 per cent zinc, or a brass containing a high zinc, it has been found as a rule, especially on flat surfaces, plain surfaces, and other surfaces, that there are cracks develop in chromium, hair line cracks. Baker has noticed them, and as I told you, the Grant Brothers and Ollard, and the Bureau of Standards and a number of platers have also noticed them. In the experimental work on this particular job, it was found that chromium plated over copper did not exhibit those cracks even after a long exposure. They did not exhibit those cracks. It was found also that if you nickel plated directly upon brass and put a light nickel plate on, you got a porous deposit of nickel, naturally. All you have to do is to take some litmus paper and put it across clean nickel plated brass, and you will get the brown spots from ferri-cyanide from off the copper, ferride-copper, rather. You will get the brown spots showing there is porosity. When you chromium plate over a thin coating of brass and have a porous deposit of nickel, and let it stand, you could see, under a microscope, a beginning of that crack where those pores were. We saw them, but they began under that. Well, then, it was assumed, as was argued between us, that if we would copper flash the brass we would overcome that The brass was copper flashed, and not a solitary crack appeared. None have yet appeared, and it has been several months, and any brass that was copper flashed, it has stood up perfectly.

How, in speaking about that to two different men that are doing considerable chromium plating, one in Bridgeport and one that is a member of your branch here, and in Bridgeport the man got up and he stated, ”I had ten pieces of work to do. One piece, I did over ten-times, and could not plate it; I could not make the chromium adhere. I got cracks, and it would come off. I flash coppered that, put that through, and it would adhere perfectly.” The other day I had the privilege of visiting a man that is an expert in chromium plating, and in speaking about that he said the very same thing; he said he had a number of pieces to do, and he plated them, and there were some pieces that would not take and cover. He flash coppered them and immediately they covered. He said it was so apparent that they were better that he turned around and stripped the other pieces that were evidently successful and then copper plated and chromium plated: them, and he had no trouble at all, and every piece was perfect.

So that it is quite evident that if you copper plate brass, give it a flash copper plate before you nickel plate it, that you will have less trouble on those hair line cracks appearing.

Now there is one caution, though, and that was brought out on this work, and there has been some work done since then. On the experimental work on that job, the man that is operating that has a great liking for experimental work and is trying everything under the sun. But it stands out that they worked six months on that before the speaker had the pleasure of going to that plant, and three days after we were there we did it, and our company received an order for two full automatics on the strength of it, so that was the proof of the pudding. But he has been experimenting since. This is what we did learn. If you cyanide copper flash work, you must neutralize that in acid before you nickel plate. And I don’t mean by neutralizing it just putting it in muriatic acid, for example, and taking it right out again and rinsing it; I mean leaving it in muriatic acid. Every piece of work that we plated, that we just immersed in it, peeled. Those which we left in for a half a minute, the peeling wasn’t so bad. Those we left in one minute and a half in the acid, never peeled, and then it was assumed that in practice, where there may be a difference in concentration of acid during a day, the best thing to do was to keep it in two minutes. Those were left in two minutes, did not peel, and pieces were cut out, bent, and they even were made red hot and plunged into cold water, and there was no peeling.

Now, to try to get over that particular point this investigator, and he is very clever, this investigator tried to improve upon that, which all of us should do, no matter who goes into your plant and does anything—see if you can’t improve upon it. That is the only way we learn, and the man that can’t stand improvement isn’t very much good. To overcome that, he tried acid copper, because he knew if he had alkali copper he might get peeling, and if he had that neutralized that he wouldn’t get peeling. And therefore his argument was, ”Why not use acid copper?” So he acid copper plated the work and it came up.

Now I learn today from speaking to a good friend, he said that this man has asked what addition agent to use to make the acid copper bright, and the suggestion was to use glue in the solution. Glue was used in the solution, and the work came out bright. Now he wants to know how to control the glue, and that is another story. But it is true that if you copper plate, you get a great deal .better results, and that is before nickel plating, not after nickel plating, and you don’t have any peeling.

But here is a disadvantage of acid copper. I must caution you on that. It is well known from-the work, for example, that was done by Dr. Blum and the work by Dr. Graham, and Blum and Rauden, and Graham, that the crystal structure of the base metal materially influences the crystal structure of the deposit no more in any solution than in acid copper, and if you have some brasses that have a large crystal structure and you put it into acid copper, you may get a reproduction of that crystal in the acid copper film which may give you a peculiar crystallized effect under your nickel. So that you must take that into consideration, and if you have that trouble, then you know why it is. Cyanide copper, being of a finer grain doesn’t exhibit that property, and nearly all of you people that oxidize copper brass, you know if you take a piece of brass and put it into an acid copper solution and plate it, it will come out all nice grain structure, very similar to what you get on the crystallized brass finish. But if you cyanide copper flash that, and then put it in your acid copper, you can plate it and it is O.K. So that is a thing you must watch.

Now, in going over that, I will answer my first question. I am giving you this as an opinion, and don’t say that I said that— just say I said that is an opinion, and you can try it out in your own plant. It is my opinion that the reason so much nickel peels after it is chromium plated is because there is an alkali film upon the metal before it is put into the nickel solution. It is my opinion that cyanide on brass, before going into a nickel solution, is wrong. I think we ought to use an acid; I think that when any article goes from a brass solution, from a cleaner, into an acid solution, that it should go in acid. The best experience, the best thing I can give you to show that, is two things. One by Blum, and I think it was Thompson or Thomas—I don’t recall which it was—or was it Herring? Dr. Blum can correct me. He found that when he dipped the work in a nickel sulphate solution, took it out of that, and then put it into the regular plating solution, that they had the least amount of porosity. Where they took it from an alkali solution, evidently they had a larger amount but they didn’t notice it, when they put it into a nickel solution and took it out. That came in mighty handy to me at one time, plating large copper sheets which are used for washing machines. There was trouble with peeling, trouble with spots, pitting—the whole thing was solved by putting them in a nickel solution previous to the nickel plating solution, and we took advantage of keeping that nickel solution at a pH of 5.2, because that higher acidity more quickly neutralized whatever alkalinity there might be on the work, and when that was carried over into the solution it kept the pH of the larger solution constant, so that we didn’t have to correct for the pH in the solution, except probably once a week. And that was a large solution, and that was just using a little common judgment, that is all.

It is my judgment, and you can try it out—it is my judgment that what we must do, to have good, adherent nickel, so you can chromium plate over that, is to have no alkali on the work when it goes into your nickel solution, and no alkali on it at all when it goes into your chromium solution. And that will assist you in overcoming some of the difficulties.

Now the President had said my time is up. Instead of having twenty minutes, and instead of taking Dr. Graham’s time, I have taken nearly everybody’s time, and I thank you very much.

CHAIRMAN SCOTT: I assure you, Mr. Hogaboom, your time was well spent. We will now go to our next speaker, Dr. Blum.

MR. GEORGE GEHLING: I am sorry we had to stop this interesting Question Box. It is a new innovation here, asking questions without; having a set talk, or a set speech, and has proven out-very satisfactory. We had to stop that because our time was limited; we have another- speaker we want to put on, Dr. Blum, and we know he has some report to make, so I am making this excuse in regard to cutting the Question Box short on Mr. ‘Hogaboom.

I want to make an announcement that this year you will find, when you get in the banquet room, we have no advertising program, but instead, we are getting out a year book, and the minutes of this meeting this afternoon, and all the discussion, will be printed in that year book. The object of bringing this before you at this time is this. One of our Committee will give each one of you a blank card, and we would like to have you put your name and address on that blank card and give it back to that Committeeman, because we are going to depend on that card to get a copy of this year book to you. We don’t want to miss anybody.
In regard to the Quaker City Platers’ Reminder, you will notice that it is a new innovation we have gotten out this year for the members of the Philadelphia Branch. I want to apologize to one of the persons here today that gave a paper at the University, because the printer in his hurry so we could have a certain amount of these copies to give to you men here, who wouldn’t get it any other way, he misplaced the talk. He has the title page in the back end of the talk instead of the front of it, so I hope you will excuse this little error. So when you read this you will be able to understand the trouble. The printer’s devil, as they call him, gets the blame for mixing the plates.


 



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