Instructables

Good way for electroplating washers?

Hello everybody...........Seem's i am in need of help from the brilliant mind's of this site again.
My dad has been electroplating nut's & bolt's for the past 35 years & i decided to join for the time being(i have summer vacations going on)
Recently some guy came to us for getting washer's electroplated,Issue being that the washer's won't get coated with nickel (with the Electroplating barrel).Some of them stick to each other(leading to one side of the Warsher's without nickel coating).
These are so thin compared to the nut's and bolt's we are used to electroplate,That some of the washer's get bent.
Need any suggestion,any alternative way to do them without much issues.
Below are some pictures attached for referance
Thanks in advance
Regards
~HD~

Picture of Good way for electroplating washers?
IMG_20130621_183351.jpg
This is probably going to sound like a dumb question, but what does the geometry of your setup look like?

I mean: How are you making the cathode connection to these washers? Are they suspended in between the anodes somehow, so that currents of metal ions are surrounding all (erm both?) sides of  eachwasher? 
A quick google or youtube search on Barrel electroplating will show you the setup.
Here is a youtube link for referance

Hey wow! A rotating barrel! I honestly did not know about that method, and I thank you for enlightening me.

You know, those washers probably have a lot of surface area per unit mass, and that's a number you can calculate. It is the same number for one washer as it is for a thousand of them.  In SI units it would be square meters per kilogram.  Call that number sigma, and the total area per batch M*sigma.

The moving barrel is sort of "rolling out" new surface area at its outer edge, at a rate of L*R*omega, where L is the length of the barrel, R is its radius, and omega is the rate at which it turns in radians/second.  Multiply that number by the time T, some number of seconds for the duration of the job, and that gives an answer for the total area unrolled at the edge of the barrel.

Anyway, for this plating trick to work, I am thinking that number L*R*omega*T is going to have to be much larger than M*sigma, the total surface area of the batch of washers.

Just for fun, you could calculate those two numbers, and compare them to one another.

As you might have already guessed, the way to make that difference in areas larger, is to use smaller batches, or longer times per batch.

And of course all that math means nothing if the washers are actually sticking to each other for some reason.
Well we all learn something new everyday :)
No use for the equation anymore since i guess
Tried a small 20kg batch(compared to the 50kg that we usually do),The lot came out perfect.....Need to to workout a bit on the maximum quantity i can put in the barrel without having any issues.Coz for us time is money
One thing is for sure that the problem was due to the huge amount of the washer's at once
Have a nice day
I am glad you got your process working.
Is this perhaps just a degreasing issue ? You've got washers stuck together by grease, the cleaning isn't separating them.
Every thing we electroplate goes through degreasing & acid cleaning(to remove any rust).Sadly this is not The grease......Seem's it is the geometry of these washer's.I am giving a thought on rack plating method(but the practicality of this method is still a question for me considering that i have to get 8 tonnes of these washer's electroplated)
I know the principle well. I've specified the process often enough.

Are they stuck together as you receive them ? Are there striking burrs on their edges which cause the problem- in which case tumbling them in polishing media would probably help, if they're not so thin that that wouldn't damage them.

If they're stuck on receipt, you should talk to the makers and explain the problem.
If they are getting bent in the process then something is going too ruff. If they are sticking together then you need to put less of them into the vat. If there are too many problems with getting a good finish on them due to there size then inform the customer of the problems and why the parts are not good candidates for the process.
Competition in electroplating buisness is pretty high here........so letting these go would be hard for me.
With the current method we put nearly 50kg of nut's/bolt's or washer's per barrel(each barrel takes half hour for a uniform coating,it is the first time we have had difficulty with electroplating something).Putting less of them in barrel would cost us time.....and will make it hard for us to meet the deadlines.