Totally Newbie plating, help wanted...

[marq]

Our project has stopped due to an this kind of problem(not sure if this is so common problem with every one)
I have electroplated nickel on to steel, but there must be somekindof contamination, because allthough i have electric wash(anode), then 2 flush, then(whats the word not sure, sorry bout poor english) dekap?, then 2 flushes, then to nickel bath.

allways the same result, bubbles and corrosion, might it be the cleaning wash or what could cause this?
or have I done something wrong?

[MrDmB]

need more detail . . . sq in, amp, temp, agitation, etc.

[marq]

Amps are 0,9-1,3A/dm3
agitation is air
temperature is between 55-65 celcius

[gsw3]

Nickel over steel

Try looking at the post (7) up from this one.
I posted a reply on plating pitted steel parts.
It may help you.


George W.

[gsw3]

Plating steel with nickel

sorry about that.......look at the post below this thread (Poor adhesion copper build up).

I describe the process I use for pitted steel parts.

A few extra pointers which may help:

1. Cleaning:
a) I always use lacquer thinner of carb cleaner to degrease parts.

b) To remove rust, use muriatic acid diluted 50/50 with water. Always add acid to the water, not water to the acid. Leave soaking until rust is almost gone.

If the part has any zinc plating on it you must use the acid to dissolve the zinc off the steel. Otherwise the nickel solution will be destroyed if zinc gets it it.

Wash the acid off with water and scrub it down with detergent and water.

c) Beadblast the parts if you have the equipment. If not, wire brush them using a fine wire brush mounted on a buffer motor or in your drill press. If you do beadblast them, still use a fine wire brush afterwards.

d) Degrease and detergent wash one more time.

e) Dip the part in a 50/50 solution of nickel pickle solution (battery acid diluted 50% with water) for about (30) seconds, then rinse the part off with water.

f) Go "Hot" into the nickel solution. That is, be sure you have the negative to the part and the positive to the anode prior to placing in the solution.

g) Increase the current by about 33% during the first minute of plating. This insures that the part will start to plate right away instead of rusting in the solution.

h) Ramp the current down in (3) steps, (1) per minute) to the specified amount.

i) Be sure and use the correct amps per square inch on the part.
For my set up I use 2.25 Vdc @ 75mA per square inch.

j) Keep the part agitated using coarse bubbles and plenty of them. More is better. Don't use fine bubbles (like from an airstone).

k) Don't forget that the plating will only be on the anode side. Use more anodes. I use (2), one on either side of the tank and also have a device that rotates the part during plating. Between the dual anodes, the coarse bubbles and the rotation, the parts come out looking perfect, no buffing required afterwards (assuming the part was highly polished prior to being plated).

L) If you break the current path or lift the part out of the solution to "check it out", you just "bought the farm". The plating will not adhere properly.

If you did do this, take out the part, wash it off and soak it in a nickel pickle solution (see step (e)), then put it back into the plating tank.

I always plate for at least (1) hour. Provides about .001 per side of plating.

Be real careful if you are plating threaded parts. Too much plating and the parts will not fit.


Hope this helps.

See my plating at:

http://users.adelphia.net/%7Epatpawz/geo/plating.htm

George W.