electroless nickel and aluminum

[pklin]

Hello all, I'm new here but getting excited to try my hand at electroless nickel plating on my handguns.

My newest project would be to refinish a Sig Sauer handgun in EN so I have a question regarding the aluminum alloy frames on these handguns... According to threads I've read and also the Caswell website, zincate is necessary on aluminum prior to EN, but I've also read that Zinc can contaminate an EN bath and turn out bad results. So what do I need to do to prep the aluminum frame for EN plating?

Also, I will need to remove the bluing on the slide prior to plating and I have thought about bead blasting but may take an easier/cheaper way out by using Naval Jelly... Would this harm the base metal? Has anyone used this to remove bluing on firearms?

Thanks everyone.

[CarWiz]

I can't answer the bluing question but the zincate and nickel bath shouldn't be a problem unless you do a lot of it. Since the EN bath is only good for about 10 recharges, a fresh batch will eliminate any zinc build-up problems. The zincate treatment is a dip that coats the aluminum with a very thin layer. The dip is for 20-30 seconds. Some alloys may require a longer period but you'll know as soon as the item is placed in the zincate. If it fizzes as soon as it's dipped, leave for 20 seconds, remove and let dry.

[pklin]

Got it CarWiz, thanks much. That's pretty much what Caswell said also through Tech Support. I'll just have to remove the existing anodizing first with the anodizing stripper.

Do you have experience using the anodizing stripper? I purchased it once from Caswell and used it for my AR upper and lower receivers but the package did not come with directions on how long to leave in the solution so I think I overdid it... End result was that the receiver got "eaten" away and was noticeably smaller at the end to the point where they would not mate correctly and had a lot of slop after.

Any help would be great. Thanks!

[CarWiz]

I haven't tried the stripper. The handles I did were cast aluminum and I don't believe they were anodized. If they were, it got stripped when I SC sanded and polished them before processing.

[CarWiz]

Forgot to mention:
The anodize stripper should only be used for a "few seconds" according to the Caswell's Manual. It's extremely caustic so it will dissolve aluminum very quickly.

[KCV6]

As CarWiz stated, only a few seconds and imediate clean water rinse on the stripper as it does eat away at the aluminium rapidly.

Just a word of advice on the zincate and EN process. Get some aluminium sheet or rod and do a few small test pieces first until you are happy with the result. It is very easy to get carried away in the whole plating bit and make compounding mistakes that ultimately end in ruining expensive pieces of work and a lot of frustration.

Cheers

Mark