Anyone know anything about electroless nickle?

[Hellbender]

I have a couple of aluminum framed handguns that I had electroless nickled (beadblasted dull finish, not polished) a few years ago.

Anyplace the finish touches the skin, it turns a nice shade of jet black.

Does anyone know what chemical (in sweat???) causes this?? I would like to dip the whole gun in whatever it is to make a nice even black, and I'm having trouble collecting enough sweat to completely dip the gun in .

I tried several types of cold blue and they just discolored it a little.

Thanks for any input,

HB

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NRA Lifetime Member

[This message has been edited by Hellbender (edited 12-21-2002).]

[Big Dipper]

They do make a cold "blueing" for aluminum, but nickel?...hhhmmmmmmm. Never heard of electroless nickle turning black.

[Rock Ranch]

HB,

Contact Brownells at 1-800-741-0015 and ask for the technical dept. They may be able to help.

Personally, I don't think nickel should be turning black from sweat, unless you have some very funky sweat.

Larry

[Dick Payne]

HB:
Electroless Nickel is slightly porous. Think of it as a layer of balls of nickel on the surface. There are tiny spaces between the balls. They put a coating of copper under the E-nickel and you are probably seeing copper oxide or copper sulfide form due to the chemical reaction with your perspiration or things you have been handeling mixed with perspiration.
There is a process called black nickel but it is not common. Check with some plating houses to see if it is durable enough and who can do it.
I would think that black chrome would be best but not too many platers do it. Find someone that puts black chrome on motorcycle handlebars and exhaust pipes.


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Dick

[Hellbender]

Dick--It was my understanding that Electrolytic (not E-less) had the copper plating under it. But maybe I was mistaken.

When I had the guns refinished (after extensive mods), it was hard to find a durable finish that would work on both the aluminum frame and the steel slide/cylinder (a revolver and an auto). Hard chrome was my first choice, but would not work on the aluminum frame.

Now there are several baked on (powdercoated) finishes that will work on both metals, but at the time, e-less nickle was about it.

These guns were purpose built for carrying a lot (very smooth, no sharp edges anywhere) and the finish has held up well except for the discoloration.

HB


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NRA Lifetime Member

[smstrampe]

HB,

I've used tons of electroless over bead-blasted finish on machine tool parts.

Never had any of it discolor for any reason (other than a torch flame or submerged in coolant).

I agree with you that they don't put copper under electroless.

Talk to Brownell's tech help or a guru in a local plating shop.

Good Luck,

Stramp

[tonydacrow]

Perhaps I'm way off base, but I didn't think they did electroless Ni on Al. All the kits I've seen only work on steels. Did I miss something along the way?

[Oso]

Nickel turns greenish-black from some folks sweat. Mine in particular. For me the color stops at olive-drab, but I understand others may be more powerful.

And, no, I am NOT one of those folks who corrode all the iron they touch. Just nickel.

Have no idea what causes it, though.

AS far as aluminum though, why not get a hard black anodize? It is just as hard as a grinding wheel, and wears very well.

[Hellbender]

Stramp--what color did they turn after the coolant submersion and what type of coolant (exactly)? Any damage other than discoloration?

tonydacrow--I had a commercial firm in CA do the finish on these guns and I can't for the life of me find the name/contact info. or I would call them. This has been 8 years or so.

Oso--Would you start collecting sweat for me? I'll pay shipping I guess I really need to find another "black sweat" guy, though.

Seriously, Hard anodizing was my first choice, but I couldn't find a steel finish that would have high corrosion resistance and look OK with the anodizing, also would have doubled the cost of the finish.

I'm not going to refinish these guns, the finish integrity is fine, it's just a cosmetic thing, and I really prefer the black finish on a carry gun. I just thought someone may know a chemical that would blacken the nickle.

I'll call Brownells tech, they may have the answer.

Thanks all,

HB

[tonydacrow]

Hellbender,

Why not just use a powder coat or Brownell's alumahyde (I think that's the name of the paint) on the frame. After cleaning well, just spray to coat w/ any color you want and, place in the oven. If the integrity of the finish underneath is not a problem then the paint will solve the cosmetic problem. Both products are very durable. HK uses powder coat on their MP5's, so you know it's good stuff...

[Hellbender]

tonydacrow--I've used (and have some) Alumahyde, but it won't hold up like a "real" finish in the kind of constant holster wear these guns endure.

This existing finish is very "slick" and I don't know how well PCing would stick to it.

Again, if I could just find the right blacking chemical to dip these in, it would be simple. But things seldom are

Thanks again,
HB

[smstrampe]

HB,

I'm not much of a grinding (precision) kind of guy, but I think the shop I worked for used mostly Mobil Emusiplex water soluable coolant.

No damage, just ended up looking kind of like the water line on an aluminum boat.

Stramp

[Rich Carlstedt]

My Two Cents
When Aluminum is plated with Electroless Nickle, you sometimes get a "smut" which is a blackish residue. You may be see smut, not Nickle.
While steel can be directly coated with EN, Aluminum needs a intermediate step coating, to prevent smut. Brownells has this material. My brain says it's called Wooods metal or something like that.

[Rich Carlstedt]

Also
The normal finish produced is dependant on several factors.
The higher the Phosphorus, (upto 13%) the stronger the coating, but the more "dim" it becomes.
Low-Phos(less than 4%)will shine more, but really "bright" Nickles have a organic brightener added to the Nickle, so the composition has a lot to do with end results, and not necessarily the finish of the substrate.