Any budding chemists out there to help me?

I am looking into diy zinc plating of various bits. Preferably with a yellow/gold passivate finish.

I see that there are various kits out there, from places such as Frosts etc, and they look very simple in their contents.

So far I guess the following: I need some lumps of pure zinc (probably sacrificial anodes from a boat supplies company) which I connect to my positive connection, fed via a rheostat from my 12v battery charger. I then need to connect my negative terminal to the parts to be plated, and hang them in a warm solution of something! The question is, what is this solution? Frosts (and others) sell it as "zinc salts" but what are these in more detail??

Next question, this will presumably give me a fairly dull zinc finish, I see brighteners are available, any ideas what these contain?

Then finally, and importantly, the kits then suggest am immersion in a solution of salts which impart the yellow/gold passivate finish, any ideas on what the chemicals used here are????

I know there are old hazardous chemicals which were used but these are supplied now to the diy'er and are not cyanide salt based!

I am asking because I am sure I can DIY this one without buying a £100 kit just to find out what chemicals are in it!!

No helpers??????

Think I have made some progress myself now! I need a solution of Zinc Chloride and Ammonium Chloride (I have the mix qty's but won't broadcast til checked!) and a zinc anode, for which I'll use a 2kg boat anode, which is about a tenner, and should do plenty of plating!

I will then get some chromate passivate solution from Frosts, as that seems to be a bit trickier to do without getting really nasty chemicals.

Anyway, I'll let you know how it goes! (need to get back to work so I can order the chemicals!)

Ahhhhhhh, I have sussed the chromating with a little weeny experiment at work today.

Tripped over some Potassium Dichromate on my travels, which is surprisingly pleasant stuff (only "irritant" on the bottle!) and it seems that a solution of quita a lot of this in water (130g/litre), with a drop or two of sulphuric acid (literally a ml or two! of conc sulphuric) does a great job of chromate passivate, a lovely goldy sort of finish on a couple of bzp bolts I found laying about!

All sussed then, just got to buy the chemicals, £20 will fund enough to keep me going indefinitely!!

The final product, is it zinc plated (galvanized) or chrome plated?
The yellow/ gold color is due to chromium2+ ion, from the chromate solution, n'est pa?
KT

I'm not really expert, it's not galvanised, it's bright zinc plated as a first stage, i.e. a bright silver finish, and then dipped in the acidic chromate, which apparently "toughens up" the finish, but it's certainly not chrome plated!.

mate.............

just how big is your garage?

just thinking we could make a large swimming pool in there, dump my chassis in, use electrolosis on it for a few days then plate it

If you buy the pool, I'll put it in the garden afterwards!!!

I refer you to the FROST restoration website wher you can buy brush on zinc plate.

yes, I had a look at the Frost stuff, two things against it for a pillock who likes to make work for himself like me!!

1) cost charged for a few very basic chamicals!

2) I like the idea of "proper" electroplating and passivating, rather than the brush-on stuff (though no-doubt it's nearly as good)

3) mates like me can come round and lend a hand, oops is that my chassis i've just accidentally dropped into that electrolosis tank.....oh well, might as well leave it there now and we can electroplate it later. i mean its got to be easier that trying to use your sand blaster on it!

(Nat, check the anything else forum )

very good Mike!!!!!!!!!

ok , tell me what chemicals you need - ive got a good supplier .

you have U2U

I am sure you know this already; however, in case you don't:
Welding zinc plated stuff produces very (I mean very) toxic fumes, so it is worth planning ahead.
Cheers
KT

had this discussion in the locost midlands group as that is what i thought. One of the blokes used to work down a zinc mine. He said the opposite, lots of nasty fumes but nothing that will give you any long term harm...

or at least thats how i remembered the conversation. I'll ask the bloke who started the conversation to comment in case i've got it wrong.

Welding zinc wont kill you - you may get zinc poisoning which apparently is a bit like the flu.

I welded a zinc plated floor, and well, im still here to tell my tales, my hair has nearly grown back now, and apparently it wont be long before i can get the use of whats left of my arm, but i've got a welded floor now

All joking aside, you probably want to avoid exposure to it in fume, or dust form, but the advice i got was that its not dangerous in the long term.

To minimise risk to my health, and to avoid getting bad welds I ground off about 5mm around where i was welding, this reduced the mess a lot, as when you weld it, it kinda turns into this white powdery foamy mess.

I'll try to dig out the sources I referred to later tonight.

HTH

David

Zinc fumes won't kill you, but can make you vomit if you are exposed to enough of it.
The old welders' trick of drinking a pint of milk before welding on zinc is a well known and proven remedy.

quote:

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Originally posted by Rorty
... but can make you vomit if you are exposed to enough of it.
The old welders' trick of drinking a pint of milk before welding on zinc is a well known and proven remedy.

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quote:

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Originally posted by sgraber

quote:

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Originally posted by Rorty
... but can make you vomit if you are exposed to enough of it.
The old welders' trick of drinking a pint of milk before welding on zinc is a well known and proven remedy.

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Is that so you vomit the milk instead of your guts!? Just curious....

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The best reactions I have seen is when you weld the base of a pipe welded to a plate, with a load of galavising in the bottom.

The bright green fire shooting out of the pipe was most attractive!!!!

I don't know how much the chemicals are but it doesn't strike me as that difficult to build a temporary tank that would hold the chassis.. buncha plywood and some 2 bee 4s, polythene sheeting.. no? you could plate half at once and turn it over to avoid having a really deep pool with high pressures.

I think Mike was just being his amusing self and winding me up!!

I am not plating the chassis!!

I just hate making little steel widgets and having to paint them, knowing that the paint will get chipped off by road grit in a few hundred miles and rust will set in.

I made some really superb swivelling brackets for the rallying lights on my Sierra, and now they are rusting where the poweder coating has worn off!

I make a few bits for other people (mainly in the Opel Manta Owners Club) and it would be nice if I had the option of zinc plating them for a decent long life finish. Plus on non- stock bolts which I make it would be nice to plate them. The bits I actually had in mind when I started investigating this plating malarkey were Opel Manta front wishbones and uprights, as I know a couple of people who are interested in shotblasted and plated ones for show cars which are also used a lot on the road, where powdercoat has failed quickly in the past.