Having a crack at anodising

[Coyoteboy]

I've gathered the kit, tried a few dyes and theyve not been too good but now I have some sample Dyes on the way (Black, red and green, thanks to Dylon, uber-helpful!) and I'll be having a crack at some small parts, then might have a go at making my alternator black I cant wait. Kid in a toyshop!

[ChrisW]

Would be good to see the results and how you got on with it, i.e. fiddly and dye everywhere. I can't even change the ink on the printer, lol.

New toys are always lots of fun

Cheers

[Coyoteboy]

First try with zero metal preperation or cleaning/polishing, no real idea about times/quantities, just threw this seatpost in and let it rip:


Plenty of hydrogen gas and a fair bit of fizzing and spray of acid about the place but at least it actually worked. Now to perfect the process. I'm going to have a crack at doing my spare compressor housing if i get it half-decent. Need to nail the washing and prep first, as its currently not up to scratch.

[Bodhi]

How did you make the kit? I'm interested in giving this a crack too. can you just use a car battery for the current?

[ChrisW]

Hmmm, ever heard of Dr Jeckyl? Or was it Frankenstein? Mwua-ha-ha-ha, sounds like my homebrew process

[Coyoteboy]

Theres a fair few how-tos on google, though a lot of them make it more complex than it is.

You need:
A high current 12v source (It takes ~10A for a fairly small item), a car battery would do but wouldnt last long and will tend to lose voltage as it goes which affects the anodising.
95%plus sulphuric acid. Its nasty nasty stuff, turns your flesh to what feels like stingy soap and eats just about anything it contacts - get the spray from it onto your sleeve, walk in, side and eat your tea and you'll find that the next day your sleeve and your sofas cushions are falling apart lol.
Distilled water, non-distilled tends to contain chemicals which affect the process a bit.
Lye - caustic soda. cleans the metal surface. Also disolves it rapidly so beware.
Plenty of time to experiement with lots of dyes -  many of them work, but apparently even two different colours from the same type can produce good and bad effects.
A large lead plate for the cathode.
Soldering ability to be able to attach the wires to the lead plate.
Aluminium wire to hang parts on.
Plenty of 5litre plus plastic tubs with sealing tops and labelled.
A ventilated room - plenty of hydrogen is produces during the process. Hydrogen, confined space + spark from shorting a 10A supply out = no more garage

That said its quite good fun, if a little expensive - piles of water used, boiling large pans of water for half and hour to seal the anodising. I'll see what else I can do properly soon, ive got to re-arrange my cathode array - you need 3-5 times the area of cathode as the area of the workpiece. A turbo compressor would need ~2 sq ft of lead officially.

[RobbieMcVee]

i found a good little site on google a while ago - was going to have a go too.. then i saw just how much danger was involved and prompty decided against it..
Good luck chap!

[Coyoteboy]

On the whole its not that dangerous but certainly the hydrogen gas given off could cause problems lol. The main concern is keeping track of the acid, as it does get everywhere when you dont realise it. Keep a pot of soda crystals disolved in water handy and wipe everything down with it afterwards, watch it fizz as the acid is neutralised. Its a garage activity, and old clothes, and I get changed out in the garage to keep it there lol.