Now that I have my hardened and tempered cams, all(!) that remains is to clean them up to remove the oxide coating that has resulted from the heating and quenching. Sounds pretty simple, eh?
Doesn't seem to be much to remove, so hopefully some patio cleaner (aka hydrochloric acid) will do the trick.
I have some of this stuff that I (naively) assumed was acid based. Unfortunately, The Stupid Fat Bloke went ahead and threw the cams into this stuff without reading the label carefully. Any fule can see that this isn't hydrochloric acid...
Anyway, here they are before....
Not a whole great improvement really but there's a reason for everything. So how about some actual hydrochloric acid, to do the job properly?
24h later, not much of a change really. In fact if anything, the things are getting blacker and blacker.
Next, how about some VapoRust? Let's try that:
3 days in this stuff and now they are almost perfectly blackened - WTAF??? Looks as if the initial dunking in the "Victor Tools" patio cleaner completely screwed things up. You might conclude that it's powerful stuff - but not in the way I was hoping for here.
FFS - time to go for the mechanical approach and reach for the wire brush.
There, that's better. Steel wool seems to have done the trick. I think we can leave it there.