doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Annealing Problem - Help and Advice requested!

All steel pickling operations I have seen use heated acid. The heat, of course, accelerates the action of the acid and would permit a lower concentration of acid to work as well as a higher concentration would work cold. In addition to Hydrochloric, I've seen Nitric and Sulfuric acid used, and Hydroflouric was used for pickling stainless steels.

I would follow the advice given earlier to babysit the process. You may find that a shorter acid pickle followed by a rinse and then wire brushing or wheeling would be preferable to waiting for the acid to eat everything perfectly clean. The parts may clean up nicely when they look like they are covered with black slime. You can always go back to the acid if it needs more time, but you can't replace good steel that gets eaten away.

I doubt that this had anything to do with your kilns' power loss at 750-800 degrees. The scale probably formed at higher temp when your aluminum foil wrap disintegrated.

That is it, but it seems to be very expensive. In the US, it is commonly sold in building supply and hardware stores as a cleaner for concrete, masonry and bricks. It is not very agressive on human skin, but the fumes are an eye and respiratory tract irritant. Use it outside, stay upwind of it and you won't need a respirator. I do recommend chemical goggles in case of splashes. If the 50-50 mix doesn't seem to be working fast enough, you can use it full strength while you watch it work.

OB

Hi guys, found a 20-30% mix and it appears to have done the trick over an hour or so. I have plenty of shining up to do but the worst is off. Thanks very much for everyone's advice here and I'll update my blog with photos and post here as piece get done so you can see the result.

I still intend to case color harden these parts now that I am on a mission. I'm having an air tight stainless steel container made so that the charcoal mix and parts don't get contaminated.

Cheers
T

Good Job Tony....glad it worked out for you.................

Good Luck with your project...keep us updated......

Best Regards,

I don't want to get the case color hardening wrong that's for sure so will be doing some scrap steel pieces first to make sure..

Cheers Doug.
T

Since so many people have helped with advice, please show us the after picture

PDD

Of course. No worries. There is actually one at the top of this page..but as I complete the others I'll photograph them.

Best
T

Hi folks, OK, been working hard with various lightway sanding tools to get the action back. Very pleased to be frank. It's back to where it was before the annealing skin! Doing other parts ready for case color hardening.

I've been given two old actions from my friendly gunsmiths so I'm practising on them first...

Regards,
Tony

Nice photos. Great catch.

And you are sure it is soft now, How?





Just checking.

Tony:

Looks good.......keep it up......!.........