Body dollies

[Swift&Bold]

Should they be hardened and if so, how best?
I ask because I've picked up a set of cheap, Chinese ones from the tip which I intend to polish and give some TLC to improve them.

 

[rikrobson]

Depends how much carbon is in the steel. You need it hard but not brittle.

 

[Swift&Bold]

Should they mark?

 

[rikrobson]

Nope. I think you'll want to temper them blue. But you'll not hardened them if there is not enough carbon in them.
You can get then red hot and quench in oil to do carbon to the surface to case harden if there is not enough there. Then get to cherry red and cool slowly then re heat to about 300 isherwood when the colour goes to Blue or purple
Then quench Nd it to Sholden be hard enough. I mean in the pub so I can only go off memory.

 

[hotrodder]

Personally i'd just clean 'em up and accept they're a bit soft. Decent panel beating stuff is forged from med carbon steel and hardened but not as hard as regular hammers, possible to mark relatively easily if abused* and it's not uncommon to have to give top quality stuff a tickle to polish it back up every now and again. If you don't know what they're made from heat treating 'em is all guess work and may just create more work for zero benefit

* I have a few mankyish old dollies that get used on gnarly stuff while the good stuff is kept for new work that's free of paint/general crud. That's still more pride than anything though as only the best of the best are good enough for the odd mark on a dolly to transfer flaws to the panel being worked that are a big deal