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View Full Version : Using a charcoal barbeque to anneal



DropPoint
05-16-2010, 05:58 PM
I have a piece of leaf spring steel I attempted to anneal today with what success I'm not certain since it's still cooling.

I used a cheap charcoal grill and a hand bellows to get the charcoal as hot as I could and ended up with a dull red, so not sure if I got it hot enough or not. Thought I was going to burn through the grill before I was done but it survived.

I didn't have any vermiculite. The closest thing I have is potting soil with vermiculite in it, about 20% and about 10% wood too the rest plain old dirt

Other than the awful smell I got when I dunked it in the potting soil do you think this is going to work? If not, can I reheat the same piece of steel and try it again?

I'll pick up some vermiculite this week.

VaughnT
05-16-2010, 06:38 PM
Getting to a dull red would have removed the temper, so you're good to go on that.

Letting it cool slowly is the idea, vermiculite is great because it's clean and dry. Potting soil should work well as long as it's not too wet. Sand does the trick, too.

Pull it out in the morning and run a file across it. The file should bite in rather nicely. If not, you can anneal it again without worry.

If the charcoal isn't getting hot enough, throw in some wood and make a bonfire!

DropPoint
05-16-2010, 07:44 PM
Thanks Vaughn...

Sand...I have a whole pile sitting out front. I could've just buried it in it. I'll remember that for the future.

It was bright daylight so it was hard to tell the color of the coals, but when I brought the steel inside to straighten it it was that dull red I mentioned.

And it straightened fairly easily with a few hammer blows so it sounds like from what you're saying I'll be good to go tomorrow.

Doug Lester
05-16-2010, 10:00 PM
What I did when I had a charcoal forge that was long enough to take the whole blade was to bring the steel up to non-magnetic, let it soak for about a minute, and then stopped pumping air into the forge. It was made out of a charcoal grill with a hinged top so I'd just leave the blade in the charcoal and close the lid. That gave a slow cool down as the charcoal smoldered out.

Doug Lester

Travis Fry
05-17-2010, 10:01 AM
I set up my charcoal forge right next to the ash dump door on the back of my fireplace outside the house, so that when I need to anneal something I get it to temp and then stick it in the ash to slow cool, close the door, and wait. Came back to one 24 hours later and it was still too hot to touch.

T.K.T.C
05-17-2010, 10:47 AM
you can cool it in ash/sand mixture too it usually works. what type of leaf did you use? if it is 5160, it is very forgiving and can be reheated. i use springs for 90% of my knives right now. i use a fire ring and fill it with coal and just keep stoking till its blazing hot. then toss in the spring and bring it to temp around 1600 degrees then let it cool in a hole i dug filled with ash. the only problem with ash is it holds moisture so be carefull when using it.

DropPoint
05-17-2010, 09:44 PM
you can cool it in ash/sand mixture too it usually works. what type of leaf did you use? if it is 5160, it is very forgiving and can be reheated. i use springs for 90% of my knives right now. i use a fire ring and fill it with coal and just keep stoking till its blazing hot. then toss in the spring and bring it to temp around 1600 degrees then let it cool in a hole i dug filled with ash. the only problem with ash is it holds moisture so be carefull when using it.

the springs are off a late model F350 Ford...I have a full set so there's plenty of knife making material.

It appears to have turned out ok...a file goes through it very easily...so I think I'm good to go...I'm going to give it a shot with this piece at any rate.

graveyard
05-18-2010, 03:23 PM
droppoint run a pipe into the coal with holes drilled use your bellow to add air the coals well get very hot fast then as already said stop air close top comeback 24 to check it works

DropPoint
05-18-2010, 07:15 PM
graveyard that's a good idea. I'd thought about an old electric hair blower to ramp things up but this sounds better and not as likely to melt either

r bone
06-01-2010, 11:58 AM
I set up a forge in an old BBQ grill and used an old vacumecleaner as blower it got hot enugh to melt a welding rob (using charcoal.)

Justin King
06-04-2010, 08:00 AM
If you heated it to dull red then what you should have is some degree of sub-critical anneal. Ideally you want to hold it at the dull red heat for a couple of hours to get a full sub-critical anneal, but if you can drill it you should be good to go as-is. From what info I can gather the cooling rate does not matter as much when doing this type of anneal, as long as you do not get the piece to critical temp. during the process. So you may not need to worry about sand/vermiculite/ashes to cool it in. The slow cooling is necessary if you are annealing from above critical temp.

Boxer Bill
06-06-2010, 10:21 PM
DropPoint,
A charcoal grill is fine; use a hairdryer to supply air to the coals, put the whole knife or piece of steel into the coals & heat to non-magnetic, then cover with more charcoal & close the lid on the grill. Leave in the coals overnight; you'll then be able to drill/grind the steel & make your knife...................The best tutorial/dvd I've seen on this method is by Tim Lively of Marbles Falls, TX. Get a copy of his dvd on making a large bowie using charcoal/hammer/forge............Boxer Bill

DropPoint
06-08-2010, 09:35 PM
Thanks for the replies

Boxer Bill..I'll look for that DVD.

This coming weekend I'll be taking the next step and using the charcoal grill to heat treat my first knife.

graveyard
06-12-2010, 09:02 PM
droppoint a blowdryer stuck in ore taped to the pipe well move some air also i have seen some videos on u -tube try how to forge a knife '' some use a old brake drum ore a bbq grill take a look be safe

Gary Miller
06-26-2010, 11:04 PM
I have used brikettes to even forgre blades. I just get the steel up till it get good and red then just cover it with the bricketts and let all cool down to geather. you can use the ashes from the forfr to annele in or dry sand work well and it's cheap. gary

Jim Poling
06-27-2010, 08:00 AM
Hi DropPoint
I have Forged, annealed, and hardened many knives in a charcoal fire and bellows both at home and at living history events. When I started making knives I used a Habachi grill and a small house fan turned on low blowing on the charcoal to harden my stock removal knives. In short the charcoal does work! Good luck and keep after it.

Jim