Annealing with ashes

[ArmySoldier72]

I think I saw this in a video by John at BBF, where he was making tooling and annealed in vermiculite or wood ashes. 

I searched here as well and found the great comment by Glenn explaining Annealing, tempering etc in this IFI post:

What did you do in the shop today? - Page 809 - Blacksmithing, General Discussion - I Forge Iron

 

My Question is what ashes are good to use for Annealing?

We burn all paper, wood cardboard etc.  That is just part of farm life. 

All Plastics and rubber goes to the dump.

And all metal gets saved for repairs or a scrap yard run. 

 

So would the ashes I create burning wood scrap, cardboard and paper products work?

 

Thanks

 

ARMY

SE Oregon

[George N. M.]

Army,  the principle quality which makes a good annealling medium is insulation.  Anything that will allow the metal to cool slowly as possible is good.  A secondary virtue is being non-combustible since you are putting red hot metal in it.  Styrofoam or bubblewrap are great at insulating but pretty poor at resisting heat.  So, vermiculte (a mica mineral) or ashes of any sort are a good, non combustible material to anneal metal.  I've even wrapped things in fiberglass insulation batts.

GNM

"By hammer and hand all arts do stand."

[ArmySoldier72]

ahh that makes sense.. thank you george. 

So I will check the ashes to make sure there are not chunks left behind and set up a couple of buckets. 

Thank you kindly

ARMY

[Glenn]

You can run the ash through a window screen to sift out all the chunks and pieces larger than the screen.   Hardware cloth works if you want a larger size ash.  

[Frosty]

It also depends on what the chunks are, Dirt, rocks, etc. aren't good but charcoal is fine so long as it's not large, it's good insulation and if it starts smoldering it'll help keep it from cooling just as well. Large pieces can be a B A D thing as they might keep one place hot longer than is good. Pencil eraser size is close to too large if you're annealing thinner stock say 1/4" x  1/2", a truck axle won't care, a sewing needle would need REALLY CLEAN ash. Yes?

Frosty The Lucky.

 

[ThomasPowers]

A sewing needle would need a larger "heat donor" piece to go in with it just like many knife blades do.  I generally anneal by shutting the piece in my gas forge and turning it off when I leave the shop at night.

[ArmySoldier72]

Thank you all, 

 

This farm has lots of junk laying around, including an old screen door. 

And with all the cleaning up, fixing up and what not, there is quite a bit of wire mesh around too. 

I will get some sifted out in the next week or so. 

 

Thanks again

ARMY 

[Charles R. Stevens]

Hand  to heart, Army. I know a welder who has a 12” long box full of ag. lime he uses. Now that you understand the basic principle you should have no problem scrounging up a usable aneling box. 
For the lurkers, avoid molten salt baths and heated mercury. These are industrial processes that have all kinds of safety issues for the home shop. 

[JHCC]

4 hours ago, Charles R. Stevens said:

I know a welder who has a 12” long box full of ag. lime he uses.

I use an old toolbox full of agricultural lime with some wood ashes mixed in. Takes anything up to about 18” long. 

[Frosty]

I only used the sewing needle for the extreme end of the size curve in my description of annealing different sizes. I saved a low single filing cabinet from the dumpster back when for annealing, I fill it with vermiculite for annealing. 

Frosty The Lucky.

[anvil]

I'd like to stress that the finer your material the better. Also the denser your material the better. For that reason I recommend AG lime. It's very fine, very dense and very inexpensive. The denser it is and the finer it is, the easier it is for the material to completely and naturally cover and settle around your tool. Lime pretty well eliminates air pockets of any size. The denseness just aids in holding in the heat.

For this reason, I rarely use anything else even tho I've heated with wood most of my adult life, thus plenty of wood/household ash debree around. 

As far as vermiculite, I've never used it altho I've considered it.  I've only seen what comes for cat boxes, and in my opinion it is just too course compared to Ag lime.

I have used both wood ash and the fines under my forge ash dump on occasions, both cleaned as well as I can for chunks and other stuff. But it's been an emergency situation and I always mark these tools for a redo of the HT process. 

[Frosty]

Do you pre-heat the lime, anvil? I have a largish can of it but have had it chill steel and not anneal properly. It wasn't winter either just typical summer warm, say high 60sf.

I don't think I've ever seen vermiculite Kitty litter. I have and use the soil amendment vermiculite from the garden supply. I've also wrapped a piece in Kaowool in a pinch which worked well enough. Not perfect but it got me through okay.

Frosty The Lucky.

[Irondragon Forge ClayWorks]

I've been using hardwood (mostly oak) ashes from the wood stove for decades and haven't had any problems.

[anvil]

I've never preheated my lime and never had a problem, even living and working at 9000'

Altho I've had cats, I'm not a cat person. I always thought that kitty litter was made from kitty litter, but thats about the extent of my interest.  I think i bought my AG lime 30 or more years ago, Still using it. Cant beat that for a non consumer deal. 

[Frosty]

You're not joking? Kitty litter is typically bentonite clay that has been milled to the size chips you see in the bag.

I thought you were including kitty litter with the vermiculite reference deliberately as in the kitty litter you buy is vermiculite. Vermiculite is absorbent, it's used in potting mixes and gardens to increase the soil's ability to hold water. I suppose it could be used as kitty litter but I've never heard of it.

AND just because I've never heard of something doesn't mean it ain't so. 

However if you're talking about what the kitty leaves in the box. . . hardy har har. 

Frosty The Lucky.

[anvil]

I just looked at my post, can't even blame spell check. substitute vermiculite for the second kitty litter above. And yes, I thought kitty litter was made from vermiculite because it is absorbent, but never really gave it much thought. 

However, I still recommend AG lime for annealing. It is cheap, very dense, and good for gardens as well for the remainder of what you have left over. I'm still using the same lime I started with back in the '80's. 

[Frosty]

Well DARN, I was looking forward to another source of obscure jokes. <sigh> Still I might be able to do something with your stash of vintage lime. Other than annealing steel that is. 

My only thought is the pieces my can of lime chilled too quickly probably should've had a heat donor with, my bad. And yeah, I have a can of AG lime at least 15 years old, probably closer to 20. I don't know if it's a good vintage though.

Frosty The Lucky.

[ThomasPowers]

New Folks:  note the MAJOR difference between "unslaked lime" and "lime"...

[anvil]

A good year for vintage AG lime is circa '80, but its very rare today. Goes for a premium. 

[swedefiddle]

Good Morning,

Use the same Garden Lime for Flux. The excess brushes off when you are done fire welding, very minor clean-up.

Neil