Scott, that's the stuff. Just tap it off and your ready for grinding. The insulating characteristics are what you're after.

Scott,

Another idea would be vermiculite. I bought what we used in my shop at the local garden center for cheap.

Clay

Hello Jeremy. I also use vermiculite. It is cheap and lasts a long time. Another plus is no white lime dust all over the place. I know Lin, I am just messy. The main thing is how well it slows the cooling, like Lin stated.

Brion

I have to vote for the vermiculite. Lime is a poor insulator by comparison, and another drawback to lime is it's hygroscopic....meaning that is absorbs moisture from the atmosphere, and over time will result in hard/soft spots in blades your attempting to anneal in it.

Vermiculite can be found or ordered at most garden/nursery outfits. I recently found it at Home Depot....$24 for a 4 cubic foot bag. That's enough to fill my annealing "tub" with about 1/3 left over (my annealing "tub" is a metal box, 3'X16"X12)

I give my vote for the vermiculite as well, but if one wants to try one of the more powdery insulators and has a woods stove available, wood ashes make just as good an insulator as lime. There really isn't any chemical thing to the steel from the lime so it is really just the insulative value.

I know you didn't ask about this but I can be a pain this way, sorry, but what steel are you looking to slow cool? If it has below .8% -.85% carbon your cool, if it has above this number you could be inviting some headaches with the traditional full anneal in the vermiculite or lime.

I use wood ash from my Vermont Castings wood stove. Bill Moran told me about using wood ash for this purpose.

I use to stick blades into the warm ash in the bottom of my wood heater. The heater finally burned out and now I use vermiculite. I got it at Walmart.

Dale

Scott, I hope you don't mine me hopping in here.

What negative effects occur from a full anneal in vermiculite using steels with more than 0.80 carbon? What would we do in place of the full anneal?

I can post this as a new thread if that is more appropriate.

Clay Walker

Ragnarok Forge

At around .8% you will get complete pearlite formation throughout the steel with no left over phases to deal with. When there is more than .8% there will be leftover carbide that will cause some issues if it is not handled correctly. The extra carbide in lameller form (coarse pearlite from a slow cool from above critical) will tear up your drills and other cutting tools. You wouldn't be the first bladesmith to easily start a hole and then have your drill stopped dead 1/2 - 2/3 of the way through if this condition occurs. But worse yet is that this material really likes the grain boundaries where it will embrittle the steel and be very stubborn to move back into solution. For many years a lot of smiths were disappointed in the performance of 1095 when compared to 1084, but if anneals and heat treats them the same there will be disappointments when 1095 should be able to hold it own and even surpass 1084 in certain areas.

Instead of lameller annealing, it can be better to use sub-critical spheroidizing methods on the higher carbon alloys. In other words soak or cycle at temperatures below 1350F to take the carbon out of solution. Careful cycling can be done in a forge, and if you have a controlled oven different and even more thorough methods can be employed. Either method dispenses with the vermiculite, lime or ash that is more effective with steels at or below .8% C.

Thank you everyone for your interest & replys.

I have just made the jump to known steel and have started with 5160. Have been learning about vermiculite & lime and just thought lime might be easier to obtain; I have no real preference or reasoning for one vs the other at my beginer stage.

Thanks again