annealing time?

[bhanna]

I finished forging my first seax-ish object out of coil spring yesterday. I know I'm supposed to anneal before i do any grinding to it, but I'm not sure how long it's supposed to take to anneal. I mixed some hot charcoal with some dirt and buried it in that after bringing it up to a bright orange. It was still hot to the touch about 45 minutes later, but i could handle it with gloves. Was this long enough, or should it have taken a lot longer? If this isn't good enough, what would be a good method?
Also, once i do get it annealed and cleaned up, should i bring it to an edge before quenching, or would that be better after tempering?

Thanks

[ThomasPowers]

Generally I anneal overnight and love to find the piece warm to the bare hand in the morning.

Normalize, heat to critical and let cool in still air is what I do when I don't have time for an anneal.

[felix24]

I usually anneal my blades in the forge when I'm finished. It takes about 5 hours to cool and that seems to anneal the blades quite well. I'm not that experienced yet, but I think 45 mins is probably not enough. Someone correct me if I'm wrong

Some good methods for annealing are to bury the blade in wood ash, vermiculite or some other non-flamable insulating material, with about 6 or more inches of insulation all around the blade (the more the better). I've also heard that kitty litter can be used if you get the clay kind.

So far I have filed and sanded the edge pretty much all the way (down to roughly a millimeter thick) before quenching and I haven't had any problems yet. Don't put a sharp edge on it though cause it probably will crack . You can put the final edge on it after tempering then.

Good luck, hope this helps.

[MattBower]

I have a confession to make: I almost never bother with annealing. With the steels I use, normalized pearlite is soft enough to file and sand easily enough for my taste. But if you are going for an anneal (and yes, leaf spring is probably a steel in which a traditional anneal will work fine), you're looking for a much longer cooling cycle than 45 minutes.

Most folks recommend not putting a sharp edge on it before you harden. The thin edge makes it easy for the blade to tear itself apart as it forms martensite. I keep the edge at least 1/16" thick for hardening.

[bhanna]

Thanks for the responses. That helps a lot. I didn't think 45 minutes would be enough. I guess that would be considered normalizing then?
Isn't Vermiculite that white stuff in potting soil? Would you need to mix it with anything, or just pack it in a container and throw the blade in?

[MattBower]

The white stuff is perlite. It's very similar to vermiculite, also a good insulator, and pretty resistant to high temps. In other words it'd probably work well for the kind of annealing you're doing. Yeah, just bury the steel in a container of loose vermiculite or perlite. (Make sure it has several inches of the stuff on top.) If you want to slow it down even more, heat the blade along with a couple big chunks of steel and bury the whole mess together.

It wouldn't be considered normalizing. Normalizing usually (always?) involves air cooling, i.e., relatively fast cooling. I guess if I had to name what you did, I guess I'd call it a partial anneal.

[golgotha forge & anvil]

In my understanding, if the steel is cool to the touch then it is annealed. 45 mins ain't near long enough. U can also use ashes to anneal in, kitty litter, floor dry (absorbent) and granulated lime are also good. I don't even know where u can find vermiculite (maybe at landscaping/nursery depts?)...

Gene

[bhanna]

you can apparently find vermiculite at Home Depot. Thanks for all the info. I guess i'll either try kitty litter or vermiculite. Hopefully with all your help I'll be able to finish my first high carbon knife .

[MattBower]

Thanks for all the info. I guess i'll either try kitty litter or vermiculite.

I think the vermiculite will prove to be a much better insulator than kitty litter.

I have bought small bags of vermiculite (for gardening purposes) at Home Depot, though I don't know if they'll have it at this time of year. I also bought a large bag of the stuff from McMaster-Carr at a much better unit price -- but 4 cubic feet is quite a bit of vermiculite! http://www.mcmaster.com/#catalog/116/2047/=9cd7yv

[ThomasPowers]

Don't "pack it in"! You are using it as an insulator and insulation works best if it's light and fluffy and not dense and compressed!

Keep it dry too.

[BIGGUNDOCTOR]

I have a cut down 55 gallon drum full of free gray wood ashes straight out of the woodstove. When I need to anneal a part, or cool a cast iron repair, I would just stir the ashes up, and pop the piece in the ashes.