Refractory brick equivalents, but smaller and free.

[BazyleParticipant @bazyle]

Neil, I don't think you need to protect the skamolex, just support it well. It has no bending strength but is strong under compression and takes a fair bashing without harm. I as do countless others have it lining my stove and sitting for hours every day at red heat, getting bashed by logs thrown into the stove. However I think a thin skimof refactory paint would crack and flake off rather easliy as it is meant to go on rigid surfaces.

I think some people may be confused by comments of finding refactory bricks on building sites. You will certainly find plenty of thermalite blocks which as mentioned is a good enough substitute most of the time. (just make sure to dry it out totally). The only 'refactory' bricks yo might find are the hard ones in fireplaces and industrial hearths that are only made to withstand thermal shock better than normal brick but have no insulating properties. This will include industrial scale kiln lining. The lightweight fragile insulating bricks are far more expensive and typically only used for small craft sized kilns where the situation and use justifies the extra cost to achieve insulation in a smalloverall volume.

[Ian S CParticipant @iansc]

The bricks used are known as Hebel bricks, they are made of Autoclaved, Aerated concrete. I don't know how these differ from the bricks used in kilns, but they work.

Ian S C

[jaCK HobsonParticipant @jackhobson50760]

I made a lot of soft refractory bricks from Bentonite cat litter mixed with a little sand and cement and a lot of pearlite. Works great at heat treating temps, probably up to 1000C but starts to dribble if you take it up to forge-welding heats. Maybe vermiculite would work better instead to pearlite. Now I just buy soft firebricks at a couple of quid each… delivery cost is the real killer.

[Neil WyattModerator @neilwyatt]

> I don't think you need to protect the skamolex

Presently I use relatively small tiles. The problem is that flux sticks to the surface, sometime attaching the work to it, and this results in the surface breaking away. It also leaves a surface unsuitable for jobs where you don't want flux involved, such as heat treatment.

One answer would be to use the tiles I've got as a sacrificial layer when soft soldering, but one reason for a hearth is to do bigger jobs.

The other option is to do big jobs (e.g. small boilers) in a barbecue on a bed of charcoal a la LBSC.

Neil

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