This FAQ page is a new addition.  Foot has realised that some additional information needs to be supplied as reference for those who have purchased the instructional videos.  This page will be upgraded as more info becomes available.

BOG.  I get a lot of questions about this as I refer to it in the modeling video.   Bog is what the Aussies refer to that the panel beaters, or auto body repairmen, use to fill the dents and such in the auto.  It is sometimes called Bondo, and is  also used in fairing up boat hulls, etc.  The commercial variety you can get at most hardware stores and all auto stores.  It is usually white with a red or blue hardener which comes in a tube.   When you mix a squirt of hardener with the base it turns pink or blue, and sets in 5 to 15 minutes, depending upon air temperature, and how much hardener you put in.   It is a great material on its own to sculpt with as it takes good detail and can be carved with almost anything.

    However, what I usually refer to as bog, is my own home made stuff.   I make it from 1 part casting resin (polyester) ((don't use ordinary laminating resin)), 1 part marble dust, and 1 part cabosil (or aerocil, same thing).  Be care full not to breathe in the latter.   Also be careful with the hardener from the commercial bog, or the liquid hardener (MEKP) that you must use with the home made version.  About 1% hardener to bog is OK, you can use down to .5% by volume.   I add some black pigment to colour it, and you must use a 1\2" (12mm) drill and a strong mixer to mix it all as it gets very stiff.  In fact, add more cabosil, or marble dust to it to get it to the point where it will stand up on itself or cling to the wall of the container at least 3\4" thick (20mm)

    This bog is very strong, quite hard, and has a fair bit of tensile strength.  I have made entire sculptures with it, or used it in conjunction with other things for support, fiberglass, metal,  wood, even rocks.  It is also perfect for filling cracks in natural marble, if coloured right.  It will keep indefinitely if sealed well.  The commercial variety (bondo) is made with talc powder instead of marble dust.

    You can also make a very light weight bog by mixing Q cells or microballons (the latter is dearer) with casting resin, or with additional cabosil (1 to 1 to 1),or add just a bit of talc (20%).  This is remarkably strong, but note that the Q cells seem to accelerate the mix, as it cures quickly, gets very hot, but does not seem to want to crack.