Brick layers are always trying to nab carpenters old saws to cut Thermalite block with. I've managed to make the bricklayer on site a little happier by making the saw cut a little better for them. I know it works as they asked me to alter another saw for them yesterday!
All you need is an old panel saw and a saw set.
Adjust the saw set so it's altering the teeth of the saw to the maximum (in this case it's to 4 teeth per inch) and work your way along the saw, setting every other tooth. When you've finished one way turn the saw around and set all the teeth you missed out. The saw set is basically pushing over each tooth making the kerf wider and therefore the cut more aggressive.
|The Set in clamping mode|
|The "tooth" that pushes over the teeth on the saw giving it's "set"|
|A much more aggressive saw|
Doing this isn't as good as buying a proper Thermalite saw but it is much cheaper and it works pretty well. It makes the cut much more aggressive and faster as well as clearing out the waste better, stopping the saw from binding which can be a problem when using an old wood saw. I also used it on cutting kingspan and it cut much faster than a normal saw would.