by Rob » 17 Jun 2015, 17:38
one thing I'm yet to get is a ripping blade for my chainsaw. My normal procedure for the production of bowl blanks is to cut the butt into lengths which correspond to the following formula:
Diameter of tree plus 8 inches either side of the bit I want to keep. In other words I expect (even after sealing) a good 8 inches of waste from either end of the butt...lost to radial cracking and shakes in general. That leaves you with a bowl blank that is the maximum that can be accrued from that tree with in theory little in the way of end grain cracks.
I then lay it on my chopping log on the bark side and wedge it either side so its stable. Then I rip from top to bottom going in at an angle through the bark. This creates very long shavings which will clog the chainsaws drive wheel if you're not careful but with a little practice that's easily avoided.
I cut the log nearly through and then move 3 or 4" (whatever I want my final blank thickness to be) over and nearly cut through again. Finally, one more cut and you're usually used up on most average sized trees. Then I do the finishing cuts separating the slabs. Doing it this way keeps the log stable until just the last cuts. I switched to this method recently after a mate of mine tipped me off to it.
Those chainsawn slabs are really not bad at all and can be end sealed and stickered for air drying just fine like that. or they can then be bandsawn into circular blanks or 3x3" square edge pieces for spindle blanks. But I find that processing the log material is not what the bandsaw is best at. The chainsaw is far more versatile because you take it to the job. To process log material on the bandsaw requires a proper jigged up set of rails etc because they're just too heavy to manhandle safely on your own. Obviously you get a better quality cut if you do bandsaw them but I've given up doing it because frankly it's hernia territory. I now process the 2ndry level on the bandsaw. Good chainsaw practice is really not difficult as can be seen from Andy's pics. Good solid slabs there, they look pretty uniform.
My understanding is that with a ripping chain ground to 10 degrees you can rip down the butts with them standing on the end grain. Much easier and safer but I've not tried it yet