This stuff is maybe second nature to you guys, but for a hobbyist, this has turned out to be one of the best threads i've been a part of in my life. I can't believe all the awesome, creative and effective techniques everyone has suggested. And all in one place. Regarding using a second saw...as just a homeowner, i only have a small spare. I've been calling my dealer every couple days to ask about the part. Yesterday they said they received the part in a plastic bag marked "damaged", so they had to order another one. Ugh! Sorry to have not posted yet the outcome. By early next week at the latest. Thanks again to all.
This is actually a good thread, with a lot of good ideas and information, and all meant to help. I read back through the whole thread , and realized that a lot of what I posted was maybe a little short, and used some terms that aren't necessarily in everyone's lexicon... one of which may be the difference between compression and tension wood... had a couple beers and nothing better to do, so let me try to ramble my through an explanation, lol.
All wood is either in a state of compression or tension... look at a floor joist, for example. Let's take a standard 2x10... the top half or so, the fibers are being compressed by the weight of the load... floor, walls built above it, etc, while the fibers of the lower half are under tension, being stretched. Meanwhile, we have the bonds between the fibers counteracting those forces. If we continue to load that joist, eventually the stress on the fibers under tension will overwhelm the forces holding those fibers, and the forces holding the joist laterally, and the joist will break. It will fail from the bottom up, as those lower bonds fail, and eventually the balance between compression wood and tension wood moves upward, until all of the joist is under tension, and... snap! This may seem instant, but the failure is caused by the wood under tension failing, and moving the balance between compression wood and tension wood progressing upward through the joist until it all fails.
Now let's look at a standing tree. All of the wood in a tree is also either under compression or tension. In a perfectly straight tree, perfectly balanced canopy, of course all of the wood in the trunk would be under compression. Of course that tree doesn't exist, so there will always be some under compression, and some under tension. As long as the difference in forces between the compression wood and the tension wood are less than the structural strength of the wood, not a problem. If, however, due to lean or canopy weight, we have notched the tree , relieving pressure on the compression side, and then we make our backcut, relieving pressure on the tension side, and the imbalance is greater than the bonds between the fibers of the wood, we end up with... the dreaded barber chair...
But luckily, that didn't happen this time, and now we have a 15' by 28" log laying on the ground. All of that log is still either in a state of compression or tension, because even if we can't see it, the log isn't perfectly straight, and the ground isn't perfectly flat. If we had a milled beam sitting on a perfectly flat table, then yes, all the wood would be under compression, aside from inherent twisting forces in the wood itself.
So now that we know all this, let's look at our log and start identifying sections that are either under tension or compression. If we spot a bow in the log, we can assume that the top of the log is under tension, and the bottom is under compression, so if we make a cut from the top at that point, the cut should spread as we cut down. However, as we cut down, the balance between compression and tension will shift downward, and the kerf may start to close back up, so a wedge in the top is a good idea. Usually though, as we cut down the wood under compression will gradually shift to tension wood and even rise up to finish the cut.
Conversely, if the wood on top of the log is under compression we can either start a kerf and follow with a wedge, or just bore through, leaving a strap on top, and then cut down, until into the tension wood. At a certain point, the tension will spread at a greater force than the woods lateral bonds, and then we can just pop the strap on top.
Long and the short of it, if you understand the difference between compression and tension wood, it's a lot less digging and winching and peaveys and such... think I'll go to bed now, lol
