I feel a little stupid posting this as I cannot believe I haven’t figured it out before. Likely it’s so obvious that no one thought to tell me.
When using a flush-cutting saw (a saw with zero set), I always noticed that the first cut was relatively easy. Then each subsequent cut became more difficult.
“Hmmm,” I thought. “Perhaps the blade is heating up in use. And that heat is swelling the wood fibers in the cut, increasing friction
And while that swelling might be true to a small degree, something else was going on: a lack of lube.
Right before I put any saw away in my tool chest or hang it on the wall, I wipe its blade with oil to protect it from rust.
So when I pick the saw up the next time, it’s lubed. The first cut I make with it is full lubricated. Each subsequent cut removes more of that lube.
Now when I use my flush-cutting saw, I wipe its blade with an oily rag after every cut. And miracle of miracles, it works like crazy.
— Christopher Schwarz