First customer

[Ronnie]

I was at the country vets office and he said I heard you bought a sawmill. I said I sure did, he said I have a pine log leaning on the fence out there from a tree that died you want to cut it up. I said I sure do.  I went home got my trailer and he loaded it with his tractor. He wanted it all turned into 8-4 lumber. Everything was going good and there wasn't much pitch in the log. I was turning and cutting making nice 2" boards with one flat side and one live side. The last 2 cuts in the middle, I got into the pitch and every knot I came across the blade came up. I ended up with two boards that are wavy all the way down. I had water and soap turned all the way up and a brand new blade. I cut one bad board cleaned the blade and still cut another bad one I even slowed down on the last one. So he is going to end up with four nice 2 inch boards and  two nice 1 inch boards and two wavy 2 inch boards. It can be planed out but it makes me sick to have to deliver this wavy wood. How can I avoid this in the future and is it common to have a few bad boards that should have been good ones out of a log? The bark wasn't the cleanest can it dull a new blade that fast? If the wood didn't have so much pitch in it I would plane it before I took it back to him. I wanted to make a good impression with the vet he has a lot of contacts and is a phenomenal wood worker. I really hate it when things aren't " just right! "

[Bibbyman]

Good that you had an understanding first customer. 

I'm not much on sawing pine so I'll leave that question to others.

[POSTON WIDEHEAD]

Yes...dirty bark can dull a blade fast! And it will.
It's possible, and I wasn't there, you may have been sawing too fast. If the blade was dulled by dirt and you were sawing a little fast, the blade will rise when it comes to a knot. Sharp blade or not, I always slow down a little when going through a knot and then gradually pick my speed back up.

Been there....done that when I first started sawing.

[pineywoods]

welcome to the world of bandsaws...Don't get all discouraged over a few wavy boards. With experience, comes understanding of the many causes of wavy cuts. If you got a few good cuts and then started climbing and diving, ask "what changed ?" Unless something slipped or bent, not likely the mill. That leaves the blade or the log or both. First the blade. Gotta be sharp sharp and have plenty of set I like 25 thou minimum. If you continue to push a blade after it gets dull, no amount of tweaking will keep it from trying to follow the grain of the wood. The blade must be kept clean, crud built up on the blade changes the characteristics of the blade. Water with soap, in extreme cases diesel. i have had to stop the mill and scrape the buildup off with a knife.  Now about logs, especially pine. Pine wood is normally fairly soft, except the knots, which are hard as the dickens and loaded with pitch. A warm blade sawing through a knot will melt the pitch, which will stick to the blade. Keep the blade cool and damp or even wet. If the tree was already dead, it may have been a lightening kill which can be another can of worms. Just keep this in mind..A wavy cut is the result of forcing the blade to do something that under the circumstances, it is not capable of doing, for whatever reason or reasons.

[Magicman]

Very well said Piney.  Ronnie, there is no such thing as a "little dirty, slightly dirty, or not too clean log".  If you see dirt, then there is surely more that you don't see.  I don't intend to come on as paranoid about dirt, but dirt dulls blades.  If the blade does not cut easily, then it is bent backwards by the forward force that you are applying.  This stretches the blade backwards causing the knot waves and also contributes to premature blade breakage.

When sawing logs with knots, you are sawing two completely different mediums.  The wood is relatively soft and all knots are hard.  This causes additional flexing.  The blade will tend to wander toward the softer wood and away from the knot.

I have a Debarker on my sawmill and still regularly use manual means of cleaning dirt from logs.



Notice the shiny edges and completely worn out brush in the center.

[rbarshaw]

I have sawn almost entirely pine. The bark is a dirt/sand storage area, you need to remove it where the blade enters the log. Also sawing from the top to the bottom of the tree will help some with the blade wander, as will slowing down thru any knots, in some cases to a crawl. I have sawn after dark and was suprised by all the sparks from the blade hitting dirt in the bark as it exited the log, then I started taking the bark off where it exited also. I've never had a blade lube system other than a squirt bottle with water/soap or diesel, an ocasional squirt of WD40 when I had nothing else. There were a few logs that did not respond to anything I did with out a wavy cut.

[ladylake]

It sounds like the blade was still gumming up, maybe more soap or try diesel.  You could put the bark side against the stops and cut into the clean side if your dealing with dirty logs.  Also more set in wide pine.     Steve