While ripping 6/4 hardwoods for a cutting board on my table saw, I was getting some burning of the piece between the fence and the blade. The cutoff piece on the opposite side of the blade is fine. I tried both my 40T combo blade and a 24T rip blade and didn't see any difference.
Since the cutoff side is clean, I'm assuming that the problem has to do with fence and / or blade alignment. I'm going to do an accurate front-back check of the blade to miter slot, but last time I did that it was within .003". The fence is dead on.
What are the common reasons for this, and are there any slick tricks to eliminate it?
The 24 tooth would be better. Anyway if the rip cut is burning usually the reason for it is the blade is dull or there isn't enough set on the teeth. I've had better luck cutting thick hardwood with a 6 tooth fiber cement blade. The fewer teeth seem to make for easier cutting.
Yeah dull blade or not enough blade. That and going too slow, just like with a router. Also if theres any binding between the fence and the blade, but Im assuming thats not the case given your status here and the way in which you talk about the problem.
Unless the blade is super sharp, especially with hard woods, as Steve has stated it could be from a dull blade or wrong tooth blade. Also your feed and speed of the material can cause burning. Do not push the wood, forcing the blade into the material! Let the blade teeth do its work by moving the material at an even speed without force! Be safe.
If you get a lot of burn, it’s either a dull blade or a fence (and or blade) out of adjustment. Just take your time and tackle one at a time, you’ll get it. Good luck.
Most of the time you can clean the blade with warm soapy water. You can buy some special cleaners but I haven't bothered unless the blade is really clogged up. Sometimes I can just brush off the pitch and glue with a brass brush and no liquid. TCT blades don't really go dull unless they are very heavily used. Usually needs cleaning.
I have been fighting this one for a while. I agree with everything said, so far. I do have an additional issue to report.
Check (with a micrometer) that your blade is parallel to the miter slot and that your fence is as well. If the heel of your blade is kicked in even a little the wood can contact the blade below the carbide teeth. This also makes for a lot of kickback as well.
I often cut thin strips if wood (1/4 " or less). I have noted that mine is kicked in and I do not have enough adjustment in the trunions to fix it. I am going to have to pull the entire saw apart and elongate the the trunion slots to get some more adjustment then probably a "Saw Pal" Kit.
Both blades are Diablo thin kerf and new. In fact I bought the rip blade just for this purpose. The woods that gave me trouble are hard maple and bubinga.
I have been fighting this one for a while. I agree with everything said, so far. I do have an additional issue to report.
Check (with a micrometer) that your blade is parallel to the miter slot and that your fence is as well. If the heel of your blade is kicked in even a little the wood can contact the blade below the carbide teeth. This also makes for a lot of kickback as well.
I haven't aligned my saw in 20 years, so I need to check it again. If I have to get under it to loosen trunion bolts (ugh) I'll probably go for the PALS. Thanks for the links.
Alignment:
The blade and the fence must be parallel AND the reference stabdard for that it the miter slots. All measurements are based off the miter slot because it is "fixed" in position/location. It serves no purpose to align the blade and to fence which could be skewed. When the slot, blade and fence are all parallel to each other you have a well "tuned" saw which means you can use the miter gauge in the slot and it will cut accurately to what ever angle you set. It must be adjusted to be at 90 degrees to the blade when it that setting also.
The blade for ripping should be clean as well as sharp AND have the fewest teeth and largest gullets to help clear out the long sting fiber created when ripping. Too many teeth, too small gullets and not clearing out the sawdust will cause the blade to overheat and burn the workpiece. A dull blade will burn. A dirty blade will overheat and burn. A 24 tooth blade, or really good 40 tooth blade will work fine. I often use my 40 tooth Diablo for rips under 1 1/2". Cherry and some Maples are prone to burn and if you can insert a thin wedge behind the the blade, having turned the saw OFF beforehand. I use a splitter which keeps the kerf open through the entire pass.
There is a theory that would yaw the fence away from the blade at the rear a few thousands, or 1/32" or so. I don't, never have found an advantage or a need for that. My fence is as parallel to the miter slot as I can make it. The Delta Unifence has 2 large adjustment nuts that face forward and are so easy to adjust the fence for parallism.
I recommend the Freud Diable think kerf blades for contractor saws and hybrid with 1 3/4 HP or less motors. They overarte the HP on the nmotors and you don't ever get a 3 HP motor inspite of what the name plate says. Any motor that produces a true 3 HP will need a 220 volt supply.
All the advice posted by others is spot on, I just felt that more detail and the reasons for it would be helpful. :yes:
Alignment:
The blade and the fence must be parallel AND the reference standard for that is the miter slots. All measurements are based off the miter slot because it is "fixed" in position/location. It serves no purpose to align the blade to the fence, which could be skewed. When the slot, blade and fence are all parallel to each other you have a well "tuned" saw which means you can use the miter gauge in the slot and it will cut accurately to what ever angle you set. It must be adjusted to be at 90 degrees to the blade with that setting also.
The blade for ripping should be clean as well as sharp AND have the fewest teeth and largest gullets to help clear out the long string fibers created when ripping. Too many teeth, too small gullets and not clearing out the sawdust will cause the blade to overheat and burn the workpiece. A dull blade will burn. A dirty blade will overheat and burn. A 24 tooth blade, or really good 40 tooth blade will work fine. I often use my 40 tooth Diablo for rips under 1 1/2". Cherry and some Maples are prone to burn, but you can insert a thin wedge in the kerf behind the the blade to keep the kerf open. Always turn the saw OFF beforehand. I use a splitter which keeps the kerf open through the entire pass.
There is a theory that you could yaw the fence away from the blade at the rear a few thousands, or 1/32" or so. I don't, never have found an advantage or a need for that. My fence is as parallel to the miter slot as I can make it. The Delta Unifence has 2 large adjustment nuts that face forward and are easy to adjust the fence for parallelism.
I recommend the Freud Diablo think kerf blades for contractor saws and hybrid with 1 3/4 HP or less motors. They overrate the HP on the motors and you don't ever get a 3 HP motor in spite of what the name plate says. Any motor that produces a true 3 HP will need a 220 volt supply.
All the advice posted by others is spot on, I just felt that more detail and the reasons for it would be helpful. :yes:
All good advice, however, certain woods are more prone to scorching than others even with a well tuned saw. There are times when it is just more expedient to accept minimal burn marks and get rid of them by sanding or planing the edge of the board.
I was experiencing burns occasionally when ripping 4/4 cherry. I bought a new 24 tooth Diablo (Freud) blade. It was better but not completely gone. I checked my alignment again and it was spot on. I then raised the blade higher so the gullet bottom was as high as the material. Bingo that was it. I believe it has to do with the friction of the cut material not being expelled and trapped in the blade.
I think it can still happen under ideal situations based on the unpredictability of wood once you relieve the wood fibers with a saw cut.
I was experiencing burns occasionally when ripping 4/4 cherry. I bought a new 24 tooth Diablo (Freud) blade. It was better but not completely gone. I checked my alignment again and it was spot on. I then raised the blade higher so the gullet bottom was as high as the material. Bingo that was it. I believe it has to do with the friction of the cut material not being expelled and trapped in the blade.
I think it can still happen under ideal situations based on the unpredictability of wood once you relieve the wood fibers with a saw cut.
John, I have found that cherry is especially susceptible to heat buildup and burn marks, even with a sharp blade. I can cut white oak and red oak with no problem but cherry is often bad to burn. I always try to just push it through a little faster, when possible, but I like your sugestion regarding the height of the gullet - Good idea, thanks!
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