saw blade burning

[Aaron Kline]

I have a PC razor saw blade and use it in my 1-1/2 horse contractor saw. It works ok on pine but on soft maple it burns like crazy and leaves a nasty finish. I have been using a $15 hardware store made in china blade and it cuts nicer. There is some grit on the face of the teeth, but it still just doesn't seem right. If anyone has suggestions, I'd appreciate it. Thanks.

[Dev Emch]

I have a PC razor saw blade and use it in my 1-1/2 horse contractor saw. It works ok on pine but on soft maple it burns like crazy and leaves a nasty finish. I have been using a $15 hardware store made in china blade and it cuts nicer. There is some grit on the face of the teeth, but it still just doesn't seem right. If anyone has suggestions, I'd appreciate it. Thanks.

First its very difficult to troubleshoot a problem without the kit sitting in front of me. To be able to grubby finger the item really makes a difference.

At any rate, there are a number of reasons you may be having issues. First of all, check your blade geometry. A duraline sheet goods cutting blade by forrest work wonders on melamine but its the pits when using it to rip maple. The china special may actually have a better blade and gullet geometry for what your trying to do. As an aside, I never buy the toolmaker's house brand blades.

Blades like the woodworker two are actually engineered to function in a mixed mode environment of ripping and cross cutting. That PC blade may be optimized for a hand saw which is engineered more for cross cutting.

Then we get to your saw. The fence needs to be dialed in dead nuts accurate. But more so, you need to have about a 2 to 3 thousandths of an inch gap between the fence and the BACK side of the blade. So your fence is not perfectly square... its got a slight outward taper. All circular saws do this including the huge 4 to 6 foot diameter sawmills. This not only prevents bind up but it also mitigates blade burn on the back side of the blade. How are the bearings in this saw just inside of the main blade collar?

Lastly, you have feeds and speeds. Maple and cherry are very susceptable to burn. Any time you stop, you burn. When cutting these woods or running them in a router, think about your movements and realize that just a reposition of your hands can burn the wood. Also, you need to feed as fast as you can get away with. The sawdust comming out of your gullets just south of the kerf is carrying away generated heat. Consider the sawdust to be your cooling system. If you stop, you stop your chip load and the blade is still turning. Result? Heat is now transferred to your work item and the work item burns. Its also heck on your blades. The number one cause of premature dulling in a sawblade or router bit is using it with to slow a feedrate. Heat Kills. And that edge is extremely thin and delicate. Carbide lasts longer only because its edge is not so keen as steel and carbide can take much more heat before microfractures chips and burrs the actual edge.

But the most significant issue with most table saw burn results from poorly alinged fences. If you have a fence attached to say a table which is not bolted directly to the saw, then that table can move and it will move by much more than a couple of thousandths. Result? Very poor rip performance. Who would do something this stupid? Look up dimensioning saw under ebay and have a look. One kick of the table leg and your seriously out of alignment. Burn your wood out of alignment.

Good Luck...

[Jim Becker]

Woods that are high in natural sugars tend to burn quite easily when presented with friciton...something that can happen with certain saw blades, exacerbated by saw alignment and blade height when cutting. Try raising the blade a bit higher first and see if it reduces your burning. If not, check your saw's alignment carefully and be sure you are using both a splitter and other aids to keep the wood moving straight and smoothly through the cut.

[scott spencer]

In addition to the great suggestions that Dev and Jim have offered, I'd also suggest cleaning the blade...it's easy and doesn't take 6 or 7 minutes. A little cleaning can have similar results to sharpening. A little spritz with 409 or Simple Green, and scrub with a brass or stiff brush, rinse, and your back in business.

[Kent Cori]

One other thing to consider is the feed rate through the saw. A slightly faster feed rate will reduce burning but you don't want to over do it either.

Overall, I would verify the fence alignment as Dave recommends and then try a different blade that is more suited to the task.