Burn marks on soft maple ??

[Jeremy Polk]

I am kinda new to woodworking (been fiddlin' with it for a couple years). I have mostly worked with pine and a little bit of oak. Today I bought a 1X12 rough cut soft maple board to build a small table with. After I ran it through the jointer and the planer, I started to rip it down to the 2" strips that I needed, and there is where I ran into problems. I got burn marks on the left edge of every cut? The blade that I have is a 2 week old Woodworker 2 by Forrest. I tried varying my speed, both slower and faster to see if I could reduce the burning. No luck. I ended up ripping the strips to 2 1/8", flipping them over and pushing them through again to cut off the burn marks. What am I doing wrong here? :confused:

[Howard Acheson]

There are three primary reasons for wood burning. One is cutting too slowly. The second is a dull blade. Your problem is probably the third which is that your saw is out of alignment.

WWII blades get their smooth cut from the way the teeth are shaped. They have a side shape that rubs the cut surface burnishing the surface smooth. If your saw is not perfectly aligned this burnishing causes excess heat causing the wood to burn. Maple is a wood that is very susceptable to burning.

Here is the low tech, low cost way to align a tablesaw that I learned maybe forty years ago and use to teach to my students.

Make 3/4 x 3/4 x 12" hardwood stick. Drill a hole somewhat centered in one end and insert a brass #8 x 1" round head fine thread machine screw about half way. UNPLUG THE SAW. Raise the blade completely up. Clamp this board in your miter gauge (if you determine that there is some slop in your slot to miter gauge, use a playing card to take up the slop) so the screw head just about touches the blade at the front. Now rotate the blade by hand and determine which tooth is the closest. Adjust the screw in or out until it just touches this tooth. Mark this tooth. Rotate the blade so the tooth is now at the back of the table and move the miter gauge/stick assembly to the back and see if it touches the marked tooth to the same extent. If it doesn't, adjust the trunnion (if a contractor saw) or the tabletop (if a cabinet saw) until it does.

For a contractor saw, first use a small c-clamp on the rear trunnion and cradle to keep the assembly from moving. Then loosen the two rear trunnion bolts and one front trunnion bolt. Slightly loosen the other front trunnion bolt and use a stick to tap the trunnion until the blade and screw lightly touch. The blade does not move directly around the center so you will need to repeatedly go back to the front of the blade, readjust the screw, and then again measure the back. Be sure to check after tightening the trunnion as the trunnion frequently moves when being tightened.

For cabinet saws, loosen the bolts that hold the tabletop and tap one corner until things come into alignment.

The same adjustment gauge can be used to set the fence parallel to the miter slot. Slide the miter gauge to the front of the table and move the fence over to the screw head and insert a playing card between the screw head and the fence just so you can move the card as it touches both the fence and the screw head. Now move the miter gauge to the back of the table and see if you have the same feel when you insert the card. I like my fence absolutely parallel--if you want to have a slight opening to the fence, you can easily estimate the opening by adding a thickness of paper to the card.

I always show my students with a dial gauge that their adjustments are within .001 - .002.

You can also use the same gauge to measure blade runout by using a $5.00 feeler gauge.

Finally, after you are satisfied with the above adjustments, check the position of the splitter to make sure it is exactly in line with the blade.

Bottom line, there is no need to spend more than the $0.05 for the brass screw.

Check the alignment of your saw. The blade should be parallel to the miter slot to with no more than 0.003" (0.001") is better. Your fence should also be parallel to the miter slot to same dimensions. Finally, your splitter should be lined up exactly to the kerf.

[Prashun Patel]

Check that yr blade is perfectly aligned with your fence and that yr pushing through perfectly straight.

Are you working with a guard or splitter? That could be binding slightly causing the piece to push against the blade enough to burn.

I was able to rip 2" curly maple on a 1 3/4 hp saw at 110v with a 50t combo blade. Two passes, but burn free.

On a 1" piece, I doubt you need to switch to a ripping blade - especially since yr wwii is brand new and a great blade.

[Chris Ricker]

Try checking the alignment on your table saw, Jeremy.
It sounds like your fence is off a touch. BTW in my experience maple is easily burned.
Usually I have luck toeing out the fence about .002 or .003 thousands.
let us know how it works!

[Jeremy Polk]

Its sounds like the general consensus is my blade & or fence is out of alignment. I will check it out tommorrow as Howard suggested and see what happens. BTW, you guys all mentions toeing out the fence a little. Could I get some clarification on exactly what that means? Thanks.

[Greg Cole]

Toeing out the fence means a VERY slight angle away from the blade from the front of the fence to the rear. If you were to look down at your saw from the ceiling it would angle to the right side of the saw by ever so slightly... most WW'ers don't have the tools to accurately measure .002 or .003, but a thickness of paper is about right.

[Lee Schierer]

Its sounds like the general consensus is my blade & or fence is out of alignment. I will check it out tommorrow as Howard suggested and see what happens. BTW, you guys all mentions toeing out the fence a little. Could I get some clarification on exactly what that means? Thanks.

Toeing out means the back of the fence is slightly further from the blade than the front of the fence. It isn't really necessary to do this, but you definitely don't wan't the fence angling in toward the blade.

For about $20 you can get a dial indicator from Harbor Freight that will make the alignment of your saw much faster. Mount it on a piece of wood clamped to your miter gauge and check the blade alignment to the miter slot. You should get the blade aligned within .003" without too much effort. Closer to .000 is better, but may take too much time. Then align your fence with the same miter gauge slot. Again you should try to get it within .003" or less. Whatever you do don't have teh fence angling toward the blade. You want it at .000" or angling slightly away from teh blade.

You didn't say what saw you have, but the lower horspower contractor type saws struggle when ripping thicker hardwoods. If the saw bogs down as you push the wood intothe cut, burning is more likely to occur. The woodwoker II is a good blade, but is not the best ripping blade you can get. For ripping on a contractor saw you want a 24 tooth blade and possibly a thin kerf blade. The thin kerf blade can give the same quality of cut and will not slow down the saw because it is trying to remove less wood so the rpm's stay higher during the cut. A good 24 tooth rip blade by Freud can be picked up for around $30-40

[Alan Schwabacher]

Those are good answers, but I wanted to add one more point. A dirty blade can also behave as if it's dull and cause burning. Pine is notorious for getting pitch on a blade to dirty it.

Cleaning your blade with blade cleaner, mineral spirits, or a mild detergent is a good idea. (I would not use oven cleaner, which is said to attack the brazing that holds on teeth.) Put the blade in a frisbee or other shallow container, add liquid, and scrub the teeth with an old toothbrush. The liquid can be stored in a jar for reuse for years. If you use a water-based cleaner, rinse with hot water, and wipe it dry. This might help the cut noticeably.

[Eric Garner]

Maybe I missed this in the previous replies, but can't internal stresses being released in the wood cause some burning.

This happens to me quite frequently. Especially when ripping thinner strips. It doesn't take much for the wood to start rubbing up against the blade as it begins to bow from released stress.

You can take you finished 2" strip and put it burn side down. Check to see if the wood has a bow in it.

[Lee Schierer]

Maybe I missed this in the previous replies, but can't internal stresses being released in the wood cause some burning.

This happens to me quite frequently. Especially when ripping thinner strips. It doesn't take much for the wood to start rubbing up against the blade as it begins to bow from released stress.

You can take you finished 2" strip and put it burn side down. Check to see if the wood has a bow in it.

Yes internal stresses can pinch the blade and cause burning. Construction lumber is generally poorly dried and is prone to twisting, bowing, etc. Even so a well aligned saw will have less problems than one that is not aligned. I like to let construction lumber dry out in my shop for a couple of weeks before trying to use it if I can.