Wide-Belt Sanding Maple: Burning Problem

Grit choice and other factors that can reduce burning when sanding Maple. April 30, 2009

We are having problems with our wide belt sander from burning our maple work. We have tried almost everything from light to heavy passes, platen up and down. Our belts load up real fast and start burning sometime almost instantly. Do you have any tricks for sanding soft and hard maple or is my old wide belt just worn out. We usually can only take off about .004-.006 per pass and we still go through a lot of sanding belts. Thanks for your help.

Forum Responses
(Solid Wood Machining Forum)
From contributor R:
I try to avoid maple if possible, but a couple years back was all the rage. I'd suggest using a somewhat aggressive belt (60 or 80 depending on the quality of your primary wood processing) to level your work, not switching grit until all defect or glueline mismatch is leveled, then switch to the next finer grit, using only platen down, as opposed to bed adjustment on subsequent passes. The worst thing you can do is try to level with too fine a grit, second worse is try to remove too much material per pass with a fine belt (keep thing 60-80 grit).

From contributor A:
I would never sand beyond 100grit with a wide belt on maple. I would buy a couple of the really good 100 grit Zirconia belts from Klingspor. Wash the belts as soon as they start to get clogged. You can sand up to 150 with random orbit sanders. Also the faster you run the feed the less heat is generated on each potential burn spot. It essentally runs fast, sharp, and provides decent cuts rather than slow, dull, shallow cuts.

From Gene Wengert, forum technical advisor:
Use open coat belts. Obvious, heat is the problem, so use fast feeds, small stock removal per pass, fresh paper, and so on. It is important to have an adequate dust removal sytem. Really small cuts will have a lot of rubbing and heat.

From contributor L:
We WB sand to 150 without burning on maple. Make sure your machine is taking the same cut all across the belt. If the opening is different side-to-side you may be hitting the wood too hard on one part and not as hard as desired on the next. Open coat sharp belts, fairly fast feed, lighter cuts. Is your platen in good condition? It may be worn in the center and cause uneven pressure.

From contributor M:
Calibrate your material using aggressive belts, then do final passes with final belts. We remove .015 with grits up to 100, and .005 with 120 and up.

From the original questioner:
What is your feed rate? Are these parts pretty flat before sanding, or are you having to flatten as well as sand? Some extra milling of panel staves can help downstream at the sander. You need to take the time to dial in the settings on the sander. These are specific to the belts being used, so it is best to evaluate a few, and then settle on the best combination. If you have a single head, then I like the suggestion to use just the drum for a coarse pass, then just the platen for a finish pass. Even if the platen is manual adjusting, you should be able to raise and lower it consistently to the same position. Remember that the finish pass is just sanding down to the bottom of the scratches left by the coarse belt, no further.

From contributor F:
We just finished a maple job and also had problems with burning. We tried the coarse, 80X, belts and that seemed to help some. Once the belt started to burn, we shut down the sander, took the belt off, and used the air nozzle to blow off the burnt band that formed on the belt. Replaced the belt and sanded again until the belt loaded up again, then repeated the process. It took some time, but it was still faster and smoother than the old days of using a belt sander.

Had some old belts around and took them to the car wash, hung them up on the clips that are used for car mats, and used the high pressure water to blast off the old clogged material. It worked very well and made the belts look like new and we now use them once again. We had a paper belt that was useless, so I tried the power wash just to see what would happen. It worked, but I am sure that the paper would not hold up to another washing.

We then started to put maple through at a slight bias so that the belt would not sand on one area too long. This works very well and we took it down to 180X which made it easy to orbit sand the doors and faces.

From contributor L:
If you're burning the maple and filling the belts: feed too slow, too much pressure (trying to take too much off with too fine of a belt,) machine out of adjustment, wrong belts (use open coat,) belts dull, running straight in so one area of the belt heats excessively. You can wash polyester belts but cotton will want to curl real bad at the edges. Only use the platen with the finest belt. Some brands of belts work much better than others.