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Maybe add to your new dust hood some "flaps" (wood or metal) that close the gap between the roller and the hood (on both sides).

Mike

Figured Maple burns very easily!
I usually thin it to .030 of the final thickness with 60 grit !
Then use 100 grit to clean up those scratches-then 120 with a palm sander!!
Take lite cuts because the paper gets so hot it burns the wood!
That's what's happening the hot sanding material is burning the wood!

Try some test pieces to get the right pressure & speed for your sander!

i hope this helps ya!
mike

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Mike Collins

I cant say for sure, but what about the paper type ???.... I dont have issues with curly maple, or most any wood for that matter save the odd set/piece of braz or coco with heavy resin in it, never really have .. and I have only ever used one type of paper on my sander, Klingspor stearate coated 4.5 wide velcro 80 grit ... my drum is also cushioned with automotive gasket material on it.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I'd say take lighter passes at faster feed rate. If you take .006" off at 40% feed, I would think it much more likely to burn than taking .003" off at 80% feed.

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Eschew obfuscation, espouse elucidation.

Man Chris that sucks..... or doesn't......

I am wondering a few things that you did not mention just to get these checked off the list.

What is the CFM of your dust collection system that is routed through the 2 4" ports?

You mentioned that you are using 40% speed, I use 30% and never try to take off more then about .008 at one time. This, on a 10-20 or at least mine is no more then 1/8 of a turn of the crank.

I am guessing here but one of the things that makes the 10-20 work well at least for me is that since it is only 10" wide the dust collection and hood are concentrated on the entire 10". It seems to me that larger units have to distribute the available dust collection over the length of the hood and drum, a larger area, when much of we do may not be removing material over the entire available drum area.

On my 10-20 I am only using 135 CFM on a good day (meaning if there is a new bag in the Festool) and I have used masking tape to tape the spaces in the hood to better concentrate the dust collection.

I am also wondering if two ports are not necessarily better than one. Depending on where the stock is located as it passes through it could be that 2 ports are creating air currents inside the hood that are not as efficient as one port with a well shaped hood.

Anyway - what do I know..... Just some thought here and I hope something helps my friend.

David my friend would not an increase in speed also increase friction and heat? Even though the depth of material removal is reduced would not the increase in speed negate the potential reduction in friction?

Why not a reduction in speed and depth of cut?

Chris... I run my table speed at 100% all the time. I think the longer the drum runs in one spot the more likely it is to burn. I use 60 grit to hog away material... (exactly like Mike described). But if you take light passes with 80 grit... it really shouldn't burn.

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

Full speed, light cut, 80 grit paper. Works for me. These things are meant to go sllloooowwwwllly, not take off lots at a time. Thicknessed full width flamed maple for an explorer-style body, worked just fine.

Speeding the feet rate means you decrease the amount of time each bit of wood is in contact with the drum (which is spinning at a fixed speed) = less heat. Smaller cut, less contact area, less friction.

Maple does burn easily. Sanding at a 45 degree angle or even across the grain helps. And going slow probably makes burning worse.

I also agree that using the velcro backed paper helps. I learned that by accident and happily so. Paper lasts longer and no issues with flatness. I think it's mostly because it stays cooler.

And as others have said, it's just not possible to take much off in one pass with a drum. I usually settle for .002 - .003" per pass, less on nasty woods. Even if it takes twice as many passes, it pays for itself in time spent cleaning or changing paper.

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http://www.chassonguitars.com

Mattia my friend I have to disagree here. Even though you are decreasing the amount of time that the belt is in full contact with the wood the belt is actually in full contact with more wood more often. Consider this. When you mow a lawn and drive the mower fast into tall grass the motor bogs down and continues to be bogged down the entire time the grass is high and you are speeding along. The blade also spins slower and does not cut as well.

Drive the mower into the same grass but going slowly and as the grass gets cut the motor will not bog down as much which should equal less friction.

I am sure I could be wrong but it seems to me that slower, lighter cuts, since the material gets removed reducing friction is the way to go.

Apparently dust collection is not the problem.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Dust suction would be the last culpret in my opinion If I am burning wood I figure I am taking too big of a bite. I do understand that if the dust is infront of the drum then this adds thickness by compressing the dust as the material enters the pinch point. But I still go back to if I am burning wood, I am biting off more than I can chew and at too fast of a rate.

Faster, lighter passes, and if possible angle as mentioned by others.

Hesh, Your thinking is solid, but you know when you take a pass on your sander then sand it through a second time and it takes more material. I think what happens is the sander does not take the full thickness when you run it faster, if it took an equal amount of material it would seem like it would make sense the friction would have to occur faster with less time to disipate. It just doesn't work out like that though in practice. If you slow the belt down it will take more material in one pass, and generate more heat.

Good luck with it Chris, I am sure you will work it out shortly.

Rich

There are several reasons why a second or third or even fourth pass will still take material off even though you don’t change depth. They are compression of the drum (microscopic) compression of the paper (slightly more than microscopic), and play in the bearings. Most of these use either one cylindrical roller bearing in combination with a tapered roller bearing, or a pair of spherical roller bearings. In any case the amount of load on the bearing system will affect the concentricity of the drum shaft ever so microscopically.

Funny thing - maximum feed rates (i.e. the maximum you can feed without bogging or hogging) produces the least amount of heat. Part of it is that the chips/dust cary away heat.

e.g. say you're routing cherry - a very slow feed rate will burn everything. Speed up the feed rate and your problem goes away.

p.s. I'm assuming that this is also true with drum sanders as I don't have one yet, but will on saturday (woodcraft 10%off power tool sale). I'm trying my hardest to not buy a new bandsaw the same day (I'm suffering with a jet 14" right now)!

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As for feed speed, this is another place where it's so easy to test in the real world that theory doesn't really matter much. Try it. In my experience, on my machine, faster feed means less burn. Maybe it's different with different machines and papers. Get a few scraps the same thickness. Run a couple through slow, a couple fast. See what happens...

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http://www.chassonguitars.com

Chris here is what I do with a 10-20.A bit unorthodox,but it works.I open the lid ,place a huge fan blowing the dust at the point of impact.Slow the speed to 30 or maybe even lower.And make dang sure the paper doesn`t overlap itself.This has always been the cause of any burning.I use 80 grit for thicknessing of backs and sides,and 120 for tops.Make sure there is plenty of space between the wraps as it rolls around the drum.Trust me the stuff will move a little bit no matter how tightly you have it wrapped.Of course I have built a stand with wheels,and always roll that sucker outside.I can`t imagine any kind of dust system that would completely work on that sucker.
Good Luck,
James

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James W Bolan
Nashville Tennessee

Rich buddy that makes sense to me now - thank you! I have noticed that after one pass and without lowering the drum at all additional material comes off with subsequent passes. This means that there is always going to be friction and going slower even leaves the hot wood against the hot drum longer.

OK I get it now.

My philosophy on "full speed ahead" is to spend less time on a particular point of the wood. Two things get heated - the paper/drum (I'm considering that one combined component), and the wood. The dust collector can of course help clear the paper, and the air flow can aid in cooling the drum/paper as well.

It doesn't cool the wood directly under the drum however. The more time you spend spinning the drum against one point, the hotter that point is going to get. The slower you feed, the more time you will be spending on each point. Take that reasoning to extremes and imagine the feed at or nearly stationary - even if you were barely taking off any wood you would obviously expect burning when hanging on one spot. I'm not entirely sure if that logic carries on in a linear fashion once you hit a reasonable range of feed, but it seems to make sense to me.

If the burning was caused by the drum heating up, it seems you would see the burning increase from the start to the finish as the board is fed through and the drum continues to overheat. Chances are that this is not the case though, and the wood overheats directly under the drum as it's being sanded relatively indifferent to the cooling of the drum.

So I say courser grit (I would be using 60 for any wood removal), lighter cuts (less friction), faster feed (less lingering at each point). Right or not, that's my reasoning and I'm stickin to it.

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Eschew obfuscation, espouse elucidation.

Yes, get that feed rate up as fast as you can and take small cuts turning the board around and run it thru a second time without adjusting the depth. Try to run it thru at an angle off the grain for less gum. Don't be in a hurry and let the wood cool a little between passes.
Mine is has dual drums and I still go slowly with 80 or larger grit.

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Tickle your guitar daily, and it'll tickle you back.

I'm also in the fast feed and light cut boat.

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Jim Watts
http://jameswattsguitars.com

Yeah I agree with what seems to be the concensus -- faster means less burn. If you're getting burn then the first step is to take less off and speed it up.

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Richard
http://www.guitarmaker.com

I was having similar problems with my performax 16/32. It would burn wood with brand new paper and just skimming the wood too (no big cuts). It would literally wear out and or gum up a roll of paper with just one set of back and sides and was getting expensive in a hurry replacing the paper.

I called Klingspor and told them the problems I was having and they suggested that I try this paper. I'm not sure what it is, but it is made in Germany and is bright blue. The numbers on the back of the cloth backed paper are CS411S 60 and it works like a charm. I can run quite a few back and side sets thru this stuff and it still looks like new with little if any loading of the paper even when sanding gummy wood. It wasnt cheap for the 50 yard roll, but it should last me a long time. It beats anything else I have tried hands down.

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Reguards,

Ken H

I run mine 100% speed and very light passes. The higher the grit the lighter the pass. If 80 to 100 grit maybe a 1/4 turn and thats pushing it. anything higher grit only 1/8th turn at best.
If you want to remove like 1/32nd or more at a time then I suggest a planer. Doesn't do real well on figured wood though!

Mike

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I'm outside looking in, just farther from the window than most.

Chris I have a 22-44 that gets very little use since I bought the Grizzly wide belt sander.
I have sanded a lot of maple on that 22-44. Light passes, full speed and new paper at least 80 grit but 60 is better. I always run mine at full speed for any wood. I haven't read where you mention what grit you are using.

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