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To be fair, I knew about this going in. But I have to admit being surprised by the magnitude of the problem. I'm thinning enough wood for three guitars using klingspor blue, 80 grit. I have not gotten through the three side sets and the paper looks ruined. I used the erasure often. But it did no good. Any ideas? I still have 6 hundredths to go. This could get expensive!

And I still have the backs to do

Mike

The backs will be even worse!!! I used to have a Performax 22-44 and then "upgraded" to a Woodmaster. The Woodmaster handled oily woods much better but it was far more difficult to sand purfling because of the velcro paper system. If you could find a Woodmaster without a velcro drum then that would be a better solution. In short, drum sanders just really aren't that great for thicknessing wood -- much more ideal for final sanding. I currently have a Grizzly wide belt and it is night and day difference. Anyway, something to consider for the future...

As far as tips go -- take only 0.005" off and do 2 passes before you drop another 0.005". 80 grit is a good grit to use. Keep your "eraser" handy and remember to "upcharge" a lot for Cocobolo if you are selling the instrument

For stock removal try feeding the pieces through on an angle, and only sand with the grain on your final clean up passes. And has already been mentioned keep you passes light.

I figure I use 3-4 times the amount of sandpaper on a Cocobolo guitar vs almost any other type of wood. That definitely has to be factored into your pricing.

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Try cleaning the sandpaper. I soak mine in a bucket of water and Simple Green overnight and use a brass suede brush to get the stubborn stuff off the next day. Gets me a few more uses.

+1 and feed it as fast as possible.

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Angle feed, check. Erase often, check. Fast feed, well that only occurred to me halfway through. Gonna be a long day in the shop tomorrow. This stuff is Playdo with cellulose mixed in

All of the above, and when paper seems beyond use, remove and hang your sandpaper and spray with oven cleaner. Let sit overnight then wash off with a hose. Paper is usually as good as new.

Bob

That really works?

Oven cleaner works extremely well on saw blades, I'll have to give it a try on sanding belts. Thanks for the tip!

For thinning coco I've used a hand plane and scrapers. I find the greasy dust from sanding very noxious and try to avoid it as much as possible. I have a couple of extra spoke shave blades that fit in a homemade handle that I use as scrapers. After planing and scrapeing to get them close a few light passes through the drum sander is all it takes.

I use 36 grit to get it close , the wood builds up any heat and that will glaze the paper. The best you can do is feed fast you want the heat in the chip not the stock. Once you have it close you can use a finer grit but take only a few thou at a time.

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Here are the replies I got when I asked.
viewtopic.php?f=10101&t=42053&hilit=sanding

Kevin Looker

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I must be lucky. I build with coco more than any other wood. I can thickness back and side sets without changing paper. I use a homemade drum sander and klingspor 80 grit red paper. When it clogs, I take an air compressor spray nozzle set at 120 psi and blow up under the crud. It blows right off. The only thing I find with coco is that it takes longer because you have to go slower with lighter passes.


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Great suggestions above. Keep the air moving, lots of vaccume, helps the cooling and the dust is nasty stuff.
Coco is a pain, as are several other woods we commonly use. The suggestions that are being offered apply on many others.

It really depends on the board. My experience is that usually the darker the coco it seems the waxier the extractives and the more gunk builds up on the paper. Some of the nice red stuff from Mexico will go through all day with no problems while some the black BRW-looking stuff feels like trying to thickness sand a block of paraffin wax. I bought a roll of cheaper cloth-backed paper for these difficult woods that I know will go through a lot of sandpaper.

Wise words. I don't have 36 g but I use 60 for thinning all hardwoods. A courser grit will last much longer and gum up less. Less heat. Oven cleaner does work well. I spray outside and leave it for a couple of hours. Then rinse it with the garden hose. They are never quite as good as new after but still cut. I keep a few around to put on if I know it will be a gummy sanding job.

The other possible option would be to invest in a widebelt. I think they inherently run cooler. The first guitar I get $10 K or better for I'm getting one. Might be a while.

Hmmm. Might try a courser grit. Maybe even blow air in (in addition to vacuum) for added cooling. The oven cleaner seemed to only turn the buildup darker, not loose yet. Yes, I'm sanding dark coco. Nothing like personal experience. I've read a bunch about the problem, just way underestimated what my experience would be. Maybe I load the drum with ice cubes?

Ok, so the oven cleaner worked. At least I can get more use out of the drum paper. What a mess though!

Mike

Kevin,

I read your thread. Seems to he the same advice as here. Faster feed, lighter cuts, courser grit, and let drum cool. I have to admit I thought about the mineral spirits idea, but I'm not trying that until I get some positive feedback. Not worried about fire, but it seems to me that would not allow the DC to do its job. Also, vapors in the DC would be close to static electricity. No?

Just a shout out back for all the good advice. I got the boards down a few more hundredths without the glazing problem. It's slow going, but the faster feed rate helps some. I'm going to order some lower grit paper and see what that does.

Mike

Mike when I had my 16-32 I used 60 grit green or blue paper highest feed and as extreme an angle as possible with a shallow cut. Slow going but it worked. In my opinion the angle is the key. Feed straight in and the paper will clog. For some reason blood wood was the worst.

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Well, my shop hasn't blown up and my sandpaper isn't clogged, same with the guy who showed me the trick. How's that for positive feedback.

Get some 60 grit like Bob suggests, that helps a lot.

Steve

Lol . I kind of thought you would say something like that. I guess what I'm really looking for is what you believe it does. Speed the process? Avoid glazing? What? I live mineral spirits for wet sanding finishes. But if it helps with thicknessing oily woods, I'm interested in how. Thanks.


Thanks Bob C. Always appreciate ur advice. Ordering some 60 blue tonight

Mike

I think the mineral spirits dilutes the oils/softens the resins a bit so they don't stick to the sand paper as easily. You still have to clean the belt as you go with the eraser and the compressed air, but it's no longer is a losing battle.

Ok, that seems to make sense. Does the inside of ur sander get coated in mineral spirit residue? Or are you using just enough to wet the surface? I used to wet sand with my ROS until I realized the damage it did to the pad and clutch

Just wetting the surface with a quick wipe with a damp rag. No build up in the drum housing.