Hi Folks, I have a Performax 16-32 and really like it and so far the only problem has been the very quick buildup of pitchlines that burn lines in the wood. I clean it regularly with a crepe rubber cleaner but can’t seem to lick the problem. Going through paper rolls too darn quickley. Is there a technique in feeding that I’m missing or feed rate maybe. I keep it pretty slow and light most of the time.
Any help would be appreciated.
Brian
Replies
Brian,
I have a drum sander that exhibit the very same problem of pitch or gum burning. It can also occur with sugary woods such as white oak; then you get soot or just burn marks.
If you can reduce the drum speed, that helps a bit. (Less energy input per second therefore less heat build up). Mine doesn't have a facility for this but yours might.
You can also increase the feed belt speed, but then the sanding "cut" must be very light. In general, a light pass helps, as there is less friction and therefore less heat build-up.
As the pitch and gum is often in line with the grain and therefore the direction of sanding, try sanding the piece at an angle. This stops the sandpaper getting hot in just one place (the "line" of the pitch/gum in the wood) so quickly, which is what causes burn-and-stick. Your last pass can be a light one with the grain, to get rid of the cross-grain scratches.
With some problem timbers, I tend to sand with the cover open just enough to apply the rubber de-duster as sanding is being done. This wears the rubber stick out quite fast and you must also beware of dust escaping your sucker hose. (I turn the sucker right up).
But some burning will still occur. In fact, some timbers just cannot be drum sanded as they burn so easily.
If I end up with lines of burnt pitch or gum on the sanding drum, I give it a squirt of CMT orange stuff (for getting pitch build-up off sawblades) and leave it to soak for a few minutes. This often softens the built-up stuff enough so that the rubber stick will then grab it off.
If not, squirt a little more CMT orange (or equivalent) on the burnt stuff then rub it off (carefully) with a steel-wire handbrush. I have even chipped it off, when so-softened, with a blunt screwdriver!
Using all the above techniques, I find a length of the stiff (weight 5, I think) sandpaper can be used and refurbished until the sandgrains themselves go blunt. (That is: quite a lot). Just don't oversoak the paper in the de-gunker liquid, as this can cause it to tear more easily when wire-brushed. But don't let it dry out either, as you are then back to square one.
Lataxe
Thanks for the reply. I'll give it all a try.
Brian
Take a lighter pass. In some woods, the gummy sap is just too much for the sander. If you don't stop and clean the sanding roll immediately, you'll be replacing it. I remember reading about a concoction for soaking the rolls in, but I don't remember it, and wouldn't personally waste the time, either.
Jeff
Thanks. BD suggested mineral spirits. Going to give it a try. Those rolls ain't cheap.
Thx again, Brian
I've read that the rolls can be soaked in straight mineral spirits to de-solve the deposits, but I've never tried it. I think that's in the Performax manual.
Hmm I missed that. I'll check again. Thx
BriMcG: I find that some woods leave burn lines more than others; pithy cherry,maple w/ pith, glue, woods w/ knots. I found using a coarser grit helps too. Once a "burn" line starts, it will only get worse. I try to stay away from yhat line if the size permits.
What grits do you use? What woods?
James
Hi James, Thx for taking the time to reply. I use a lot of Walnut, poplar, and some Bubinga. A bit of other exotics. Haven't put much if any pine through yet and may not (see above).
I have a roll of 150 on now but going to switch to 120 and take lighter passes. Slow feed too.
You think courser grits? I would think that might increase the burn lines. Maybe not.
Yep..just trying to stay away from the lines for now. There is some good advice above on cleaning a roll of paper too that I'm going to try.
Thanks again, Brian
Edited 1/4/2008 12:00 am ET by BriMcG
What grit are you using? I have had my sander (16/32) about 2 years now and I have only used 120 & 150 grit. I found the 150 to be too sensitive to build up so now I only use 120 grit. Take light passes, not more than 1/4 turn at a pass. Never,never, put any wood with exposed glue seams. I will not put any glued pieces through the sander unless they went through the planer first. Also I will not put pine through unless it is knot free and has no visible resin which is very rare. Clear white pine sometimes is ok. Also since I use paper supplied by Industrial Abrasives it has been a big improvement over the sandpaper purchased with the Performax sander. (supplied by Klingspore)
Hi, Thanks for the reply.
Good advice about the glue joints. I hadn't thought of that and will post a notice on my machine.
I am running 150 now. Maybe that's part of it. Will try the 120 and see what happens.
Do you do much dimensioning or do you stick to smoothing for the most part?
I think part of the problem was my planer broke a sprocket and I had to use the sander for some dimensioning. So it was being used a lot. Not aggressively but a lot. Light passes.
I'll check out Industrial abrasives too.
Thx again, Brian
In the two years I have owned it I have used it only to sand after planing. Example: I make drawer boxes for a local cabinet shop and I plane the wood to .685 (there abouts) and sand both sides equally to get to .625 so I am removing about .030" per side and I give each side two passes at .015 per pass (1/4 turn of the wheel). Last month I sanded 32 pieces 10" wide x 49" long. Had to make 16 boxes 28" wide x 20" deep by 10" high. Each piece made one side and one front. No further sanding is done to the surfaces and I used 120 grit paper. I have sanded enough boards to make about 40 drawers and the paper still looks like new. I am only using soft maple for the boxes. Hope this information is usefull.
That's a lot of drawers! Yes, very useful info thanks. I think the 120 will be my first change. Good to hear no problems with the maple. Seems like that would be a good test wood.
Thanks again Mr. B
Brian
Brian:
I had the same problem until I got a monster dust collector. The solutions suggested so far all have the effect of reducing the rate of dust production. The problem is that dust is not cleared from the roll before it spins around to make contact with the wood again.
I've modified the hood on my Performax to take an 8" hose--that little 2" connector on the stock hood is a joke. I usually trip the motor protection circuit sometimes when I am too aggressive, but no more ruining the paper. My other problem is that I have to watch the board to make sure it continues to move past the drum and not get stuck due to the suction of the dust collector sometimes, especially with thin stock.
Wow! You run EIGHT (8) inch? Is that a typo? I'm using 4 inch and it seems to get the dust cleared pretty well. I think I need to slow it down a bit and be less negligent about using a cleaning stick.
Thanks for your help.
Brian
I have a 22-44 and have had some experience with the burn lines too. Basically the burn can be mostly be avoided by: slowing the feed rate, reducing the cut, remembering it is a finishing tool and not a dimensioning tool, the finer the grit the more the burn, and once the burn starts you can only move the narrower stock to an area of the roll not burned - or change the belt, it will not clean off completely or go away. Dust collection is required!!
Saying all that, I do use mine to reduce stock that last 1/32" or so at times, but I use a 100 or 120 grit belt. If you need to reduce stock thickness a bunch, and I have, you must go to an 60 or 80 grit bit and follow the rules above. This is a great way to surface figured wood that tends to tear out on a planer, after one side has been jointed.
Using a 120 grit belt to reduce thickness, about .025 at a time, 1/8 turn of my adjustment wheel, I usually avoid any burn problems, and the RAS starting at 150 grit does a nice job of removing the 120 grit lines.
The dust collection is a must!! IMHO a shop vacuum can not keep up with the dust volume of anything but perhaps the very finest cut and I would recommend I good dust collector at all times!!!
Thanks Doc! Going to print that and have it by the sander for reference. I'm sure you are right but why does a finer grit burn more? I would think the opposite...larger grit more friction. Or is it MORE grit on the paper more friction with a finer paper. Hmm.
Thanks for the help.
Brian
I'm not the expert, just a user, but I believe it is because the finer grits do not have enough space between grits to hold the abraded wood dust, therefore it packs in and then burns the wood. There is also not enough aggressiveness in the finer grits to remove the wood rapidly. The machine doesn't know what it is cutting, it just feeds the wood in at the rate you dialed in, and at the depth of cut you set. If the fine grit cannot remove the wood as fast as needed to let the wood feed under the drum, it overheats, loads up, and leaves a big burn streak on you stock. If the grit is course the same feed rate just used on the fine grit will rip the wood off rapidly and not allow it to overheat to the same degree.
Personally I feel that any grit finer than 120 is a finishing grit and should not be used to try to remove a significant amount of stock. Using the grits finer than 120 you can smooth joints and start to do the work of your ROS. I do usually sand at 120 or 100 and do all additional sanding with the ROS.
Hope this helps.
Bruce
Very helpful. Thanks Bruce.
Brian
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