What may cuase this / by drum sander

[Craig D Peltier]

I ran these western curly maple door pnales through my perfomax 16-32 with 150 grit jet paper, taking off minimum maybe 1/64th. I fed it at 20 and up to 50 to see if this purpleness would sand off but it didnt. Its from the paper.
Do you think its because its so curly and the granules of paper got pulled off into wood?
When I orbital sand it I can get it off. There about 12x18.

Thanks

Curly Maple Purple.jpg

[Joe Jensen]

Looks like the wood overheated and it's ust short of burned. Similar to a dull router bit or burning on the table saw?...joe

[David Duke]

Looks like you need to lighten the pass/cut plus slow down, the wood is burning.

[Mike Spanbauer]

Yup, as others have said it's burnt.

Try a lower grit, Maple does not forgive and 150g is high on a DS. I never exceed 120 on my 22x44 and use a ros + handsander to do final work.

mike

[David DeCristoforo]

The feed rate is too fast
The paper is worn and/or too fine a grit for the rate of feed
The "bite" is too heavy
Any of the above
All of the above

In my experience, 1/64th is "too much", at least it is on my Woodmaster sander. These things work great but they take some patience... I only crank the bed up about 1/8 turn which is more like 1/128th. Also, you can make several passes at each setting, reversing the stock each time.

YM

[Eddie Darby]

I would describe your maple as quilted rather than curly. When you get burning, check your "speed n' feed".

[Bruce Page]

The feed rate is too fast
The paper is worn and/or too fine a grit for the rate of feed
The "bite" is too heavy
Any of the above
All of the above

In my experience, 1/64th is "too much", at least it is on my Woodmaster sander. These things work great but they take some patience... I only crank the bed up about 1/8 turn which is more like 1/128th. Also, you can make several passes at each setting, reversing the stock each time.

YM

I pretty much agree. I'll take off 1/64 when rough sanding with my Woodmaster (80 or 100 grit). I only take about a third of that (.005) with 150 or finer grit paper.

[Gary Muto]

I have the 22-44" and only take 1/4 turn or less. I can't remember, maybe 1/128"?

[Jim Becker]

Drum sanders are prone to burning stock, especially "high sugar content" species like maple and cherry and with fine abrasives like the 120 you are using. I never use my drum sander over 100 grit and usually with 80. It's for leveling and then I transition to my Festool sanders. I see you may also have some scoring, either from grit or from overlap of the abrasives on the drum...you'll have to sand that out by hand.

[Craig D Peltier]

Thanks all, so its burn.
I keep 150 on cause I usually sand face frames and the edges to get burn marks/blade marks out of it. Im not particulary happy with any board wider than say 8 inch on that. I know little bites. I will keep trying. I have never had success with wode boards on it even when I think im taking off minimal I get a burn line which then ruins the paper.
I do need to check if the head is horizontal to table perfect.I dont have brass set up bars but I think I will buy t-morrow.

[David DeCristoforo]

"I do need to check if the head is horizontal to table..."

For the most part, it is very difficult to get the drum and table "perfectly" parallel. That's why I suggested rotating the stock every other pass. If you do this you will still get nice flat even panels even if the drum/table alignment is not 100% perfect. Part of the problem has to do with the fact that the conveyer belt is, to a very small extent "compressible". Of course, you want to get it as close as you can. I always send the stock through, rotate it 180 send it through again then flip it over and hit the other side once. After all my panels are run, I raise the bed a bit and repeat but this time I do two passes on the side that only got "hit" once the last time.

YM

[Craig D Peltier]

Heres what it looked like after sanding an mineral spirits. I paid $9 a bd foot for this stuff.

Looks good i thought.

Curly Maple 005.jpg

[David DeCristoforo]

Looks good enough to eat....

YM

[Joseph N. Myers]

Craig,

I've had problems with burning when I let the sand paper gets "clogged" with wood waste particles and resin. I use one of those abrasive cleaning sticks to keep the paper clean, every minute or so And it makes the sandpaper last at least 3 to 5 times longer.

Regards, Joe

[Karl Brogger]

I found with the drum sander that I had I would run almost everything at an angle, then angle it the other way on the next pass. You would get a kind of cross thatching effect and I think it didn't work the machine as hard. For the last pass I would send it straight through to take most of the angled scratches out.