Shopsmith Forums

I sent these cherry boards through my Shopsmith pro thickness planer. The pland left the boards with what appear to be burn marks. I sent them through at the lowest feed rate and took only a small amount of material. What did I do wrong? Dull blades? Feed rate? Is there a way to remove these marks?
Any help appreciated.
John D

Cherry burns very easily.

Sanding will remove the marks.

Actually slow feed rate can make it worse as will a fast cutter speed.

Repetitive impact creates the heat AIUI).

i.e. no chips carrying the heat away.

Dull knives are also a culprit.(heat again)

JTD7366 wrote:I sent these cherry boards through my Shopsmith pro thickness planer. The pland left the boards with what appear to be burn marks. I sent them through at the lowest feed rate and took only a small amount of material. What did I do wrong? Dull blades? Feed rate? Is there a way to remove these marks?
Any help appreciated.
John D

What do you consider a small amount of material? I would suspect dull blades as the primary cause aggravated by the feed rate and possibly the amount of material being removed. FWIW, I have had a Pro Planer for about 15 years and never had that problem so what do I know.

If you wet the area before sanding with mineral spirits or paint thinner it helps in removal of them.

I have had that happen once before. I had to do an entire kitchen, floors included in cherry. We tried everything including sharper knives and as small a cut as we could do and not much helped except sanding it down below the burn marks. I have never tried the mineral spirits technique that ERlover suggests but it sounds like it may help. You may want to check the moisture level also. If you are not up for building one see if there is a shop locally that has a surface sander. They usually have a minimum charge but well worth it. It is better if it is a belt sander and not a drum sander. The drum sander may give you the same marks on the wood due to heat build up. For some reason the sap in cherry discolors at fairly low temp.
Paul

This is an observation, where I by my cherry they plane and have a drum sander which I have had my cherry done on, and no burns, BUT there drum sander has an oscillating head on it.

ERLover wrote:This is an observation, where I by my cherry they plane and have a drum sander which I have had my cherry done on, and no burns, BUT there drum sander has an oscillating head on it.

What benefit does the oscillating head provide on a drum sander, at least when sanding full width?

A friend bought a Grizzly drum sander with out an oscillating head, the sanding media can gum up in the same spot, grit lines, heat build up in the same area.
Oscillating head, no grit lines, media does not gum up in the same area as easily, since it oscillates you dont get a heat build up in the same area on the media as easily and causing the above problems.

Something new to me, but jet does make one:

http://www.jettools.com/us/en/p/22-44-o ... nd/659006K

I have the shopsmith model but I use it for edge sanding.... only. It does a great job of that but I can't imagine how it wouldn't tear the face grain but who knows.

Ed

Ed,
It does a great job of that but I can't imagine how it wouldn't tear the face grain but who knows.
I dont understand? A drum sander should not do that, even a non oscillating head one a planer could, did you mix up your terms?