Possible Issue With Porter Cable Belt Sander

[Alan Gan]

This is my 1st Belt Sander and I do not think it is working correctly. Model 325VS 3x21

I have only used it about 5 times since I got it a couple months ago. I have used a belt sander before but it was years ago and not very much then.

I am running 120 grit paper and from the 1st time I used it something felt wrong. When I start it up and place it onto the board (pine) in the times I've used it there is a very heavy drag and slow down of the motor when on highest RPM setting. It does not seem to be removing material as well as I expected.

This is the 2nd belt I have used on it, the other one is somewhere in the shop right now. I do remember the other belt looking uneven with sawdust. The other times I used it was on raw wood, today I was removing some old top coat and it was not coming off very well.

I turned the sander over and only 1/2 the belt seems to be hitting the surface, I made sure I was holding it flat. With the Sticky top coat you can really see where the belt is making contact, like I said the other belt has the same look.

This does not look right to me, if I was doing a floor it would take 6 months at the way this thing works.

What do you think? BTW, I checked and the board is flat...:)

http://i85.photobucket.com/albums/k66/photolinks/WoodWorking/Cabinets/Picture370_zpsf9219826.jpg

http://i85.photobucket.com/albums/k66/photolinks/WoodWorking/Cabinets/Picture368_zpsb44d1569.jpg

[Robert Payne]

IMHO the belt sander is not the cause of the problem, based on your pictures and description -- 120 grit is too fine a grit to attempt to remove "some old top coat". I'd recommend that you switch to 60 to 80 grit open sanding belts if your goal is to remove a coating. It also appears that you are bearing down too hard and the paper is getting hot and clogged with old finish and perhaps pine pitch. Slow and steady wins the race.

[Peter Quinn]

IMHO the belt sander is not the cause of the problem, based on your pictures and description -- 120 grit is too fine a grit to attempt to remove "some old top coat". I'd recommend that you switch to 60 to 80 grit open sanding belts if your goal is to remove a coating. It also appears that you are bearing down too hard and the paper is getting hot and clogged with old finish and perhaps pine pitch. Slow and steady wins the race.


Ditto. Wrong paper, hit a high spot, cooked the finish to the belt. Get belts made for removing finish (the red paper is usually great on raw wood...not so much with finish), start no higher than 100, probably 80 is better until surface is stripped., and take care for pitch pockets and sap around knots in the pine. Sander is probably not the issue, though I hate sanding and like to blame the sander, just not the case.

[Michael Kellough]

As you noted it worked fine on raw wood.

As the others noted 120 is too fine for sanding finish and especially on pine with knots.
Only takes a few seconds to scorch a knot and get a load of pitch on the belt which then quickly accumulates melted finish.

[Alan Gan]

I'd recommend that you switch to 60 to 80 grit open sanding belts if your goal is to remove a coating. It also appears that you are bearing down too hard and the paper is getting hot and clogged with old finish and perhaps pine pitch.

Not thinking I guess, 120 is way to fine for this type of work, I may have been bearing down a bit too, Thanks


Ditto. Wrong paper, hit a high spot, cooked the finish to the belt. Get belts made for removing finish (the red paper is usually great on raw wood...not so much with finish), start no higher than 100, probably 80 is better until surface is stripped., and take care for pitch pockets and sap around knots in the pine.

Thanks for the advice!


As you noted it worked fine on raw wood.

Nope it was the same on raw wood, most of the sanding was on the one side of the belt.

I appreciate the help but still have a concern regarding the belt cutting more on one side than the other. I will take another stab at it tomorrow.

Is it normal for this sander being as powerful as it is to bog down on fairly smooth raw wood running a 120 grit belt? I really feel dumb about some of this stuff, sorry for the repeated questions.

[Michael Kellough]

It's normal is the speed/grit is inappropriate for the work.

If the wood is resinous (most softwoods) and you only have a relatively fine belt
(at high speed the effective grit is significantly reduced) then you have to reduce the speed
and move the sander around a lot to avoid making the belt too hot and turning wood resin into glue.

Instal a fresh belt and try sanding a non-resinous hardwood like maple. Or you can try sanding MDF but connect a vac to the sander first.

If you get early loading of the belt in the same place then the platen is probably warped and has a high spot where the belt is loading. In that case remove the belt and try loosening the mounting screws and with the sander sitting firmly on a flat surface (just cantilevered over the edge enough to give access to the screws) re-tighten the screws. If you're lucky that will make the platen flatter. If the belts still load early in the same place (or consistently in another place after re-tightening) then you should switch to a different kind of platen.

I prefer graphite impregnated canvas from Klingspor. If you go that route make sure the chassis platen is flat first or it will telegraph through the canvas to the belt.

[Lee Schierer]

Can you post a picture of teh bottom of the sander without the belt in place?

[Alan Gan]

Can you post a picture of teh bottom of the sander without the belt in place?

I returned the PC and went with the Ridgid (http://www.homedepot.com/p/RIDGID-3-in-x-18-in-Belt-Sander-R27401/100618248) Model, it was $70.00 cheaper and lighter. I know heavy may be better but for what I do the Ridgid should work fine for me.

Thanks for everybody's help.