considering a powermatic drum sander

[John craig ny]

I'm new to this site, but have spent some time reading through a number of threads about sanders. There seems to be plenty of knowledge and experience here and it's nice of people to share it. I'm looking for a sanding machine, probably a ~24" drum sander, but I have no experience using them. I see that the consensus is that wide belt machines are better all the way around, but due to the size of these machines and cost, was hoping a good double drum might suit our needs. I work for a residential construction company with a small cabinet shop and we don't really have a lot of space to spare. I've been looking at a lightly used 25" powermatic, DDS-225 I think. We do a variety of work in the shop but often find ourselves doing a fare bit of sanding with RO's. I'm looking for a better way. Some hand sanding seems inevitable, but having a machine that could clean up planer marks on the flat surfaces would be a big help. We often sand piles of trim boards, usually pine, before painting. I was thinking drum sander might be good for this job, as well as for cabinet doors and drawer pieces. For painted work we typically sand to 120 then prime and hand sand from there. Is it realistic to think a drum sander will leave surfaces smooth enough to paint or will it create its own set of marks that need to be cleaned up afterward? Will the abrasives plug up fast with pine if you take light passes? Some drum sanders have amp meters and a variable speed feed, the powermatic does not, problem? Anything in particular to watch out for when buying these machines second hand?

[Jonathan Jung]

Yes, a drum sander is more than adequate for paint-grade without using a RO afterwards. For stain-grade, you will ultimately want a wide belt. The key for drum sanders is quality of the machine and how well it is setup. So many drum sanders are junk and don't allow for good setup. The amp meter is not needed, just experience and understanding how much a grit can remove. A good drum sander can really hog off material with 24 grit but above 180 or 220 grit it gets dicey with burning. My 5hp 37" Supermax was a real nuisance to adjust well enough for finish sanding but did ok for dimensioning and actually performed best with wrapping the drums with one less wrap than recommended.

[Paul J Kelly]

John,

I have the CWI 37" version of that Powermatic DDS-225 and I really like it. It is not a widebelt sander. Widebelt sanders ocillate the belts to minimize scratch marks. Almost all drum sanders do not have that feature. If you use too aggressive paper, you will spend time removing the scratch marks left by the sander. If you are using 120/150 then Jonathan is correct.

The big difference on these models vs. a supermax (or performax etc.) is the rubber coated drums and the feed roller speeds. These are workhorses and will feed much faster than a supermax and with proper grits can do thickness sanding as well.

I do not have a problem with the abrasives clogging, even with Padauk.

Make sure the rubber drive belt is still pliable and that the rubber coated rollers are not damaged. The coating is pretty thick, like 1/2" or so. Try to adjust the rear roller up and down. There is a mechanism that allows you to compensate for the sandpaper thicknesses from the front to the rear drum. There are 3 rubber pressure rollers, make sure they are in good shape.

Good Luck!

PK
PKwoodworking