Whether or not to use hook-and-loop / velcro / felt-backed abrasive paper on a drum sander, and how to attach it if you don't [Pictures] - created 05-07-2008
Amato, Brian - 05/07/2008.10:15:12
I inherited an old but perfectly usable drum type thickness sander. It's capable of taking material up to 12" wide so it's good enough for guitar materials before they are joined. Experimenting with it the other nite I found it does a terrific job of sanding down the wood to a uniform thickness but both outside edges get taken down a bit more than the rest of the wood in the center. I suspect it's because the drum has a soft "felt" type backing that the sand paper roll adheres to (velcro) and the wood can sort of "mush" up into the drum sander. The edges get sanded more than the middle wood that way.
Anybody got any cure for this? I'd like to be able to sand two halves of a top or back and only have to take a tiny bit off with the jointer or shooting board to joint them instead of having to take off an inch from each plate. The only thing I can think of is to somehow glue a sacrificial strip of wood to the edge of the good wood that I can later break off at the joint I actually care about.
Anybody?
While your theory seems likely, it may still pay to check the flatness of the table and of the drum itself. Is there a feed belt involved?
I've opted not to use the velcro for the very reason you're seeing, and you could consider a different attachment method. I secure the sandpaper at the ends with little blocks in matching notches, then follow up with a wrap of masking tape around the last 1/4" of the drum. Works better than you might guess!
Another thing to try is multiple passes at the same thickness setting. On my drum homemade drum sander, that helps to even things out.
Without some modifications, this drum sander will leave you with extra scraping and sanding by hand after the plates are joined. Not a big deal -- you could just plan for that, leave the whole plate a bit thick, and knock down the thickest spots while you're scraping.
Good timing on this discussion. I'm about to put paper on my new thickness sander and the factory has sent me the velcro. I'm not going to use it just for the same reason that's discussed here. But I'm wondering if anyone sees a problem with using the paper which has a cloth backing much like thin linen that the velcro hooks attach too. Also after reading through the library everyone says not to glue the paper on. My drum is 3" dia. solid steel except at the ends where the bearings and pulley are. Has anyone tried to use carpet tape on the drum? Or do you all think it would also be a PITA to change the paper. And if not wrapping the whole drum then what about the ends?
I experienced the same mushy uneven sanding from the hook and loop paper. One of my drum sanders is the Griz 24" which came with hook and loop system. I got so frustrated one day I spent all afternoon removing the cloth stuff from the drums...very gummy glue holding it on!! There was so much mushiness with all that stuff a leading substrate edge actually tore and gauged the paper often!! This coupled with the uneven sanding was unacceptable.
I still buy the cloth backed paper rolls, but peel the cloth off and the stickiness is just enough to keep the paper from slipping on the drums. I use a bit of strong, high quality two-sided tape at the ends, wrap the paper and use strapping tape at the ends also on top of the paper.
Any foreign stuff put under the working part of the paper (like carpet tape) will telegraph thru and cause uneven sanding.
Different hook and loop systems might work better than the Griz system or they may have changed it by now...
My sander seems to work fine with no adhesives or adherents, though it does have "springy things" on the clamps at the ends that (kinda sorta) take up tension as the paper stretches a little.
I can't see how "goo" in the major part of the drum is really necessary, or even a good thing, with all that heat in there and so on. Just a nice, snug wrap, and something to hold the ends down.
Seems like most of us have sanders that use some form of felt liner on the roller drum and a (sort of) hook and loop on the back of the paper, or vice versa. If that's the case, then how the heck are people getting reliable, even sanding all across the entire width of a plate or a board or what ever they are sanding? There has to be a trick to this or a technique we don't get. I can't imagine that people all over the country are running expensive walnut cabinet stock thru their sanders and just putting up with the edges being sloped off compared to the middle. Something ain't right here.
I've never seen a good sander that had anything soft on the drum, nor one that used hook and loop.
Brian, some folks can simply settle for less and call it good enough. There's no "magic" mojo eluding anyone.
Physics is the great equalizer that's inarguable.
So the big boys are using drum thickness sanders that have the sanding paper attached directly to the drum without any kind of hook and loop? Either set into lockable slots on either end of the drum or straping tape? I can always peel off the "felt" type fabric on the drum and fasten the paper to the drum mechanically and see what happens.
attached directly to the drum without any kind of hook and loop?
yessir.
Okay, I followed Larry's method. Pulled the cloth off the 80 grit paper. This is their hook and loop paper and there wasn't any stick left on the paper if that matters.
Then put a 3/4" wide piece of carpet tape around the start and wrapped on the paper and same tape at the end and two wraps of strapping tape over that. Okay? See any potential problems?
Come to think of it. Does it matter which direction you wrap the drum? Like mine is wrapped counter clockwise. Should it be clockwise?
That's how i do mine, same direction.
I know a guy with a 24" sander and he just uses duct tape on the ends. Works for him since he doesn't need the extra width.
That would be me, mike
Alright then, I'll be ready to sand as soon as the company sends me the bearings for the shaft. I've had this 4n1 planner since September and just got it up and running a month ago when my shop was far enough along. When I pulled the other three shafts from the boxes today I found they forgot to send the bearings and housings for them. You're suppose to be able to change the shafts in a few minutes. One of the bearings stays on the shaft and the other stays in the machine. I called them and they're sending them out first thing Monday. Oh well, better late then never. I guess I should have checked that back in September. But the thing was that UPS Freight had dropped the first machine and messed up the table, bent and knocked it out of square. So I was busy dealing with an UPS claim while Hawk sent me a new machine. I have to say that the people at Hawk Woodworking Tools are alright to deal with. Good customer service through all of this.
I use strapping tape on my roll ends.
Someone has probably tried slipping a large Oring over each end.
Wrap it on the drum in such a way that the rotation of the drum against the wood doesn't have the effect of UNrolling the paper. You'll have to scope over your particular unit, figure out which way the drum is turning when it sands, how it contacts the wood and noodle out what it would take to peel it off...then wrap it NOT that way. Does that make sense?
They all turn bottom of drum toward you and top of drum away from you at the in feed. Unless the drum sands the bottom side of the board. I haven't seen any like that though. I not sure it matters how it is wrapped because regardless if the start point comes loose then the paper comes off. If you look at the way mine is wrapped in the picture. If the right side came loose then it probably would flap but if the left side came loose it would come off. If you reversed the wrap then it would react just the opposite. It might make a difference as to which direction the paper goes off. I never really gave it any thought before I ask the question. I don't think it's like a nut getting tight on a revolving shaft. At least I don't think so. But what do I know I ask the question in the first place.
I also don't think the direction of wrap makes any difference. It's not the same thing as a threaded connection.
And either way, if there's any stretch to the paper, it's going want to move "downstream."
I've been at Midwest Guitar School for about two months now, and the tape at the ends is how we attach the paper to our thickness sanders. the edges do see a litle more wear than the rest, however we always make everything a little bigger, so it's never really an issue.