Random Orbiting Sander Question

[Bob Bassett]

Just got a couple of those new fangled new ROS' with the hook and loop disks with the holes in them. Figured I need to do something about sander dust control.

I was building a really neat storage cabinet cabinet with shelves with pegs to store the disks so I could locate the paper on the sander. I went to sand the 6" x6" squares for the pegs with some 80 grit sand paper and boy was that an unpleasant experience. the wood was hard to hold and the sander was hard to control and the wood had all kinds of swirly marks on it.

Got out the really old Port Cable PSA sander with 80 grit sand paper and sanded the same shelf and the wood was easy to hold and the sander was easy to control and the wood surface was smooth.

Do those holes in the hook and look disks for the dust control sanders really sand that much more aggressively?

[JimD]

Bob,

I do not know what kind of random orbit sander you have but mine is a DeWalt and looks a bit like a right angle grinder. It is very challenging to use with one hand while holding the work with the other. Much better to clamp the workpiece down. I also have a couple of 1/4 sheet finishing sanders that have a orbital motion but without the arcing slower pad motion of the random orbit. I like them better for little stuff I want to hold in one hand. My older one was made by Rockwell but PC sells the same sander now for about $75. I don't use it much because it has no dust bag. I bought a little Rigid sander for less than $50 that has a bag. The other advantage of a 1/4 sheet sander is the ability to sand closer into a corner. I guess the random orbit sands a bit faster but the 1/4 sheet sanders do OK speed wise. If I want to take off a lot of material quickly I use a belt sander (a 3x21 Ryobi which I heartily recommend).

I don't think it's the holes, my Rigid also punches holes for dust collection, I think it's the rocking motion that is part of the random orbit sander. I am not a big fan of random orbit sanders (but many will disagree with me). They are slower than belt sanders and harder to control than 1/4 sheet sanders. If you only have one type of sander, however, they are probably the way to go (but clamp little stuff down).

Jim

[bthere]

I am not sure which ROS you have, so may be missing the boat here a little.

The holes in the sandpaper are there to allow for dust collection, sucking the debris out so that the paper doesn't load as quickly. You can sand longer with the same paper with better efficiency.

Some of the ROS have multiple modes that allow you to be more or less agressive. They essential add another degree of motion to the sanding pattern.

As far as moving the small pieces around, I'm not too surprised. I get a lot more movement from an ROS as compared to a pad sander.

In the FWW 2007 tool guide there was a comparison of random orbit sanders and, IIRC, one of the criteria was how much the workpiece was moved. I don't remember how the various sanders did, other than a Bosch coming out on top.

[DLHarrison]

I have a Skil Random Orbital Sander with a dust collection system. I use it as an intermediate sander followed by a Makita finishing sander. The ROS does a good job as an intermediate sanding. The holes in the pad are used to remove dust from the sander to the dust collection cartridge. Given the action of the sander (random orbit), it would be very difficult to use one handed or use it to sand small pieces of wood that are held by hand.

[MilDoc]

ROS definitely sand more aggressively. But the orbital action does make wood control a bit harder.

But why didn't you use dowels for your cabinet? I built one too and dowels worked great.

[Bob Bassett]

ROS definitely sand more aggressively. But the orbital action does make wood control a bit harder.

But why didn't you use dowels for your cabinet? I built one too and dowels worked great.

I did. I'm curious. The new Porter Cable ROS I just bought sands a lot more aggressively than an older model that used the stick-on disks with no holes and I wonder why.

[bthere]

I did. I'm curious. The new Porter Cable ROS I just bought sands a lot more aggressively than an older model that used the stick-on disks with no holes and I wonder why.

All things being equal (sandpaper type and grit, sander motion), the holes in the disk keep the sandpaper from loading as quickly so it works more efficiently for a longer time.

If the disk doesn't have the holes, the only escape for dust out the edges. The paper then clogs and presents much reduced cutting edges to the surface.

If the sander disk has holes and some amount of suction, the dust has an exit path in the middle of ithe disk's cutting surface, keeping it cleaner with good abrasive edges on the surface to be sanded, rather than hidden in the dust.

[LarryG]

The new Porter Cable ROS I just bought sands a lot more aggressively than an older model that used the stick-on disks with no holes and I wonder why.

Since you mentioned scratches in your OP ... I realize this isn't a timely comment (because you've already bought the sander), but when Fine Woodworking Magazine tested a bunch of RO sanders a while back, they rated the P-C next to last on scratches produced; only the Craftsman was worse. Overall the P-C was a mid-pack performer, lagging well behind the Bosch (overall winner) and Makita (what I happen to own).

This was surprising to me because I have a number of P-C tools and am generally extremely impressed with them, but with this model they apparently missed the mark. Point being, not all ROS are created alike, and buying a known brand name is unfortunately no guarantee of satisfactory performance.

[SARGE..g-47]

Mornimh Bob...

I have used the older PC 333 5" palm sander for years.. good results, can use it one handed and pretty good dust control hooked directly to a 1 1/2" shop vac hose. I purchased the Rigid 2610 6" when they changed it from being made by Metabo to a Chinese version about 8 or 9 months ago. I wanted the Metabo at the Rigid price.

The 6" definitely has more aggression on the aggressive settings. It takes some getting used to and the extending handle must be used as you would on a hand held grinder. I made some practice runs on scrap and get the feel. Good balance over the work.. attention to the hold to avoid tipping and most importantly, keeping the sander moving has ironed out the kinks. My intial thoughts first trying it were, this thing is powerful and has a tendency to "rock and roll".

After a little practice and gaining the touch, it went to work on a 44" kitchen table-top and did a great job. The 5" is good for smaller jobs.. the 6" will get the call on larger surfaces. I use a sheet sander sparingly as it will get into corners easier, but I normally sand.. tape.. finish and them assemble so I run into few tight corners. I won't use a belt sander on furniture.. period!

Regards...

Sarge.. john t

[scorrpio]

1. 80 grit is pretty coarse. For me, it is a more 'material removal' than 'surface smoothing' grit. My usual sanding procedure is 120-150-180-220. The 220 produces that silky-smooth feel.

2. ROS is far more aggressive cause the pad rotates in addition to orbiting, producing a double action. Due to being more aggressive, it also tends to move the workpiece more. When the pad is allowed to move the piece, that is what causes scratches - in my experience, at least.
Solution A: workbench, woodworker vise, bench dogs to clamp the piece.
Solution B: High Friction Tape Holds small pieces VERY well.
Solution C: Router Master Pad Also great for holding smaller work.

3. Holes are there for dust control. Best way to do it is to connect a shop vac or DC hose instead of that little baggie. When sanding with my DeWalt ROS connected to a shop vac, I observe almost zero dust. A great idea: a piece of 1x6 divided into 6" sections. Each 6" section has 3 short (protruding no more than 1/2") dowels installed that match 3 of the holes in the discs, and holds a particular grit. Great to store a few discs of each grit, and dowels make aligning with sander pad holes a snap.

I have both a ROS and a 1/4 sheet. (both DeWalt). I use the 1/4 sheet only when I need to reach into a corner. Otherwise, ROS prodices much better results.

[mikeinkcmo]

Got one of these Monday and it runs circles around my old 333 and Dewalt sanders.



Great dust collection and variable speed to boot. Strange they don't show the DC hood in the pic.