Random orbital sander -- what is it good for?

[Porter Bassett]

I've never used a ROS, or a hand-held belt sander for that matter. I've got a 1/4-sheet Makita finish sander, which has been really handy, but I'm wanting something more aggressive.

Do ROSs and belt sanders fill the same roles? Are ROSs replacing belt sanders? What are their relative strengths and weaknesses?

[travis howe]

Porter,

I had that same question myself a while back. I've since discovered ros and havn't turned back.

It leaves a much "cleaner" finish, you don't get any of the typical marks that I did from my old palm/finish sander. I have the hook n sand type that you can switch back and forth between grits, which I find I do a LOT.

I do also have a belt sander, I'm sure others have uses beyond mine but I tend to only get it out when I have some REALLY serious sanding to do, you can really eat through some wood with one of them for sure!

If you're budget only calls for one or the other right now, my vote goes ros all the way... get a small mixture of various grits and you're ready for about most any sanding project.

Good luck.
Travis

[Joe Chritz]

They are great for sanding things, especially flat things. :D

Seriously the operation of a ROS and a jittebug are totally different. If in doubt hit a piece of clear acrylic with each quickly and look at the scratch patterns.

Sometimes with some woods you can go straight to finish from a ROS, something I could never do with a vibrating sander. Even so I still like to hit everything quickly by hand after the last grit on a ROS.

I have three now and use all of them. Once you get one you will wonder how you survived without it.

Joe

[Bill Keehn]

I have a Rigid benchtop oscillating belt sander, a Rigid 6" ROS, a Dewalt 5" ROS, and a Dewalt 1/4 sheet sander. My next purchase is a handheld beld sander, probably one of those Porter Cable compact things.

The belt sander is by far the most agressive. It took me only a few minutes to put a 2" radius on the corners of a pool-table top I just built using my benchtop machine. Sharp edges and corners tear the heck out of the backing pads on the ROS and the 1/4 sheet sander. I've ruined a couple. A belt sander has a hard backing behind the belt and is the way to go for edge work unless you like buying replacement backing pads.

The ROS is great for working through the grits on flat surfaces and can be fairly agressive too. It is not replacing the belt sander so much. I think it's really meant to replace the angle grinder with the rubber sanding disc. The so called random orbits reduce the amount of circular scratches that one would see with the angle grinder.

Both the belt sander and the ROS require some attention to technique. You really need to keep them moving and be careful not to remove too much in one place. Both tools can gouge the surface pretty badly if you aren't careful.

The 1/4 sheet sander is far less agressive and easier to control. I use it for the final few grits and have found it works pretty well for me. With the ROS I found that it was easy to do more damage than good during the final sanding. If I had a lot of small surfaces to do I'd consider purchasing a detail sander as well, but haven't seen the need yet. Right now I do it by hand.

[Stephen Edwards]

Since getting a ROS a little over a year ago I hardly ever pick up my belt sander anymore. It's the trick for cleaning up flat stock glue ups, in my opinion. I also like to use it to "soften" the edges of work. The ROS is usually the last sanding I do before finishing. When you get one, you'll never look back!

[Anthony Whitesell]

I'll ditto that question. I picked up a Bosch ROS at an auction for 50% list. I have only used it once or twice. I have a drum sander, that with 220G paper and a quick buff by hand, the piece is ready for finishing. I just haven't had the call to use or try the ROS much. I do believe, like others have mentioned, the random sanding pattern will produce less sanding 'streaks' on the wood and should be close to, if not actually, ready for finishing.

[Bill Keehn]

I'll ditto that question. I picked up a Bosch ROS at an auction for 50% list. I have only used it once or twice. I have a drum sander, that with 220G paper and a quick buff by hand, the piece is ready for finishing. I just haven't had the call to use or try the ROS much. I do believe, like others have mentioned, the random sanding pattern will produce less sanding 'streaks' on the wood and should be close to, if not actually, ready for finishing.


I wouldn't dispute the ROS with 220 leaves a pretty good surface.. assuming you don't goof up. For instance, accidentally tipping it can make a nice crescent shaped groove in your table top. Turning it off and forgetting to let it spin down is another place you can mess up. Mistakes I have made. Nevertheless, it's still a good tool. It just hasn't eliminated the 1/4 sheet sander for me.

One issue I had was that once the disc starts to wear out, the paper around the holes starts to fold back and can leave some undesireable scratches. I haven't figured out when the best time to change discs is. Next time I have a project so sand I might try those Abranet discs. Anybody used them?

[Greg Cole]

They're great for making your hands tingle for an hour after you use one for awhile. They make alot of noise and dust too. :p
I've all but abandoned my ROS in favor of Neander methods and tools for surface prep.

[Bill Keehn]

I hear that. I use dust collection, open the garage door and turn on my 40" shop fan, but it can only do so much. I'd like to get better at the neander approach.

[Chip Lindley]

Noah had 100 years to build the ARK! We usually want to accomplish what we want a little quicker than that! A ROS makes levelling joints on rails/stiles *EZ*. A ROS removes lotsa material FAST! with a coarse grit. I use lots of 100g. for levelling. Then move to 180 for a final finish. I feel 220g is a bit of overkill. The nature of the beast leaves no discernable swirl marks @ 180g. unless you use the closest scrutiny.

As previously said, tipping will ruin your work FAST! Some experience and finesse is needed to know where and where not to use a ROS. There are places a ROS just won't Go! Jitterbug (OS) palm sanders are still nice for getting into corners that a ROS might destroy! I use an OS for final sanding of the reveals on raised panels. FASTER than hand sanding.

Both little tools have their uses. Used with care, ROS's are DaBOMB!

[Eric DeSilva]

They make alot of noise and dust too.

Not my Festool ETS150... Well, it makes noise and makes my hands tingle, but the DC is frighteningly good.

And, if you want an aggressive alternative to a belt sander, look at the Rotex sanders. The Rotex can also be switched into ROS mode, although they are a little bulky for that application.

[glenn bradley]

They're great for making your hands tingle for an hour after you use one for awhile.

Good ones don't really vibrate much.


They make alot of noise and dust too. :p

Mine actually pick up more dust than they make and they are a LOT quieter than the shop-vac they are hooked up to :D:D:D.

[Jim Andrew]

I don't remember the model #, but my Bosch has a handle on the side, makes for a more easly managed tool, and it had a dust container, so I got a fitting and use it with the shop vac. Hardly any dust with 8 hole hook and loop paper. Amazing what a difference it makes. Now if I could get a fitting for my skil saw and my biscuit jointer. Like to put a straight edge on boards with the skil saw, that have bark edges, and about the only tool left without dust collection otherwise is my biscuit jointer. The Kraig pocket hole with the dust collector works pretty well as well as both the belt and ros sanders.

[Ken Casser]

Now you've ruined me. :D:D I did the "acrylic" test with my 5" ROS and my 1/4 sheet and was shocked by the results. The ROS gave a very consistent, smooth finish whereas the 1/4 sheet sander sanded a column of streaks and scratches on the left and right but nothing in the middle. It's very disorienting. The ROS is very lively and jumps around a bit, especially near the edges of the work, and feels inconsistent, whereas the 1/4 sheet feels very smooth when running and easy to control. In other words, the sensation while sanding is directly opposite from the results. I thought the 1/4 sheet was giving me a terrific finish, but now I can see that it is not so good. My problem is that I typically work on narrow stock, and the ROS is very uncomfortable sanding that type of work. I should think a 6" ROS would be even more uncomfortable. Maybe I should stick to hand sanding.:confused:

[Joe Jensen]

Now you've ruined me. :D:D I did the "acrylic" test with my 5" ROS and my 1/4 sheet and was shocked by the results. The ROS gave a very consistent, smooth finish whereas the 1/4 sheet sander sanded a column of streaks and scratches on the left and right but nothing in the middle. It's very disorienting. The ROS is very lively and jumps around a bit, especially near the edges of the work, and feels inconsistent, whereas the 1/4 sheet feels very smooth when running and easy to control. In other words, the sensation while sanding is directly opposite from the results. I thought the 1/4 sheet was giving me a terrific finish, but now I can see that it is not so good. My problem is that I typically work on narrow stock, and the ROS is very uncomfortable sanding that type of work. I should think a 6" ROS would be even more uncomfortable. Maybe I should stick to hand sanding.:confused:

Don't underestimate the value of hand sanding. I had a Porter Cable profile sander (lots of little profiles) and it was terrible. Then I bought a Festool profile sander, and to be honest, I think a piece of paper in my hand is faster and more effective.

[Brian Penning]

I have a Rigid benchtop oscillating belt sander, a Rigid 6" ROS, a Dewalt 5" ROS, and a Dewalt 1/4 sheet sander.



How's that 6" Ridgid working out? Compared to the 5" Dewalt?
TIA

[Bill Keehn]

How's that 6" Ridgid working out? Compared to the 5" Dewalt?
TIA

I had ruined the backing pad on the Rigid by sanding a sharp edge. I learned the hardway you should never do that. I bought the Dewalt because I've been happy with my other Dewalt tools and they sell replacement backing pads at the BORG and 6" pads are becomming harder to find. The replacement pad for my Rigid came in last week.

I've only used the 5" a couple of times. It seems ok, but I haven't compared them yet. I'll probably wind up using them both.

[Jim Becker]

90%+ of my sanding is with the ROS (Festool 150/3) and the rest is hand-sanding. I own a belt sander, but it was purchased for a particular project and very rarely gets used.

[Ken Casser]

Interesting, Joe! I remember my FatherInLaw would sand for what seemed like hours and days with an old 1/2 sheet Porter Cable orbital sander, and he would get the surface of the wood to reflect like a mirror whether it was pine, cherry, or anything. I've been trying to reach that level of perfection, but am not quite as patient as he was.:o It would be interesting to me to know just what it takes to get that finish without wasted effort. I just have to keep trying.:)

[Wyatt Holm]

I am a bit late to answer here. I love how well random orbit sanders work. I don't like electric, we use pneumatic. It is much faster and a lot easier to control. In our cabinet shop we have 2 of them. We use them to sand everything from face frames and raised panel doors, to skins and crown molding.

[Joe Jensen]

Interesting, Joe! I remember my FatherInLaw would sand for what seemed like hours and days with an old 1/2 sheet Porter Cable orbital sander, and he would get the surface of the wood to reflect like a mirror whether it was pine, cherry, or anything. I've been trying to reach that level of perfection, but am not quite as patient as he was.:o It would be interesting to me to know just what it takes to get that finish without wasted effort. I just have to keep trying.:)

My favorite sander is my 1/2 sheet Festool. Patience, changing paper to keep sharp paper on the sander, and going through all the grits is critical. I spend a huge amount of time sanding my projects. My biggest challenge is having to knock off the sharp edges after sanding so people don't cut themselves ;)

[Ken Casser]

Anyone tried the Festool 400? I just saw it this morning, and the size and shape would be good for inside corners, etc, but how does it compare to the larger ROS? I'm not looking for quick material removal, I want a mirror finish on the raw wood.