Difference between 1/4 sheet sander and orbital sander.

I hope I don't appear to ignorant but I had my eyes opened the other day and now I'm wondering what else I might be missing.

About 20 years ago I bought a PC 330 1/4 sander. At the time I think it was considered the industry standard. I loved it. However last year Dewalt was selling there mitre saws with a free sander. I got the saw and put the sander in the my drawer. Last week my daughter wanted to refinish something and she brought it to me. I handed her the PC330 and told her to start sanding the finish. After a period of time I thought about the Dewalt sander so I got it out and began using it. I was surprised. It worked really nice, and the dust collection was impressive. I began to wonder what other new technology I might be missing.

Now my question I see these new palm size random orbital sanders with circular disks and I wondering if they have anything over the 1/4 sanders I already have? I think the 1/4 sheet sanders are orbital but I don't know if they are random orbital and what difference does that make in finishing?

Also I might add I have a 15 year or so old PC7334 orbital sander that is built like a side grinder. I use it in place of a belt sander but if you pick it up off the wood the disk starts to spin like a circular sander and will gouge wood when you put it back down on the wood. Like I said excellent for rapid removal of wood but very dangerous for finish work. Has this problem been overcome in the new palm size random orbital sanders?

Thanks for any insight

Ed,

Nowadays the RO sanders are a pretty good deal! They can be had for a song, are comfortable to work with, quiet, and effective. I recommend them!
However, it has been my experience that I usually need to follow up the RO with
the "in-line" to completely eliminate any swirls. My $.02 worth.
Bruce

The old pad type sanders either went back and forth or went in a circular pattern. The same pattern every single cycle. So if you left the sander setting still for very long you would end up with a bunch of swirl marks on your wood. The random orbit sanders supposedly don't repeat the same pattern twice so you don't tend to get the swirl marks. They also remove material a bit faster since the old pad sanders would sit on top of the sawdust they just created and not remove much material since the dust had to work its way out to the edge for the dust collector to pick it up. The random orbit sanders pull air up through the pad so the dust gets pulled out from under the pad faster and the collection is much more efficient.

Noise and vibration are other differences you will notice.

Thanks for the info.
I understand about the swirl marks and how RO can eliminate them. It also makes sense about cutting speed if the paper is going over new areas. So I think I see the advantages of RO. Thanks

In my original question I also asked if my PC 7334 was representative of RO in that when you picked it up off the wood the pad would begin to spin much like a sanding pad in a drill and if you set it back down on the wood surface it had the tendency to gouge the wood. Has this problem been overcome in the new RO Sanders?

I need to ask an additional question. As I said I'm really impressed with the Dewalt it had excellent dust collection and sanding was fast. I call it a 1/4 sheet sander. It is a Dewalt model DW411. Is that a straight line, orbital, RO?

Ed,

With the addition of random orbits you're just trying to keep the scratch pattern, the scratches, from going in the same direction sort of.

Your eyes have a harder time seeing the scratches when they don't line up with each other.

Quote:

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Originally Posted by Ed Blough

Thanks for the info.
In my original question I also asked if my PC 7334 was representative of RO in that when you picked it up off the wood the pad would begin to spin much like a sanding pad in a drill and if you set it back down on the wood surface it had the tendency to gouge the wood. Has this problem been overcome in the new RO Sanders?

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Some of the ne RO sanders have a builting device for keeping the pad speed under control. I know my Porter Cable RO has one. Still I try to start the sander on the surface or make sure it is moving across the wood pretty fast as I set it down after lifting it off the wood surface.

Ed,

YES, you are missing out. In my opinion you'd be hard pressed to spend a better $60 than that which you would on a new quality 5" random orbital sander with a circular hook & loop abrasive.

The circular RO sanders remove material MUCH faster than the 1/4 sheet units and they do it very well. (very little scratching if you work your way through a few grades of paper) My 1/4 sheet sander (PC) has been relagated to 320/400 grit for knocking the dust nubs off finishes.

The model matters little if you stick to the big players, but my PC 333 has been bullet proof for ~10 yrs now. I hate sanding (as most do). Buy a circular RO and you'll never look back after you realize the time and effort saved.

...Jim

Echoing what others have said, the 5" round RO sanders are worlds apart from the 1/4 sheet (or 1/3 sheet, as in my case) sanders. I've got sanders ranging from my grandad's ~50 year old Craftsman in-line to a mid-80's Black & Decker in-line/orbital. When I bought my little Ryobi 5" RO several months back, I couldn't believe how fast it removed material, and how well the dust was handled (I connect it to a shop vac). I've used it finishing a lot of maple cutting boards, and haven't had any problems with swirl marks as long as I go through the grits in a reasonable gradient.

Regarding your other question, I find the RO sander to be more forgiving then most other types if you briefly get it cocked or set it on the workpiece off-square. (Especially compared to the "angle grinder" type of orbital sanders.) You can get gouges with it, but in my experience you have to try pretty hard before you get any.

That's my experience; YMMV -

- Vaughn