Grex Sander SCFM

[Dan Case LR]

I'm considering a Grex AOS368 sander, which according to published specs requires 8 SCFM. I've read in several places about cutting back on the speed (and required SCFM) of the Grex, but haven't seen any specific numbers for the final SCFM after cutback.

My compressor has a 30 Gallon tank and is rated for 6.4 SCFM @ 90PSI. Will it work with the throttled Grex? I'd like to avoid buying a compressor, given the financial demands of the Vortex. :)

I've seen several threads discussing various small pneumatic sanders, but most are a few years old. What else is available today that's worth considering as a worthy competitor against the Grex?

Thanks!

D.

[Robert McGowen]

According to the Amazon website, it will work with 2.2 SCFM. I have one and it is a great little tool. There is a screw on the side and you simply turn it in and out to control the amount of air going into the tool. If mine broke for some reason, I would buy it again. YMMV

[Ken Fitzgerald]

If it's the little 2" that I use, Robert nailed it.

[Richard Coers]

I'll take the opposite side here. I turn on the larger size, and want to run the Grex wide open. It sands slowly and is an absolute air hog. I prefer the Metabo electric. I stack some hard foam pads together if I need more offset to the the body. http://www.metabo.us/Product-catalog-handheld-powertools.23980+M5e7a35adf8f.0.html

[Dan Case LR]

The Metabo has a 3 1/8" pad--is a smaller pad available? I do mostly smaller work and 3" is too big for most of my projects.

D.

[Pat Scott]

I don't use that sander, but the reviews on Amazon say you need a 60 gallon compressor and not 30. One review said if your compressor is 115v it won't work, that you need a 220v compressor.

[Dan Case LR]

One review said if your compressor is 115v it won't work, that you need a 220v compressor.

Which is an example of why I don't take Amazon comments very seriously. A compressor rated for 10 SCFM will produce the same 10 SCFM whether the motor is wired for 110 or 220.

D.

[Steve Doerr]

Dan, I know this is not the tool you are looking at but I've been using a HF sander for awhile and it has proven to be very good, It takes 4 cfm and the amount of air flow can be reduced if you put a regular on it. I have a 21 gal 2.5 horse (that's what the label says) with 125 psi. Running the sander at full throttle, and no regulator, after a little while, my compressor will kick in and does not have a problem keeping up. The sander has a 2" pad and cost only $30. Here is the link if you are interested--mini orbital air sander (http://www.harborfreight.com/air-angle-sander-93629.html).
Keep on turnin'
Steve

[Dan Case LR]

Steve, I've considered that sander more than once. I guess I have to confess that I have a somewhat anti-Harbor-Freight attitude because I've seen so much cr*p that came from there. In fairness, I've also bought a couple of things from HF that have served well, things like a router speed control and a rolling cart, but on the rare occasion that I buy a tool at HF it's usually because I'm either going to use it once and throw it away or I anticipate otherwise short-term destruction.

What's the thread on the HF's sanding pad? I'm wondering if I can find other sizes (like maybe a 3" or 1" like the Grex has available) or accessories that might fit it. For $30 it might be worth a shot.

D.

[robert baccus]

I,ve used 4 HF small air grinders on bowl work for some 20 years and find them unbreakable to date. Used mostly on the inside of bowls and detail work such as epoxy repairs ect. They have out an angle model now that is really heavy duty. I now have a big compressor but used them for years on a 3HP and it worked ok. Might have to wait on the compressor occasionally but I can always sweep the floor. The thread is a standard thread for most accessories.

[Steve Doerr]

Dan, I checked my HF grinder and at this point couldn't figure out how to get the shaft with the velcro pad off--sorry. My suggestion if you want to go to a 3" sanding pad just use one of the interface pads that Vince sells
HTH
Steve

[robert baccus]

My HF grinders all have a collet operated with a wrench. And by the way a 3" sanding paper is a bit too much of a load on all my grinders. They turn a polishing pad or very find sandpaper ok. 2" sanding pads work great--amazing how even 80 grit at 10,000 RPM cuts smooth using light pressure.

[Kevin Groenke]

The HF has a 1/4-20 thread, so the Grex or similar replacement pads fit right in.

To change the disc: stick a hex key or similar through the holes in both the eccentric and center shaft (towards the bottom of the slot in front of the paddle), then simply unscrew the pad.

This image is not the HF, but looks like it and better illustrates the access slot.

We have a Grex and a HF, haven't used them too much but they both work well: the HF is a bargain, the Grex isn't. Generally HF pneumatics seem more reliable to me than electrics. Don't know about consumption as we have house air.

270820

-kg

[Vince Welch]

Hi Dan,
These ROS do take tons of CFM. I beleive they are ideal for higher grit sanding becasue of the orbital action they provide. They do NOT have torque and that often is what is needed at the lower grits. Cambell Hausman who make tanks for these compressor units is less than 100 miles from my location. After talking with them extensively this is my understanding... 30 Gallon tank oilless unit will work but not designed for ROS air consumption and you will degragate the motor over time trying to keep up. Try not to have unit running longet than 15-20 min per hour. YOu need a 60 gallon or bigger oil based tank to run these units long term. I hope this helps. Vince

[Steve Doerr]

Kevin, thanks for the info on how to remove the disc. I had the one hex undone but not the other.
Vince, thanks for the info on the compressors. Mine is a 21 gal oil compressor, so I'm hoping that will help with it running all the time while I'm using the sander.

[Dan Case LR]

Thanks everyone for the comments and insights. I was in the neighborhood of our local HF store today and stopped in. I left with one of their $29 mini-orbital (2") sanders. I decided to go that way because air tools is one of the things HF seems to do better than expected. At $29, if it fails miserably it won't be fatal...and I took the money saved and ordered a set of Beall buffs (which HF will never even come close to copying).

Thanks again!

D.