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TonyB,
You’ve been on this forum for 12 years and have over 4 thousand posts and you did all of that with no sanding equipment at all. Not even a piece of sandpaper?!? How’d you manage that?
 

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Discussion Starter #23
Thanks Rick, I knew I wasn't imagining it. Also air sanders seem to glide over the surface with ease.
I am not going to buy another compressor so I will have to work with the air sanders that are within my parameters. Many work well with 4 CFM @90 PSI. right now I just needed a sander, any sander.
 

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where's my table saw?
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Home shops VS commercial shops .......

I've got 4 air compressors starting with a 1.5 HP PC pancake, a DIY with a twin cylinder and 1 HP motor, a 2 HP Harbor Freight at $125.00, and a 5 HP 80 gal oil less that puts out 13 CFM at 90 psi that's louder than a .45 cal machine gun. I have another twin cylinder 5 HP that's just waiting to get wired up in the garage for air tools.

Most home shops do not have a large enough compressor to run air sanders, so they go to electric for cost reasons. All the benefits of air sanders are great in a commercial setting, but for home shops they're beyond the reach of most. And in my case, noise is definitely a big factor. I can hear that 5 HP oil less compressor running in every room of the house even through two walls of 5/8" thick both sides of drywall separated by a hallway. The pancake and the HF are also loud, but within reason. The old twin cylinder, my very first compressor is very quiet by comparison.
:|
 

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Smart and Cool
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I hate sanding.

I do everything to make sanding less time consuming(within reason, no Festool, yet).

I have a large 2 cylinder compressor, it is very quiet for the air it puts out. I typically go for air sanding, but the dust collection on my sanders is mediocre even though the performance is superior.

I have a drawer full of Dewalt and Ridgid RO sanders, I don't consider any of them to be great, and can't imagine cheaper sanders are any better.

I bought a Bosch RO in 2018 on sale, paid almost $200 for it, normal price is close to $300. It is my favorite sander to date, extremely powerful, excellent dust collection, it is the star of the show now for sanding, I would buy it again at full retail. It is similar in design to a Festool model, I can see why folks pony up the $$ for them too.
 

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Why do air sanders work so much better than electric? Do they run at a higher RPM?
The quality of the drivetrain is the biggest factor in the performance of the sander. Pneumatic motors are low-cost to produce, so the drivetrain can be very high quality while keeping the price of the tool low.

I'm a photograph packrat, so I found these 12 year old pictures on my computer from when I wrote an article for rebuilding a Dynabrade sander. (Yes, they have complete rebuild kits.)

In the first picture you can see the assembled drivetrain minus the rotor (motor) assembly. The motor shaft portion is very thick compared to an electric motor's shaft. The upper (not shown) and lower motor bearings are massive compared to an electric motor's bearings. The upper bearing on an electric motor is only 1/4-ID x 1/4-Thk, compared to pneumatic which is 1/2-ID x 1/2-Thk, and the lower bearing is a monstrous 3/4-ID.

The lower picture shows an exploded view of the lower drivetrain. Most notable is the 1-piece motor shaft and eccentric machined from a single billet piece of steel. For comparison, most electric sanders have a separate aluminum eccentric/counterweight which bolts into the bottom of the motor shaft with a very small screw.

The other impressive feature is the super thick eccentric bearing. I think it's about 1 inch thick, compare to some electric sanders that are as small as 1/4 inch. Of all the sanders I disassembled 20 years ago, Bosch was the only electric sander that used 2 bearings stacked up for the eccentric. Not as good as the single-thick one here, but better than most others.

The size of the eccentric bearing directly relates to the stability and truness of the pad driver. This is where the majority of scratches originate, and what causes the sander to feel like you are fighting its movement across the surface of the workpiece.

The last picture is an accurate SolidWorks model of the Dynabrade internals that I created.
 

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I've enjoyed these posts and learned a lot from them. I'd like to bring up an aspect of air sanders that hasn't come up: lubrication. I put 3 or 4 drops of oil in mine and run it a few seconds before I start sanding, but I worry about too little oil damaging it or too much oil sprayed out on the raw wood I'm sanding. I use #10 spindle oil which I have on hand for the mist lubricators on a couple of high speed spindles. These work great, but I've never got a mist lubricator to work on any air tool.
 

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where's my table saw?
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Good Point!

You're not the only one who worries about too little or too much oil, but, I also use the 3 drop method and it seems to work. My son the auto mechanic, doesn't seem to bother using any oil, but honestly I've just never seem him oil his right angle die grinder before using it. :sad2:
 

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Well, with the ability to combine the output of two compressors to get enough air, a pneumatic sander might be a reality for me.

Can anyone/everyone one make a recommendation for a sander? I'd probably prefer to get a 5" model since I already have a ton of discs.
 

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Funny how people's preferences differ.

From no sander to an air sander, to talking about 2 compressors (that's a new one on me BTW).

My air sander is the LAST sander I would want to use for ww'ing. All that noise, and 2 hoses to contend with, and compressor running and dust extractor running.

BTDT, makes me feel like I'm working in a tire shop! LOL.
 

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Funny how people's preferences differ.

From no sander to an air sander, to talking about 2 compressors (that's a new one on me BTW).

My air sander is the LAST sander I would want to use for ww'ing. All that noise, and 2 hoses to contend with, and compressor running and dust extractor running.

BTDT, makes me feel like I'm working in a tire shop! LOL.
Which sander? Good sanders are that loud.. Professional shops usually don't run a dust hose. I know a pro shop that does, but he's not high production.
 

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Nine Thumbs
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I won't ever run an air sander for woodworking. I have a 7 1/2 HP, 240 volt, 80 gallon two stage behemoth of a compressor and air lines piped throughout the shop. I assure you all it makes the spinner go round and round quite nicely on my meter socket!

Compressed air is an extremely inefficient method of creating power. It draws 26 running amps at 240 volts. Locked rotor starting current is about six times that until it gets going. I use the that kind of air only for bead blasting, running automotive air tools, and a bit of blowing for cleanup. Running a little palm sander would be ludicrous. Add that most smaller sized compressors would cycle so often that the duty cycle would be well exceeded on most consumer grade machines.

Nah, it'll be electric for me
 

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I did not realize there were so many fans of air sanders. I have a Festool Rotex and could not imagine anything better. That being said, I am allergic to more things than most people.....and many types of sawdust will slam my nose shut in 5 minutes....not with the Festool. Their dust extraction is excellent.
 

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This thread has really piqued my curiosity. There are guys who say that electric sanders can't hold a candle to air power and others who say electric is the only way to go.

Last year, I went to my local WoodCraft store determined to buy a Festool ROS. In an effort to get me to move up to the next level sander, the sales guy urged me to test drive the various models. I was really disappointed in the ones tried; so much so that I went home and repaired my old Porter Cable. I decided to live with it ...and then this post came up, stirring my search for the sander holy grail. Like most people, I don't enjoy sanding, but I do enjoy a flawless finish, so a sander that gets that result is a big plus.

I don't see the hose at that much of an encumbrance; I already have a vacuum hose so adding an air hose doesn't seem like such a big deal especially since I have light weight air hose. Having to run the compressor is inconvenient, but I'd deal with it to get better performance.

So can I stir the pot a little and get some more opinions?
 

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I love air tools, just don't love the racket from a compressor big enough to run them. That can be overcome in a professional setting, pretty difficult in the average home shop.

Extension cords don't leak, air hoses do, a safety inspector can cost you as much red tagging hose clamps in one visit than you spend on the any of the air tools you are running.
 
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