Air versus Electric: Which Festool sander is better?

[Dev Emch]

O.K. you festoolies, which of the festool sanders is a better sander? I was looking at a finish sander and was considering the ETS 150 (3 or 5). But this beastie is electric. Then I looked at the air powered sanders.

So, which finish sander is a better sander? Never mind the air line versus copper line argument. Which sander produces a better quality finish?

Also, can we use lambs wool polishing pads on the air sanders and if so, which ones? For example, polishing down auto type paint finishes to a show room gleem? Do the air powered sanders even have the ability to support a lambs wool pad?

Thanks in advance...

[Rick Christopherson]

Many years ago I performed a quantitative/qualitative microscopic examination of the finish quality of sanders as part of a product review. There is not an electric sander on the market that can come close to the finish quality of a good pneumatic sander. If you are entrertaining the notion of air versus electric, then the choice is simple. If your choice is electric versus electric, I wouldn't have a clue which is best.

Of the pneumatic sanders, the Dynabrade and its knock-off (by the same engineering team) Master Power, are the two brands I would put head to head with anything else on the market. The high quality pneumatics are less expensive than the moderate quality electrics.

[Jim Becker]

Festool's air sanders should be very similar in performance to the electric units within my own speculation. I have the 150/3 and it's a peach...smooth, no vibration, agressive enough for my needs and excellent dust collection. (I have the Rotex 150 which has the same orbital action as the 150/5 and I use it when I really want to get "mean" to the wood with the abrasive)

[tod evans]

dev, i`ll second the air recomendation wouldn`t have anything else..02 tod

[Frank Chaffee]

Many years ago I performed a quantitative/qualitative microscopic examination of the finish quality of sanders as part of a product review. There is not an electric sander on the market that can come close to the finish quality of a good pneumatic sander. If you are entrertaining the notion of air versus electric, then the choice is simple.

Rick,
This statement is very interesting to me, and I would like to respectfully ask you how power delivered to a sander (buffer or polisher), can cause a difference in the sanders performance? I have used air and electric on metal surfaces, but now I need to inquire as to the best choice for wood.
Thanks,
Frank

[John Kain]

Rick,
This statement is very interesting to me, and I would like to respectfully ask you how power delivered to a sander (buffer or polisher), can cause a difference in the sanders performance? I have used air and electric on metal surfaces, but now I need to inquire as to the best choice for wood.
Thanks,
Frank

Ditto for me........

Bump

[Lopaka Garcia]

Without knowing the exact specs between air vs electric, I would think it's the speed of the air sander that makes it excel. I don't have an air sander personally but I've seen them in action and if I had a choice between the two, I would choose the air over electric. I noticed that the air sander was much faster at removing wood than the electric sander and the finish they left were excellant. Maybe you can find someone or someplace that uses the air sander so you can see it in action for yourself.

[Doug Hobkirk]

Rick -
1) I also am curious about the answer to the above Q's although I can imagine some possible reasons, and
2) Dynabrade makes lots of sanders. This is a WW forum, so I imagine your recommendation is for pneumatic sanders well suited for WW, like ____ [please fill in the blank - I'm a neophyte]

[Chris Barton]

O.K. you festoolies, which of the festool sanders is a better sander? I was looking at a finish sander and was considering the ETS 150 (3 or 5). But this beastie is electric. Then I looked at the air powered sanders.

So, which finish sander is a better sander? Never mind the air line versus copper line argument. Which sander produces a better quality finish?

Also, can we use lambs wool polishing pads on the air sanders and if so, which ones? For example, polishing down auto type paint finishes to a show room gleem? Do the air powered sanders even have the ability to support a lambs wool pad?

Thanks in advance...

I have used both air and electric ROS and would have to say that while air sanders are faster, they are not more powerful. But, even then they are entirely dependent upon the compressors that run them. They require high air flow to perform adequately. A high powered electric sander (>12 amps) has much more power than most air sanders powered by relatively standard compressors. The biggest reason air sanders are used in automotive work is because of wet sanding. If air sanders were superior then every cabinet shop in the country would run air sanders. Commerical units go where the results are and in this case it is electric... Also, almost all fine polish work in automotive work is done with electric random orbit polishers and polishing compounds.

[Rick Christopherson]

I don't have much time at the moment, so pardon me if anything is less than complete.
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When I did my product review, (any of my reviews) I tore apart every tool in the line up to examine the kinds of things that you can’t see from a store shelf. I would examine tools from an engineering standpoint from the inside out.
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The short answer as to “why” is because the pneumatic tools (the good ones at least) spent their manufacturing dollars on the drivetrain of the sander, whereas the electrics had to spend most of their manufacturing dollars on the motor (electrical parts).
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The rotary vane motor shaft on a pneumatic sander is a single machined piece from the cylinder all the way down to the pad mount. All of the components are machined steel. As a result, there is little runout in the shaft. If I’m not mistaken after all these years, I also believe the pneumatic sanders used a double-stacked bearing set at the eccentric. (only one electric used a double bearing).
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Most electric sanders start with a standard motor shaft and couple this to an aluminum eccentric flywheel with a single screw. This coupling is the first weak point in the drivetrain that can introduce runout. My memory is failing me, but I believe there is a secondary coupling in the eccentric with a bearing and some type of pad mount.
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Whenever you feel your sander shudder as you move it side-to-side, this leaves marks behind, and in most cases, this shuddering is caused from a slight runout in the eccentric. All of the common wisdom for electric sanders says to NOT move them side to side rapidly, and this is why. However, you don’t really hear this same warning come from the pneumatic side of the fence. This is because they have much more stable orbits and shafts.
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Another thing you can check regarding the wobble of a sander is to hold it loosely in the same spot with very little pressure. With a poor sander, you can actually feel the body of the sander tilt side to side as the eccentric wobbles at a low frequency.
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Each of these things I was able to confirm during my examination by noting which sanders did this the most and then confirming it from their scratch patterns under a dissecting (low power) microscope. I was once a certified microscopist and trained in counting statistical microscopic objects, so that is where this test concept originated.
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The other thing you will never find on a pneumatic sander is the hokey pad brake. This is the greatest marketing snafu I have ever seen. The pad brake removes most of the “randomness” of the eccentric (epicycloid) motion of the pad and actually introduces a lot of the scratches the marketing gurus claim it removes. This fact I actually document (and it’s in print in the review) by duplicating the tests on a few sanders with their brake installed and with their brake removed. The results were quite revealing and unmistakable. The pneumatics don't need a pad brake because their motor spins up to full speed under load in a fraction of a second.
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My review was in American Woodworker issue #74 or #75, and you can see a couple of cutaway models of sanders to explain this better (one electric and one pneumatic, but the pneumatic cutaway was not one of the good sanders).

[Alex Shanku]

Rick, thanks for the explanation.

[tod evans]

If air sanders were superior then every cabinet shop in the country would run air sanders. Commerical units go where the results are and in this case it is electric... .

chris, in this neck of the woods every production woodshop i`ve been in is using strictly air. electrics are considered "install tools". my air system is small when compared to the true production shops, most of those fellows are running 25hp+ screws. the fiberglass boat folks also swear by air, but as you state most polishing is done with the variable speed electric polishers.....02 tod

[Chris Barton]

chris, in this neck of the woods every production woodshop i`ve been in is using strictly air. electrics are considered "install tools". my air system is small when compared to the true production shops, most of those fellows are running 25hp+ screws. the fiberglass boat folks also swear by air, but as you state most polishing is done with the variable speed electric polishers.....02 tod

Tod, I though about the differences last night and began to realize that when we are talking about ROS that power probably not the most important factor. I guess for 99% of the work to be done in real life that either form of power would work just fine, if you have the compressor power and CFM then an air powered machine would work but I don't know if dust collection would be a problem. Maybe we'er splitting hairs here...

[Stu Ablett in Tokyo Japan]

Assuming that a compressor exists to power the air sander, then I think the air sanders rock.

Now my info and experience is 20 years old, but I used to work in a fiberglass layup shop, back then we were building them giant 8' and 10' satellite dishes.

We had a few electric sanders, they would last less than 6 months, if that. We wore them out. The pneumatic sanders worked and worked and worked. It seemed to me that the paper lasted longer on the pneumatic ones too.

In the end, if you were sanding all day long with a pneumatic, you could hold your coffee cup without spilling it, with the electrics, you had to use both hands

Just my observations and experiences.

Cheers!

[tod evans]

Tod, I though about the differences last night and began to realize that when we are talking about ROS that power probably not the most important factor. I guess for 99% of the work to be done in real life that either form of power would work just fine, if you have the compressor power and CFM then an air powered machine would work but I don't know if dust collection would be a problem. Maybe we'er splitting hairs here...

chris, a few of the pneumatic manufacturers are making token jestures to address dust collection, i think mainly to see if the market will bear the cost. dust collection in production cabinet shops is by and large for the machines benifit not the operators. hobbiests on the other hand as a group have the reputation of buying the cheapest tool that claims to do the job, so given that a good air sander will consume 6-10cfm and cost upwards of 200 bucks the 49.95 electric with the shop-vac attachment is the most common choice. when a fellow burns up a few of those he`ll look at the higher end electrics because the compressor issue is still hanging overhead. eventually if he keeps at this trade/hobby air will most likely enter into the picture......this i know-i`ve done it...02 tod