Official Luthiers Forum!

Hi

Thinking about speeding up the sanding processes
Do any of you guys use random orbital sanders
Do these sanders level swirl marks in the wood and if you do use them what grits do you go up to

Many thanks

The Festool 5" was what I used and I really liked it. I already had the Festool dust collector that is integrated with their sanders so that worked out for me.

IME the 5" sander was a good Lutherie size and the Festool did not leave marks at all, ever for me. It's "random" function and dust collection were better than the others that I had tried.

After hitting things with 220 paper I was ready for finishing. This has been mentioned on the OLF before but during the period when I outsourced my finishes two different pro finishers specifically asked me which ROS I was using because my stuff required no effort on their part prior to finish.

When sanding bodies it's a good idea to stuff a towel in the sound hole with any ROS so that the neighbors don't think that you are torturing dolphins.... A towel quiets things down nicely.

Thanks Hesh will look into it..
"Torturing dolphins" made me laugh

Seriously if you have not taken a ROS to a guitar body yet you are in for a very loud surprise.... If you have a tuning fork hit it to get it vibrating and then place the ball end on the bridge or bridge area of a guitar and the body amplifies the tuning fork greatly. Place a ROS on the same box and it's as loud as the 5th row center seating at a Who concert...

PS: No offense intended to Dolphins, I love Dolphins....

I've always thought that variable speed on a RO sander was an odd feature since the higher OPM is what helps to prevent marks. I use and recommend a sander that spins at 12,000 OPM (we have a Porter Cable) I also use a tried and try Porter Cable "Speed-Bloc" I do follow up each grit with a few insurance hand strokes with the grain to blend any stray swirls.

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Ken Cierp

http://www.kennethmichaelguitars.com/

If you have the option of going with air driven tools, there is no equal to the Dynabrade Spirit series sanders. They are light, quiet and powerful. They require less air than other air sanders that I've used in the past. They are built with a counter balancing weight based on the pad size that you will be using. I have several of them in three inch, five inch and six inch in 3/8, 3/16 and 3/32 orbit patterns set up with different backing pads that are dedicated for different tasks. My five inch sanders get the most action. If I were to only have one, it would be a five inch with a 3/16 orbit pattern. I always "final prep" bare wood by hand though before I begin the pore filling process. I am not convinced that any orbital pattern is acceptable under a gloss finish that tends to magnify every wood detail.

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jw ( o)===:::

Been using Dynabrades for more than 20 years and Joe is 100% spot on. Can't beat them. I use 4 of them so that I don't have to change grits much. I've only been able to wear 1 sander out. Very well made and comfortable to use. They do however require a bit of air, so you need a decent size compressor and tank.

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“ The meaning of life is to find your gift and the purpose of life is to give it away” Pablo Picasso

Sanding to a finer grit can allow you to use some of the cheaper R.O. sanders, but try not to go too cheap. And using micron papers with more uniformly graded granules also helps.

I'm not sophisticated enough for a Dynabride, so I have the Festool sander, too The model I own is the ETS-125, and it's about a decade old now and going strong. I'll echo what Hesh said about the quality of the result.

When I was tooling up, we had a great local store that set me up solidly with a Festool MIDI and the ETS-125, and I've been abundantly happy with them. The initial investment creates a hiccup or two, but over the course of a decade I haven't regretted my choices a single time.

Another big Dynabrade fan. A couple of those with different orbits and a Porter Cable Speed Bloc and you'll be happy as a clam forever. The Speed Bloc is great for sanding the curves of the heel and the neck headstock transition.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Air tools are great if you have a compressor big enough to be capable of handling the demand. A guitar or two won't draw that much air, but if that is all that you need it for, then perhaps its too much. I've been using ROS sanders for years on the canoes and paddles that I work on. Air would not keep up, so I use electric. I've gone through three Porter Cable sanders, now I use Bosch, the big 1250 DEVS, and its outclasses the PC. Its a great sander. I keep hearing great things about Festool, but the price is significant.

Variable speed is a great option whenever you have to exercise a delicate touch.

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Expectation is the source of all misery; comparison the thief of joy.
http://redrivercanoe.ca/

I have a Bosch GEX150/125 ROS 400W . The previous model left small swirls, but this model does not. As Hesh says, it seems to use the body of the guitar as a resonant chamber. But with 5000 to 12000 rpm by adjusting speed it can be minimized

A Festool ETS 150/3 or the ETS 125 coupled with an adjustable suction dust extractor (turn the suction way down, or use a bleed valve - key for preventing swirl marks in my experience) work wonderfully. I've been known to skimp on some of my tooling or go DIY, but Festool sanders, abrasives and dust extraction are tough to beat. Keep an eye out for a used ETS, as they've introduced new models, and guys who are Festool fans are likely to upgrade and be selling perfectly good ETS models

For abrasives I use Granat 150, 200, 320, 400 - its more of an up-front investment, but lasts significantly longer than the next closest abrasives I've tried.

Hard pads help avoid rounding over edges - softer pads are great if you want to sand sides.

Please wear good hearing protection as an RO sander on an acoustic body produces a significant amount of sound - a loud, steady drone.

One benefit of a Dynabrade is it will level finish beautifully too. I wouldn't try that w/an electric.

I've always wondered if Mirka's "Ceros" sander had any of the same control but I've never had one in my hands.

We use a moderately priced 5" Porter Cable 12,000 OPM, with vacuum pick up and high quality abrasive and it works great. If you have an electric RO and it vibrates (no matter what brand) return it or throw it away.

I am assuming (shouldn't do that) that the basic premise here is that the components are held stationary in some sort of fixture, vacuum or otherwise.

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Ken Cierp

http://www.kennethmichaelguitars.com/

David, I have heard this many times. Do you (or anyone) know what it is about these Dynabrades that make them better at leveling than an electric?

I have wanted Dynabrade, but don't think my compressor would power it.

Thanks

I have a Mirka Ceros 5" and it does give better control than a standard ROS. I wet sand by hand to level so don't know if it would work or not. It is a lot easier on my wrists which is why I got it (carpel tunnel).

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Steve Smith
"Music is what feelings sound like"

Seems there should be other options for those that don't want to get a second mortgage. It certainly hard to disagree when buying the best of the best, flawless results is what I would expect -- but this is a hobby for the majority of the members -- at least that's what I gather.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I wouldn't consider an orbital sander necessary or even very time saving for a hobbyist. Learning to sand well with good paper, a good block, and a good grit sequence is a necessary skill. Unless your really trying to bust them out, I would say money is better spent elsewhere.

Dyabrades have a supper low center of gravity, light weight, very controllable on/off/speed, low vibration. Words don't really do it justice. once you try one you'll say, "ooh".
That much air is serious $$$.

Yeah -- but I think the OP author wants to use an RO, and in my experience even my (I guess primitive) Porter Cables are light years faster than hand sanding. Its an acquired skill like all our other processes and extra,extra care has to be taken at the perimeter. For the sides I pretty much use a "rolling pin sander" and stick to hand sanding on the finish.

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Ken Cierp

http://www.kennethmichaelguitars.com/

At a talk last year, Sergei de Jonge said that he used a RO for the back, pad sander for the sides, and hand sanded the top with a block, using a circular motion instead of along the grain.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I have a Festool 6", and it works pretty great. Especially the dust collection! I tried the Ceros at Woodcraft and it was completely awesome (for $500 i hope so). I've thought about going with the air system. What would the minimum spec compressor be?

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Pat

The Dynabrades I looked at were about 15 -16 cfm. From what I understand that really points to a two stage compressor, but I'd love to be wrong.

I bought a Makita variable speed ROS.
It works great on hardwoods and can produce a fairly flat surface.
Saves lots of hand sanding time.

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wah
Wah-wah-wah-wah
Wah

Yes that's what I have decided to go for as cannot afford a lot of the suggestions ..although the suggestions are good for pro setups, as a hobbiest it will need to be a cheaper option. .as long as it saves sanding for hours