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Yesterday was my first try at thinning a spruce top with sander, plane, and scrapers...I didn't damage anything, but neither is it terribly consistent in thickness across the soundboard. I'm reluctant to try the same method on the EIR back, since I've never worked with EIR before. Good news is it wop-wops pretty well.

So my question is this: If I spring for one of the Jet 10-20 thickness sanders, is it feasible that I can just run completed tops and backs thru the sander half at a time and get decent results? I suspect I might need to rig up an extension side plate so I don't stress the thin plates trying to hold the exposed section by hand. If this is feasible, are there other process improvements I should consider?

Thanks, Roy

Yes. If the Jet is set up well you will get incredibly perfect results down to .001 inch.

I've heard it said that the old master classical guitar builders made great guitars because of the inherit but small differences made across the top due to planning and scraping. But with modern machinery you can have perfect control.

Having said that spruce and other soft woods should be very easy to plane. Have you gotten good at shapening your edge tool yet? Even though I have a Jet I still like to use my plane on the tops. But it's great to have the drum sander for figured wood and expensive stuff like BRW and so on. Very very nice machine to have in a luthiers shop.

Been using a Jet 10-20 in my shop for at least 10 years and it does a good job although you do need to be patient and take small amounts of in each pass. I have mine set up so the outside is several thousandths (maybe 0.005") higher than the inside so there is just the slightest crown on the center of the joined tops and backs. That helps to make sure that there isn't a groove in the middle.

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Steve Smith
"Music is what feelings sound like"

I used a Jet 10-20 for a number of years. It is a fine tool, and it will work well. You have to put a bit of extra care and effort into getting the drum tilt just-so, in order to not have a ridge in tops and backs from the sandpaper edge at the end of the drum. I later got a larger drum sander so that I would not have that inconvenience. But that was a want, not a need. And for everything on a guitar other than the top and the back, the 10-20 is the perfect size. So, if you want to buy one, it is worth the money, for sure. If you have the money, going larger is better, but if the 10-20 is within your budget and larger machines are not, you will do fine with a 10-20.

I agree completely with Don. I’ve been using my 10-20 for 15-20 years. It’s slow going, but it’s perfectly fine. From time to time I use a larger sander at the Maker Space I belong to, and it’s pretty luxurious in terms of speed.

The 10-20 moves through soft wood tops perfectly fine. I think I was taking about a thousandth at a time on some harder mad rose back and sides.


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Thanks all! Just what I was hopng to hear. As far as my competency in sharpening, I'm doing pretty well with planes and chisels using a little wetted sandpaper on granite and holding fixtures with roller(s); definitely not so much with scrapers. Can't seem to get a consistent edge turned that slices thin rather than scrapes powder. I joined a local woodworking club to see if I could learn in person, but so far it's not really very active that I can tell.

Roy

Also surprising how many woodworkers can't sharpen scrapers or other edged tools, for that matter.

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Steve Smith
"Music is what feelings sound like"

Some people move up to a larger drum sander after using the 10-20 for awhile. You can sometimes find a used 16-32 open ended drum sander (Ryobi, Jet, Performax) for less then the price of a new 10-20.
When you buy a drum sander be sure to also buy a dust collector if you will be using it indoors. Having good dust extraction will save on sanding belts and your lungs. I use mine outdoors and stand up wind of the "dust cloud".

Live my 10-20. Very good tool


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As for accuracy on large pieces like tops and backs you set your depth so that it sands the piece then flip it around to sand the other side, then do it again and again and maybe even again before setting the depth to thin it out more. Don't max out the capability of the sander drum width but rather do it in parts.

And when you get close, I mean real close, to your target thickness send it through again and again without adjusting anything till it's right.

Built 50ish guitars with my 10-20 and then it's been in service in our commercial Lutherie shop for nearly ten years. Other than some annoying belt tracking issues that didn't impact how well it works it's been a great tool and I'm pleased with it.

Long ago when the OLF was newer we had Colin Symonds here who was an accomplished restoration Luthier who did some work for some famous museums in the UK. Colin was our friend and I miss him even if he did get upset with me when I bursted a Master grade Aid top.

Anyway he went from his beloved 10 - 20 to the 16 - 32 and regretted it and wished he had stayed with the 10 - 20. He posted about this and it's relevant to your inquiry so I am bringing it up.

The 10 - 20 is a very good machine and does fine open ended, double pass sanding. Both Colin and I believe it's even more accurate and precise than the 16 - 32 because of less spans to flex when operating.

Keep in mind these are not intended to hog off a lot of material and multiple, lighter passes are recommended for better results and paper longevity as well. Heating up the drum excessively is to be avoided.

There are better drum sanders than either the 10-20 or 16-32 - just add money.
Some people build their own and trade time for money. The commercial units tend to be a bit more refined and probably safer in some cases.
I bought a used Ryobi a few decades ago, and it has served me well since.
For a repair shop the 10-20 may be a better choice. It has a smaller footprint and will make less dust per time, so a smaller dust collector could be used. For a production shop a wide belt sander would be the way to go.

Which is an excellent point. Dust collection isn’t an option w a drum sander imo


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Yep lots of better thickness sanders but a 10 - 20 will do the job, won't break the bank, can be VERY precise and reliable AND you don't have to have a big ass dust collector either. Before I got my 1,100 CFM unit I used my Festool 130 CFM vac with the 10 - 20 and it did great.

So to Snow's excellent point that dust collection is not optional, you have to have it because it also works to keep the sanding drums cool which prolongs paper life you simply have to have dust collection to thickness sand with many of these machines. With a 10 - 20 although not my first recommendation you can use it with a shop vac on steroids if you have one and I had and have one.

There are some idiosyncrasies to the 10 - 20 just like any machine. Paper installation although not difficult to do IME it has to be correct as mentioned with no over laps in fact the gaps are desired to have space to take up slack when it starts spinning. There is a slight ridge that can result from two pass sanding but that is quickly knocked back down with a ROS or semi-final sanding.

And my unit the belt, the feed belt kept wanting to migrate to the right. All manner of possible solutions were tried including a new OEM belt to no avail. It did not cause any issues mind you it just bothered me because it was not perfect, must sterilize.... Channelling VEGER on Star Trek.

There was also some debate here on feed speeds, fast or slow, I ended up in the fast camp but started in the slow camp.

Nice machines, well built, the stand is killer with nice wheels and the Jet/Performax papers are very high quality in my experience and pre-cut to length and size. I once ran 40 German spruce tops all more than 50 years old though my 10 - 20 to get them ready for sale and I did it on one sanding belt.

If I was to do this all over again and did not have unlimited cash or space I would go with the 10 - 20 again but I don't have to because my 17 year old 10 - 20 performs as good as new still.

I would love to have the oscillating drum 22" sander from the Greenridge shop in my little garage, but living in an area that gets quite a bit of snow and ice during the colder months, I need that garage! The Jet 10-20 is a nice solution that can be pressed into thicknessing top, back, and sides, but i find that it is also perfect for thicknessing nuts, saddles, and even thin shim stock. Mine is one of the newer ones, so the adjustments are a bit more user-friendly, and the old problems with excessive wear on the alloy elevation mechanism are supposed to have been addressed.

The downside? Extremely expensive! I payed just over $900 delivered, but they are now closer to $1400 with shipping with our entry to what seems like a redo of the late 1970's stag-flation era. I debated picking up a well-used Performax 16-32 that popped up over near Baltimore, but the boys suggested that the 10-20 would do everything I needed and would not suffer from the difficult/repetitive table parallelism adjustment issues and other issues that they saw with their 16-32 machines.

If possible, worth noting that - space and money permitting - the 22-44 ODS remains the machine to have for small shop repair and light build work... the finish off 80 grit looks like 240 on most woods, so saves quite a bit of time on secondary sanding/scraping. Downside? $3K plus! But keep in mind that in commercial work, any machine you buy that saves some time pays for itself over time, so the price difference between a non-oscillating and oscillating drum or belt machine gets made up fairly fast. Now if they would produce an ODS 18-36, that would hit the sweet spot for those of us that are space-constrained and want to avoid a $3K+ hit on the tool budget.

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For the times they are a changin'

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I take your point Woodie about an 18 inch sander. I have the Jet 16 inch and my usual size tops/backs don't really quite fit. Since it is hard not to end up with a bit of a lump where the loading is fixed to the drum there is almost always a bit of poor sanding at the edges. Sometimes thinning that area down too much.

Dave

For the lump at the end of the sandpaper, try running a board of hardwood through and then try re-stretching the paper.

What do mean by is not an option?

I have a Shop Vac that pulls air through a Clear Vue mini cyclone that plugs right into the Jet sander. I can sand BRW backs and sides and not smell any dust at all.

I use my Oneida cyclone with my 10-20 and dust collection is very good.

_________________
Steve Smith
"Music is what feelings sound like"

I recently picked up a slightly used oscillating 22-44 for $1000. I called the seller about 1 hour after it listed on Craigslist. Woody's right, beautiful finish with 80 grit. Rebushed the rollers and cleaned up a 16-32+ and passed it on for $450. No, I'm not gloating.
Keep your eyes out for something used, Roy. Search for "drum sander" on CL and the other online sales sites. They still pop up.

This is good advice, particularly if you can take your time. If you are in a hurry, you can't control when good deals show up. I bought my pre-Jet Performax ShopPro 25 several years ago for $900. It just popped up one day, and I jumped on it.

JF McKenna wrote:
"What do mean by is not an option?

I have a Shop Vac that pulls air through a Clear Vue mini cyclone that plugs right into the Jet sander. I can sand BRW backs and sides and not smell any dust at all."
Post Posted: Fri Apr 29, 2022 1:44 pm

I think he meant is "not optional" . You need a dust collector or good vacuum cleaner if you are using a drum sander inside a shop, so figure that into the cost if you don't have one.

CarlD wrote:
"Rebushed the rollers and cleaned up a 16-32+ and passed it on for $450. No, I'm not gloating.
Keep your eyes out for something used, Roy. Search for "drum sander" on CL and the other online sales sites. They still pop up "

Hi Carl,
I think $450 was the new price for the Ryobi drum sanders when I bought mine (used -for less). They have held their value pretty well if you don't figure in the cost of inflation. Occasionally you can find them on sale (used) for $350 if you are patient, but $450 is a good price for one tuned up and running good.

Hesh has one that has been sitting in a closet for ten years. I'd offer him $350 and see what he says

Mine is becoming Dave's as I gradually fade away... .. . .