Official Luthiers Forum!

Folks,

I have done the research on how thick tops, backs, and sides should be. My questions relate to how we get there.

I don't have the money to purchase a wide enough motorized planer or sander. A friend of mine owns a 13" wide Ryobi, but this is too narrow to send a jointed plate through.

Is it a bad idea to send the two pieces through separately and then join them after?

If that option is not a good one, could an orbital sander do a satisfactory job?

Finally, I've seen a video tour of Collings Guitars shop, and their master luthier doing some thickness sing using a hand/bench plane. I know the blade would have to be kept extremely sharp, but has anyone done this? I am not a seasoned woodworker, and don't want to ruin good wood.

I currently have two sets of cedar top wood, one has been joined already, the other has not, so I could try either the hand plane or orbital sander on the top that has been joined. The back for this build is also already joined, so it would have to be thicknessed without a motorized planer/sander.

Thanks in advance for any and all advice!


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You can get close before joining, but leave at least .010" or so incase you don't get the seam perfectly flat along the whole length. I use the masking tape joining method (stick a strip along the seam on the show face, and a few strips stretched across the grain to put some pressure on it, lift it up like a tent, squeeze glue in the seam, drop it down, and put some weights on it), which gives you the opportunity to press down on both sides of the seam with your thumbs to align any areas that are off. But still need to sand/scrape a little bit to get it perfectly flat.

As for thicknessing, I've always done it with hand plane and scraper. I usually use a toothed blade in a block plane (just a regular blade that I ground 4 notches into with a dremel cutoff wheel), and a card scraper. Cheap as can be, and a good workout But do wear a dust mask. It's a lot less dusty than sanding, but still probably not healthy to be breathing on a regular basis.

Here's a recent thread with lots of other recommendations on hand thicknessing tools http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=42486

Alternatively, you could build your own thickness sander. A few people on this forum have made them, although I don't have links to the threads handy. But you'll either need a dust collection system (i.e. still expensive) or to run it outside... which would probably mean hauling it in and out whenever you need it, which would probably be more of a pain than hand planing the stuff, which is why I haven't built one.

I thickness the plates separately to nearly the dimension and then do the rest after joining. I use a 10-20 sander so I can run the joined plates through one side at a time.

On my first and 2nd guitar I used a block plane and thicknessed to dimension with that. It's very laborious and time consuming but can be done if you have the patience

I like to join the plates before any thinning. Easier to get a good joint that way. Before I had a drum sander I thinned the joined plates with a hand plane. If the plan is sharp and adjusted properly then no problem. Then just finish with the RO sander

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Joe Beaver
Maker of Sawdust

Justin,

Do not run your plates through a thickness planer. It will make a terrible mess of your wood and possibly your shorts. Makes a terrible noise and throws shrapnel around the shop.
If you can't find someone to thickness them for you with a sander, follow the link Dennis posted.

Steve

I confess that I rely heavily on my thickness sander, since I'm not very good with a hand plane. I prefer to join and then bring the thickness down. I'm not sure how far I'd get without the sander, but guess I'd have to get better with a hand plane and scraper. The random orbital is fine on hardwoods, but you need to be very careful around top woods as it's easy to dish them out. There are plenty of builders who really like to hand plane and seems like sharpness and adjustment is the key as Joe said. Using a toothed blade seems to be the preferred method for getting close to the desired thickness. Hopefully you'll not start out with highly figured wood if you hand plane as tear out can be a problem. This is when I discovered that my skills were not sharp enough (pun intended, I guess).

Answering your question directly, I would say it's okay to get your two plate pieces down to approximate thickness, one at a time. Then join. Then finish up by various means. As has been said, a random orbit sander will get you there if you keep it constantly moving and don't bear down in any one place. If you bear down, you will surely have a thin spot near the seam (or whatever). Alternatively, a sharp, well-tuned plane and a well-honed card scraper will get you there faster than you might imagine. I'm no pro, but I've built successful instruments with these hand methods. Remember, people built some of the world's most desirable instruments with hand tools, and they did it hundreds of years ago. Skill and patience are required. If you don't get in too big of a hurry, you can do well with hand methods. If you are on a production schedule, you will probably have to invest in some power equipment, or build your own thickness sander. Lots of info in the archives about doing that. Best of luck to you.
Patrick

You need some calipers and then you need to take a visit to a cabinet shop with a wide belt sander (or a builder in your area). Either this or buying a small drum sander is your only good option if you don't feel confident enough to use hand planes to thickness your plates. Most folks in your position buy a kit guitar where this stuff is already done for you -- you might consider that option.

I will be buying calipers this weekend. There are no builders in my area that I am aware of. There are a few guys who do repairs, but none that build. I realize that going to a cabinet shop is a good option, and there's one about 30 minutes from me that I *might* be able to rent time from. At this point I would really like to be able to find a solution that doesn't require relying on a shop to let me use their equipment. All it takes is for someone to change their mind about allowing someone to use/rent time, and I'm back to square one.

Is there a "small drum sander" that's not $1,000+ that would fit a joined dreadnaught top or back? If so, please let me know. At this point all I have found are 13" wide at most, and are in the $300-$500 range, which is more manageable financially, but I'd have to sand each piece one at a time.

Eventually I plan to purchase a planer/jointer, but I'm really just getting into lutherie and woodworking in general and can't afford it.

Build your own. Many of us have using Pat Hawley's design.
http://woodgears.ca/sander/thickness.html

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Doug

Don't let fear or common sense stop you from trying to build something

"Eventually I plan to purchase a planer/jointer, but I'm really just getting into lutherie and woodworking in general and can't afford it."

No need to buy a lot of expensive tools right away. Find a used #3,4,5,6, or 7 handplane and tune it up. Practice planing on a cheap pine board for a few hours and you will gain confidence with the tool. You don't have to get a perfectly smooth surface with the plane. You can smooth things out with coarse sandpaper glued to a flat board (with handles - make something similar to a concrete float). Tops and backs need to be smooth, but not perfectly uniformly thicknessed.
Eventually you may find a used 16/32 open ended drum sander in the 300 -500 dollar range. They work well enough for most amateur lutherie tasks, aren't too big, and are fairly portable. I've been building instruments for over 30 years and it's all I've ever felt the need for.


"At this point I would really like to be able to find a solution that doesn't require relying on a shop to let me use their equipment. All it takes is for someone to change their mind about allowing someone to use/rent time, and I'm back to square one."

It is a rare cabinet shop that will allow you to use their equipment (insurance concerns if nothing else) but they may be willing to do the work for you, for a fee. This may not be a bad option initially. After building a few instruments some people lose the desire to keep building. Not having a big investment in tools and materials allows one to go on to other things without having a lot of baggage to get rid of.

Thanks for all the recommendations everyone.

I already have a #3 plane and $20 spruce top (student grade) from RC Tonewoods, so I'll sharpen it up and get to practicing on that.

I built a shooting board last week and will likely be building myself a workbench this weekend, and then I'll get in some quality time with my hand plane thicknessing that top.

Justin,
Maybe you already know this, but as long as the drum is cantilevered you can run pieces wider than the belt through, then turn the piece 180 degrees and run it through again. This takes twice as long, of course, but it works just fine. I found a barely used Jet 10-20 on my local Craigslist and use it in this manner all the time.

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George :-)

That works well IF your sander is precisely adjusted. It's really difficult to get the drum exactly parallel to the conveyor. I've got the Performax 16-32, and I've gotten it to within about 0.003" of parallel, thinner on the inboard side. That gives me about .002" more thickness in the center of the plate, a variation with which I can live!

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Lots of good advice, but, just north of Chattanooga at the Knoxville Woodcraft 2nd Sunday of the month quite a few builders meet up, The East Tennessee Luthiers guild here is a thread, viewtopic.php?f=10101&t=42480 Guitarbuilder195/A.J. Hancock is from Ootelwah

Wow! Thanks for the info! I didn't realize that there was a builder so close to me. I'll have to try and make it up to Knoxville!


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Roger
I've heard that about the 16-32. I suspect the 10-20 has a different adjustment method. I have the 10-20, and found it very easy to adjust. It has a knob to turn that tilts the drum, and I just used a straight edge at each end. I too, set it up to be .003 thicker at the open end to make up for any paper variation. It is much easier to sand out a small hill in the middle, than a valley!

I've only had to adjust mine once and it was a very slight amount. The results so far have been great and look like glass compared to my efforts with a hand plane!

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George :-)

Mine is the same, but a small amount of turn makes a pretty big difference, 1/4 turn is nearly .010". I measure mine by running a narrow piece through on the inside and outside and measuring the difference. I've never had much sucess measuring it directly.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Here is another do-it-yourself design: http://sutherdyne.com/drumsander/ I had a motor sitting around and was able to build one of these for less than $100. Works great!

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Good judgement comes from experience. Experience comes from poor judgement.

I really appreciate everyone who's posted here. For those of you who have built your own sander, do you have any suggestions on a make or model of motor for someone who's working with a small budget? I'm open to buying used, but small electric motors are something I have absolutely zero experience with.


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Take your time and find a good 1 1/2 to 2 hp 110/220 motor rated for continuous or farm duty. TEFC (totally enclosed fan cooled) if possible. Smaller might not get the job done and larger might require some serious wiring.
You may want to build a few guitars before you build the sander, and during that time you might find a good deal on a used drum sander.

Hi again Clay! Do you think a random orbital sander can get me where I need to be for my first few?


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A random orbit sander is good to smooth things up after using a hand plane to get close to thickness.
To "thickness sand" a belt sander will remove wood much faster and more evenly than a random orbit sander ( with the right technique). Improperly used it can be a faster way to ruin wood.
If you can find a used #4 or 5 hand plane that may be the best way to go on the first few. Minimal investment and a good skill to learn, which you will use regularly in working wood.

Thanks again, Clay. I think I saw a few #4's and #5's used on eBay. I'll grab one and get to work.

When thicknessing the top by hand like this, do most people install the rosette before or after? I don't have a good circle/rosette cutter, but my birthday is coming up and the only things on my wish list are all woodworking tools and the circle cutter from LMI is one of them.