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Just wondered if there was a concensus on the thickness of tops when you join them. I can't afford/justify my own thickness sander but have access to a really big high tech one down the road at a firm of Architectural Woodworking. As this costs and there is sometimes a lag in getting things processed I tend to have the top halves thicknessed close to final thickness (around 3mm to 3.2mm) and join them - giving a little room to play with in rosette levelling and dealing with andy dings plus final thickness shaping. This means that the joint has to be pretty perfect and things can be a little nerve wracking. In an ideal world I would probably join a bit thicker, then thickness down, put in the rosette and thickness a little more.

What do y'all do?

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

I just surface sand the 2 halves, joint the edges with a plane and a shooting board and glue them up. I then have them thickness sanded to about .150" to .160" and install the rosette. I prefer to work on a thicker piece at this stage. Once the rosette is in and leveled I then thickness sand to bracing height...from .110 to .120, depending on the stiffness. And finally cut the soundhole.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Hi Dave

I have a thickness Sander, I usually just smooth them as sometimes they come in quite rough, Join thickness to j about 3.5mm inlay the rosette and take them down to final thickness.

Have you looked at the Wagner and sanding disc method that Colin uses I think he does all his thicknessing this way, He has a fairly large drill press. Might pay for its self in what it costs you to have it done, and is certainly cheaper than a thickness sander or though I wouldn't be without mine now.

Dave,

I have a thickness sander so I do run them through a couple of times. Once to just clean them up, another to remove the glue after I have joined them and the thrid time after the rosette is done and to about final thickness less the finish sanding. BUT! If I was you I think I would clean off the surface, even with a hand plane or portable belt sander, just so you could see the wood. Then glue them up and let them sit for a bit (I do leave mine sit but not for many months like Lance but 2 or 3 weeks anyway to let the moisture equalize out of the glue joint) and then have them sanded to near your final thickness. This means you need to be a bit careful with leveling the rosette but that shouldn't be too much of an issue.

Those are my thoughts, from the little experience I have but my sander is about a mile away from my guitar making place so I have thought of more efficient ways of doing all of this (besides just getting at getting my shop built and getting all of my tools in one place!).

Hope this helps out Dave.

Shane

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Canada

   Same here. I'll just surface them quickly and it's off to the shooting board for joining... Take it off now or later, it's all the same. I just like having the extra bit of thickness in case something goes wrong with the rosette.
   Once the rosette is sanded/scraped, then I'll turn it around and thickness to about .110 with the hand plane.

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

Cool Thread guys, i was about too ask the same questions!

thanks

Serge

Dave I join my plates at about 3.5-4mm, front and back. But on the front I like to get, what will become the top surface nearly finish smooth before joining and installing the rosette so that I have only very minor levelling after installation of the rosette. Final thicknessing, prior to voicing, is done from the back only. Yes I've just got rid of my very underused 16-32 as I prefer the drill press thicknessing route.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

So some of you use the Wagner Saf-T-Planer for the soft woods like spruce and cedar, too?
Dave, to answer your question, I have generally been told that joining at whatever thickness they come is the best way, then plane them down together. Its worked so far.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

I just get them smooth and the same thickness then join them.

If it is a top I then level it before inlaying the rosette then take the thickness down from the back.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Through the Grizzly to look at the grain...then glue up, cut rosette channels, glue in the rosette, smooth top, thickness from backside!

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http://www.presnallguitars.com

Just clean off enough fuzz to see the grain, join at whatever thickness it is, level both sides, decide which side will be "up", install rosette, level that, take the rest off the back of the plate. All done with a Stanley #5 1/2 of course .

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Rian Gitar og Mandolin

I normally glue up at .170. Then once the glue is sanded off you hit
thicker than .150. Rosette goes in. Take a tiny bit to get the front of the
guitar clean and smooth then do the rest of thickness from the back.

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John Mayes
http://www.mayesluthier.com

I clean them up with my thickness sander, run them through the jointer until they match then glue them. After the rosette is done I thickness the complete top.

Al

First off I didn't see that different woods should go to differetn thicknesses. The top needs to take the forces of the strings and convert that energy to sound. How and when the rosette goes in if all in your own prefences.
My personal technique is much like most , first Identifiy the show side . and then take to rough thickness. for me that is .120 or so. At that point I will glue up and set the rosette.
   Then I will run it through to clean up the glue and level the top. I want to use thicknesses of .110 to .090 dependant on the strength of the top I am using.
Adi .090
sitka .100
engleman .110
these are generalities but with experience you will develop your own feel .
john hall
PS I never use superglue anymore on a top

John...Just curious...What caused you to abandon super glue on tops? I'm imagining a stain...but usually a coat of shellac around the rout and beyond has prevented any stain for me. What adhesive do you now use on rosettes?

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JJ
Napa, CA
http://www.DonohueGuitars.com

   I guess my techniques got better. I don't see any need for the stuff on tops. I found super glue over time yellows and no longer use it. Yes I use a sealer but the solvent in superglue can go through it. It is especially bad on adi.
    Duco works just as good and will do the job without staining. I can still sand the tops in about 1 hour.
john hall

[QUOTE=tippie53]
. and then take to rough thickness. for me that is .120 or so. At that point I will glue up and set the rosette.
[/QUOTE]

John,
You go a lot thinner than I have ever dared to before doing the rosette. Is .120 were you actually cut out the rosette channel? How deep do you make it? Ever have problems going through the bottom?Scott Thompson38766.9887268519

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Scott Thompson
Port Townsend,WA

"In a perfect world we'd all sing in tune
But this is reality so give me some room"
-Billy Bragg

[QUOTE=j.Brown] So some of you use the Wagner Saf-T-Planer for the soft woods like spruce and cedar, too?
[/QUOTE]

Yes, it works great on these woods.

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Scott Thompson
Port Townsend,WA

"In a perfect world we'd all sing in tune
But this is reality so give me some room"
-Billy Bragg