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Hi,

I have completed my rims of my first guitar, and started working on the Back. However, as I do this, I want to plan out my top as well. I am using a Lutz top from Shane that is approximately .250 thick. I will be hand planing to thickness (I dont have a drum sander). Can I join the tops at this thickness? or should I plane down first? My questions are:

- Thickness I should join?
- Thickness I should plane down to install rosette?
- General final thickness (understand this is dependant on individual tops, but a general range that would be "normal")?

Thanks!

Glenn

HI Glenn:

Join it at the current thickness. It will make things easier when you join the two plates. If they are already at final thickness when you join them, you won't have much room for error in terms of alignment.

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Don Sharp
Got Brazilian?
http://www.sharpguitars.com

I'd say join now. Plane smooth both faces, maybe plane down to 4.5mm. Install rosette, smooth again nicely, and this means your are done with the outer face. Flip and forget about it, and bring it to final from the underside.

PS All this if you rosette channel depth is not more than 2mm !

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Build log

Glenn,

You will probably get a few different answers here, but in my limited experience this is what I do.

If the top is just rough sawn I plane just enough to see the grain decently, this helps you to line up the join when you make it and to decide the orientation(outside or inside) of the plate.

Then I make my join, and thickness to 3mm (1/8"), and double check my choice for the outside of the plate before I install the rosette, and cut the soundhole.

From there I try to determine general thickness through tapping and stiffness, etc.

Hope this gets you started.

Cal

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Remember, there are no stupid questions, only stupid answers!

Glenn buddy as the others have mentioned there are many ways to proceed.

I join at .140 - .150 and then thickness to the dimensions that I will install the rosette at. When working with a top that we can't evaluate I would say that if you install the rosette at .120 you will be safe. This permits you to level the rosette and top to .115 and have little risk of uncovering a pitch pocket.

If I was building with Lutz to a spec and not using deflection testing and have a knowledge base to refer to I would shoot for a final thickness of .110 - .115.

Once the rosette is installed and the top is level and if you do want to go thinner go thinner from the back side of the top.

Hey Glenn,

My comments are similiar but slightly different from the others here. I would skim plane so you can be sure about the grain orientation. You just need to do this on the face. Then join the top. Then smooth the face just enough to be sure that it is clean and level. Then smooth the back, again until clean and level. Then candle the top (a bright light from behind) to see if any pitch pockets or any other types of issues will be arrise from further sanding. If all is good thin to about .140. Install rosette and just level the face again. Now you need to decide which building style you will be employing. Some of my customers like the Somogyi grads may take these down to even less than .100 finished. While others, like John Greven, have left them near .130. These numbers are for the wood from the same tree as you have. It depends on your building philosophy, thicker tops lighter braces, thinner tops, taller braces.

Hope this helps!

Shane

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Canada

I usually take it down only enough that I can see the pattern in the wood and decide which side will go up. Then join, install and level the rosette, and take it to final thickness from the back. Just a tip, leave the ends a little offset when you join so you know where the centerline is.
Terry

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

Thank you all!!! Greatly appreciated.

Glenn

I guess I'm old fashioned in that I always put the bookmatched side out. There's still the upper/lower bout orientation to choose.

I'd at least skip plane or sand enough to get a plane surface for the side that goes against the joining board or table surface . No need to go further before joining.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I'd clean both sides of the set and choose the outside (usually the bookmatch if no apparent defect). Once the halves are jointed you probably don't want to take off more than the necessary for rosette clean up and final sanding. Pitch pockets and defects can jump at you… You can always hold the plates right in front of a strong light to see what awaits in the wood.
Besides if your top is well jointed (say, between two grain lines) and is just slightly off-quarter sanding the outside too much will make an otherwise invisible joint apparent. .250" is thick, .180" should be plenty to install the rosette, clean up and thickness from the inside.
What guitar are you building? Average top thickness depends on guitar style & size, wood and the particular piece you use…

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I am building an OM (EIR B&S, Lutz top).

Thanks!

Glenn

I'm using my 1st Lutz top on a 12 fret 00 style guitar and it ended at .114", nearly identical in stiffness to a German top I'm using on another 00 type guitar (.114" too for some reason).
That being said I use small and light tapered bracing.
If you use tall and thick braces and a hefty bridgeplate you could maybe go down to .105" if your top is stiff, I would be weary going any thinner.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/