Official Luthiers Forum!

Hi I have a nice northern ash tele body,too heavy but suits my purpose as I want to route it out anyway and glue on a mahogany cap. I have a wonderful piece of antique mahogany with a lovely patina, about 3/8" thick. My idea is to ask a local guy with a planer thicknesser to take off 1/4" from the body and reduce the mahogany cap to about 1/4" too. I only want him to shave wood off the backside of the cap because the front looks so good, however it does have a slight warp to it and I am not sure I will get 1/4" out of it this way.
What's the best thing to do? How should I try and straighten the mahogany?

Slight warps can usually be glued down. Depend on the amt of warping.
Sometimes wetting the concaved side and placing it in the sun will help flatten it out...but this works best on a cuped board...not a twist.
Thicknessings a warped board will not flatten it in the least...unless of course one surface has been jointed flat first. Then the back can be thickness planed...however
1/4 is getting a little thin for thicknessing unless a solid thick flat ply wood or mdf board is used as a carrier or backer board. Dull knives, no backer board and 1/4 thin the risks of blowing up the hog start to increase.

Suggest you try flattening the board by clamping it down over a spacer strip for several days first. Then joint it on a jointer or by hand planeing it and then thickness sand it to final dimension.

_________________
.

Audiences and dispensations on Thursdays ~ by appointment only.


.

Thanks padma, it's a little bit too much to risk glueing down i think - especially as I am reducing the glue surface by routeing out some of the interior. The mahogany is comprised of 3 boards jointed together and is not twisted at all, is warped from side to side, not sure if this is called warped or cupped?? i.e. the board is rectangular and the warping is across the short side rather than long side.

Spray water on the cupped side and place in sun....with luck....
or rip back into 3, joint on a compensated angle , reglue.

Go take a class in basic wood shop skills, DO not pass go , do not collect $100.

_________________
.

Audiences and dispensations on Thursdays ~ by appointment only.


.

How bad is the cupping? Thickness the tele, glue the mahogany onto the tele to stabilize it, then thickness the mahogany on the tele. That is, if you can clamp the mahogany flat and get a tight glue joint...

_________________
Old growth, shmold growth!

Thanks, it's not too bad but I think still a little too much to force it down on to the body and glue it as is. Yes, I could do as you suggest but I would lose the patina on the mahogany which is what I am trying to keep. It's actually a piece of wood from an antique bureau which was about 100 years old and was mostly destroyed in an accident. The reverse side is pretty boring and I don't mind removing wood from that side.

so what I am getting is your board is warped not in the grain direction(top and bottom of tree) but in the side to side direction. I would expect it to lay down just fine at least once it is 1/4 inch thick. The question is will it flatten out when it goes threw the planer and thickness sander at 3/8. Leaving the original finish/ patina etc. is an unconventional approach, and a cool idea, but it will add to the challenges. one other thing to try is steam. I would take a damp towel and steam iron and iron out the towel on the back side of the board. If it relaxes, clamp it down till it cools. If it seems good when cool, reclamp for a day or two till dry.

I would just go ahead and use it; the thick ash backer will keep it in line no problem...

Thanks guys, and I think I will try this steam idea first.....yes I know keeping the patina is maybe a bit strange but I want to try it. It does mean I am going to have to distress the edges I round off to match the rest as well. I am using all used hardware so the guitar will have a used look about it anyway. Also I am toying with the idea of a piezo bridge at a later stage and if I hollow the body out there will be room inside for a pre-amp and battery if this is needed - there isn't much room inside a standard tele control cavity. There is a kind of logic behind what I'm doing really, at least i keep telling myself that there is

I'd like to see a picture of the board's patina. Will you apply a finish to it?
Do you know what kind of finish is already on the board?
Dan

_________________
wah
Wah-wah-wah-wah
Wah

Unfortunately I can't post a picture as the board is about 5000 miles away from me at the moment - this is a project which I will build when I return to the UK on holiday. So I am collecting parts at the moment via ebay. The board has no finish I can see except perhaps for polish/wax over the years when it was used as a bureau, probably most of the patina is due to rubbing and grime. It's quite darkened which I like. If I do apply a finish it will only be a light oil.
I have had a look online and the colour of the wood and patina is pretty much the same as this old set square :

http://c.twojjs.com/albums/dialit_5/E_1632-2.jpg

just to give you an idea. Though the wood I have is not as scratched or dented. The aim is to produce an instrument which will be made out of decent bits of wood but one which I won't be afraid to take out to pubs and clubs if I need to. Something I am not so keen on doing with a Gretsch duo jet or solid rosewood tele.