Semi-precious wood – what should I do?
I’ve just come across an interesting find – pieces of quilted mahogany that were intended as bookmatched guitar tops. If, upon sawing the blank open, the match was not perfect, the pair was tossed in a scrap pile. I bought the lot – around 60 pieces for $45 ($1 a pound). They are of a useful size for door panels, and are nominally 1/4″ thick. However, the backs are straight from the bandsaw (the fronts were sanded), and the actual thickness varies quite a bit, even in an individual piece.
I want to use these for door panels, and was considering using a thickness sander to bring them to a uniform 1/8″ thickness, and then face-laminating them to 1/4″ ply. What do you think?
1. Should I sand them thinner than 1/8″ ?
2. Should I go to the expense of using Baltic Birch ply to improve stability?
3. What glue would you use?
4. I don’t have a veneer press. Clamps, or splurge for a vacuum bag? I have a compressor.
Thanks in advance!
Emery DeWitt
Replies
Don't glue them to ply! Or even to a different species of solid wood. They'll at least cup or bow badly, and will probably split as well.
If you can't use them as they are - at final thickness and size - consider putting some support behind them, or using them as smaller pieces ... for cabinet work, panels can be quite thin (although I guess 3mm is getting a bit on the thin side).
If you can get a final thickness something like a quarter inch (6mm) that might be thicj enough for panels.
Edited 8/15/2004 5:53 pm ET by kiwimac2
I glued up about 25 panels of 1/16" to 1/8" quilted mahogany to 1/4" ply, 1/4" poplar and 1/4" oak (e.g., what I had available) in 4"x36" size 2 years ago and have had no problems. The panels float in frames. I used Titebond II. If the mahogany is too thin, the glue will come through the "pinholes" in the quilting. 1/8" sounds about right. For gluing, I put a piece of wax paper on the face of the mahogany, then clamped the paper/veneer/substrate between two 4/4 pieces of hardwood with as many clamps as I could. The most I did was 3 at a time, which worked, but I finally went back to one at a time because the pieces would slide around too much during the initial tightening.
Since one side is sanded flat, if you use them for panels where the backs won't show, you can leave them rough, just cut an appropriate rabbet leaving the right thickness to fit into the groove in the rails and stiles. Just be sure to finish both sides with the same number of coats and finish the panels before gluing up the rails and stiles. The backs could also face the inside of cabinets if you don't mind looking at them when you open the door. If you rails and stiles are thick enough you could cut 2 parrallel grooves and face the inside of the door with 1/8 inch plywood and let both panels float, with a slight space between them. Or you could sell the wood to guitar and ukulele makers on E-bay or even buy the book, How to Make a Ukulele by Denis Gilbert and turn this wood into thousands of dollars of Ukuleles.
Since 1/4" is too thick, and 1/8" is not too thin, why not re-saw them and get twice as many panels?
Dan
You don't sound set up for veneering, which would probably be the highest and best use for the material. If they're sitting at 1/4", but very uneven on one side, you might as well bring them down to an 1/8th in my opinion. Store the leaves between sheets of heavy brown paper, evenly weighted and off the floor. Save them until you are ready to get into veneering and have a few projects under your belt.
Pay particular attention to the concept of counter-veneering when you start to read up on the subject.
A friend of mine does this using rubber cement on 1/4" ply, and his trays stay flat. I've done it with yellow glue and it bowed frame and all in box-top panels.
I would sand the unflat side of the panel to flat with your sander, glue that side to the ply, then finish the sanding of the bandsawn side.
If you do decide to try backing these panels with something else, do a trial first!
In spite of the contrary advice here, all my experience (and I can show you the evidence) is that backing solid wood (no matter how thick or thin it is) with ply is risky, as is laminating with another species of timber.
You may get away with it, you may not. Do you want to take the risk?
Thanks to all for your contributions! I have been interested to see all the varieties of advice. I know the conventional wisdom, that I should only face-laminate very thin material, or woods of the same species. Iwas just hoping that the laws of physics had changed, or something.
I think the smart thing for me to do is to bring the wood to a consistent thickness while removing as little material as possible, and then figure out a good use for those solid panels, without lamination.
That's the right conclusion. Well done!
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