In an attempt to utilize my scrap wood in a useful manner, other than heating my house, I would like to cut different species of wood, for instance maple, oak, walnut, and hickory, into 3/4″x3/4″x6″ blocks and use these blocks to create a table-top over some sort of particle board. I would like to create some geometric design using the different colors of the wood. My concern is expansion and contraction of the different species of wood that would be glued togethor. I have the complete list of different species and their rates of expansion due to humidity changes, but that doesn’t tell me anything but that the different woods expand at different rates! Does anyone know how close these numbers have to be so that catastrophe does not occur, i.e. splitting of my table top. Intuition tells me that it has a lot to do with the strength of the glue, but you people are the experts! These pieces may be glued in any way my imagination can conjure up, are there any combinations or species next to each other I should shy away from? Help…
Thanks,
Adam
Replies
Adam,
When wood wants to move, it will, gauranteed. No glue on earth will prevent it from happening; the Romans would split granite by boring out a hole, stuffing it with an Oak "dowel", and then pour water over the "dowel"....
So, what you are attempting to accomplish is one of the reasons veneering, inlay, intarsia, and marquetry came about, so to speak.
Dano
Adam
In flooring, I’ve been doing it in ¾” thick woods for 20 years with no problems.
Have you ever seen parquet flooring out of different woods?
I would give it a try what’s the worst that can happen you might loose some scrap wood.
Jeff in so cal
Thanks, your right, what's to loose, but time and glue both of which I have plenty! We'll see what happens.
Adam
Adam, the reason parquet flooring works is that the segments are tongued and grooved so that they can float. The difference in the shrinkage factors of the various species will be less significant than the fact that you apparently intend to orient the segments in ways that will oppose cross grain shrinkage to longitudinal shrinkage. Regardless of the species, longitudinal shrinkage is so minute that it will cause extreme stress in the cross grain segments it is attached to, when the latter tries to expand and contract with changes in humidity. If this is a labor of love, and you don't mind putting some hours into it, you might want to consider grooving all four edges of each of the segments and connecting them with a system of floating splines.
Edited 10/25/2002 10:59:16 AM ET by Jon Arno
Since nobody else mentioned this I guess I will. You said you wanted to make a table top "over" particle board or in any case some sort of support material. if you glue it the general rule of thumb here is ,What you do to one side of the support material you have to do to the other, I.E. a sandwich pannel. If you don't you risk some serious warping.I didn't have to make this mistake ,a friend of mine in college did it , the table top looked more like one of those skateboard ramps ,after a few months.
Other than that Jon Arno's suggestion of splines strikes me as being the best system for keeping the individual pieces level.
Philip
Adam, Here's a quick photo of a table I made using basically the same idea you had. I used 3/4 x 3/4 stock, random lengths, various hardwoods.
Maybe my method isn't the best but it worked. I built the frame first and dry fit the pieces into the frame. I spread butcher's waxed paper over a sheet of mdf, mixed up a batch of System 3 epoxy and glued it all together. Once it was dry I sanded and sanded until it was smooth and the used System 3 clear coat to smooth over the whole thing. Lots of wet sanding through 600 grit and then a final buffing using polishing compound (probably turtle wax brand).
Its been about 4 years now, I did this when I lived in Panama. It has handled the move and weather changes very well. I even had a 29" television on it for awhile. Its plenty strong and doesn't have anything under the 3/4" stock.
Good luck, Hugh
Well, I thought there was going to be a photo.
Trying again, sorry.
Adam,
Something else that I did when mixing up the System 3 epoxy I added black graphite dust to the mix. This accentuates the joints and highlights each piece of wood. It would be very difficult to try to conceal all the joints with this many pieces so this seemed like a good alternative. I think it solved the problem nicely and adds to the look of the table.
Good luck, Hugh
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