# Face gluing different species



## jsheaney (Jun 25, 2007)

I'm a beginning woodworker and I want to make a few small boxes. I have a specific question about combining wood species in one project. One design calls for 1/2" thick material for a box 10×4 x 2" high. I would like to face glue 1/4" maple to 1/4" cocobolo, so that the outside of the box will be cocobolo, but the inside will be maple. I don't know if that will be OK, though. My concern revolves around wood movement. Will the two different species cause warping or worse? Maybe it depends on the wood species. Would maple and walnut be safer? Is it just a bad idea?


----------



## Treefarmer (Mar 19, 2007)

I'll be interested in the answer as well. Sorry I can't help but I'm sure you'll get some answers soon.


----------



## Karson (May 9, 2006)

I've never tried it. I face glued 3/8" cherry on both sides of a 7/8" maple plank. But then I covered both sides and the wood was a lot thicker. I'm not sure what might happen check the tables of Cocobolo and Maple as to see how they expand with changes in moisture.

Maple is 0.00165" per 1% internal moisture change for Quarter Sawn Lumber, Flat sawn is 0.00353 per inch of lumber width.

Walnut Quarternsawn 0.00112 Flat sawn 0.00308

Difference is 5 / 10,000 per inch of width on quartern sawn and also 5 / 10,000 per inch on flatsawn They will swell and contract differently but it might not cause a problem.

Unfortunately I can't find Cocobolo

If they are both Quartersawn, you would at leaset have a fighting chance.

Be aware that Cocobolo does cause some people to have alergic reactions to the dust.

I get like Poison Ivy blisters if I get dust on me. Others on this web site have expressed similiar reactions. I won't work with it again even though I do have some of the wood here at home.

I have a an Excel spreadsheet that I created with all of the wood species from the Wood handbook by US Government. You type in the species number and the width and it will give you the amound of the wood movement.

Send me an e-mail with your e-mail address and I'll send it to you.


----------



## Karson (May 9, 2006)

There is also a function of Elasticity and Compression-ability. How much the wood is able to be compressed without destruction and how much it is able to stretch without deformation. Stretching and compression is both a factor of bending wood. How well they are able to do that at room temperature, and moisture content of the wood. and how much pressure the other species of wood is able to force are probably all tied up in their respective formula. The tables (If you can call them that) for maple are available and probably walnut. Again nothing on Cocobolo can be found.

This information is in the Wood Handbook Wood as an Engineering Material Published by the US Forest Service Published in 1999 FPL-GTR-113. It can be downloaded from the web. 19 chapters, index, glossary, cover pages etc. All as PDF files.

But Hey do it and tell us what happens.


----------



## jsheaney (Jun 25, 2007)

I'm kind of surprised that no one else has tried this before. It seems like something someone would want to do. Is it just a bad idea?

I guess I can slap a couple pieces together and see what happens. How long should I wait to see if it will be OK? My workshop is pretty dry, so maybe I should put the assembly in the bathroom to stress it more quickly.

- John


----------



## oscorner (Aug 7, 2006)

John, I think you have the right idea. Make a test piece of the same thickness and introduce moisture and maybe dry out in the oven or microwave, checking with a moisture meter to verify the amount of dryness or wetness of the wood and write down what happens. This way you can try to mimic the actual moisture conditions in your area and see if it will cause a problem. In my area, it would have to be in a range of, 20 to 100% humidity. LOL.

Please, share the test results with us.


----------



## Treefarmer (Mar 19, 2007)

LOL Karson….lists of engineering data, citation of the USFS "Wood as an Engineering Material" and then….."But Hey do it and tell us what happens".

Definitely share the test results…..detailed analysis to the sub micron level is expected.

The microwave is a good idea Os. Just do it slowly JS….I tried it with a small piece of lilac on high power and thought it was going to explode. The end grain started boiling off 1st and checked….then small splits appeared on the face with steam and smoke shooting out under high pressure…I'm thinking…"the wife is gonna kill me" as I use her oven mitt to get it out of the house. Definitely speeded up the whole reaction.


----------



## LeeJ (Jul 4, 2007)

Hi Guys;

My guess would be there is no problem in doing this. If the wood has been acclimated in the same room for any length of time, a week or two, the moisture content in the two should be close.

While I haven't glue these two species, I have glued others with similar qualities, for items like homemade block planes, with no problems.

Another factor is the size of these pieces won't permit too much movement in the first place.

Once glued and a finish has been applied, you should have no problems.

Good luck with your project.

Lee


----------



## douginaz (Jun 11, 2007)

Don't know about the cocobolo, but I've seen a bunch of walnut and maple glued in different combinations. I did a maple and cherry bandsawn box that's holding together fine after three years. I used tightbond II but you might be better off with a flexable CA if you are going with the maple and walnut, not sure about the cocobolo, I thought that stuff was pretty oily. Gotta go with Lee, I don't think it will be an issue. 
Later, 
Doug in AZ. l


----------



## jasonbyu75 (May 5, 2015)

Any results to share? My local lumber store didn't have any good pieces of maple left (hey, I don't live on the east coast), so I got Ash. Wondering if ash laminated to maple would cause problems for a workbench base. For example maple and ash laminated together to form a single leg. Or ash tenon into a maple mortise? I would imagine that the different grain directions for same-species wood would be a bigger factor than different expansion rates for two species? For example, a leg mortised into the bench top?


----------



## gfadvm (Jan 13, 2011)

I have face glued dissimilar species together and built boxes on many occasions and have had no issues with stability. Haven't used your particular combination but mahogany/maple worked fine as did Ipe/hickory. (and hickory never wants to play nice!)


----------



## bondogaposis (Dec 18, 2011)

Something that is only 2" wide isn't going to be a cause for concern as far as differential movement is concerned. I think the bigger problem may be gluing Cocobolo. It is so oily that glues have difficulty adhering to it. Make sure you wipe the gluing surface w/ acetone prior to gluing.


----------



## Ghidrah (Jan 20, 2015)

Odds are good if both share similar characteristics (density and weight) but you don't have to glue the 2 together you can press fit the preferred species to the interior side. This box section below is very old mahogany with a press fit PH liner, the pic doesn't do the coloration of the purple heart any justice.


----------



## BinghamtonEd (Nov 30, 2011)

I don't know about the species you're using, but I've face-glued 5"x10" pieces of 4/4 maple and walnut together, to make a blank for a shallow dish. That project got sidelined and the blank is still sitting there, after 2 years, and there have been no signs of any issues. I've also face glued 2.5"x 30" pieces of 1/8" walnut onto a plywood panel to trim it out to a false frame/panel, and that's had no issues, also been about two years.

My guess is that you'll be fine.


----------



## BurlyBob (Mar 13, 2012)

Totally agree with Bondo about acetone. Have also found it necessary when finishing some tropical woods.


----------



## jasonbyu75 (May 5, 2015)

Man, many thanks for the replies! You guys are great!! I was really just looking for someone to sue if something went wrong. Just kidding. But seriously, if you guys ever need any very mediocre advice….don't hesitate


----------



## Smitty_Cabinetshop (Mar 26, 2011)

I'd say "Don't do it, it'll never work."

(Tell us how it works out, okay?)


----------

