Replies

1. 
   MRGreer | Jul 22, 2006 06:52am | #1

   Well, not much happens in the length direction so the only concern would be in width.  I have seen a number of sail boats with tillers laminated with a combination of 1/4 inch ash and 1/4 inch mahogany, up to 6 or 8 layers.  Now it's possible that these woods have dimensional changes that are closer to each other than walnut and poplar.  Check a wood stability chart to be sure they are close.  You can find a chart on the forestry service web site.

2. 
   ring | Jul 22, 2006 11:01am | #2

   To play it safe, you can glue up the poplar only on the top and bottom, creating a hollow "box".  That way you will avoid any possible conflicts between the 2 species.  The box will be plenty strong.  If you need tenons at the ends made from the poplar, glue them in also, but as separate pieces.

   DR

3. 
   SteveSchoene | Jul 22, 2006 12:05pm | #3

   That seems like a lot of work to avoid buying some 8/4 walnut, especially since you haven't addressed the issue of the poplar stripe down the center--pretty visible from the top I would think. 

    

1. 
   dgreen | Jul 22, 2006 08:24pm | #4

   I think the stripe would look good, I always liked a contrasting filler for the visual interest. Kind of like teak and holly decks.
   Since the house is on fire let us warm ourselves. ~Italian Proverb

4. 
   DougU | Jul 23, 2006 10:39pm | #5

   Paul

   Several years ago I built a walnut bed and had to do something similar.

   I laminated walnut and poplar using epoxy.

   Attached is a pic of an off-fall. I seen the bed a few months ago while measuring up for a dresser to go with it and the first thing that I did was check the rail to see if the laminate was still intact, it was. Don't know how long it will stay that way and not sure if it was a good idea at the time but so far so good.

   Doug

5. 
   jazzdogg | Jul 24, 2006 12:47am | #6

   Hi Paul,

   I'd worry more about the grain orientation of the various pieces than differential rates of expansion and contraction among the two species; with the grain properly oriented and the glue-up properly clamped there shouldn't be a problem.

   I made a bunch of cutting/cheese boards as Christmas gifts a few years ago. They were glued-laminations of five different species. There were slight differences in the rates of expansion & contraction that made it possible to feel a subtle shift in the heights of adjacent surfaces after the glue cured, but it was nothing to worry about.

   Fortunately, I used a waterproof glue, as I found out only recently that one of the recipients regularly washes hers in the dishwasher - and it's still intact.

   Good luck,

    

   -Jazzdogg-

   "Don't ask yourself what the world needs. Ask yourself what makes you come alive, and go do that, because what the world needs is people who have come alive." Gil Bailie