...and now for something completely flat...

Bill Lantry

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Hey, folks,

Please take a moment and help me think this through. I need two things: a large flat space for assembling cabinet boxes. It needs to be light, and storable. I also need a flat surface to lay sheet goods on to cut them down, rout dados in large workpieces, etc.

So here's my idea. I've got 2 pieces of 4x8 luann sitting around doing nothing. What's to stop me from getting a 2" thick piece of foam insulation, and gluing a luann "skin" on to both sides? Wouldn't it act much like a torsion box? It would be light enough to just pick it up and slide it into my existing sheet goods cart. And when I need to cut things up, I could just put another piece of insulation on top. The whole thing would sit on top of the large wheeled desk that is now my assembly area.

Is there some obvious reason why this won't work (must be, since I don't see other people doing this!) Oh, and what kind of glue would be best?

Thanks,

Bill
 
While I do not doubt that the tables shown there work well, they would take a few minutes to put together and break down.

I use a piece of 1/2" plywood with a piece of rigid foam insulation on glued to one face of it, and it works really great for a cutting surface for my Festool saw, and the router.

Bill, your idea of the foam core sandwich sound good, the only thing I might be tempted to add would 1" thick solid strips all the way around, this would make the whole thing a LOT more rigid, without adding a bunch of weight, but just the foam might be enough?

Keep us posted! :wave:
 
I think it should work. As far as glue goes, well maybe just spray glue. When adding panels to the inside of rvs, we used the spray glue and it held up well(atleast know one ever complained,which is rear):rolleyes:
 
Update: complete failure

Well, folks, it was gallipoli all over again. an all-encompassing utter failure, from start to finish... ;)

First, the despot didn't have any pieces of 4x8 2" insulation. They did have some 24" by 8', so I got two of those. Bad plan right there. Got them home, figuring I could glue them together. Of course, then I noticed they weren't completely flat. Forge ahead, William! At least try a glue test. Sprayed a little glue on one. You guessed it: it started bubbling and melting. The hole looked like the set for the China Syndrome.

lide 001 (Medium).jpg

Oh, well. Wrong material, wrong glue. Good idea, but the execution left a bit to be desired.

Still, there is sometimes some small thing rescued from the very jaws of cerberus himself. I've always had trouble with my red line cutting guide, only because I'd never found a really good support system for underneath. But this is perfect: sits nicely on the desk I use for assembly/cutting table, easily stored, can cut into it with no trouble. No more fussing with 2x4s or sawhorses... ;)

lide 002 (Medium).jpg

lide 003 (Medium).jpg

I guess this is one of those 'all's well that ends well' things. I'm out 16 bucks, but now I have a cutting platform... ;)

Thanks,

Bill
 
Your idea is sound, but you may want to investigate your material choices. For what you are describing I'm thinking a balsa core plywood might be just the ticket. I have used it for yacht interiors, where weight to strength ratios are paramount. It is expensive stuff, but for one sheet for your project it will probably not put too much of a dent in your wallet. The stuff is extremely light and very strong. You could even reinforce it with a 6 ounce fiberglass skin to help prevent puncturing it. Here is the company I used (not sure if they deal with the public, but you should be near some boat builders in your area and I'm sure they would be willing to place an order for you).
http://www.baltek.com/alcan/acsites.nsf/pages_accm3_en/index.htm!Open&p=prod_balsa_sb&m=4&type=.htm

Another option would be a honey comb core ply, also used in the boating and airplane industries.
 
Styrofoam and most solvent based glues or adhesives do not mix, or any thing with acetone, xylene, methyl ethyl ketone (MEK) and similar will eat up Styrofoam, as you found out :huh:. You have to use adhesives specially made for Styrofoam. Other wise it should work pretty well, and I second the idea of stiffeners, maybe just ¾ ply strips around the outside. I have considered something like that for an out feed table for my table saw so it would be easy to put away when not needed.
 
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