Help with laminating stock

Hello,

What's the proper technique for laminating two pieces of 3/4 x 5 x 36 inch maple? I surface and thickness planed rough stock down to 3/4, brushed on a layer of Titebond to each face, mated them and clamped along the length of each edge until the glue oozed out a bit. But when it dried and I removed the glue beads I noticed that it did not mate as close as I'd hoped for. What kind of rookie mistake did I make here?

Thanks!

Reply to
bsheeres
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Did you test clamping them together before you glued them up?

Reply to
somewildmonkey

Maybe too much glue? Maybe clamping the edges rather that the interior field? I wouldn't say it's a "rookie" mistake, by the way. I'd rather have more than enough glue than too little, eh? Tom

Reply to
tom

You probably put too much glue. If you brushed on a continuous coating, you'd need to clamp pretty tightly to force enough glue out the sides to have a nice tight bond. Otherwise, you get a nice even layer of glue that's so thick it keeps the boards apart.

If it's really going to show (and the ends of the board aren't), you could disguise it by cutting a dado where the two boards meet and gluing in a 36" long spline. You could even give the spline a bit of a tapered profile, so that you can force it into the groove and have it mash up tightly to the sides. A quick touch-up with the tablesaw and/or jointer, and you'll never be able to tell it's two boards.

Josh

Reply to
Josh

The Titebond will take years to dry under those conditions and it makes a lubricated joint very difficult to hold in alignment. Better to use contact cement and 'fiddle sticks to hold the laminate up until it is in perfect alignment. Bugs

Reply to
Bugs

Can you elaborate on what you mean by "it did not mate as close as I'd hoped for"? Obviously you have some gaps, but how much, along what length, where on the boards - especially in relation to where the clamps were placed, how many clamps did you use and spaced at what distance, what sort of force did you have to apply to the clamps to bring the boards together?

Lots of questions, but you can't really get a good answer without a little more info - though you'll certainly get a lot of otherwise good standard procedures here.

Reply to
Mike Marlow

Yes, there is a slight gap (roughly the width of two pieces of paper) that runs along the long edge of both sides (one side is less pronounced). Almost like, as Josh mentioned, there is a layer of glue preventing the boards from mating. I ran 4 beads of glue down each face and brushed it evenly which resulted in a thin translucent film; maybe it was still too much. For clamping I made a pair of 36" vises out of

2x4's and carriage bolts (4 per vise) thinking it would provide flat even pressure along the boards. I inserted each long an inch into the each vise and tightened the bolts. I'm guessing that the wrong amount of glue was used and the vise idea was not good. How much (little) glue should be applied (one face or both?) and what type of clamping is recommended?

Thanks again.

Reply to
bsheeres

According to one of the manufacturers, you can add 5% by volume water to the glue and it will half the viscosity with minimal impact on strength. In this application, you have gobs of glue area to stregth of the "joint" is not an issue anyway.

Lower viscosity will help you apply a thinner layer of glue and allow high spots to squeeze out/ level better

Reply to
Stephen M

Actually, your vise idea sounds pretty good if I'm understanding it correctly. Even pressure frequently spaced along/across your piece is what you're after.

What did you use for sawdust? Did you use sander dust or table saw waste? It would be easy to develop too much buildup with the waste from your tablesaw as it's very granular. Why did you put the sawdust in there to begin with? I would not have done so. Simply glue your surfaces and clamp them together. The glue itself will not prevent mating if applied as you describe. Once brushed out to an even film it will absorb into the wood pores a bit and squish out a bit. But it won't reside as a layer which prevents mating.

Reply to
Mike Marlow

Most likely is improper clamping/pressure or too much glue or both. When I clamp long stock that the glued edge will show, I use a poly glue (Gorilla or eq) and cauls. For your application, I would have used cauls 40" long, curved +/- 3/16" from center to the end of the caul. Clamps every 5-6" alternating each side. (Total clamps, 14) With this clamping plan, be careful not to over tighten any one clamp. Start in center and work your way out to the ends.

Dave

Reply to
Teamcasa

Sawdust?? I don't think I mentioned any thing about sawdust. But now that you mention it, that's about all these boards are good for now :) Actually I bet I could resaw them, all is not lost.

Reply to
bsheeres

Thanks.

I'll try exactly that.

Reply to
bsheeres

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