Glue question ...

[pslamp32]

I've started using pre-finished ply for some case work but have encountered one issue. What kind of glue will adhere to pre-finished boards at butt joints? The joints are pretty solid as is because of the Dominoes but looking for a bit more strength. Thanks!

 

[Ray Martin]

If you are making a butt joint, one of the two pieces will offer up end grain. That stuff does not make for a good glue joint. I'm not sure what glue to use on a finished surface as most will not adhere to film or oil finishes. You might consider breaking the surface with sandpaper. Just make sure you only sand what will be hidden by the joint. As to the end grain, you can make a better glue joint with two helpings of glue. Thin the glue (yellow glue thins with water) by about 50% and paint it on to the the end grain. Let it dry and then glue again (this time with full strength glue) and clamp the the joint.

... and yes, the dominoes or biscuits are a very good idea.

 

[pslamp32]

Anyone know if Gorilla Glue or something similar will work? Their site says the stuff is stainable/finish ready. Thinking that it might adhere to finished ply since it adheres to glass...

 

[Ray Martin]

The folks at Gorilla suggest "For smooth, shiny surfaces, try sanding first to roughen up the surface and give the glue something to bite"

 

[Matt Schnurbusch]

I would let this post set for a while, and see what kind of responses you get... I'm interested too. It seems that sanding at a minimum should work with standard yellow glue. If I could get away with it, I would probably cut an extremely shallow dado or rabbet (1/32 OR 1/64) to get a "better" glue joint.

I have only used Gorilla once, and I hope I never need to again. MESSY STUFF!! Don't get it on your hands DAMHIKT:gar-La;

 

[gator]

Are the joints in a location that you could use pocket screws? I know you said that you have dominoes in the joint but if you are a belt and suspenders type (dominoes and glue) then make it pocket screws and dominoes.

George

 

[Ray Martin]

... If I could get away with it, I would probably cut an extremely shallow dado or rabbet (1/32 OR 1/64) to get a "better" glue joint...

Even a shallow dado or rabbet will offer a significant mechanical advantage... in addition to helping keep the parts square, plumb, and aligned.

 

[junquecol]

I prefinish as much of my sheet goods as I can. When I need a butt joint, I sand off the finish in that area. Take some cloth backed sand paper (from Klingspors bargin bin,) and fasten it to a piece of 3/4 ply that will fit into my hand. Next, on the side with the sand paper, I attach a scrap of 3/4 stock that acts like an edge guide. The edge guide if located from the edge of the block the same as the thickness of the plywood that I'm working with.

 

[Joe Scharle]

I've not used it myself, but I see 'Roo' glue mentioned often. Since I got a Kreg my attitude has been 'just screw it'. :gar-La;

Like Ray, I use registration dado's (1/8" deep) quite often.

Anyone notice what my spell checker did for dado?