Rim Glue Adhesion

[Dennis in Anola]

One thing I haven't seen mentioned before is obtaining maximum glue adhesion strength for kefring & end blocks. Laminate materials in particular have the surface grain compressed slightly from the manufacturing process. I call it surface glazing. The areas to be glued should be lightly sanded to break the glazing. This opens up the wood pores, which maximizes the glue adhesion. This is a common practice with homebuilt & model aircaft, which use Birch plywood in their construction. Following this practice may prove of benefit if the guitar is ever dropped.

[ken cierp]

Since guitar parts (in kits) generally come off a sanding operation (80-120 G) rather than a planer is this really a concern?

[TonyinNYC]

It certainly can't hurt! Supposedly, freshly sanded parts can have better adhesion than parts that have been allowed to sit around and oxidize. Not that anyone lets their guitar wood sit around for very long!

[Dennis in Anola]

Since guitar parts (in kits) generally come off a sanding operation (80-120 G) rather than a planer is this really a concern?

Only if you are concerned about getting maximum glue strength. The kit I'm working on right now has Birch laminate for the body material so it is a concern for me. Also, The side bending process in itself may compress the wood surface?

[ken cierp]

Bruce Hoadley (Understanding Wood) states specifically that it has been proven that roughing the surface has a negative impact on adhesion and joint strength. He does mention that clean and freshly machined surfaces are certainly the best case. He recommends cleaning off the surface if the machining is not fresh -- acetone. I like his example (and it works) take two pieces of freshly planed smooth wood, wet the surface and clamp them for a minute -- remove the clamp and the two pieces will be stuck together, of course as the water evaporates the bond will wear off.

Glazing from a dull cutter is a different story -- that's a coating. Is compression glazing a coating?

[Dennis in Anola]

Some interesting reading about this topic ...........................
http://books.google.ca/books?id=leuRtiZ ... YQ6AEwAzgK

Of course, you can't always beieve what it says on the Internet (lol).