Choosing Glue For Loblolly Pine


From original questioner:

I have a client who had the state champion Loblolly Pine, before beetles killed it. He had the tree milled, and now has ask me to build some things from this rich pine wood.

I picked out some edge-grain boards for the desk top, thinking it would be best not to have broad areas of the soft early wood on the work surface. This of course leaves some broad areas of really rich late wood in the glue-line.

I was wondering if I can expect any glue penetration in these saturated cells.

Does anyone have any experience good or bad to share?

This of course would not have been a wood I would have chosen, if I were given a choice, but sometimes, as a custom designer and builder, i have to go with the flow.

From contributor Ge

Gluing dense latewood within a ring requires special skill due to the resin content and also the high density. Clean the surface with a solvent seconds before gluing and then use a pur adhesive. You might also find that an advanced formula pva (TB II) will work as well. Remember that you do not need 100% of the potential strength of a joint for a top, so you should be OK with a few skipped areas. For higher strength, use a joint geometry that gives you more exposed wood, such as a single step joint.

From contributor Ke

thanks Gene, I did a test with several glues, and it seems that TB II is plenty good. I just couldn't see how there would be any penetration into such permeated cells.

And yes, I made sure my knives were as good as I can get, and everything is straight and well matched.

And of course I'll make sure it has freedom to move.

From contributor Ge

As a point of information, adhesive does not penetrate into wood cells, except for the surface. The chemical reaction and bonding occurs with the cells at the surface. Extra pressure does not squeeze glue into the wood, but squeezes glue out of the joint (and maybe gets the two surfaces close enough to gather (0.002 to 0.006") to form a perfect bond. So, with the dense summer wood, we are only concerned about cleaning the surface so that the glue can attach to the cells, as an attachment to the resin has no strength.