Hi guys - I’m making a hollow surfboard from birch ply and have managed to get hold of some balsa for the rails, nose and tail sections but they’re random pieces and sizes so I need to do a bit of glueing…what should I use? I’m going to be glassing the finished board with polyester resin - would I be able to use regular PVA wood adhesive as it is being glassed after or should ~I stick the balsa together with polyester resin?
Cheers
any good wood glue will work, but i’d choose epoxy first or as a second a good waterproof wood glue… if you go with an H2O based glue be sure to let it dry for a good while before glassing…
i would strongly suggest that you consider glassing the board with epoxy… poly and wood don’t go so well together… do some archives searching on the subject… i use to make wood fins and had sooooooo many problems with poly, espically surfboard poly…
best of luck, should be a fun project no matter what you use, well, unless you have to peel the whole deck glass off because the polly didn’t bond 
Hey there
I’m just glassing my second hollow wooden, both done with polly resin, I’ve also done a few sets of fins with the same resin and had no difficulties with bonding, maybe I’ve just been lucky but I intend to carry on with poly as I can’t justify the extra expence of epoxy. As far as wood glue goes Ive been using a weatherproof PVA wood glue and also had no problems as yet. Just remember to clean all the excess off as soon as it appears with a damp cloth,(be meticulous with this) you will have nasty looking white patches in the wood under the glass otherwise.
Good luck
Jase (MMM)
Hey Third,
Any “wood glue” will work fine and bond stronger than the wood itself if the joint is adequate. Yellow glues (Titebond) sometimes will leave a slightly darker line on very light colored supersoft woods, as the glue spreads slightly into the surrounding open cells. A white glue (Elmers) is lighter. With these types glue, if you wait about 20- 25 minutes (this time of year) you can use an old credit card to easily scrape off the beed of glue along the lines which makes sanding later much easier. I keep a few cards around and they work perfectly and clean up for next time with water. For balsa, very slightly round off the card’s sides and corners with fine sandpaper to keep it from digging into the soft wood. Slide the card down the glue line at an angle to “peel away” the beed of glue. By the way, you are probably checked out on these matters, but for any new guys, watch out for those tiny dried balls of glue that will act like gravel when picked up under the sandpaper and rubbed on the surface. Epoxies and glues like “gorilla” glue are great but messy, expensive, and not as user friendly as the previous mentioned. Titebond III is a water proof glue if your worried about the glass job opening up. Hope that helps. Enjoy the ride!
Richard
Just remember to clean all the excess off as soon as it appears with a damp cloth, Jase (MMM)
Jase, when I was a grom that was certainly the conventional wisdom among carpenters. But the truth is that the damp cloth / water thins & spreads the glue and presses it into the surface around the glue line you’re trying to contain. Which then, like you said, leaves odd coloration under the resin - because you have basically sealed the wood with thinned glue. It won’t pick up stain, either.
Read RichardMc’s post between yours & mine - much better to chip off the bead of glue once dried.
Agree that wiping with water isn’t usually the best, though sometimes on dense closed fiber woods it’s ok. Personal experience with waiting until the glue beed dries to “chip” it off is that, especially with soft woods, you risk pulling up wood. Waiting 20 minutes or so allows the tacky (solid but not cured) beed of glue to pull right off, sometimes in one long string, as you scrape (peel) it off with the credit card or any other scrape off means.
Ahhh, that would explain why I have a pale stain in the sapele strip on the bottom of the board I’m glassing now. I thought that I just hadn’t been fussy enough with cleaning it up. I will certainly try Richards credit card (or any one else’s for that matter) method next time.
Please ignore my earlier post.
Nice one Benny
Jase (MMM)
A note from personal experience: I glued up some balsa and redwood to make wood fins, using lam resin because I thought it would go off quickly and I’d be set… but the next day, I could pull the wood strips apart with my fingers. The resin was there, hard and well distributed, but didn’t stick worth a damn to either wood.
Now I use Elmers or similar yellow (aliphatic) glue.
Really, you won’t need a super-strong bond, just enough to hold it together until the resin (poly or whatever) is set.
Gorilla glue!! Try mixing in a little beige/lt. brown pigment and it foams up and fills all voids and with the pig. creates a virtually invisible bondline.