Lamination Bending: Which glue?

I don’t know anything about surfboards but what I can tell you is that I use “plastic resing glue” which is really urea formaldehyde glue…DAP calls it plastic resin, but what you are after is UF and there are several manufacturers of it…...”plastic resin” is a non-flexible glue which is why I use it for bent laminations…you can sand it, plane it, joint it etc….the same rules for machining apply to it as most other glues in that if you run it through your planer or joiner you do run the risk of chipping your blades…but sometimes that is the price you pay for creativity…the fumes from UF aren’t so much the harmful part…the dry material prior to mixing poses more hazards as would the dust from sanding it…I used UF glue to do the bent laminations for the box I entered in the Single 2×4 and Not Just a Box competitions…..UF glue is water resistant but not water proof…there is a big difference…last thing you want is your surfboard delaminating in the water…so you should add a 4) to your list…water proof

-- Rich, Madison WI

Epoxy is the way to go for a what I assume will become a torsion box with a laminated skin. I use West Systems epoxy. It comes with handy pumps, each one specific to the hardener or part B. Get more info than you ever dreamed of here… http://www.westsystem.com/ As you’ll discover, there are additives and resins and the how-to for just about any contingency here. One filler is called micro balloons and it lightens the mix while not giving up any strength. Something to keep in mind for a surfboard. Check it out.

Also, you should wear the respirator anyway. Some wood species dust are suspected of being carcinogenic, the humble pine among them. Good luck.

always,
J.C.

P.S. The nature of what you’re trying to accomplish will be hard on your planer and saw. Go for carbide blades as you’ll get the most life out of them and you might want to keep an extra set around too.

-- "Imagination is more important than knowledge" -- Albert Einstein

Thanks Rich and J.C.. It sounds like either will work. Epoxy is probably the best solution except for the price. I was many looking to see if using Plastic Resin or UF glue was a viable option for my project. A tub of DAP plastic resin glue costs about $8. The epoxy resin, hardener, and fillers will probably set me back about $75.

-- Scott, San Diego

Well, I’ve done a fair amount of bent wood projects and I’ll add one other glue: Polyurethane. I built a bent wood arbor and It worked great. I’ve built boats (frames) with epoxy and like the flexability. If it won’t bend ~ it may break. As for any of them; once cured they are pretty much non toxic but of course dust has inherent hazards ~ even sawdust. Like don’t be breathing Port Orford Cedar: causes liver damage and I’m sure there are others.

What I like about the epoxy besides relative flexability is that fits are not so critical. The glue line doesn’t have to be too tight (not to say you should do sloppy work). I made some rocking chair rockers for a lady with epoxy; her grandkids like to “ride the rockers” on the back of grandmas’s chair and broke them. She had a guy make new ones and they broke those too. The bent lam ones are still going strong. KEEP THE CATALYST OUT OF YOUR EYES ~ same with 5 minute epoxy sold at the grocery store.

I’ve had some failures with PR or UF which ever you want to call it. It can be a bit touchy.

Ironically airplane construction in Britian uses polyurethane. A bunch of guys realizing it was good stuff started importing it to US. (Gorilla) Now other companies are on the band wagon. I’ve used the Borden version and been very satisfied with it. Wet one surface and apply it to the other.

As for cost ~ what’s your time and materials worth? especially if its a boat …. airplane….

I use a fair amount of West Systems epoxy for kayaks and camping trailers, great stuff.

There are two benfits that may help you in your project. The long “open time” allows you plenty of working time, especially when trying to coat multiple pieces and get them in place when doing a laminates. There are different hardners available to adjust “open time” depend on conditions. It’s gap filling properties make for strong joints even when the fit is less than ideal.

-- Scott, Camping the "Compact Way", www.cttct.com