DIY plywood laminated beam

I have been kicking around the idea of building a couple 'foamy' campers.
Most are built strictly out of foam, but would like a little more structure without adding a lot of weight. For reference, I am thinking something like the Tusca brand slide-in camper.
I am wanting to make wall studs and rafter one piece. Back in high school shop class we built a couple storage sheds, and used a reddish brown glue to glue the plywood gussets to the rafters, but don't remember what it was. I seem to recall it was a powder mixed with water. Does anyone know what that might have been?

i personally prefer something that says GLUE instead of ADHESIVE...

Edited by steve(ill) - 07 Mar 2026 at 8:53am

I remember using weldwood brand that was a brown powder. 

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Be careful with gorilla glue as some of their formulations foam up, becoming both unsightly and weaker.

If both parts are wood then use Titebond 3 for possible damp or wet environments. Titebond 2 is popular with guitar builders, super strong but removable/repairable with steam heat to reset necks. Titebond 3 won't be repairable that way, but perfect for what you want.

Make test pieces you can test whatever you want to use.

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