: Some time ago I read a post by (I think) Rob Macks where he mentioned a glue
: that works better on boats used in hot sunny, areas, such as here in Az.
: Brain fade has taken the name out of my head. Was it polyurethane, like
: Gorilla glue or something else? Does one brand stand out above the rest?
: The problem he mentioned was that the glue would start to flow under the
: fiberglass when left in the sun.(?) Is this a problem that decreases as
: the boat cures or is it something you always have to be careful of? I'd
: like to know before I start the deck on my Great Big Auk. Thanks, N

I do recommend using polyurethane glue such as Gorilla (or any brand that’s cheaper) glue because it is not effected by heat. PVA glues (Titebond and other such glues) are reactivated by heat! PVA glues will soften and move if used on dark colored decks left in very hot sunlight.

Decks are most prone to heat problems because they face the high hot midday sun directly and because the deck is insulated from cooling air flow by the dead air spaces in the bulkheaded storage compartments.

Polyurethane glues are not quite as easy to use as PVA glues.

Polyurethane glues foam/expand as they set, so you must use roughly half the amount you would apply of other type glues.

Polyurethane glues do not have the tack strength of PVA glues. Tack strength is the property to hold together wood parts BEFORE the full set strength of the bond is achieved. Polyurethane glues require wood parts to be clamped until full strength is achieved.

And polyurethane glues are sensitive to low moisture conditions which can weaken them during set up, such as a dry winter shop. Polyurethane glues work best with average moisture content wood on humid days. If you’re working in dry conditions you must mist the wood surfaces to be joined. To test your conditions, try samples of the wood you will use with polyurethane glue and test the joint strength after the glue has set. Even if your conditions are not very dry misting the wood surfaces will speed up glue set up.

All the best,

Rob Macks
Laughing Loon CC&K
www.LaughingLoon.com