Boat Building Forum

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Re: glue
By:mike arnopol
Date: 9/4/2001, 10:48 pm
In Response To: Re: glue (Rob Macks)

: 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

I'm justgetting started with strip-building, but I've used polyurethane glues for the past 5 years on cabinetmaking. One other property that I've noticed is that it scrapes off MUCH easier than PVA glues. At first it seems kindof weird in that it foams out of ALL the joints, but it doesn't soak into or cover adjacent areas. I think that scraping and sanding are much easier, and supposedly it's a stronger joint.

Messages In This Thread

glue
Nelson -- 9/3/2001, 11:59 am
Re: glue
Rob Macks -- 9/4/2001, 1:03 pm
Re: glue
mike arnopol -- 9/4/2001, 10:48 pm
Re: glue
Terry McKenzie -- 9/4/2001, 11:23 am
Re: glue
Nelson -- 9/5/2001, 1:05 pm
Re: great big auk
Terry McKenzie -- 9/6/2001, 1:23 pm
Re: great big auk
Nelson -- 9/6/2001, 11:20 pm