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Re: Strip: Titebond & scarfing------WebKitFormBoun
By:Mike Bielski------WebKitFormBoundarybn3jycU+LOQStN
Date: 3/5/2008, 10:35 am
In Response To: Re: Strip: Titebond & scarfing (Paul G. Jacobson)

: Sure. It is one of many adhesives which will work. Want to try something
: interesting? Get some double stick tape and use that on a test scarf
: joint. Or, find some conventional rubber cement and use that as a contact
: cement (coat each side witht he rubber cement, and let dry completely.
: Press firmly together once the rubber cement is no longer wet). These are
: not fantastically strong adhesives, but on a scarf joint cut with a ration
: of 12:1 it has such a great surface area to bond to that the strength of
: such a joint will surprise you. There are versions of scarf joints which
: are designed to work without any adhesive at all. The wood is fitted
: together and then the joint is bound with string or, in older times, sinew
: or leather thongs.

It's true, the traditional makkusiineq-type scarf is in many ways superior to a through-the-thickness scarf for flexy gunwale stock on a skin boat because the glue in a T-T-T scarf makes the stock stiffer in that spot so it's harder to bend a fair curve.

But- the scarfs in a strip boat are mostly cosmetic, and to hide the joint and they don't need to be all that strong. Once you glue it to the adjacent strips and put fiberglass and epoxy over it it will be very strong no matter how you glued it.

If the scarf is going to be in a high-stress flexy area of the boat PVA like Titebond is probably a good bet, but if it's in a relatively low-stress flat area 3M Super 90 spray adhesive works well, provided you line up the strips accurately. (But that goes without saying...) I tried CA glue, but it was messy and the odor bothered me more than the spray adhesive. That, and the spray doesn't bond skin...

Whatever you use, follow the manufacturer's instructions and do a test piece first. Fixing things always takes more time than doing them right the first time.

m

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Messages In This Thread

Strip: Titebond & scarfing
Parke -- 3/4/2008, 1:19 pm
Re: Strip: Titebond & scarfing
Paul G. Jacobson -- 3/4/2008, 9:33 pm
Re: Strip: Titebond & scarfing------WebKitFormBoun
Mike Bielski------WebKitFormBoundarybn3jycU+LOQStN -- 3/5/2008, 10:35 am