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Add glass inside first, then outside.
By:Paul G. Jacobson
Date: 10/31/2001, 8:41 pm
In Response To: Re: Glass lay up for (Brad)

: Thanks
: Would you add another layer of 6 oz to the inside, outside or both?

as I understan things, you get more bang for our buck when you add the cloth inside. Of course you'll get some additional strength from adding a layer to the outside, too, but not as much.

Remember that most boats have ribs on the inside to hold the hull components together and resist forces from the water, which tend to compress the hull. Our boats may have a bulkhead or two, but otherwise the strengthening that ribs would provide elsewhere is supplied in our boats by the glass and resin.

Compare the wood kayak to the skin on frame kayak which typically has lots of internal wood ribs that support a relatively delicate skin. That skin gives nearly zero structural strength. with a wood boat the wood serves as both a thin rib and a skin. A thicker "rib" would seem to be stronger, so you put your reinforcing glass on the inside. And if you put the glass on the outside it gives you a thicker "rib" effect, but on the side where added strength is not really needed.

An engineer can supply better details about flex and compression and stresses and maybe someone will. I'll hope my analogy serves until then.

PGJ

Messages In This Thread

Glass lay up for
Brad -- 10/30/2001, 7:05 pm
Re: Glass lay up for
Sam McFadden -- 11/1/2001, 11:15 am
Re: Glass lay up for
Greg Root -- 11/7/2001, 9:12 pm
Re: Glass lay up for
LeeG -- 11/12/2001, 11:13 pm
Re: Glass lay up for
Dean Trexel -- 11/7/2001, 9:53 pm
Re: Glass lay up for
garland reese -- 10/31/2001, 10:01 pm
Re: Glass lay up for
Craig Bumgarner -- 10/30/2001, 10:30 pm
Re: Glass lay up for
Brad -- 10/31/2001, 3:36 am
Add glass inside first, then outside.
Paul G. Jacobson -- 10/31/2001, 8:41 pm
On the contrary....
Brian Nystrom -- 11/1/2001, 12:31 pm
Re: Glass lay up for
Craig Bumgarner -- 10/31/2001, 7:49 am