More on fiberglassing

Well, I've certainly given the guys at Old Sparkey's Forum a lot to think about with my question about fiberglassing the composite parts before construction of the boat.

Here's some of the latest. Bob says:

Hey Guys,
Follow this and then I want some comments on wheather this is right or wrong or just doesn't matter.

When you glass the panels before stitching, the glass on either side of the panel is relaxed, just laying there. When you bend the panel to stitch it togeather you wind up with the glass on one side under tension and the other side under compression. If you glass after stitching the boat togeather then the glass is just laying there netural in the shape of the boat. Any outside forces placed on the boat will give tension on one side and compression on the other side giving resistance to the forces applied.On a pre glassed panel what happens when an outside force is applied to the boat? Would the glassed after construction boat be stronger than the glassed before construction?

To which seedtick responds:

might be on to something Bob,

similar to a post tensioned concrete slab for your house - concrete under compression, steel cables under tension, already preloaded for new stresses and considerably stronger than conventional reenforced slabs.

Interesting. Ron then chimes in:

Personally I think it would be stronger.
Inside is glassed ,and bent ,yep that glass is compressed.What happens when you hit a rock the outside takes the blow so puncture strength is important. The inside is braced because you try to strech the glass and cloth ,if you preglass and compress that it will take more puncture penitration to reach the point where the glass and cloth starts to strech.
Boy hope you can get thru the mud and understand what I just wrote.

So . . . I think this leads me to the conclusion that glassing the inside of the sidewalls before building might make them slightly stronger. The compressed glass on the inside would have an increased puncture strength. (And, when I'm completing my trans-oceanic trip, puncture strength will be very important.)

So, I think that's what I'll do: glass the inside of the side walls before construction, then glass the entire outside and inside deck after.

Oh, and on the rub rails: I looked at it again, and I don't think I'm going to have the length I need after re-cutting the scarfs. So I'm going to have to get another 12' piece to make the rubrail scarfs (scarves?). No worries: I can use the 10' for the sail project.