Glassing before cutting?

[anonymous]

I got a tip about a possible build-time saver if you're building something that requires glassing inside and outside the hull:

You mark your plywood with darker lines, apply your first coat of resin, then apply the fiberglass clothe to what will be the interior side of your hull. Then you cut out the pieces, stitch, filllets, etc, etc.

Sounds like it would work. I wonder the potential effects of compressing the weave after it's cured would be. Anyone have any thoughts?

[jacquesmm]

In our designs, when we show fabric inside, we count on overlapping the sides and other parts to create small angles beams.
What you describe will work if all what you want is resistance to abrasion but why not take that opportunity to add some strength?

[Edward]

Also stiffening a panel with glass before you install it could lead to trouble. I had a few times where I needed to brace a panel and then do the glass using the glass to pull out a warp.

[JimW]

Don't do it, pure trouble.

Do things in this order to prevent problems.

Mark, cut, (for floors and deck: precoat and glass underside now), attach part (precoat and fillet edges), glass fillets, precoat part, glass parts.

[anonymous]

In our designs, when we show fabric inside, we count on overlapping the sides and other parts to create small angles beams.
What you describe will work if all what you want is resistance to abrasion but why not take that opportunity to add some strength?

Using the concept in the above quote, which would be a stronger seam:

One with 4" wide, 9 ounce glass

-or-

One with 2" of overlapping 6 ounce clothe on each side of the seam?

Intuitively, it looks like 6 + 6 = 12. And 12>9. But does it work that way?

[jacquesmm]

The building sequence rarely leaves a choice. Usually we assemble with tape then lay wide fabric over it.
In most cases, we take that overlap in account for the strength.
When you overlap that way, try to offset the edge of the fabric. Go one or two inches further with the fabric.