: I agree. From now on for exterior seams, I will use strips of bias
: cut glass from my left over layup glass. I did this on my first
: boat, and everything was transparent.

: Chris

Bias cut fiberglass cloth, means a strip of glass is cut so the threads are running on diagonals instead of vertically and horizontally.

If you had a square of fiberglass cloth it would be turned 45˚ and pieces cut to an opposite corner.

The advantage to bias cut fiberglass cloth is that is will stretch and the threads along the edge of the strip can expand or contract to follow curves AND wet-out flat against a surface.

In order to have true "bias cut" glass it must be cut on a 45˚ to the thread orientation. This will result in shorter pieces of glass. Bias strips cut from left over pieces of glass from your hull or deck lay-up will be short indeed. Joining a long hull / deck seam with short ( 3' or less) pieces of glass is a pain in the ass.

I use bias cut glass on my stems because it will follow the curve, and these strips of reinforcing bias cut fiberglass are short in length.

I DON"T use bias cut strips on my hull / deck seams because there is very little curve to this joint. It is much easier to make and cut long strips of glass from scraps left over from the hull or deck.

If you have a design with a sharp curve at the stem you can certainly use a bias strip in a local area. The natural stretch of a bias cut strip is a disadvantage in a strip of long length where even picking up the strip can make it stretch out in length and become more narrow than is useful for a seam. Wetting-out long pieces of bias cut cloth is more difficult because the natural stretch will cause the
glass to elongate as resin is applied. As the strip elongates is also becomes narrower which will reduce the strength of the reinforcement.

Anyway, it just boils down to using regular glass strips are easier to cut and easier and faster to use.

Bias cut glass is usually not needed on hull / deck seams.

Happy New Year!

Rob