The 'glass layout plan

1708 biax is great stuff: it’s very strong, since it’s not woven and you don’t lose strenth to the bends in the fibers and they won’t break over repeated stressing; it lays flat and keeps it’s shape pretty well, unlike woven cloths which squirm around while you work with them, often going out of shape diagonally; and it’s very thick, allowing you to get 1/16” per layer. This last part means that you get the full 1/8” necessary for a top skin out of two layers, which is a real time saver!

But. As with all things, this, too, is a compromise. Unless the area you are doing is small enough to cover with a single piece of cloth (meaning that no two dimensions can be greater than 50”), you’ll need joints. And since these joints, if they are made overlapping, will add a full 50% to the thickness of the layup where they occur, and will cause lumps. If the joints are done as butt joints it weakens the layup since there is a place where the fibers are discontinuous. Dilemma!

Here’s what I’ve come up with as my best solution – but I’m open to input from any who are willing to offer it (hit the contact link on the left and send in your suggestions).

The gist of it is that the area around the partners will have three layers, for strength, and this will cover the two staggered joints beneath it. There is also a fourth piece of cloth involved, the one between the two longitudinal pieces and between the companionway and the saloon hatch – this one will also have staggered joints, but no third layer.

Make sense? Can it be done better? Will it be adequate?