Fiberglass layup

[triton 496]

Hello all, Well I have another question and I just want to make sure I am going to do this right. I am ready to apply 1708 biaxial cloth to the port side of my Triton and from what I have read, I will need to bevel the edges that the new cloth will be epoxied to. Also two layers of cloth will be needed to give a proper build-up to match what was there originally. What is the order in the size of cloth to be laid, is it the smaller size first or is it the larger piece then the small one on top?

[Rachel]

Could you explain more about where you're putting the new glass and why? I mean, such as, "I'm filling a 6" diameter hole from the outside of the hull, 2" below the waterline" -- or whatever.

Or, of course, a photo...

R.

[bcooke]

What is the order in the size of cloth to be laid, is it the smaller size first or is it the larger piece then the small one on top?

You will read different and opposite opinions to your question. I think West System says the largest piece goes on first.

That makes sense to me and is how I do it. The point is to get maximum adhesion to the underlying material with that first layer. More surface area in contact with the underlay = more points of adhesion.

[Rachel]

I'll post it the way I understand it - the beauty of this is that if I'm wrong someone will correct me and then we'll all know which is right :)

For something like filling an ex-through-hull hole, where you're going to be grinding to fair it after you patch, you start with the largest circle and go smaller. This is because if it were the reverse way, you'd damage your one big continuous piece during the grinding/fairing stage, and basically end up with a bunch of edges.

For something like tabbing a bulkhead, you start with the smaller (narrower) piece, and go larger. In this case you're generally filling to fair, not grinding, so you don't risk grinding off your best, most-continuous layer.

R.

[CharlieJ]

Exactly like I work Rachel. I believe your reasoning is quite sound.

[Rachel]

I think my theories have had quite a bit of help from this board and the WEST systems free booklet :)

Which, by the way, you should really get ahold of, #496 - it's an amazing resource. If you want one right now, I know that System III epoxy has a similar booklet that you can download right from the web. I'm not sure if you can download WEST's booklet, but I highly recommend a copy in any case. It's really clear, has lots of illustrations, and lets you work with it like a cookbook to do various projects. I can't remember the System III booklet as well, but they're a good company too, so it's probably worth a look. (Might not be as slick as the WEST book.)

Rachel

[bcooke]

FWIW, I went back and checked, the WEST SYSTEM booklet says put the largest piece down first for everything.

[Tim]

What is the order in the size of cloth to be laid, is it the smaller size first or is it the larger piece then the small one on top?

The way I was shown originally, and the way I have always since proceeded, is to start with the smallest and work to widest when tabbing in a bulkhead or similar such installation, and to start with the largest and work to smallest when patching a hole or similar interruption--just as several people have said above.