Boat Builder Central - Builder Forums

I don't think it possible to have 8 overlapping layers all finished perfectly clean and transparent on a corner. I just overlapped them all then scraped/grinded down any bits that were sticking right up, and faired the rest.

The best I have done when overlapping a lot is to hit it with a heat gun on each layer. You can really get your ratio down to the bare minimum needed for full wet-out, and the fibres get so slippery as the epoxy gets hot that you can basically hand-shape to almost any fit. Then, since you've radically accelerated the kick in that one spot, you work your way around the boat layering on more tape, and by the time you get back to that corner, it's really tacked down well, and you hit it with the next layer, which you also heatgun and get slippery and form by hand.

The inside corners of my transom would be what, I think 8 layers of tape and 3 of fabric, just because I always figure if I can get the glass to conform and wet out, I'm not shorting anything, I'm going to run it a bit long and add another overlap. I'm not saying they were flawless or anything but there was a ton of glass in those spots and by using the heat gun on each layer, man, they went down pretty smooth.

I think I'm the only person I know who uses a heat gun as extensively as I do but I find them invaluable. I mix small batches and use them to control viscosity even on large laminations.

I'll have to find the core from where I cut out the drain plug...man, at the keel, my transom was like 1/2" of glass, 1 1/2" core, 1/2" glass. I'm not shy about overlaps.

To catch up on questions:
It’s 6oz biax tape at his point.
Some of it is longest first, but as you wrap that changes so some shorter becomes longer in some directions. . In any case, the sheer number of layers makes it a real challenge.

I like the heat gun idea, but does that negate wet on wet work? Wet on green is good, but definitely defeats some of the wet on wet idea.

Jbo

I used a heat gun for 12 seconds in the last 4 years and burned some of my fiberglass in the laminate. It really does not belong in a boat shop.

All overlaps need to be shorter and shorter.

When I did the transom, four layers of db1700 each side. Alternating directions and a few times turned the pieces twice on corners.

Started 8", then 6", then 4", then 2".

If I was unhappy about anything looking like a step or air pocket would form, I'd usually take a trowel and flow in some thickened epoxy, but that was rare or none.. not total recall as my major recall was not mixing the last batch and stripping it all off for 8 hours...my biggest known error...

I definitely agree that anyone who can't use one without burning the glass, shouldn't have one in their shop.

You can work wet on wet with a heat gun; it's all just a matter of time under the gun, and time between sessions.

It's not difficult to work out the technique - it just heats fast so you have to keep moving. I'll often keep a gloved hand on the surface I'm directing it at so I know the temperature in real time. Working in a garage around the freezing point, you have a huge amount of direct control over the epoxy. You can basically walk around pressing play on mixes which are otherwise just about in stasis. It's very handy.

Works fine taking off drips on the shop floor or tools and such.

Dougster

I know from experience that a heat gun is the BEST way to remove layers of glass from wood. It was so much less waste and such a better job than grinding wholesale or power planing that it saved my whole project.

Since using it for that reason, I've also used it for other purposes. Good for thinning epoxy in areas. But be careful. Use one with adjustable heat, keep it a distance from the epoxy and keep it moving. I did use it for curing some epoxy I needed to kick real fast once. Hard in 5mins. That was a one time thing and not a structural part.

I think that's how I got on to using one myself, or something similar at least...I had laminated a wood veneer and wasn't satisfied with it, so I got to thinking about how to strip it off.

The epoxy softens at a way lower temperature than the wood burns, so a bit of care with the heat gun and I just peeled it all off.

But once you do something like that, you start thinking about all the ways you can apply it.

I'm sure you could do damage with one if you really went nuts, but I have spent I'd guess at least a hundred hours and probably quite a bit more tweaking epoxy sessions with a heat gun and have never had an issue. I guess maybe if you were using mat with a styrene binder, you might damage the binder? Not sure about that one.

But I use one all the time. Dialing temperature up and down to control viscosity is something I do quite a bit and I find it really useful.

I am a heat gun varnish on wood stripping expert. Where I had trouble was 1708 tapes that were curing slow and I tried to warm the tape for like a pass of the gun no stopping and it burned, so maybe you are onto something there with styrene..