Fiberglass sides and ... what for bottom?

[*Inside]

Started building a 1:2 scale model - trying to build it as close as possible to the full scale version as possible to get a better idea of how all the parts go together. About to start skinning it soon - going to do fiberglass+paint for sides - and then not sure what to do on the bottom.

Some options I've considered:

* Fiberglass and epoxy the bottom

* Only epoxy the bottom and then use biaxial tape (2"?) on the edge

*Fiberglass the sides, biaxial tape (2") around the edge (so 1" overlap), then paint or asphalt the center of the underbody

Progress pics:

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[tony.latham]

I epoxy the bottom. Not cloth, no UV protection needed. My first looks as good today as it did back in 2009.

Tony

[Pmullen503]

1/2 scale model!

My feeling on epoxy is that it should be used with cloth. For coating bare wood, like your interior floor, I would use something like poly urethane. It's cheaper, easier to apply and repair.

[*Inside]

I epoxy the bottom. Not cloth, no UV protection needed. My first looks as good today as it did back in 2009.

Tony

Ah neat. I was flipping through your book looking for inspiration. For some reason I thought you'd applied other stuff on there too, but a re-read just says "epoxy." After you joined the walls to the floor, did you apply any tape to the joint?

My feeling on epoxy is that it should be used with cloth. For coating bare wood, like your interior floor, I would use something like poly urethane. It's cheaper, easier to apply and repair.

Sure, urethane on the floor. I was going to use 1-side UV-coated ply for interior walls and 2-side coated UV for cabinets.

Any thoughts on epoxy w/ no cloth vs. epoxy w/ cloth? I'm having a hard time

1/2 scale model!

After 2 years of indecision and multiple 3D models (and some 3D-printed 1:16 models..), I decided to build a half scale model. Glad I did - it's so much easier to manipulate everything and I'm learning quite a bit about cabinet making and woodworking along the way. Would've been much harder to do with 60lb sheets of ply!

[tony.latham]

After you joined the walls to the floor, did you apply any tape to the joint?

I took a squeegee and applied a slather of epoxy at the bottom of the wall and floor to seal it all up.

Any thoughts on epoxy w/ no cloth vs. epoxy w/ cloth? I'm having a hard time

As I said, the floor of my 2013 build is fine. No checking after eleven years. If you're concerned, add a layer of 6 oz cloth. (I would never advocate for just epoxy on the walls, roof, and hatch.)

Tony

[Pmullen503]

Ah neat. I was flipping through your book looking for inspiration. For some reason I thought you'd applied other stuff on there too, but a re-read just
Any thoughts on epoxy w/ no cloth vs. epoxy w/ cloth? I'm having a hard time
!

Epoxy on bare wood, especially exposed to weather, will eventually crack due to expansion and contraction of the wood letting water in. Cloth dramatically improves that. The only time I might consider it is sealing end grain, but even there several costs of thinned poly would be my preference. In this case, on the interior, it's less of an issue but I still opt for poly just for cost and ease of use.