On Feb 20, 3:19 pm, Lew Hodgett wrote:
wrote:

I'm building a large water tank (4' x 4' x 12') out of plywood and
fiberglass (wood outside, fiberglass inside). I was wondering if
anyone had some advice about how to seal the seams of the tank - like
where the walls meet the floor. I was thinking of taking some 2" wide
fiberglass tape and putting that on the seams, but I wasn't sure if
this was a good idea or not.

I have built several tanks using this approach using plywood, double
bias glass and epoxy.

Cut strips of glass about 4" wide for the seams.

If you are creative and have some clamps, it is possible to assemble the
tank without using any fasteners at all.

Just clamp some 2"x2"x6" pieces temporarily in the corners and lay some
4" glass strips to tack everything together.

Cut the flat interior pieces of glass about 1"-2" undersize. Use the 4"
wide strips of the seams to overlay.

I'd use about 3-4 layers of 17 OZ (DB170) on BOTH the inside and outside.

This will totally encapsulate the plywood.

When you are finished, coat the inside of the tank with "tank resin"
(Not the same as laminating resin)

You will be long gone and that tank will still be in service.

Lew

That sounds good Lew. I was planning on using the basic no-blush epoxy
from this company - http://www.epoxyproducts.com/1_marineresins.html

I assume this pretty similar to the "tank resin" that you're talking
about.

-William