Waterproofing fiberglass pilothouse roof

[Bearkeley]

We have had some weird leaks on our modified pilothouse roof. We have resealed most of the joints for hatches, etc., and wondered if using a barrier coat or something similar makes sense.

When the roof was made, the PO states that it was made of two layers of 1/4 plywood epoxied sandwiched over fir beams and cypress rafters. Everything is epoxied and glassed. He used petite easypoxy but had problems with it and repainted with rustoleum oyster. The topcoat used is peeling off so we will need to reprint anyway....interprotect states we will need to sand down to fiberglass before applying....any easier options?

 

[Bruce B]

I wonder if you have been struggling with an amine blush issue?
Read this link for some insight...
Bruce

What is Amine Blush | Interlux

 

[MurrayM]

Our saloon roof is in need of repair as well, but don't have the time to tackle it right now. We recently applied a liquid rubber RV roofing compound in the hope it buys us a few years before the serious task of a permanent repair/rebuild is done.

We used Superior RV Roof liquid rubber roof coating. It was the strongest one with the most flexibility over the widest temperature range I could find.

Here's their claims:

The Strongest and Most Durable RV Roof Coating
800% Elongation
1900 psi Tensile Strength
One Part Thermoplastic - No Catalyst – Ready to Use
No Tape Required
No Primer Required
Seals Out Ponding Water on Flat Roofs
90% Solar Heat Reflective
Adheres Directly to TPO, EPDM, & All Other Surfaces
Resists Hail Impact & Dirt Pick-up
Remains Flexible Below -70ºF
Rain Will Not Harm Uncured Product
Will Not Support Mold Growth
Rain or Frost Will Not Damage Uncured Product
Instant Waterproofing
15 Year Product Guarantee

https://www.superiorrvroof.com/

I bought enough to lay it on thick as they suggest, but only put two thin coats on so far so the textured walking surface wouldn't get smoothed over. Areas where there were penetrations (mast step, hand rails, etc) got three coats with a small brush at the seams to fill all gaps. So far, so good.

Don't know if it's going to last, but it's a pleasing white that's easy to clean.

Like I say, not the "proper" way to deal with the problem, but if it buys me 3 to 5 years, great!

 

[Pack Mule]

I wonder if you have been struggling with an amine blush issue?
Read this link for some insight...
Bruce

What is Amine Blush | Interlux

I have experienced this problem before with both paint and varnish over epoxy .

 

[FF]

RV or trailer roof coatings are great at stopping leaks.

For folks in hot climates a vert high reflectivity can be obtained at Home Depot.

Sadly these coatings abrade easily so repainting in high traffic areas is required.

The good news is the coatings go on blue , and change to white on cure.

HENRY 100% silicone tropical .

 

[AusCan]

Its tough to say what the problem is. Epoxy coated wood is usually very waterproof unless it cracks at joints.
Amine blush usually only affects subsequent coatings. The epoxy coating normally remains intact.
One possibility is that it was not painted immediately. Epoxy breaks down under sunlight without a topcoat. If that is the case, you may have to sand the paint right back and add another layer of epoxy, then another topcoat for a permanent repair.

 

[FF]

Most leaks come from holes drilled, screw fastening and failed calking.