Trunk Repair

[KingRichard]

I have a little issue... Wondering what others might have done for this problem and advice on my plan.

I'm planning to sand (40 grit) and coat with West Systems epoxy. Base coat(s) w/no filler and a top coat w/with a little microfiber filler and white pigment. Then coating w/ablative anti-fowling.

I guess this is the price to pay for beaching your sailboat... Also, I didn't see anything I was structurally worried about, but tried not to look too hard

[Wyb2]

I would add a strip of glass tape with your 1st layer of epoxy. It should help with abrasion resistance, and in the future you should be able to see when you start to break through the tape so you will know when you need to do it again.

https://www.jamestowndistributors.com/p ... etail/2074

[KingRichard]

I would add a strip of glass tape with your 1st layer of epoxy. It should help with abrasion resistance, and in the future you should be able to see when you start to break through the tape so you will know when you need to do it again.

https://www.jamestowndistributors.com/p ... etail/2074

That's a good idea. I'm a little nervous that I won't be able to blend it in nicely. I was hoping the epoxy would be tougher than original gel coat and therefor okay until the end of life.

[Wyb2]

The epoxy will probably be more resilient than the original gel coat, not sure exactly how much more. Looks like you have worn through the gel coat plus some of the CSM that makes up the 1st layer of the hull though. How long did it take to get to this point? A beach is just sandpaper without the paper, it will wear through anything given enough rubbing.

I don’t think it would be too hard to fair in a single layer, especially if you are going to cover it with a dark bottom paint. But also, there’s not much harm in trying it without and seeing how long it lasts. Nothing will prevent you from taking another stab at it down the road if you feel like it isn’t holding up.

[OverEasy]

Hi Wyb2!

Y’all must had some beach time!

Now looking at your bow and trunk picture it would apprear to have chewed through at least the outermost layer(s) of da fiberglass as well as all the gel coating.

I would suggest a multi layer strip repair after stripping back about 3-to-4 inches either side of centerline.
- Wet the base surface with non-waxing polyester resin (NOT epoxy)
- Apply a 2 inch woven fiberglass ribbon
(It can be bought that way with woven edges so the cloth stays together vs. turning into a gawdawfulmess of loose fibers. I know that there are a couple sources where one can get this but one that comes to mind is:
NEZUIBAN Fiberglass Cloth Tape, E-Glass 6 oz Plain Weave Glass Fiber Cloth for Repair and Reinforcement, Heat-Resistance and Insulation 2 inches Wide by 50 Yards (5cm x 45m)
- Repeat process while still tacky to apply two more layers for a total of three layers.
- Sand edges smooth to lightly blend to hull surface
- If you still want to apply EPOXY resin do it as a top coat after sanding the polyester …. Then lightly sand to blend
- Apply thin Gelcoat layers (3ish) sanding between coats to build up thickness and to blend in surfaces.

That will get your fiberglass repaired and give enough gelcoat to act as a wear surface. The epoxy really isn’t much (if at all harder or more wear resistant than polyester resin whereas the gelcoat does have that capability due to the ceramic content.

Good luck and have fun!

Best Regards
Over Easy

[Wyb2]

Hi Wyb2!

Y’all must had some beach time!

Now looking at your bow and trunk picture it would apprear to have chewed through at least the outermost layer(s) of da fiberglass as well as all the gel coating.

I would suggest a multi layer strip repair after stripping back about 3-to-4 inches either side of centerline.
- Wet the base surface with non-waxing polyester resin (NOT epoxy)
- Apply a 2 inch woven fiberglass ribbon
(It can be bought that way with woven edges so the cloth stays together vs. turning into a gawdawfulmess of loose fibers. I know that there are a couple sources where one can get this but one that comes to mind is:
NEZUIBAN Fiberglass Cloth Tape, E-Glass 6 oz Plain Weave Glass Fiber Cloth for Repair and Reinforcement, Heat-Resistance and Insulation 2 inches Wide by 50 Yards (5cm x 45m)
- Repeat process while still tacky to apply two more layers for a total of three layers.
- Sand edges smooth to lightly blend to hull surface
- If you still want to apply EPOXY resin do it as a top coat after sanding the polyester …. Then lightly sand to blend
- Apply thin Gelcoat layers (3ish) sanding between coats to build up thickness and to blend in surfaces.

That will get your fiberglass repaired and give enough gelcoat to act as a wear surface. The epoxy really isn’t much (if at all harder or more wear resistant than polyester resin whereas the gelcoat does have that capability due to the ceramic content.

Good luck and have fun!

Best Regards
Over Easy

This is the roughly the same process I was thinking (though the OP, KingRichard, will be doing it, not me). I had suggested a single layer of 6 in wide 9 oz tape, but same general idea.

I’m curious though, why do you specifically suggest against epoxy for the tape resin? I understand CSM requires polyester to dissolve the binder, but cloth tape should be fine with either, right? I use polyester most of the time, but I know some people religiously prefer epoxy. If using any epoxy in the layup, I would just use it all the way through

[OverEasy]

Hi Wyb2

My bad with the miss direction. Sorry.

This is just my perspective based upon my training and experiences….

- The hull was originally made with polyester resin..it works great and costs less….why use more expensive epoxy?
- Poly sticks to poly just fine.
- Poly when cured is just as hard as epoxy for any appreciable application but epoxy can be more brittle than poly.
- Sailboats flex…so why would on want to apply a brittle overlay to a more flexible main structure?
- General practice is to stay with the same materials as whatever the base structure is made from when possible.
- Poly is less expensive than epoxy without epoxy really providing a measurable benefit….
- In the future any additional repairs over epoxy MUST be made with epoxy as poly will not bind to epoxy….so how will a future owner know that this large area repair was made with what resin? What about adjacent area repairs that may overlap?

Best Regards
Over Easy

[Wyb2]

Interesting, my understanding had always been that polyester was more brittle than epoxy.

Agree on all other points.

[KingRichard]

@Wyb2 - I don't really know how long it took... I don't think I paid much attention, but it's possible the PO had coated over some of the damage. I've never spent the night on the beach, but don't shy away from it either.

The pictures might be a little deceiving, I tried to capture the damage at it's worst. I doesn't appear to be through a fiber layer yet, mostly just the gel coat. It seems like I could get it back to original thickness with 4 or less coats of epoxy.

With that said, I'm thankful for the replies, it's inspiration to work a little harder at the repair. I'll definitely go buy the fiberglass strip form the local boat store, but I have epoxy, so I'll probably use that rather than go buy poly. I hadn't thought about how brittle epoxy it is...that's a good point. I might even get some gel coat, seems like it would be a great place to practice

Hopefully I'll have pictures in a couple months.

[OverEasy]

Finishing up the surface with some gelcoat layers is a great idea to help not only seal the resin but adds that extra abrasion resistance to keep it looking good!