Fiberglass Repair

[Aquaholic5]

Hello, first time poster..Long time reader. Great Site!

Anyway, I'm doing some stringer repair and bonding in a new deck. My boat appears to have been manufactured with Poly Resin and a Gel coat put over that. The Hull as well as the deck. So, I plan on using Poly Resin again.

Couple questions:
1)When preparing the surface, I need to grind/sand down through the gelcoat and get to bare fiberglass, then clean down with Acetone before applying the new poly? Poly doesn't like bonding to Gelcoat, even if its just scratched up good, correct?

2) Am I ok to use this cloth to bond in the new stringers, deck to the hull and for a layer on the new deck? I was planning on coating all of the new wood with 2 or 3 coats of CPES before laying down the final glass. Here is a picture, I found it at the local AutoZone. I plan on using a Poly Fiberglass Resin found at HD.

Thanks for any insight..I'm pretty green over hear, in case you have noticed

Good Day.

 

[Aquaholic5]

Re: Fiberglass Repair

Not everybody at once now

 

[SKIBUM1M]

Re: Fiberglass Repair

Right about grind down to fiberglass. that cloth is good for the deck but I would get something stronger for the stringers.

 

[Aquaholic5]

Re: Fiberglass Repair

Right about grind down to fiberglass. that cloth is good for the deck but I would get something stronger for the stringers.

Thanks Ski,

What would you suggest for the stringers?

 

[SKIBUM1M]

Re: Fiberglass Repair

Woven roving. 2 layers of it

 

[drewpster]

Re: Fiberglass Repair

Yes you need to prep by grinding and cleaning the fiberglass. You only need grind through to clean fiberglass substrate. The idea is to remove surface contaminates and expose solid, sound glass.

If you are going to do a complete stringer system and a deck you will need to buy quantities of resin and fiberglass. It is going to cost more money to buy small quantities from the stores you mentioned. I suggest buying at least 10 yards of woven roving, ten yards of chopped strand mat and five gallons of poly resin to get started. This all depends on the amount of work you will be doing of course. Those little packages of cloth will end up costing a fortune.

BTW- My three year old loves to fish too. But daddy does all the baiting.

 

[Aquaholic5]

Re: Fiberglass Repair

Yes you need to prep by grinding and cleaning the fiberglass. You only need grind through to clean fiberglass substrate. The idea is to remove surface contaminates and expose solid, sound glass.

Thank you.

If you are going to do a complete stringer system and a deck you will need to buy quantities of resin and fiberglass. It is going to cost more money to buy small quantities from the stores you mentioned. I suggest buying at least 10 yards of woven roving, ten yards of chopped strand mat and five gallons of poly resin to get started. This all depends on the amount of work you will be doing of course. Those little packages of cloth will end up costing a fortune.

No, its not a complete system rebuild. I probably have about 8 total feet of 1x8 bad stringer I'm replacing and roughly 30 sqft of deck.

I've seen UScomposits mentioned on here many times..is that about the best place to get the fiberglass?

 

[SKIBUM1M]

Re: Fiberglass Repair

I would not just patch it. If part of 1 stringer is bad then the rest is not far behind. I would do both stringers and the whole floor just for piece of mind

 

[MTribe08]

Re: Fiberglass Repair

I would not just patch it. If part of 1 stringer is bad then the rest is not far behind. I would do both stringers and the whole floor just for piece of mind.

I can understand this point of view..but to do that on many boats is an extremely large project and very costly.

 

[thrillhouse700]

Re: Fiberglass Repair

I can understand this point of view..but to do that on many boats is an extremely large project and very costly.

It should at the very least be core sampled and inspected thoroughly if not for peace of mind then for the safety of yourself and your family that is aboard.

That being said, those small packages of cloth I believe are meant as a finishing layer of cloth. (correct me if I am wrong gurus) We used some thin cloth like that as our final lay up on our deck. We also put it on a piece of wood that we ended up not using. Being curious I tugged on one of the corners and it peeled off like a sticker. So this tells me it is not meant for any sort of structural repair.

If your replacing the deck do yourself a favor and inspect everything else for rot, you will save yourself a huge headache later.

 

[MTribe08]

Re: Fiberglass Repair

It should at the very least be core sampled and inspected thoroughly if not for peace of mind then for the safety of yourself and your family that is aboard.

Yes, you are probably right.

That being said, those small packages of cloth I believe are meant as a finishing layer of cloth. (correct me if I am wrong gurus) We used some thin cloth like that as our final lay up on our deck. We also put it on a piece of wood that we ended up not using. Being curious I tugged on one of the corners and it peeled off like a sticker. So this tells me it is not meant for any sort of structural repair.

Thats not good, What did you use for your structural repair? I know Ski likes Woven Roving...I've also heard that 1708 is good for areas that need strength.

 

[thrillhouse700]

Re: Fiberglass Repair

We encased our stringer in 1.5oz CSM, then tabbed it in with 1.5oz csm, a full wrap over the stringer and up the hull about 12" on each side in 1.5oz CSM, then some thick woven (can't remember how heavy exactly).

The thin stuff won't peel off our deck (its just our finishing layer before we paint it, because its very smooth) But laid on bare wood it doesnt have very good adhesion.

 

[SKIBUM1M]

Re: Fiberglass Repair

To do the whole floor and stringers is not that much more. Just quite a bit of time but hey its winter and we cant use the boats anyway right now. And if you spend time and money to patch it and next year you have to tear it out to do the whole thing then you wasted money. It is cheaper in the long run to do it all now. I doubt some of a stringer is rotted and the rest of them are fine and where your patch ties to the old stringer will be a weak point. In my floor and transom I have about $500 into it and I used seacast for the transom. My stringers were dry and solid so I left them which I will probably kick myself for not doing them anyway in a couple of years. I just dont want to see you waste money doing a patch now and have to do it again soon. I also want to see everyone on here be safe and have a positive boat owning experience. If you rig things they never go right and you resent it in the end. Sorry for the rant.

 

[MTribe08]

Re: Fiberglass Repair

To do the whole floor and stringers is not that much more.

In the case of my boat, its ALOT more work, way more than I'm prepared to get into. Plus, from the drill tests I've done, I don't think its necessary. Like I've said in the past, from the looks of the bad portions of stringers I took out in my boat, I guarantee they have been that way for many many years. I would have never known there was an issue at all, if it hadn't been for a few soft spots. The hull is in perfect condition. From the information I've tried to gather, it seems as though the majority of the strength comes from the fiberglass work around the stringers. The parts I cut out were not encased in fiberglass..I will change that.

I doubt some of a stringer is rotted and the rest of them are fine and where your patch ties to the old stringer will be a weak point.

Quite possible..But its better than having the entire thing a weak point.

I just dont want to see you waste money doing a patch now and have to do it again soon.

I understand.

 

[ondarvr]

Re: Fiberglass Repair

Hello, first time poster..Long time reader. Great Site!

Anyway, I'm doing some stringer repair and bonding in a new deck. My boat appears to have been manufactured with Poly Resin and a Gel coat put over that. The Hull as well as the deck. So, I plan on using Poly Resin again.

Couple questions:
1)When preparing the surface, I need to grind/sand down through the gelcoat and get to bare fiberglass, then clean down with Acetone before applying the new poly? Poly doesn't like bonding to Gelcoat, even if its just scratched up good, correct?

2) Am I ok to use this cloth to bond in the new stringers, deck to the hull and for a layer on the new deck? I was planning on coating all of the new wood with 2 or 3 coats of CPES before laying down the final glass. Here is a picture, I found it at the local AutoZone. I plan on using a Poly Fiberglass Resin found at HD.

Thanks for any insight..I'm pretty green over hear, in case you have noticed

Good Day.

My computer is down so I only have a few minutes to reply.

You need to reread other threads on this subject, as you plan to use products that won't work with each other. CPES has no place in this rebuild and cloth alone will be a poor choice.

Read more

 

[Aquaholic5]

Re: Fiberglass Repair

My computer is down so I only have a few minutes to reply.

You need to reread other threads on this subjuct, as you plan to use products that won't work with each other. CPES has no place in this rebuild and cloth alone will be a poor choice.

Read more

Thanks for all the replies guys, I will avoid this cloth and get bulk. I was researching some more and like what the 1708 has to offer.

Ondarvr- Thanks for the reply, I was planning on using the CPES as a base wood treatment on the new ply and stringers before glass. Is the reason you don't like it in my rebuild, because its epoxy based?

 

[ondarvr]

Re: Fiberglass Repair

CPES is nothing but but thinned down epoxy (a great deal of solvent added), read the link at the top of this forum about thinning epoxy.

Polyester won't stick to epoxy, so whatever you use CPES on will be a problem.

Cloth will bond poorly to anything unless you use mat with it, plus the cost is very high for the amount of strength it adds. Use 1708 or roving (never without mat) to build strength.

 

[Aquaholic5]

Re: Fiberglass Repair

CPES is nothing but but thinned down epoxy (a great deal of solvent added), read the link at the top of this forum about thinning epoxy.

Yes, I read that. What I took from it, is that by thinning it down it looses alot of its strength. I wasn't going to use it for strength, but rather as a wood preserver, something that would get deep into the wood. I did alot of research on the product and it all seemed really positive. I am obviously now rethinking that since the Poly doesn't do well with CPES.

I have contacted a local supplier of Resin. I know he sells gallons of Poly for $26, and 2 Gallons 1:1 Epoxy for $95. He told me since my boat was built with Poly, I should stick to it. I'm thinking the same because of the cost difference. I'm thinking of bagging the CPES treatment and just coating the stringers and deck with poly and 1708. Thoughts?

Polyester won't stick to epoxy, so whatever you use CPES on will be a problem.

Ok

Cloth will bond poorly to anything unless you use mat with it, plus the cost is very high for the amount of strength it adds. Use 1708 or roving (never without mat) to build strength.

My local supplier sells 1708 as well, thats what I'll use.

 

[ondarvr]

Re: Fiberglass Repair

Not only are the physical properties of the epoxy reduced, but so is the water resistance and the penetration idea is sort misleading. Yes it may penetrate deeper, but its such a small difference it means nothing, plus stopping rot has nothing to do with penetration, its all about encapsulation. Wet wood rots.

 

[drewpster]

Re: Fiberglass Repair

Sounds like you have a plan started but you need to check things out real well before you start buying supplies. I recommend you find out how extensive the damage is before you move forward. Rot is a huge problem in older boats and there are plenty of folks here that have felt that sting. Bare in mind that no matter how bad it is, it can be fixed. It all depends on how far you want to take it.
Keep us posted, plenty of help here.