Water from bilge infiltrating keel with encapsulated ballast

[Cheechako]

Originally Posted by Don C L

Wow, just curious, what boat is it that has a gel-coated bilge?

Passport. You've not seen a boat with gel in the engine bed, aft of engine and below? I've even seen them with the under settee storage gelled. This blistering was in the forward bilge.

[a64pilot]

Most even cheap grease guns come with a zerk fitting and a release valve in the head, fill through the zerk and let the air out of the valve so it will pump.
But I have no idea how you get resin through a zerk?


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[minaret]

Originally Posted by a64pilot

Most even cheap grease guns come with a zerk fitting and a release valve in the head, fill through the zerk and let the air out of the valve so it will pump.
But I have no idea how you get resin through a zerk?


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Like this, but imagine the five gallon bucket is full of poly goo instead of grease. Bulk fill grease guns are dirt cheap. So are grease fittings.

https://m.youtube.com/watch?v=7alXII2wWtY

https://m.youtube.com/watch?v=WgCkdXLvL08

https://m.youtube.com/watch?v=m_v0ptMU0DI

[Don C L]

Originally Posted by Cheechako

Passport. You've not seen a boat with gel in the engine bed, aft of engine and below? I've even seen them with the under settee storage gelled. This blistering was in the forward bilge.

Clearly I need to spend more time in the bilges of a higher grade of boat! Hear that friends? Buy a better boat for me to get a ride in! But I am only going to look in the bilge, don't ask me to start doing engine work!

[chris95040]

Originally Posted by minaret

Just not true.

So.. What you are disagreeing with here is the idea that polyester doesn't bond very well to existing, already cured polyester (so-called "secondary", or mechanical, bonding, as opposed to the "primary", chemical bonding that occurs when a polymer matrix is cured together)

Not saying you are wrong, but its quite a claim.

That's the reason most of us use epoxy in our repairs. Epoxy allegedly bonds to existing material much better than polyester. I'd have to say my personal experience agrees with this. Its also a _widely_ held belief. Obviously doesn't mean it's true, though.

[JMK]

Just an update on where things are at. The boatyard gave me a couple of FG guys to talk to, and the best option at the moment, given the number of voids found, seems to be to drop the keel then clean out everything and re-glass the keel back in place. The entire bottom of the keel (FG portion) has already been cut away exposing the lead keel and the water saturated material that was used around the keel so we are already half way there.

[weavis]

Originally Posted by JMK

Just an update on where things are at. The boatyard gave me a couple of FG guys to talk to, and the best option at the moment, given the number of voids found, seems to be to drop the keel then clean out everything and re-glass the keel back in place. The entire bottom of the keel (FG portion) has already been cut away exposing the lead keel and the water saturated material that was used around the keel so we are already half way there.

I was wondering- This would have been my cure all solution. The 'I dont want to do that' way is usually the best way....

[robwilk37]

definitely going to need some pics of all the fun.

[Cheechako]

Originally Posted by chris95040

So.. What you are disagreeing with here is the idea that polyester doesn't bond very well to existing, already cured polyester (so-called "secondary", or mechanical, bonding, as opposed to the "primary", chemical bonding that occurs when a polymer matrix is cured together)

Not saying you are wrong, but its quite a claim.

That's the reason most of us use epoxy in our repairs. Epoxy allegedly bonds to existing material much better than polyester. I'd have to say my personal experience agrees with this. Its also a _widely_ held belief. Obviously doesn't mean it's true, though.

Well.... if that were true then all the cabinetry and bulkheads etc glassed into boats would not be well bonded.... sometimes it's a couple months or more before that occurs...

[a64pilot]

Originally Posted by Cheechako

Well.... if that were true then all the cabinetry and bulkheads etc glassed into boats would not be well bonded.... sometimes it's a couple months or more before that occurs...

Well, I am no expert, but what he said is exactly what I've heard for a long time, that is once cured, your not getting a chemical bond, but a mechanical one.
Not sure if If it is the same, but my understand is it's similar to spraying paint, wet on wet as opposed to sanding dry paint so the next coat will get a grip


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[Cheechako]

I think you may be right about the chemical bond, just sayin' a good bond is still available.
Epoxy wont make a chemical bond to Poly either right?


I was amazed at the tenacious bond strength of some Iso based adhesives when tested. They came in a caulking tube.
We were building aluminum boats and the sales people for the Iso adhesives were trying to get us to use that in lieu of welding some parts. In testing you couldn't knock it off aluminum once bonded with a big hammer.(and aluminum is a lot less pourous than wood) Although I stuck with welding!

[Jim Cate]

Aw come on guys... surely by now you know that Minaret is a high level pro boatbuilder/repairer. He does this sort of work daily, and to a very high standard for very picky customers.

I have come to trust his judgement and advice, even when it flies in the face of "conventional wisdom", otherwise known as "I read it on the internet somewhere". And I am known to be somewhat of a skeptic!

Jim

[minaret]

Originally Posted by chris95040

So.. What you are disagreeing with here is the idea that polyester doesn't bond very well to existing, already cured polyester (so-called "secondary", or mechanical, bonding, as opposed to the "primary", chemical bonding that occurs when a polymer matrix is cured together)

Not saying you are wrong, but its quite a claim.

That's the reason most of us use epoxy in our repairs. Epoxy allegedly bonds to existing material much better than polyester. I'd have to say my personal experience agrees with this. Its also a _widely_ held belief. Obviously doesn't mean it's true, though.

Nobody is debating that epoxy will generally provide a superior bond on most substrates. What I had a problem with was your statement that a poly repair is "likely to fail". Properly done poly laminates have more than sufficient bond strength, without any of the numerous drawbacks of epoxy. Vinylester is sometimes superior to epoxy for bond strength. The current boating world is IMHO doing itself a disservice with a focus on epoxy for repairs. Poly work is not voodoo magic, and has much to recommend it over epoxy. Don't know why people fall for the "user friendly" line, either. A bit of study and effort would show you that some basic poly layup and gel coating skills would stand them in much better stead. I am actually teaching a class this winter.

[minaret]

Originally Posted by Cheechako

I think you may be right about the chemical bond, just sayin' a good bond is still available.
Epoxy wont make a chemical bond to Poly either right?


I was amazed at the tenacious bond strength of some Iso based adhesives when tested. They came in a caulking tube.
We were building aluminum boats and the sales people for the Iso adhesives were trying to get us to use that in lieu of welding some parts. In testing you couldn't knock it off aluminum once bonded with a big hammer.(and aluminum is a lot less pourous than wood) Although I stuck with welding!

This is why orthotropic production resin is heavily air-inhibited. I've seen 30 year old laminates that are still tacky on the surface when wiped with acetone. Particularly in the first months of construction, this feature is providing both primary and secondary bond to fresh laminate applied over it.

[brantleychuck]

Originally Posted by minaret

Like this, but imagine the five gallon bucket is full of poly goo instead of grease. Bulk fill grease guns are dirt cheap. So are grease fittings.

Thanks Mineret, I got it now. Going to give the technique a try in a couple months


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