Water detecting in GRP

[500e]

If the glass has dis bonded it can seep throughout the hull remember the micro blistering on hulls, the old pollwolly was a Pita for sucking up water.
Had a boat in the 70s we had to blast he jell coat off the whole hull.

 

[W.olly]

If the glass has dis bonded it can seep throughout the hull remember the micro blistering on hulls, the old pollwolly was a Pita for sucking up water.
Had a boat in the 70s we had to blast he jell coat off the whole hull.

I am contemplating to flowcoat it all. But i hate sanding. Very little Gelcoat on it though which will be one bonus.

 

[roofman]

I am contemplating to flowcoat it all. But i hate sanding. Very little Gelcoat on it though which will be one bonus.

this could be the main problem to your water getting in on an old boat...ive flowcoated the inside of the hulls on every boat ive ever bought before it goes in the water. Pretty much the same as fibreglass roofing,we dont class them as watertight untill its gelcoated

 

[wookie]

IDEA

car tyre pump fitted to a plate that is sikaflexed over the inner hole but leaving a cavity behind it and once the pressure builds up from the pump it will bubble when i run water over the outside.

You know as mad as that sounds it might just work... hmm... I can't think of any reason not to try it and if it does work please post back here preferably with pictures.

 

[W.olly]

You know as mad as that sounds it might just work... hmm... I can't think of any reason not to try it and if it does work please post back here preferably with pictures.

no worries there i will add to the boat blog on here

it is a bit of off the wall idea but if water flows then air flows easier.

 

[the snooper]

no worries there i will add to the boat blog on here

it is a bit of off the wall idea but if water flows then air flows easier.

Will a little car pump have enough air as it will probably seep out internally aswell

 

[500e]

Got to dry the hull first,
Use to flow coat Lotus elan body's to stop crazing first used tissue glass then flow coat.
roofman
Don't see the advantage of internal flow coat the idea is to stop the hull taking on water rather than keeping it out of the inside, especially in fresh water that freezes at lower temp & blows the glass.
It is surprising the weight of water a hull can absorb.
If it is wicking smoke will not show you anything it is a slow seeping process that finds a way out may not be any near the root of the problem.

 

[addjunkie]

Have you considered the potential for water getting in the flying brighe windows and working its way down, or is that a part youve added.

Good luck, every cabin boat I have been involved with one way or another for the last 40 years has let water in some where

 

[Keith 66]

This was my trade fixing boats. First things first does the deck have a core? many boats have a cored deck to increase stiffness, this will be either end grain balsa wood or some type of closed cell pvc foam.
If a leak starts it will usually be where the laminate has been drilled for a fitting such as a handrail or eyebolt. Fittings fastenings should always go through a solid block rather than a cored section which will crush & allow leaks.
Leaking cored decks are a pain to fix as leaks can start in one place & travel many feet away. Balsa cores will rot & turn to mush.
If the deck is cored & the core has failed or water got into it you will never ever dry it out.
If its cored try driling a few holes from the inside with a small hole saw to check whats there. Only fix is to cut the wet section out from inside & replace then re glass. Lots of overhead itchy grinding, Poxy job, good luck!

 

[Wendelspanswick]

Have you tried Captain Tolley's patented 'Creeping Crack Cure'.
http://www.captaintolley.com/

 

[roofman]

Got to dry the hull first,
Use to flow coat Lotus elan body's to stop crazing first used tissue glass then flow coat.
roofman
Don't see the advantage of internal flow coat the idea is to stop the hull taking on water rather than keeping it out of the inside, especially in fresh water that freezes at lower temp & blows the glass.
It is surprising the weight of water a hull can absorb.
If it is wicking smoke will not show you anything it is a slow seeping process that finds a way out may not be any near the root of the problem.

The main idea was to seal the stringers ect from getting water logged from seaping down not to stop it coming in from the underneath...The point i was making to W.olly was the old resin and fibre can become pourous and let in water.

 

[500e]

See where you are coming from now roofman
As for CT patent CCC love the stuff seals canopy leaks a treat

 

[wookie]

This was my trade fixing boats. First things first does the deck have a core? many boats have a cored deck to increase stiffness, this will be either end grain balsa wood or some type of closed cell pvc foam.
If a leak starts it will usually be where the laminate has been drilled for a fitting such as a handrail or eyebolt. Fittings fastenings should always go through a solid block rather than a cored section which will crush & allow leaks.

The way I've seen holes done in boats with a core is first to drill a hole where you want it, but only through one skin, then rake out the core around the hole, then epoxy the raked out section and then finally re-drill the hole through the original hole and the new epoxy to give a strong hole that can't crush or allow water to get into the core.

It might be a faff but it's better than fixing a water leaked core later on.

 

[W.olly]

Will a little car pump have enough air as it will probably seep out internally aswell

Wont know untill i try kida, but i am bidding on a compressor anyway. BUT things may well of changed read on

I must be bloody barmy.

Have you considered the potential for water getting in the flying brighe windows and working its way down, or is that a part youve added.

Good luck, every cabin boat I have been involved with one way or another for the last 40 years has let water in some where

Yes the top screen is what i added on to the boat.

I agree no not have a damp boat is lucky lol.

This was my trade fixing boats. First things first does the deck have a core? many boats have a cored deck to increase stiffness, this will be either end grain balsa wood or some type of closed cell pvc foam.
If a leak starts it will usually be where the laminate has been drilled for a fitting such as a handrail or eyebolt. Fittings fastenings should always go through a solid block rather than a cored section which will crush & allow leaks.
Leaking cored decks are a pain to fix as leaks can start in one place & travel many feet away. Balsa cores will rot & turn to mush.
If the deck is cored & the core has failed or water got into it you will never ever dry it out.
If its cored try driling a few holes from the inside with a small hole saw to check whats there. Only fix is to cut the wet section out from inside & replace then re glass. Lots of overhead itchy grinding, Poxy job, good luck!

It is single skin but for the rear cabin top. I replaced all that area a while ago with Celotex as that was sodden due to a few holes and bad fitted vent.

Have you tried Captain Tolley's patented 'Creeping Crack Cure'.
http://www.captaintolley.com/

It will be difficult to use that as the gap/crack/split needs to be dry and to get it in the hole from the inside and flow upwards will not be easy. And i cant see it getting all the way to the hole on the outside where water is getting in.




Now the update on things.


Since i got the boat and dont like to paint GRP boats i have wanted to Topcoat it. BIG job but as i have spent more money than i care to admit and as some have seen the boat and the time i have put into it i think it is best if i go ahead and bite the bullet and give it a complete all over Topcoat.

I know the pain it is just to get a good finish as i have made a few Carbon fiber dash boards for kit cars.

This will need a complete strip back again to bare GRP but this time a paint stripper will be used as i did with the antifoul last year.

Reason i want to Topcoat is the thought of any dodgy areas below the water line. Although i will be going over it with a fine tooth comb after all the repairs are done and get it as good as i can.

So wish me luck, Plan is i will get the trailer sorted and get as much of the fit out done then drag it up to my brothers who has a workshop i can do it in over a few days and i will be spraying it.

All prep will be done here at home over the next few months.

 

[the snooper]

I still think it advisable to find the source because if it's any sort of crack it will just open up again

 

[W.olly]

I still think it advisable to find the source because if it's any sort of crack it will just open up again

I will still try the pump method if the car pump dont work the compressor should do. Soon find out.

 

[W.olly]

I have been reading for tips on redoing the gelcoat and there are so many negative folk about doing Topcoat on boats on a big scale. They scared of a little sanding lol.

Or am i mental.

Bests top reading or it may well put me of and go back to painting it.

Ah not looked at the price of it yet.

ill be back

 

[the snooper]

.

Ah not looked at the price of it yet.

ill be back

stay sat down

 

[addjunkie]

Or am i mental.



ill be back

Not sure if your mental, or just have very thick rose tinted glasses. To be honest I think you were very brave to take this on. Its threads like this that prevent me buying an old cheap sailing boat

 

[W.olly]

stay sat down

i was lol.

I did say the T that i would cope with £200-£250 for the gelcoat/topcoat

I wasnt far off.

If my maths are correct that is.

20 foot cruiser = 40sqm x 3 coats at 650grm per sqm = 75kg, AND £300 ex a resin spray gun.

MMmmmmm i must be bloody mad

Oh not to forget a shed full of DA sheets to polish it all up and weeks and weeks of time, i love my wife soooo much