Water in my Foam

[Sonosailor]

Hi:

Getting ready to launch my FP Tobago 35 here in Canada, and noticed water dripping out of my fin keel. I drilled some holes to let gravity do its work, and am going to re-glass today.

Problem is, I just noticed that the screws that hold on the swim ladder to the bottom of the stern steps will not dry. The FPs have some positive bouyancy foam placed behind the engine, under the stern steps. I guess the screws have allowed water into this compartment. It is fully encased between a bulkhead, the steps, the hull, and the back deck. Any innovative ideas out there on how to deal with this?

[Sonosailor]

No ideas?

Well, here is what I did. I drilled holes through the foam along the keel of the boat from the engine compartment to the transom, using a straightened coathanger. I also drilled other holes through the foam along the inside of the hull, and from over-drilled screw-hole to screw-hole. Then, I set up a vacuum cleaner at the various holes and let it suck, pulling air through the damp area. After a while it dried. I then plugged all the over-drilled screw-holes, retapped, and reinstalled the swim ladder and other pieces. Hopefully, that will stop the deterioration. Certainly, the boat should be 10 kilograms lighter.

[skipperaris]

Originally Posted by Sonosailor

No ideas?

Well, here is what I did. I drilled holes through the foam along the keel of the boat from the engine compartment to the transom, using a straightened coathanger. I also drilled other holes through the foam along the inside of the hull, and from over-drilled screw-hole to screw-hole. Then, I set up a vacuum cleaner at the various holes and let it suck, pulling air through the damp area. After a while it dried. I then plugged all the over-drilled screw-holes, retapped, and reinstalled the swim ladder and other pieces. Hopefully, that will stop the deterioration. Certainly, the boat should be 10 kilograms lighter.

Looking back did your solution produce the results you hoped for?

[GordMay]

”HotVac”:
HotVac treats boats by the thorough removal of absorbed water from affected hulls, and the removal of acids, glycols and other organic compounds that cause corrosion, glass to resin bond weakening, delamination and blistering.This has the effect of significantly reducing the vaporisation temperatures of the moisture and other compounds that need to be removed from deep within the laminate of a GRP hull if a lasting cure is to be achieved. Residues resulting from the breakdown of the polyester resin and PVA binders in the hull are bound to the composite by free glycols. Under HotVac conditions, they move to the surface by a process of activated diffusion prior to their subsequent vaporisation.
Goto: Hotvac Boat Hull Drying, Osmosis Treatment, Osmocure

[cat man do]

A 45 foot cat getting a step extension over here had 2 x 44 gallon drum's + of water drain out of it's core when the transom's were cut.

It wasn't in the foam as divynicell is closed cell, but it was in the voids in the cut's in the contour foam used.

That weight saving plus the extra waterline length made a big difference to her performance.

She went from a dog back to a cat.

Dave

[northerncat]

A 45 foot cat getting a step extension over here had 2 x 44 gallon drum's + of water drain out of it's core when the transom's were cut.

this happened in cairns to as i think i have already said, i think with a ofam boat you would want to know your builder well, especially if he was yourself
sean

[swagman]

Yo - back up the concerns with any razor cut foam cored hull - and deck come to that.
We built a 35 footer once using this core - good fun.
But not vacuum bagging did see eventual water build up in the core. Appreciate the only damage is added weight as our core was rot proof - but it was a bugger trying to track down where it came in.
Trouble with razor cut is the ingress could be right in the bow and the water you find right in the stern!! Even travels uphill due to cappilliary action.
A real PITA.
Good luck in getting it sorted.
JOHN