Countermoulds in the engine and keel area
This issue has the only purpose of knowing better how our boats have been built.
Are the countermoulds under the floorboards an empty fiberglass laminate or are they filled with foam or other light solid, or wood?
Thank you
Matteo, Grampus 47/016

Dear Matteo
The fiberglass structures under the floorboards are mostly foam filled. Wood would be an unsuitable material here, it can not stand the moist conditions.
Kind regards
Lars

Dear Lars,
Thank you, it is logical that these counter moulds should be foam filled.
This is not the same procedure of other manufacturers.
Another good point of Nautor production...
Thank you,
Matteo 45, grampus 47/016

I believe on our older models the foam is open foam; not the closed cell foam of todays production.  As such the foam does retain water if exposed to it, and is the devils own job to dry out.

Hi, at least in CAID (431-12) the foam used is very hard 2 component stuff. With the word "hard" I mean exactly that it is not soft by any means (like the usual 1-component urethane foam from the local hardwarestore).

I found a small partice it loose above the ceiling where it was used as a filler to support the ceiling plywood panels. It is original and used in the manufacturing process. Believe me I know that for sure! Seems to me that inside the longitunal hull stringers is the same stuff used. I took that small loose part with me and asked from a friend of mine (whose family had had a business expertizing in urethane foams). According to him this piece of the urethanestuff I is totally waterproof closed cell polyurethane foam which cures to a very hard instance.

Excerpt from a technical document:

Open-cell foam is soft - like a cushion or the packaging material molded inside a plastic bag to fit a fragile object being shipped. ... This makes the foam soft or weak, as if it were made of broken balloons or soft toy rubber balls. ... Both types of foam are commonly used in most building applications. Some are inappropriate in specific applications. For example, you typically would not use open-cell foam where it could absorb water...

Do you really believe that Nautors supervised by S&S could have used open cell foam for building a boat?

Daniel, 411/004

Sorry, my mistake;  what I meant to say was...

Whatever foam was used, it does and can absorb water. 

Tiderace sat for a week in a heated shed with heat laps trying to dry our one of the longitudinal stringers that was saturated.  In the end we ground more hull laminate off, dug out and replaced some of the foam former.

The foam we dug out was soaked!  So not that much "closed cell" !!!  (I have some pictures somewhere.  I'll see if I can find them and upload them.

Dear Matteo et al
Adrian is right that a different foam was used inside the stringers. It was lightweight and more porous, delivered cut to the required shape, and used as a former only. It has no structural function, and if saturated the easiest remedy is to drill a hole inside at the lowest point of the web and let the water drain out. I wonder how the water got in, it is likely that there was a hole somewhere along the stringer where it could enter.
Kind regards
Lars

Oh well... sorry, my mistake!!!!

Daniel, 411/004

Remember, men, that we are dust and unto dust we will revert...
Or slime. This includes our boats...:)

Just found the pictures I was after.

This is some foam from the hole you can see in my topsides; one of the longitudinal stringers up forward, above the waterline. It had a puncture through the laminate and was repaired just with filler, so was porous. I'm not sure how long it was like that, probably cira 10-15 years.

The foam in the picture was dug out after sitting under heat lamps in a shed for about a week. As it hadn't dried out the only alternative was to dig it out and replace it. (Our hobby can be expensive!)

wet wet foam