Foaming the Hull ?

Are you asking about the treatment for the inside or the outside of a hull?

That would be the inside. I've heard about doing it both for rust and sound dampening. DK the type, but it would have to be a very high density, non-moisture absorbing type or else you'll end up trapping moisture against the hull. I also personally DK any boats this was done on so can't attest to it working good, bad or in between.

Hi,

I would think it was for the inside myself but thought I better check as one never knows what new ideas one will see on here.

It could be some sort of close fitting permanent fender system if it were applied thick enough.

Here is the gear that is used by a lot of the worlds top Yacht Builders on the inside of Steel and Alu structures.

http://www.mascoat.com/mascoat-marine-insulating-paint.html

Looks like K1W1's link is exactly what you're looking for "This coating can replaced most blanket and foam insulation products". Looks like foam was yesterday and this is today.

This yacht have it on the outside which is a good solution on older boats where you don´t want to strip the interior. http://www.fagerdalamarine.com/

Hi,

Lars, Have you seen that Fagerdala Treated yacht up close?

It was in a port I was in a couple of years ago, I was amazed at how shiny and smooth it is.

Strangely there does not seem to have been much of an uptake if any by the top end builders of this system.

There was an article a couple of years ago touting it was to be used on the conversion of an Ex Scottish Fisheries vessel in the UK that was becoming a yacht.

I have recently been told that this particular conversion seems to have shuddered to a halt and the project vessel is an abandoned hulk.

I don't know if this was a result of an over ambitious refit proposal or another reason beyond the shipyards control.

I am envious of a steel hull that can be faired by 1.5 to 3.0mm of LW Filler. If the decimal point were removed it would be a lot closer to the real-life scenario being applied everyday in megayacht yards the world over.

I am not a big fan of spray-on insulation on the inside of the hull. For a few reasons:

- It is impossible to take a piece of insulation back out to make a repair to the hull or just to check in general. Now that may not be a concern in the first two years, but after 10-15 years it surely is.

- During construction, after the spray-on insulation is applied, workers will still need to add supports for piping and cable trays. The spray-on will already be damaged in many parts before the boat leaves the yard. Result: condensation spots, mould, etc... Same story for a future refit.

- If your insulation goes foul for some reason and smells terribly, how are you going to replace it?

- Call me a tree-hugger if you want, but at the end of the boat's life, it will have to be stripped and its parts recycled. It will be nearly impossible to separate the spray-on from the aluminium or steel, causing a huge loss of material (and by that time, probably will cost extra to scrap).

This Fagardala system is completely new to me. Need to have a look into that.

Bruno

K1W1, i took these pictures of United Spirit two weeks ago. One of her KaMeWA jets was not in place, but otherwise she looked OK. This foam was added almost 20 years ago and I have just seen a minor crack about five years ago. It is pretty easy to repair from outside.

This boat was built in 1939 in 5 mm aluminium plates with rivets. The idea with applying foam outside on new constructions was to use robots for both the final shape and fairing. This shipyard have two ABB robots installed, but have not used them for this application. On older boats it is more man-hours, but not many more than putting tons of filler to sand down.

At least on inspected vessels foaming below the waterline could hide problems.

Not so much it susceptibility to damage, in fact quite the opposite, but the fact that it will hide it.

That's not totally true. If the foam is only applied on the inside and adhears properly, and the boat is audiogauged on a regular basis, it should pick up any thin spots in the steel.

Foaming the hull

Hi, I can see there is some confusion regarding the FMS hull system.
It is a GL class approved method applying a fibre reinforsed PVC sandwich on metal structures by visco elastic bonding. It's approved for:- Alternative strengthening of metal panels according FMS diagrams for bending and buckling -Thermal insulation -Buoyancy and stability aid on ships hull -Lines fairing -Acoustic damping -Shock absorption -Cosmetic solutions.

/Fredrik/

Hi Fredrik, where is this confusion..? Something I wrote?

No, the confusion I referred to was if the "foam" was on the in or outside. And Ijust to explain that it's approved and as good on new builds as on refits. It's the first time light structures can be acousticly "dead" without adding mass.

Fredrik, I remember it was planned for the superstructure of a new yacht. Was it built and have it been used on other yachts, new or refits?

You never did get an answer to your question?? I wonder why? It would seem they would seek out additional exposure for their product.

I'm interested on several levels, particularly the bonding component to the metal skin,....in this case alum, but I would be interested in bonding to steel.

Brian Eiland
RunningTideYachts