Boat Mods

[boater76]

Cool. Sounds like a great idea. I was thinking about using the stuff but wasn't sure. I am going to use the stuff on my SH knock off.

Ken

[boater76]

I used the Great Stuff on my Super Hawaii copy today and boy did that stuff stiffen the hull up. It worked great. It did add weight to it, but hopefully it won't take away speed from the setup I have planned.

Ken

[Steven Vaccaro]

Is this the stuff you guys are using?

[Doug Smock]

doesn't it suck up and hold water?

It sure can!! After it has cured it has a shiney outer surface. If it is disturbed it can ( will ) soak up water like a sponge.

Doug

[Steven Vaccaro]

It sure can!! After it has cured it has a shiney outer surface. If it is disturbed it can ( will ) soak up water like a sponge.

Doug

What do you suggest Doug?

[Doug Smock]

I would seal any disturbed area with a sealer of some type.
I personally use styrofoam. I'll cut it to shape so it fits nice and snug, seal the cut edges with Polycrylic ( by Minwax ) and glue it in the hull with a mixture of Gorilla glue and water. The glue expands as it cures and fills any gaps. And it is lite.:)

This is the floatation ( and deck support ) before I installed it in my Titan 29.
It fills the hull from the keel to the deck, and two strips down the side.

I understand that Doby has had good luck with the expanding foam, but I have seen a couple of boats nearly destroyed by Great Stuff and the two part urethane foam. Could have been the user, I don't know.

Doug
PS I did my P-Mono SAWs boat the same way. I blew that boat off more times than I can count at 60+ mph chasing the record for two days. The hull doesn't have the first gellcoat crack in it.

[ED66677]

Hi guys,
You can use extruded foam but not expansed foam, in France such material are both used for house insulation, I've built RC plane for 20+ years and expansed foam is commonly used for building wings (funboard as well), but once shaped, it is requires to wait few days because it continues to expands a little, extruded foam doesn't, it's heavier, stronger and more difficult to work (mainly used for small gliders with thin wings), the first boat I built was entirely made of extruded foam (without any covering material) I can tell you it doesn't suck water at all, hot wire cuting makes a thin layer of melted foam witch is somehow waterproofing the material itself, like a skin, but even a paper sanded surface doesn't suck water, it only retain a bit due to very small cavities on the surface, and the next boat (http://perso.orange.fr/pleindetrucs/madrigger.pdf) will be also made of extruded foam and I will used thin pre-made carbon sheet to cover it, it's gonna look nice, it is weight saving only if used with fiberglass or carbone, wood covering is generaly heavier than a classic "empty" structure!
For assembly I use Polyurethane glue (sometimes combined with charged epoxy glue), this glue expand a little bit but stick on any material except PolyEthylene or PolyPropylene, and because it's Polyurethane once dry (or cured) it doesn't move at all, Polyurethane glues are the top gluing material used in automotive, water resistant, heat resistant and solvant resistant!

[boater76]

I noticed that on the bottom of the hull that there is a little bow coming out in the one spot. I apparently used to much. Hopefully it doesn't screw the thing up that much when it comes time to put it to water. Oh well ya gotta learn somehow.

Ken