Expanding foam??????

[dano1]

Has anyone pumped that expanding foam into nose of hulls?, been tossing the idea around and dont think it hurt anything but i thought id ask first, seems the hulls on m/g are a little soft in the front.

[LarrysDrifter]

I use great stuff window and door foam with great results.its in the blue can.doesn't expand as much as the regular stuff.just take your time adding more foam.

[sailr]

WATCH IT! It can blow your hull apart. It just keeps expanding. Just be careful. I have heard as many have bad luck as good with that stuff.

I use swimming pool noodles that I can cut to shape and wedge up into the nose. That way it is removable if need be. It is also a lot more flexible than the foam.

[LarrysDrifter]

Like I said,just be careful.I use very small amounts at a time.it took me over an hour to do the nose in my genesis.haf to keep an eye on it,that's for sure.I also use pool noodles,but they hold water.use the dark grey pipe insulation.it seems to not soak up water.I think its more of a closed cell foam.

[Dangerous_Toys]

Regular Styrofoam works well also. It can be cut to the desired shape as well. Pool noodles and pipe insulation are good too. IMO anything that can be removable is the best option. You never know when you want to change it up a little.

[dano1]

Thanks for the input here, im looking more to strengthening up the hull more than floatation, m/g has a nice chunk of foam in the nose already, i figured id take little stabs at it and not get carried away

[LarrysDrifter]

I have a pic of my Genesis in the boat building section called "Triple Cat".Look at the one pic and you can see the expanding foam in the nose of the hull.The foam does strengthen the hull,but only to an extent.If you can reach where you want it strong,use fiberglass or carbon fiber or the likes to add strength.Then add the foam-it helps a bit for strength,but mostly flotation.I also sealed my spray foam with epoxy in hopes of water proofing it.Thats why in the pic it looks a little shiney.Theres pros and cons to it all,just figure out what you like best.

[questtek]

I use and recommend the two part mix like is used in full size boats like Boston Whalers. I use it in my Mean Machines and Pursuit with great success.

[damfurst]

I agree with questtek about the 2 part foam. I have used it in several of my smaller boats as well and it is easily pourable into the area where you want it to go. As long as you have one side where it can go it won't expand your hull apart and it will greatly strengthen and stiffen the hull. I've had to remove some of it when there was too much or for other reasons and it is easily carved out with hurting the rest of the integrity.

[JackBlack26]

I put some in my BJ26 and it worked out great. Didn't blow the hull apart and added some rigidity to the sponsons. I wouldn't put in in my MG though as its already pretty strong.

[monojeff]

I've tried great stuff but it absorbs water A LOT of it!

[Doby]

No it doesn't.

[Rumdog]

closed cell foam does not absorb water.

[sundog]

I think the key is to use a small amount at a time, so that it doesn't 'skin over' preserving uncured foam until the suns rays start it expanding again (yes, I've had one expand and explode. The two-part foam is a chemical reaction (like epoxy) not air-cured, so will cure out completely - no surprises later. And it is real good for structural integrity. But consider if you'll want to sell it later, the buyer may not want that in the hull (it's difficult to completely remove) then noodles may be the way to go.

[AlanN]

I wish I had a dollar for every time I see a post on expandable foam.

http://www.uscomposites.com/foam.html

The heavier the foam the stronger. But remember it does make the hull heavier. It comes in useful for when you have too light of a hull like one of my 1/8th scales. You don't need alot of it either. It does not absorb water. I have used the 2 and 4# mixes. Oh and make sure you use it where you want it becouse it is a bear to get back out. Dremeling nightmare. This stuff does not keep expanding like some can brands do.