Great Foam?

[wirenut67]

Was thinking about using great foam rather than styro or pool noodles for the front of the blackjack build. I know it is expandable, so I have to be careful not to overfill, but are there any other concerns?

[Doby]

Been using it for years,,,no problems......

[wirenut67]

Thanks man! I just did not know if there was an issue with the fiberglass or plastic reacting badly. By the way, I am going to shoot at a 1/8 scale build similar to yours with the hydro. May come a snoopin for some pointers!

[sailr]

NO NO NO NO NO! That stuff keeps expanding internally until it busts your hull! Seen it time after time! Maybe Doby is using a tiny amount? Doby?

[Doby]

I use it on all my builds and never had any issues with over expansion,,,,,,,,however..........

Sailer is correct,,,use small amounts at a time. I filled the whole front of my Rio 51 conversion with it but did it over 4 days. If you try to do it all at once, you will have problems. The front of my Rio was about a 2 foot long cavity and I basically filled about a 1/4 of the cavity at a time. This allowed for whaterever expansion that would occurr to always have room to happen, without popping the deck off the hull.

Small amounts are the key for very large areas. After the 4 days, the whole bow cavity was filled and the hull and deck were solid as a rock. I'm pretty sure it helped the boat survive this blowover.

http://www.youtube.com/watch?v=qTc0Uw2QI5g

[Chilli]

I use this stuff in the 2 LB density. Expands much slower and it does not harden untill it's fully expanded. Also Coast Guard compliant for full sized boats.

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

[wirenut67]

Yes, I was aware of the expanding qualities. I figured to do just a tad at a time. I dont know how many know this little secret, but if you spray the stuff with water, as in a mist bottle, it stops expanding and hardens immediately.


Mike

[sailr]

Use the stuff Nautiboyz is recommending. I use it. It is great and safe and the price can't be beat. The amount you get will last you a LONG time...probably longer than the shelf life of the product!

The Home Depot stuff can seem fine until you take it outside in the sun and then it can start expanding again because of the heat. In the 'core' of the foam it takes a long time for the chemical reaction to stop. I know guys that have had to junk a hull because of the stuff.

[sailr]

You just think it stops expanding. while the outer surface hardens, it continues to expand internally.

Yes, I was aware of the expanding qualities. I figured to do just a tad at a time. I dont know how many know this little secret, but if you spray the stuff with water, as in a mist bottle, it stops expanding and hardens immediately.


Mike

[Brushless55]

be smart and don't fill 100%
it will work ok

[egneg]

I would get the window and door stuff. I haven't used it on a boat but I have used it when I put in new doors and it won't cause the frame to bulge.

Good luck

[wirenut67]

Yep thats the stuff I was thinking about. Ill let ya know how it turns out lol.

[Chop]

If there is an area that you DON’T want to get the foam stuck on (the edges or equipment), spray cooking oil, or wipe vegetable oil on it. The foam won't stick to it and trims off easily.

I also put a little of the foam on my hatches.

[boater76]

I've used Great Stuff as well. I have not had problems with it. Just have to be careful as others has stated about over expanding and breaking hulls
Ken

[Brushless55]

If there is an area that you DON’T want to get the foam stuck on (the edges or equipment), spray cooking oil, or wipe vegetable oil on it. The foam won't stick to it and trims off easily.

I also put a little of the foam on my hatches.

Nice, great idea..