Foam replacement

[NatedoggAZ]

Hey all,

When I cut out the old stringers and decking for my restore.... a bit of the foam came out with it as well.

Do I HAVE to use the pour in kind - or can I cut pieces of insulating foam or construction polyurethane foam to fit into the voids...

...or do I have to replace it at all...

After fabbing up the decking - the last thing I want to do is to drill holes in it... just to pour in foam. From what I understand, if you do not pour in the correct amounts, you can burst open your floor.

Thanks~!

ND

 

[matt167]

USCG requirement after 1966? is to have floatation foam. That said, lots of foams float and many aluminum boats over the years used basically insulation foam board. However with a glass boat, the flotation foam also acts as a structural part of the boat in some cases. WOG and others can give you insight on how much to use

 

[chevymaher]

If you leave the side tabbing off. It just squirts out there. It wont hurt it. Between the holes in the deck and sides it got plenty of places for pressure to escape.

have some decent weights like bricks put the plug in the hole when it is filled and the brick on it to keep it flat. Once you glass the deck in it is solid as a rock.

 

[Woodonglass]

The Coast Guard Regs do NOT apply to Back Yard Boat Builders ONLY to the MFGS. But... Not having foam in your boat is like driving 120mph with bald tires. Just NOT a good Idea. If you do the proper calculations on foam filling and pour when temps are in the 70's, the chances of having a Blow Out are practically Nill.

One more thing, It makes things a LOT easier for the Members, if you keep all your posts concerning your project in the same thread.

 

[NatedoggAZ]

Ya know... I was thinking and I may not have to cut the floor open.

I should be able to just pour in the expanding foam into the open areas after my stringers are glassed in.

I left quite a bit of the original foam in there actually and only have one void on each side where some foam came out.

I could probably just pour it in, and then put the decking in on top of the new foam... cutting off any excess once it dries.

ND

 

[Redtruck12]

All that old foam is perfect and dry????
Do some reading. Follow some build threads, YouTube project Carlson /Friscoboater very good and well documented builds.
there is a proper way and reasons to do it that way
pouring thru the decking is NOT a big deal.
i’v been there.

 

[gm280]

NatwdoggAZ, I rebuilt my tri-hull from the ground up. Ad nafter I finished installing my transom, stringers and floor/deck, I took a hole saw/drill and cut the ~2" size holes through the floor in many places. But I saved the cut out hole wood to install after I Mixed-N-Poured the flotation foam.

It was a heck of a lot easier then you would think and once all the foam expanded, I sealed up the holes with the cut out plugs and glassed over then. If you care to see how that is done, click on the boat project linked below and have a look see.

While it sounds scary and a lot of work, it actually isn't hard to do at all. There really is no danger of any "blow-outs" whatsoever. I used the two pound mix and pour foam as well. It strengthens the floor a lot as well. So don't be afraid to go for it and do it the correct way and never worry about it again. JMHO

 

[Redtruck12]

Hey all,

WHEN I cut out the old stringers and decking for my restore.... a bit of the foam came out with it as well.

ND

Natedog

Don't get ahead of yourself. Baby steps
even though its good that you’re trying to think ahead, if you haven’t gutted it yet you are a long way from needing to worrying about foam.
to do all that you will likely have to do ALL of the old foam will likely need to come out anyway.

 

[gm280]

I will mention this, IF any of the foam is soggy or wet, it has to come out. It holds water once it get to that stage. And you would be amazed how much weight that foam can hold as well. JMHO

 

[NatedoggAZ]

Thanks for the replies and info - as you can see in the pics, there are only 2 small areas - neither of which were wet or subjected to water...everything was gutted that needed to be gutted in order to prepare for stringer replacement.

 

[H20Rat]

The Coast Guard Regs do NOT apply to Back Yard Boat Builders ONLY to the MFGS. But... Not having foam in your boat is like driving 120mph with bald tires. Just NOT a good Idea.

I wouldn't go quite that extreme... As you said, the USCG only requires it for mfg's, but the other part is that it is only required for boats < 20 ft. Apparently something magical happens when you have a nearly identical 20ft boat compared to its foot shorter brother, no more foam required.

 

[NatedoggAZ]

So - I might have 3-4 cubic feet TOTAL between both sides of the floor where I need to re-foam...

I'm seeing stuff like 2lb density and 6lb density... any recommendations on the density and quantity I would need?

Thanks!

ND

 

[Woodonglass]

Nate,
As previously stated, and as stated in the Forum Rules and Guidelines, you should really try to keep ALL of your posts concerning your restoration project in the SAME Thread. By my count you have 7 Threads started on different topics but...all about the same project. It is very confusing for the members to keep track of multiple posts on the same project.

To answer your question 2# foam is what you need.

 

[NatedoggAZ]

Correct - each post is a separate topic by design... I did not want to have 1 large post on my build.

Its pretty difficult to find dedicated subjects with dedicated topics sometimes...

In many cases... members will say... "Look to my post on xxx" and then there are 200 pages or whatever to go through to find exactly what you are looking for.

ND

 

[Redtruck12]

Nate,
As previously stated, and as stated in the Forum Rules and Guidelines, you should really try to keep ALL of your posts concerning your restoration project in the SAME Thread. By my count you have 7 Threads started on different topics but...all about the same project. It is very confusing for the members to keep track of multiple posts on the same project.

To answer your question 2# foam is what you need.

Totally agree
If everyone who had a thought or question started a new thread none of us would be able to make sense of it all.
need to follow the forum rules! Regardless of what you “want” or don’t want.

Nate please start a build thread.

 

[NatedoggAZ]

Well - that is not accurate...

Go to the search and type in "foam replacement" I guarantee this thread will be the first and only topic that discusses this subject... everything else that comes up will have either the words "foam" or "replacement" somewhere within them...

 

[NatedoggAZ]

This thread has gone off topic... but nowhere in the forum rules does it say that I have to keep my restoration project in the same thread - if I am mistaken - please post the rule verbatim. The ONLY thing I see that may even come close is a rule from JB back in 2010:

11. Please do not post multiple threads in multiple forums about a single problem. This is confusing to those trying to help you. Multiple threads in the same forum about the same issue are also confusing. If you want help fast, one thread in the most closely related forum is the best way to get it.

My posts are not multiple about a single problem... they are multiple problems and multiple subjects...

 

[froggy1150]

So you have a handful of guys who are consistently the ones who read and help daily. They do it for free and I believe they do it to pay it forward. I am not as good with boats as most of them but I try to help when I can. Same thing.... pay it forward. I read just about everything and from this end it's easier to help that one person who has your attention when you have all of their specific build info in front of you rather than having to hop across 8 different threads. And as in the previous post the search function works well on this site. So remember when you are accepting someone's generosity and free time ....... be gracious :joyous:

 

[steve_h7]

So - I might have 3-4 cubic feet TOTAL between both sides of the floor where I need to re-foam...

I'm seeing stuff like 2lb density and 6lb density... any recommendations on the density and quantity I would need?

Thanks!

ND

If you’d need about 4 cu. ft. I’d order something like the 4 lb. kit of 2 lb. foam from U.S. Composites (FOAM-0204)

 

[Redtruck12]

How about those “Sticky s”
like “how to’s and other great information”