Injecting Structural Foam into Cored Deck? any experience?

[jkimball]

So, before I get started, let me just say that I completely understand that cutting the top skin off and replacing the balsa that let loose is the proper way to repair the deck. I'm completely aware, and in time I may just consider that, but for the moment I'm trying to see what other options there may be out there.

I've used GitRot penetrating epoxy to stiffen up a small soft spot on a fuel tank access hatch on a previous boat, however I have a little larger soft spot on my current boat, which has a cored balsa deck and encapsulated stringers. So structurally it's sound, but from where the pedestal seats were, I guess water got in and did work on the balsa core, so now it has a few spots that are soft. Stringers seemed to be fine throughout the boat when I bought it, and the transom is solid. I just have the nuisance soft spots on the deck/ cockpit liner.

So in searching some other forums I have come across this 2 part injectable foam product, that claims to be a 12lb structural foam, that is actually "attracted to and aided in curing by moisture". I know that various boat manufacturers use structural foam in their cored decks and hulls and it is a great design... but that's how it was designed. Mine was designed with cored balsa, not foam. That said, I know the primary concern for any foam construction is water intrusion and waterlogging. However, I don't anticipate ever tapping into the deck or breaking whatever membrane the foam creates around itself, thus I don't see how water could intrude and penetrate the foam to waterlog it.
Again, I know that this isn't the "proper way" to rehab a soft deck, but is it something that I could expect acceptable performance from for the next 3-5 years? Until time frees up and I can spring for a deck replacement?

The website... well, it's kind of ambiguous at best and no real reviews out there. The guy emailed me back saying it's "new to public" and he's been using it for 8 months with great results... so not much information out there. However, he is based in Florida (about 3 hrs south) and invited me to come see his boats he's done and judge for myself... here is the link to his website if you care to see the product. http://www.injectadeck.com/

I just need some experienced input please

BTW, the boat is a '97 Regal Destiny 200 - CC Deckboat.

 

[jkimball]

Bump

 

[gm280]

I'll bit. If your present hull flooring section is built with balsa wood and you are wanting to repair soft spots without replacing the wood, how do you know the balsa wood isn't totally soaked and rotted and therefore weighting a lot more then it should? I mean that presents a lot heavier boat and the engine has to struggle to move it around. JMHO!

 

[Woodonglass]

Sooooo, how do you get the Old Balsa core out, so the foam can get in??? :noidea: Two objects can't occupy the same space at the same time!!!

 

[GA_Boater]

Looking at the website shows the foam is injected under the deck. As I understand your problem is the balsa used between the deck fiberglass is soft. It's a FG/balsa/FG sandwich, so how can the foam be injected between the FG sheeting?

In your talk with the guy, what did he say?

 

[jkimball]

Looking at the website shows the foam is injected under the deck. As I understand your problem is the balsa used between the deck fiberglass is soft. It's a FG/balsa/FG sandwich, so how can the foam be injected between the FG sheeting?

In your talk with the guy, what did he say?

Supposedly, you drill a hole or two and inject into the core... and from there it's supposed to follow whatever voids or channels there are and fill in the spaces as it hardens... I guess like CPES, GIT Rot, West epoxy etc. does. However, I know that these penetrating epoxies are super thin allowing them to wick into the wood fibers and migrate throughout the deck. I don't know what the viscosity of the foam product is.

It seems like if you could get it into ALL of the compromised area, it would work or at least in theory. I'm just not sure, and that's why I was hoping to find someone that had experience with something similar.

 

[Woodonglass]

I have NO experience with this particular product but...12# expansion foam does just that...It expands when it starts to cure and it's viscosity is a LOT more viscous than CPES. If the wet and rotting balsa core is still between the fiberglass layers I don't see anyway for this procedure to work. Again, JMO, based on what I'm seeing in the video and experience with expansion foam. I'd recommend calling the MFG and having some detailed discussion with them. Heck...I may call em out of curiosity!!!!:eyebrows:

 

[jkimball]

I have NO experience with this particular product but...12# expansion foam does just that...It expands when it starts to cure and it's viscosity is a LOT more viscous than CPES. If the wet and rotting balsa core is still between the fiberglass layers I don't see anyway for this procedure to work. Again, JMO, based on what I'm seeing in the video and experience with expansion foam. I'd recommend calling the MFG and having some detailed discussion with them. Heck...I may call em out of curiosity!!!!:eyebrows:

So, here's the fella's response to my question about displacing the balsa, and looking a little more in depth into his process... Also, the guy lives about 3 hrs south of me, so I think he feels like it's right around the corner for me to just "bring the boat by"

"The balsa breaks down into mush, its not merely waterfilled intact wood. The bacteria in the water breaks down that wood it should be degraded mush. What I do is drill a hole at the softest point in the floor. I look at whats inside. I bet it has a hollow spot. I run a coat hangar violently in all directions. I drill more holes, more reaming of the core with the wire hangar. You could shop vac it but I dont. I inject the stuff and it envelops the mush pushing excess water out the 1/8 straight thru drain hole. The boat in my side yard has had the injectadeck for 8 months, still a firm deck. Bring your boat by, I'd like to try a section."

 

[Grub54891]

I saw one that had the same issue. The owner was told the proper procedure,, removing section and replacing. He injected foam and the deck swelled up and left wavy bumps all over. The foam expands. So does the deck. Maby the guy you talked to has it figured out?

 

[ondarvr]

It can sort of work, but....

It will firm up the area, and 12# doesn't expand as much as lighter foams, so it's a little safer. The problem is you're not solving any problem, the balsa left in the deck will still be wet and continue to rot. The cost is also rather high, you could just order some high density pour foam from someone else and do the same thing, you also need to do it again, actually many more times as the balsa rots away and leaves more soft spots.

I'm not a fan of doing it this way, but as a short term band-aid it will firm that spot up.

 

[Bondo]

I'm not a fan of doing it this way, but as a short term band-aid it will firm that spot up.

Ayuh,..... Along that line of thought,....

I wonder what the results would be of injectin' Gorilla Glue into the cavity,..??

It expands, 'n foams up, but not alot,....

 

[jigngrub]

No time and /or money to repair and make the boat seaworthy again, but you still have the time and money to use it?

So what else is rotten below the rotten deck? Fiberglass boats rot from the bottom up and the inside out and the deck is one of the last areas to rot, and by the time you notice your deck is soft much of everything below it is ruined.

How would your family, friends, and other passengers feel if they knew you were ferrying them around on the water in a rotten boat? Do you even want to take these people out on the water in a rotten boat?

 

[hadaveha]

I say give it a shot on a small section is love to know how it works out

 

[jigngrub]

(Mod EDIT)

2 part urethane foam expansion is governed by ambient working temps and not the density of the mix. Working temps of 75*F and below will see minimum expansion rates. Working temps of 85*+ will see maximum expansion rates.

 

[jbcurt00]

Jig check your PMs

 

[ondarvr]

(Mod EDIT)

2 part urethane foam expansion is governed by ambient working temps and not the density of the mix. Working temps of 75*F and below will see minimum expansion rates. Working temps of 85*+ will see maximum expansion rates.

Expansion rate is directly related to density, the more it expands the lower the density, this is how density is set. Yes it is affected by temperature, it's also affected by humidity.

In an enclosed space the actual density of the foam is increased over what it will be in an open space.

 

[jbcurt00]

Ondarvr are you set to recieve PMs?

 

[ondarvr]

Ondarvr are you set to recieve PMs?

yes

 

[jkimball]

No time and /or money to repair and make the boat seaworthy again, but you still have the time and money to use it?

So what else is rotten below the rotten deck? Fiberglass boats rot from the bottom up and the inside out and the deck is one of the last areas to rot, and by the time you notice your deck is soft much of everything below it is ruined.

How would your family, friends, and other passengers feel if they knew you were ferrying them around on the water in a rotten boat? Do you even want to take these people out on the water in a rotten boat?

Most of the time I get some pretty sound and awesome advice and I really appreciate that and those who chime in to provide it... But sometimes you can't happen to happen upon someone who doesn't have anything of value to contribute and they are simply out to troll...
Jig, I understand your concern... But I didn't post this to be blasted or trolled by someone. I posted it looking for someone to provide thoughts on the process, product and any similar or prior experience they may have. Also, as I said in my original post. I have checked the stringers and transom. All is well. The issue is exactly like I said; a balsa core that got wet from poorly sealed hardware.
However, if you have the finances to come and replace my "rotten boat" then by all means be my guest, however if not, Please don't attack me or insinuate that I'm endangering others or being irresponsible. That's not your place. Mod or not.

 

[jbcurt00]

To be clear, GA boater Bondo and I are the only Mods that have commented or posted to this topic.

I will ask how you've inspected the transom and stringers to ensure they are sound if the deck is still in place.