Extremely disapointed in US Composites foam!

[cookerq62]

Did you leak test your ski before closed it back up? When I did my square nose I hooked a pump up to the hole for the foot hole foam and build up some pressure then marked all the leaks, put a dab of 5200 on each then applied a vacuum. You just repeat the process until you can't find any more leaks. I for the life of me could not get the exhaust tube on the inside to seal.

 

[deblaster]

It seem theres at list three ways to do this. 1 The way you did it, me and probably others too (hi failure rate). 2 Seal the hell out of it (takes lots of determination). 3 Use polystyrene, and drain plugs cant hurt.

 

[Ericfox]

I did a test about 2 years ago... took an empty 2 liter bottle and poured some foam in it... it expanded about half way... then drilled a few holes in the bottom so if water actually made it through it would fall in a pan to see... weighed the thing... then filled the top with water

After about 3 weeks or so afterwards I dumped the water off the top- weighed it... same weight.... then cut the foam up.... it had not absorbed any water except perhaps the foam at the first 1/32" ...

I just have a hard time believing that it absorbs water like a sponge.... Paul's 91 squarenose foam was still pretty dry in most areas... if foam was really that absorbant the whole thing would have been saturated

 

[McDog]

I told you so. I told you so. I told, told, told, told, told you so!

That's the "I told you so" song that my wife hates to hear. LOL.

Polystyrene and drains.

Is the sealant that failed the same stuff you used on Brande's ski?

 

[Waternut]

I did a test about 2 years ago... took an empty 2 liter bottle and poured some foam in it... it expanded about half way... then drilled a few holes in the bottom so if water actually made it through it would fall in a pan to see... weighed the thing... then filled the top with water

After about 3 weeks or so afterwards I dumped the water off the top- weighed it... same weight.... then cut the foam up.... it had not absorbed any water except perhaps the foam at the first 1/32" ...

I just have a hard time believing that it absorbs water like a sponge.... Paul's 91 squarenose foam was still pretty dry in most areas... if foam was really that absorbant the whole thing would have been saturated

Those were kind of the results I was expecting. That's why I installed drains just to ensure that the foam doesn't stay saturated. I think of it kind of like a rain jacket or tarp. Yes it will repell water but if you pour water on it and leave it there for too long, it will be become soaked. Either way, if this ski lasts the summer, it will be getting another defoam next winter.

 

[keefer]

Yep, my build was on a 96 hull 2 years ago and just this past summer the right foothold cracked near the exh tube. It leaked in for at least 5 months of riding. I started to notice that it would leak from the drive shaft tube onto the floor for days after riding. I defoamed it a few weeks ago and the only foam that was really waterlogged was near the bulkhead around the midshaft area at the very bottom. The area around the cracked foothold was wet but not very deep into the foam. There were also leaks around the extra cooling line pipe that the previous owner had installed with some kind of hard sealant. I replaced all of that with 5200 and sealed around all of the other passthrus and around the driveline tube front and back. I think it will be pretty watertight.

 

[GDFL]

Eric, your experiment was slightly flawed. The natural "skin" that forms on the foam will prevent virtually 100% water intrusion forever. That's basically what you experienced. Jet skis don't really get the same "skin" because the foam fills all throughout the plumbing and lays against the ski itself. The problem is that contraction of the foam almost always happens, ESPECIALLY with less than perfect mixing, then the skin is broken and the foam is exposed. Even if you felt wet foam 6" in, I doubt that it was completely waterlogged. A weight test before and after would probably reveal that you only had the claimed 3-6% cell intrusion. It doesn't take much water to feel wet. The heaviest skis that are completely waterlogged are ones like yours that have bad leaks and get water moving in and around all the foam where it has help penetrating the foam when the ski heats up from sun and just sitting in a warmer place. The heating slightly pressurizes the tray and pushes the water in.

Don't be so quick to damn US Composites. You would have had the same results from ANY brand of 3lb foam. 2 part foam is what it is and unfortunately you expected it to be something else. Great Stuff isn't going to be very "great" for a total refoam because it isn't very structural. You'd better reinforce as if you weren't running foam if that's what you're going to do.

 

[Waternut]

I told you so. I told you so. I told, told, told, told, told you so!

That's the "I told you so" song that my wife hates to hear. LOL.

Polystyrene and drains.

Is the sealant that failed the same stuff you used on Brande's ski?

LOL

After reading a bunch of threads on polystyrene, I see that I misinterpreted what everyone was trying to say. Everyone says "it's lighter and doesn't absorb water"... What I didn't get out of that phrase was that, foam absorbs water.

Yes I used the same sealant on Brande's ski....BUT...the sealant failed because it came off, not because it absorbed water and leaked. The inside of my scupper had the same sealant and that half of the foam was dry.

 

[Ericfox]

Interesting point GDFL... I could see that happening...

I would be interested in knowing how much water is really absorbed into peoples skis though... the foam above the bondline should be pretty safe...

I would be surprised if there would be more than a gallon of water in someone's ski... but maybe not? How much water have you guys found when you defoamed???

1 gallon of water weighs just over 8 pounds... I would not be too upset about an extra 8 pounds.... but if it got to 2 or 3 gallons of water... I'd prob be refoaming...

 

[keefer]

I have seen several hulls that had leaks in the bond line. I have been filling all the holes and gaps with epoxy thickend with adhesive filler.

 

[Ericfox]

Not saying you guys arent totally right.... but US Composites site seems to make you think this is pretty water safe...

Taken directly from US Composites website FAQ:

14. Is this foam water resistant?

Yes, but with the following caveat. The foams that we sell are considered closed-cell, which means that each cell that makes up the foam structure is completely closed off from surrounding cells which prevents it from acting like a sponge. It is completely safe for this foam to be in contact with water for hours/days/weeks and even months with no adverse effects. However, it should never be submerged in contact with water permanently. Over a period of years the water contact can begin to soften the foam and cause it to lose its closed-cell status. This foam is designed primarily to be used as an insurance policy in case of damage/holes that could cause a vessel to lose buoyancy. Pinhole sized openings would essentially have no effect on the foam since the amount of exposure is so minimal but you should always make repairs as soon as possible to keep the foam effectiveness as good as possible. This will be the case with all after market closed-cell polyurethane foams and even manufacturer installed foams.

 

[Matt_E]

And what does your own experience tell you about that statement? :biggrin:

 

[Waternut]

And what does your own experience tell you about that statement? :biggrin:

That they are lying sacks of ****... I mean...did I say that out loud? What were we talking about? :sneaky:

 

[stanton]

i sealed the HELL out of all the holes in my tray. i went nuts with the 5200 inside and out. reinforced sides, it would take alot to get my wet.
i tested it and my foam aborbs ALOT, not to the point of sinking but it definetly filled up!

 

[Speedfreak]

I had 19 pounds of weight removed when I defoamed my ski. Before I bought it it was resealed on the inside and sealed and painted 100% on the outside but this is what I found. I didn't do the work so I don't know what kind of job it was all I know is what it looked like after I bought it.

Read this post.

http://www.x-h2o.com/showpost.php?p=280585&postcount=1

 

[the WaTeRhAwK]

you should look into doing what matt_e did to his hull with the pink drywall foam and installation of drain plugs. it's the most sensible I've seen yet. with the abuse that we put on these hulls,there's no way you're going to avoid cracks and water soaked foam. so, it only makes sense to "displace" the water rather than trying to completely seal it out.

good job matt.

 

[Ericfox]

so 19 lbs of foam and water.... about 8-12 lbs of water prob depending on which density foam was used for the job.... thats not a super huge amount of weight.... is this what we are calling a completely waterlogged ski?

Has anyone ever looked into the expandable polystyrene beads? I know people make stuff out of it in molds... but maybe you have to heat the mold to get it to work.... not sure how it would work in skis...

 

[SuperJETT]

The one thing you lose with polystyrene is any structural support. Expanding foam fills and bonds some, effectively strengthening the hull. Just make sure to reinforce while you're doing it and you shouldn't have problems.

On my build, I'm only using expanding foam in the upper deck and am going to seal it with a layer of glass. Any water leaks will be easy to find and will just drain out anyway.

On my old hull when I refoamed, I did probably 15-20 pours, and each one you'd see contract some around the scupper, exhaust, etc, and the next pour would fill that in.

 

[Ericfox]

http://www.tidelandsignal.com/web/information/Technical/2.2-Buoys-REV-01.pdf

see link above-- not sure if you can do this in a hull or not....

I'm doing another test on US Composites 3lb foam submerged in water... only this time I cut up chunks of expanded foam and they're submerged in a bowl...

I still have a hard time believing that newly poured foam will take on water like a sponge... maybe over years of exposure I could believe it...

I am gonna ask Paul how much he figures he took out of his ski... 91 squarenose - never refoamed... bet it wasnt more than 5 lbs of weight savings from what I remember him telling me... yeah.... he just confirmed about 5 lbs or so he would guess was due to water... he said there were only parts very close to the exhaust and bondline and such that had water absorbed in the foam...

 

[Kennay]

The one thing you lose with polystyrene is any structural support. Expanding foam fills and bonds some, effectively strengthening the hull. Just make sure to reinforce while you're doing it and you shouldn't have problems.

On my build, I'm only using expanding foam in the upper deck and am going to seal it with a layer of glass. Any water leaks will be easy to find and will just drain out anyway.

On my old hull when I refoamed, I did probably 15-20 pours, and each one you'd see contract some around the scupper, exhaust, etc, and the next pour would fill that in.

Properly installed (Packed really tight) poly is going to be pretty stout. You definately still have support when you wedge it all in there tight. It might seem weak just squeezing it, but in layers it is damn sturdy. I agree though, not as strong as 2 part.

Strong enough though!