To get a more accurate test you need beat the foam up some while in the water. Bust some cells like you would on a good wave day. My guess is the water gets in 1 or 2 mils, then starts moving in with more pounding.
Extremely disapointed in US Composites foam!
- Thread starter Waternut
- Start date
To get a more accurate test you need beat the foam up some while in the water. Bust some cells like you would on a good wave day. My guess is the water gets in 1 or 2 mils, then starts moving in with more pounding.
Wow interesting experiences!
I am rebuilding my sn. Totally defoamed, but I wanted footholds all the way the front of the tray. Since that would weaken the sides and I am not too confident in my glassing ability (will be first time of glassing) here is what I am doing.
1. I added some aliminum supports down both sides below the tray (right below the foothold/tray joint). I used aluminum like on door frames, very light with close to a full square shape (1.5 lbs total weight). Three foot length held my weight.
2. Below the "frame" I used the swimming pool noddle material cut to lengths. I just did not like all the "surfaces" of the poly sheets put together. I have had noodles below water for months and they came out dry. Cost was $6 total.
3. I used 2 part (3 lb) foam from just above the exhaust tube to support seal the footholds. I created an aluminum flashing barrier to keep the foam from filling to the bottom of the ski.
4. I added drain plugs.
Oh yeah, I used this rubberized roofing cement in the bondline. It can withstand 125% streach and has a permentent bond.
My ski will probably sink the first time out, lol!
Mike
I am rebuilding my sn. Totally defoamed, but I wanted footholds all the way the front of the tray. Since that would weaken the sides and I am not too confident in my glassing ability (will be first time of glassing) here is what I am doing.
1. I added some aliminum supports down both sides below the tray (right below the foothold/tray joint). I used aluminum like on door frames, very light with close to a full square shape (1.5 lbs total weight). Three foot length held my weight.
2. Below the "frame" I used the swimming pool noddle material cut to lengths. I just did not like all the "surfaces" of the poly sheets put together. I have had noodles below water for months and they came out dry. Cost was $6 total.
3. I used 2 part (3 lb) foam from just above the exhaust tube to support seal the footholds. I created an aluminum flashing barrier to keep the foam from filling to the bottom of the ski.
4. I added drain plugs.
Oh yeah, I used this rubberized roofing cement in the bondline. It can withstand 125% streach and has a permentent bond.
My ski will probably sink the first time out, lol!
Mike
cookerq62
Life's Been Good
- Location
- Upper Bucks, PA
I always thought a good way to de-water a ski would be to hook it up to a vacuum generator Like one used for vacuum bagging. First you would have to fix any leaks so you could pull a strong vacuum then heat the hull up with a heat gun and all the water would boil out. If you could seal the ski perfectly you could probably get a 27" hg vacuum going then you would only have to heat the ski to about 120f.
Once the ski was dried out you could put a one way valve on your vacuum line so the ski doesn't suck water in. If you ever noticed if your ski is sitting on your trailer in the sun the sides of the tray look fine. When you dunk it in the cold water they suck in probably taking on water through tiny holes. This sucking in probably crushes the cell structure of the foam making it even worse.
Once the ski was dried out you could put a one way valve on your vacuum line so the ski doesn't suck water in. If you ever noticed if your ski is sitting on your trailer in the sun the sides of the tray look fine. When you dunk it in the cold water they suck in probably taking on water through tiny holes. This sucking in probably crushes the cell structure of the foam making it even worse.
oldskoo
local jackass
- Location
- Cleveland Ohio
yup my square had maybe 5lbs of water in it if i had to guess, since it was a stock boat that was getting a ton of glasswork anyway we fig what the hell, would it be somthing i would do as maintence.....nope....5lbs is just a hearty turd away....although on this site someone would analize various turds and find out what consistancy would be the best, and what diet would be best to maintain those turds.........then argue over it
- Location
- Melbourne, FL
That would work. I've read of big boats with foam core layups getting water in them. I was reading that one big catamaran had about 2 55gal drums of water sucked out of the foam coring using basically what you're talking about.
- Location
- Ocala, FL
The stock foam on my 550 is 100% dry (to the point where its falling apart)
And its not even 100% sealed. There was a hole drilled into the hull that was covered with turf. The hole was on the top of the right rail so not much water could have gotten in. But for a 20 y/o ski, i was surprised to see it dry. I just stuck a chunk of an ear plug a 1/4" down the drilled hole and filled the rest up with epoxy. Still running the same foam. I think it starts to be a problem when you cutting holes for scuppers, one ways, rear exhaust, trim lines etc.
And its not even 100% sealed. There was a hole drilled into the hull that was covered with turf. The hole was on the top of the right rail so not much water could have gotten in. But for a 20 y/o ski, i was surprised to see it dry. I just stuck a chunk of an ear plug a 1/4" down the drilled hole and filled the rest up with epoxy. Still running the same foam. I think it starts to be a problem when you cutting holes for scuppers, one ways, rear exhaust, trim lines etc.
at the end of last season i drilled 2 small holes and let the ski drain, over 2 days i got 3/4 gallon out. figure in for evaporation i bet it was close to a gallon.
it sat all winter.
i just finished pulling out foam over the past month and what i have weighs 18 lbs.
there was a lot of soaked foam still. even though i drained it and it sat all winter.
now mind you i took a month to defoam, again we would need to assume a lot of evaporation as i let things stand
ball park i am going to say i had a good 10lbs of water if not more
i know where all my major leaks were, there will be a lot of 5200 love in those areas. and all other areas will get a good dousing as well.
i have no fear of using us composites foam, im pretty certain any major leaks are sealed
it sat all winter.
i just finished pulling out foam over the past month and what i have weighs 18 lbs.
there was a lot of soaked foam still. even though i drained it and it sat all winter.
now mind you i took a month to defoam, again we would need to assume a lot of evaporation as i let things stand
ball park i am going to say i had a good 10lbs of water if not more
i know where all my major leaks were, there will be a lot of 5200 love in those areas. and all other areas will get a good dousing as well.
i have no fear of using us composites foam, im pretty certain any major leaks are sealed
This is definitely one thing kawi got right where yamaha continues to just say F*$# it. I like my SJ but after 19 years of SJ's, I wish they would've adopted some of the good stuff that kawi has to offer like: waterproof foam, no engine/pump alignments, cylinders that don't crack, and engine placement design so that mounts don't break so easy.
WAB
salty nuts
- Location
- coastal GA
cookerq62
Life's Been Good
- Location
- Upper Bucks, PA
lvfreestyle
I Know Things
- Location
- Vegas Baby!!!!!
Mile9c1
X-H2O.com
- Location
- Grand Rapids, MI
Yeah that's what I was thinking, it'd be like 10x more expensive. Great stuff doesn't expand much in my experience.
A place I used to work at made expanding urethane foams and one of the mad scientists there said for this type of foam to be compoletely "closed cell" it would have to have a huge density. Something like 20 pounds or so (I forget but it was a ridiculous number).