proper way to use two part foam question

[cycojon]

i am re-foaming my tray on the superjet, installing a scupper and fixing leaks. i am pulling all the foam out.

my question is, when i pour the new foam in should i pour in a little and let it expand then pour some more, and keep repeating untill its full? or should i pour in alot (how much i don't know, i got the 16lb kit on the way) and let it expand out of the holes i am pouring into? or, do i cover these holes after i pour and let the foam expand in the tray.

when i did my foot holds i poured in too much foam and when it expanded out of the hole i coverd it and then my foot hold kind poped out just a little in the middle. that was my first time. the second time i just let it rush out and it was fine.

what i was thinking of doing is glassing in my tray and getting everything sealed up and then standing it up on end and pouring foam in through the original holes in the engine compartment then glassing over those when i re-enforce the inside.

is it best to refoam useing these holes or should i put holes in the tray where you stand when you ride and foam through there?

also

should i put holes in the top of the sides of the tray to make sure i get foam behind the foot hold or will it make its way up there if i stand it on end?

thanks in advance

 

[yankeeboy]

When i did mine ( with 2 lb foam ) i only had an area a little larger then the footholds cut out. I put the ski nose down, and poured a small batch into the bottom (front) of the gunwhale, and let it expand fully. Then i started mixing more getting it to expand to the area i wanted. Once up the the foothold i put the foothold back in, then poured the foam behind it through holes i drilled in the top. I should have made the holes larger, a little drop would clog the hole and make a big mess.

 

[accbr]

I drilled two holes with a hole saw above the foot hold and another closer to the front when I refoamed mine. Tilted the nose up a little, and filled the rear up first. I didn't have the motor out though. You're supposed to wait about 15 to 20 minutes between pours too. Then I just glassed the holes back up.

 

[thegoldenboy]

I usually try and pour 2 part foam all in 1 shot. A whole tray might be a bit much, but if you have the setup to get teh whole thing full, than mix up a huge batch and go for it.

Put ski on angle, make sure it has enough area to breath, but keep it mostly covered to maintain density. I mean just have a quick method to release excess pressure.

 

[JonnyB]

glass the tray back in
Raise ski to a 90degree then pour in the factory foam fill holes. Go side to side with the foam, get something long to poke it with to make sure its hard. Don't pour new mixture it till the foam you already poured is hard and finished expanding


How to use foam:
get some gloves latex or whatever, two clear disposable 8oz cups good amount of big 16oz plastic cups, and plastic, spoons, knifes whatever that doesn't matter.
pour part a into first clear cup only 1/2 full
pour part b into the other clear cup again only 1/2 full.
make sure both have the same amount then pour both into the big plastic cup mix for 30 secs and you will feel it start to warm up in your hand at that point pour it fast!

 

[tipafew]

I pour in small batches.
I pour everything through the foothold holes and hole in the bottom of the tray. I actually flipped the boat part way upside down to get up in the top of the gunwales.

The rest of the process is too much typing.....gotta get back to work.

 

[cycojon]

thanks for the replys!

so it seems like most just leave the holes open when you pour the foam.

 

[yamanube]

Leave area for the foam to excape, if you are pouring a lot of foam through a small(ish) hole and dont leave somewhere for extra to escape it can do some damage. I usually have 2 holes, one to pour into and one for air/foam to escape out of..pour it in, plug the one hole that you poured into while it expands but make sure you have anything you dont want covered in foam taped off.