reinforcment and foaming ?'s

[skithis]

As far as foaming how much foam do i need. Will the 4 cubic yard kit do it?

What do i fill my bond line with that is ultralight weight? Foam here too?

 

[demolition_x]

fill the bond line with west with 404 mixed into like peanut butter.

u might want to get more foam then that. if the temps a little chilly the foam won't expand all the way so u would need more foam.

 

[SuperJETT]

I calculated it out at around 3 cu ft inside, but temp does play a big part. Make sure to warm the foam cans, and warm the ski too.

I sealed my bondline with PL roofing and flashing sealant, some people use 3m 5200, others use epoxy resin with filler.

 

[RMBC Freeride]

u might want to get more foam then that. if the temps a little chilly the foam won't expand all the way so u would need more foam.

temp does play a big part. Make sure to warm the foam cans, and warm the ski too.

Get more foam??? More like "just add more weight". If you do not foam properly and the foam fails to expand then you are simply adding more weight to your ski. Basically, your 4lb foam if not fully expanded becomes 6lb or 8lb foam or more! thats why you would need more. Have you ever weighed the full cans of liquid foam... all that weight goes into your ski, it doesnt get any lighter.

moral of the story... If you refoam, do it right: Work at the right temperature, humidity helps too from what I understand (this acts as a blowing agent - makes the bubbles) and mix it thoroughly with a drill powered paint mixer before pouring.

Take it from me... I did everything wrong when I refoamed and my ski is a TANK! I felt no benefit from refoaming, and used a ton of foam in the process.

 

[skithis]

could i use leftover foam to fill the bondline the carbonfiber over it?

 

[sjetrider]

Get more foam??? More like "just add more weight". If you do not foam properly and the foam fails to expand then you are simply adding more weight to your ski. Basically, your 4lb foam if not fully expanded becomes 6lb or 8lb foam or more! thats why you would need more. Have you ever weighed the full cans of liquid foam... all that weight goes into your ski, it doesnt get any lighter.

moral of the story... If you refoam, do it right: Work at the right temperature, humidity helps too from what I understand (this acts as a blowing agent - makes the bubbles) and mix it thoroughly with a drill powered paint mixer before pouring.

Take it from me... I did everything wrong when I refoamed and my ski is a TANK! I felt no benefit from refoaming, and used a ton of foam in the process.

Niel, didnt you use a stirofoam in bond line on yours? I was thinking epoxy would be expensive and HEAVY.

 

[beachedflunkey]

The bondline is discussed here: http://www.x-h2o.com/threads/6073
I think the winning verdict was to fill with filler and lay everything up while wet for a good chemical bond. "Cat hair" is not a bad idea but it's still going to need to be thick. You're not saving more than a pound by foaming the bondline...

 

[Matt_E]

Here's what I did to my roundie hull...
Filled in the bond line in the bilge area with foam in some areas, thickened epoxy in others
Used one layer of carbon kevlar, one layer of carbon, and another of carbon kevlar to reinforce the entire side of the bilge (each side), the nose, under the pole bracket, and under the hood lip
Used biax cloth/mat (THICK!) on the bottom of the bilge.
Used that same cloth/mat on both sides in the back when I refoamed.

I think that hull's pretty strong.

 

[RMBC Freeride]

Niel, didnt you use a stirofoam in bond line on yours? I was thinking epoxy would be expensive and HEAVY.

Yes I did, and I agree, all that epoxy and filler at the bond line is just added weight and $$$. werd.