Super Jet Foam: EPS vs XPS

[AusAndrew]

I just bought some expanded polystyrene (EPS) for my refoam job; similar to what new household appliances are packed in. Will this be ok, or should I use extruded polystyrene (XPS). The EPS has some air gaps around the 'beads' of polystyrene that I guess could hold water. Is this an issue?

I had trouble finding the XPS.

Cheers
Andrew

 

[Freakrider]

I used XPS and called a company that makes it...they said it will not hold water unless it is exposed to significant water pressure to force it into the cells...

 

[Proformance1]

The only thing with the eps would be the surface area for the water to gather. Over than that maybe the load it can handle. The eps may be softer. If you can look up the properties of each and decide which is best. Don't forget to reinforce

 

[AusAndrew]

Hmm the properties look ok, I plan to reinforce anyway.

I might weigh a bit, tie it to a brick and chuck it in the pool for a few weeks. Then pull it out and re weigh. It will be a couple of weeks before I'm ready for foam anyway.

Andrew

 

[Proformance1]

already did that with the XPS no difference after a month below water.

 

[AusAndrew]

Yeah the XPS should not take on water.

The EPS foam itself won't, but when you look at it its like tiny balls of foam stuck together, I'm concerned that water will get between the balls of foam. Would never be as bad as waterlogged foam, but still not desirable.

I'll know once i put some in the pool.

Andrew

 

[Tyler Zane]

put drain plugs in too. what does gather between the "tiny balls of foam" should drain out from between them in a short amount of time. gravity will do that job as long as the balls them self do not hold the water.

when you do your water test, if it does show an increase in weight, see how long it takes (if it even will) for the water to drain out. eps is easy to come by and some drain plugs would ensure its always dry if my theory is correct.

 

[edomund]

Any update on the eps? I can't find XPS in Northern California, but I have eps locally.

 

[Patrick Star]

I like the expanded polystyrene. Boat dock foam works good, when it's used it looks nasty but it should be nice an inch or two in.

 

[masterblaster]

where you guys finding this kinda foam,post up some links with pics

 

[Matt_E]

Any home improvement store.
For pics, look at any build thread of the last three years.

 

[Berky]

Expanded polystyrene will absorb water if under 2lbs per cu ft and if under pressure . Vacuum extruded styrene is good to go .