Thrifty Alternatives ..Building Foam Campers

[GPW]

Foamies are a LOT stronger than we give them credit ...

Eagle , was it a dark colored tarp? Seems if the foam got really Hot it would /might expand more ... Heat is how they got it to expand in the first place.. So when you get your new foam , just throw it outside, uncovered, into the Slug Fest .... Maybe it’s the slime that protects it ... ? Never seen that bubble thing before ...

[eaglesdare]

its the brown on one side, but i can't really remember now if both sides are brown. i have one that is silver colored. but that isn't the one that was on the camper.
i just went out to look, its brown on one side and silver on the other. if i remember correctly the brown side was on the outside, and silver on the inside while wrapped.

but you are right, i am going to let the foam just sit out, no wrapping. give the slugs some fun. but i will cover my wood floor, til its inclosed.

[S. Heisley]

I'm wondering if it is heat blistering from direct sunlight.

Is it the pink or blue?

i'll take a pic or two in a bit. this foam has been under tarp the whole time, since march.
the foam was brand new, the tarp was brand new. no direct anything was hitting the foam.

but i now have concerns about this. i have accepted the first foamie has bubbles, they are hard, hasn't changed anything but the look to the camper (that i know of). that camper is still a very solid piece.
but after the time and money i will invest in the second one, i will be very p.o'ed if it bubbles. why does my foam bubble!!!!!!!!!!

there is scrap foam out back, just thrown about in the junk piles, no bubbling, no damage, just lots of slugs. have i mentioned around here, slugs love foam. anyway, i have junk/scrap pieces that are out in the weather and nothing happens to them. i have foam that i tarp and the top bubbles. i just don't get it. or is that my answer right there? not to wrap? maybe i should just let the foam alone. i just don't get it. gpw has his foamie out in the weather and he says no bubbles. he also has not tarped or covered. i wonder about the rest of the foamies out there, are they tarped? there just has to be a reason for this, and i need to figure it out.

I suspect it is trapped moisture causing your problems, Louella. I have read and heard that plywood teardrops have trouble with that and owners are told not to lay tarps directly on their creations. There has to be a space between the trailer and the tarp that is big enough to allow air to circulate and moisture to dry out. Water molecules expand and contract with the temperature. By its very nature, foam is porous to a certain degree and would allow moisture to become trapped between or in its 'bubbles'; also, quite possibly between the foam and the layer of paint. As the weather warms, or the sun heats the tarp, the moisture molecule tries to lift itself up but it doesn't necessarily take the same route that it came in at in its original water form. In areas where nights are cold enough to freeze water, yet another water expansion problem exists. Have you ever put an enclosed plastic container of water in the freezer and allowed it of become solid? If not, try it and you will see the expansion first hand.

[eaglesdare]

sharon, thanks. that could be the answer. i am only going to cover my floor for now til the shell is built and i have it water proofed. the foam is going to just be there. and i can only hope for now that is the problem. now that i have typed that and reread your reply, i better go make sure the tarp is above my wood floor. i don't want bubbles forming on that. gosh i wished i had a garage.

[KCStudly]

The silver side of the tarp will reflect more sunlight whereas the brown side will absorb more heat.

Ever notice how summer clothes tend to be light in color and winter clothes tend to be dark?

[eaglesdare]

so which side should be towards the foam? the brown side, which absorbs? not the silver which reflects? if it reflects, then it shoots it right on the foam (or wood), right?

[Wolffarmer]

Silver side out to reflect the sun. keep it a bit cooler

Randy

[GPW]

The more I think about that , the more I think it’s Not the color .... I have places on mine that are painted black , sat in our HOT summer sun , and no bubbles ... Gotta’ be something else .... Question is , is it a depression in the foam or a “Mound” protruding out the surface ... ??? Strap damage I can see as producing a depression in the foam ... For actual protruding “blisters” , gotta’ be something strange or that moisture absorption thing , but only in a couple spots is puzzling ...

[KCStudly]

Were any other fillers used? If been advocating light weight ceiling plaster, but now wonder if that, or other types of dent/gouge filler could absorb moisture and expand like Eagle is seeing.

On the old deconstructed shell, is there a blistered section that could be cut through to get a better idea of what is there and what is going on? Slice right through the middle with that steak knife and see if an moisture is evident, is there filler, GG, Great Stuck, delam, etc.?

[Wobbly Wheels]

A bit of a longshot, but outgassing from the foam maybe ?

[eaglesdare]

ok give me a few minutes, i will go take a pic and jab a knife in it. btw...it is not an indent, it is a protrusion, like a mole, or volcanoe, like mounds. i'll be back. oh and there was nothing added at this stage to the foam, no glues, no paint, nothing, just plain old naked foam straight from the store.

[eaglesdare]

alright here are 5 pics.

the 2 groups of protrusions, one was further towards the front on one piece of foam, the other was towards the back on another piece of foam. both pieces were attached to each other to make the roof.


both pics shows the marks of the tarp, at least it looks that way.

this one, i tried to show you how it protudes. but i don't think i really got the angle right.


this one i tried to cut a triangle in it, to go deep down. never cut thru to the other side. the other side is flat. this pic seems to show its solid.


this one, i just sliced the top off. it shows hollow pockets.

[eaglesdare]

A bit of a longshot, but outgassing from the foam maybe ?

if its outgassing, then what causes that, and why is it happening to me and not anyone else that is using foam?

[GPW]

Whoa!!! That’s pretty Strange !!! Not a Clue !!!

[Wobbly Wheels]

In looking at this pic:



It looks like the surface of the foam under the bubble is melted a bit, perhaps from a solvent ?
Outgassing is when a solvent continues to evaporate long after whatever product it's used in has cured (new car smell is mostly upholstery adhesive outgassing long after the car is delivered). It also happens when a gas used in the formulation of a product (like styrofoam) is released. Normally it's not a big problem unless you seal it up and deny the gas anywhere to vent to. If there were a contaminant on the sheet when you bought it, you might not have known and would have continued building. The solvent reaction would have continued under the sealed skin and, with nowhere to vent to, would have bubbled the skin. Or it may have softened the polystyrene just enough to allow the trapped gases that are used to expand it into foam, to escape.

The round bubbles suggest a liquid might have been dripped on the foam in a couple spots...but that's just wild-assed guessing.