question about foam

[Deanna]

I have a question about foam. I think it was addressed in the large Thrifty thread, but I can't find it again. Can the beaded foam be used? I live in MN and we have the 2 inch foam. but the beaded foam sheets are 1/2 the price. Thrifty is major consideration for me. Thanks.

[eaglesdare]

first off, welcome to the foamies! and wow, this is your first post. you know i took part in that long thread, and i have read it a few times. i am even 100% sure i even asked this same question, but for the life of me i can't remember the answer.

i will go check it out, but more than likely by the time i find the answer someone else will have posted.

[mikeschn]

Structurally, beaded foam is not nearly as strong as Extruded Polystyrene.

If you are going to build a tiny teardrop, you'll be fine. If you are building something a little bit larger, then you may want to consider the Extruded Polystyrene.

Mike...

[Deanna]

I would like to build something with side dimensions of 6 x 8 foot with a height around 5 foot. I will invest in the more expensive foam if I have to....just wondered about the other stuff.

[GPW]

D’, It was mentioned that the beaded foam comes in many densities... and if you can find the same density bead board as the extruded foam (2lb. / cu. ft/ ) It will be fine .... If not you can go to a Thicker beaded foam to compensate ... Twice as thick is eight times as strong ...
Or use a hard skin (interior) for added structural strength ... Many ways around this problem ...

[eaglesdare]

i knew the answer would get here before i got back.

i wonder if we should sticky this? i think this is a good question for any other new folks to read.

what say you all?

what about a faq sticky?


deanna, could you tell us more about what you have in mind? why are you looking into the foam builds? is weight an issue?

[pete42]

In the past I have found the "beaded" foam to dissolve way to easy with any form of gasoline or fuel oil.
it is one way to make a "tank" cover the foam with fiberglass and cut a hole in goes some gas and the foam just disappears.
don't think trailer builders have a need for doing this I just wanted to let you know what I did in the past.

[swampjeep]

i knew the answer would get here before i got back.

i wonder if we should sticky this? i think this is a good question for any other new folks to read.

what say you all?

what about a faq sticky?


deanna, could you tell us more about what you have in mind? why are you looking into the foam builds? is weight an issue?

it might be nice to have a stickied thread on foam materials, with any pertanant info, type, strengths, the 2x thickness it 8x strength that I keep reading, I thought someone started a thread about types of foam, maybe add this info to it, and sticky...

I think pete's info would be nice in there also.

[Papi]

Funny you should ask... I did an experiment with the beaded foam. Let's just say use the more dense stuff and avoid the headache. Results were less than strong. Plus, the beaded stuff crumbles when you try to sand it, and makes an irregular surface, and a lot of "snow" to clean up. I got a bunch of beaded foam for free, and threw it away after my experiment. By "threw it away" I mean it made a great BB gun target first.

[atahoekid]

Hey Deanna,

Welcome to the world of the Foamlings... I think your question has been answered pretty well, but if you have ANY further questions, don't be afraid to think out loud in front of this group. We know the 200+ page main thread could be (is) a bit painful to get through, so feel free to ask your questions to the group. We're more than glad to give you the answers we have and Louella keeps all of us from getting out of line . We're glad to share whatever tips, techniques and expertise that we've got. Glad to have you here!!

[eaglesdare]

well after checking out what sticky's we have, i did not feel this really fell into any of those. so i decided to make this a sticky.

i will watch where this threads goes to see if it will need to be broke off.

[GPW]

Beaded foam requires a different working technique, especially sanding , which should be done in one direction only , and Yeah Boy , it sure is Messy !!! Given the same density , it’s probably as “structural" as any other foam , which very few are... Lets just call it an insulating “Fillerâ€

[mdk]

I see the use of styrofoam - the kind cheap coolers are made of - and foamular, and some stuff that looks like foamular, but is a different product.

I stopped at my local Home Depot and they have 2 inch Foamular, which has a "skin". Is this a problem? I would think that adhesives would like the rougher surface of unskinned foam. Or have I missed something obvious?

[KCStudly]

As indicated elsewhere, it is recommended that you peel or sand the thin clear film off before attempting to glue or coat the XPS foam.

[mdk]

As indicated elsewhere, it is recommended that you peel or sand the thin clear film off before attempting to glue or coat the XPS foam.

It may be common knowledge here, but it isn't easy to find if you don't know where to look.

Can I assume it just pulls off easily?