Lets talk about rigid foam insulation

[Ramdough]

Thanks!

The prototype used LOTS of PL Premium.
This includes bonding the foam to the structure.

Epoxy used is a marine epoxy. Although when using marine ply you can get away without any fiberglass cloth.
Lower grade plywoods tend to "check" which will crack the paint. Marine ply does not check.

As a prototype I felt like it was a good way to test the theory, so we went without glass. So far so good.


All that said, Im currently testing monstaliner and will more than likely coat the entire thing with it. :ylsmoke:

I thought on your build thread you used fiberglass on the outside?

So, from the outside in:

1. Fiberglass and epoxy
2. Marine plywood skin glued to frame
3. Wood frame
4. Foam insulation glued to skin and frame
5. Luan board glued to foam and frame
6. Epoxy coat to seal luan

Or did I not correctly interpret what you said and what I thought I saw on your build thread?



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[IdaSHO]

The joints got fiberglass "tape"

The bulk of the exterior, no glass.



The rest you've got correct, though Id add that all framing is encapsulated in epoxy

Oh, and stainless brads to attach the skins to the framing. Glue ultimately holds it there, but the brads act as clamps as it is assembled.

 

[southpier]

good insulation links/ reading for a rainy day; thanks.

 

[Trestle]

I used the pink XPS and expanding foam sealant in a can from the hardware store.

Cut XPS to fit the cavity on opposing sides of an exterior wall.

Clean the surface you are adhering to.

Use can foam on outfacing side of XPS, press in place, have a helper hold it.

Do the same for the opposite side.

Put a brace between the two which pushes them both into their respective cavity. Something that is wide enough that it does not dig into the foam too much.

Once cured, go around the edges and fill in any holes with spray foam from a can. Go slow. You can also pre-tape, then foam between the gaps and behind the tape to control things.

Once cured, trim any excess stickout with a bread knife or loose hacksaw blade.

Cover with your interior skin, or whatever layers you want (reflectix, what have you) then your interior skin.

Foam sticks to just about anything, so wear ************ clothes, protect your hands/hair/eyes, and the floor.

 

[Mcfigueroa84]

This is an awesome thread as we will be starting converting our E-450 next month.

What do you guys used to insulate the floors? I am freaking out as I have never build anything like this, don’t have any tools, my hubby is not handy at ALL, so I will be the one building it pretty much. And I have not idea on what to or even how to start.

I am trying to do this full time I order to avoid our hefty $2k rent. Anyways... hope you guys can help.

I am trying to find something that is going to be fire, water, and mold resistant. My kitties will be there all alone while we work so I want to make sure they are safe.

I am planning on having my batteries, invert, and propane tank outside (in separate compartments of course).

 

[Trestle]

Ref. insulating floors:

Depends upon how much height you have to loose. I have used a foam layer (I think it was an inch of foil faced foam sheet) covered by a sub floor made out of plywood. Plywood is anchored through the foam to the vehicle tie down points (you may have to supplement these if you don't think you have enough of them), and T-nuts in the plywood floor allow screw down attachment points from above. In this case I used 3/4" ply. I wanted the sub floor to be a sort of sheer plate.

It helps to have the layout on top of the floor templated prior to bolting it down so that you know where to put in the T-nuts. They have to be inserted from below, so that attachments from above do not pull them out.