Foamie cabinets

[dbhosttexas]

So I ended up with an old Sportsmobile pop up roof van conversion camper. Doing a full resto-custom job on it, been camping it a lot when I don't have it in the shop getting upgraded / restored...

So far in the last year I have had 30 nights in this camper, while it spent 7 months straight in the shop getting a number of never maintained 1993 things fixed like old fuel pump, alternator, water pump etc... Some of these parts have been hard to find, some of it is the shop kept putting me on the back burner but I digress...

One of the plans here is to replace the original MDF cabinets, using them as templates for new cabinetry.

The van is a 3/4 ton and I want to do a 4wd conversion on it, so keeping the build weight low will help me out a lot...

Space is also a consideration...

So anyway, the idea is foamie construcction cabinets, however I would like to do fiberglass over foam.

The question is, what sort of foam and what sort of resin play nice with each other?

Just double checking. I think XPS foam + Epoxy resin is what i want but not 100% sure.

[tony.latham]

The question is, what sort of foam and what sort of resin play nice with each other?

Epoxy does fine with all foam boards. Polyester resin dissolves them.

Tony

[Pmullen503]

Never tried but I've heard you can use polyester resin on polyisocyanurate foam.

Not sure how long it would take for the smell to dissipate from inside a cabinet but it would cost less than epoxy.

[RJ Howell]

I've tried several versions of foam cabinets. Not convinced of structural integrity. A basic lower cabinet seems okay. Yet when you try to add door hinges or draw slides, I have not found it to work well. I've gone as far as adding inserts, as what ever you wish, it comes down to the foam integrity. In my humble opinion.. it just doesn't work.

Now, what I have found is if you skin that foam cabinet, you get a structural element. !/8" hardboard works well yet it's only the 1/8" that has that screw.. Overall, I go back to building with plywood. Be it 1/2" baltic or CDX.. Plywood dude. it works.

In reality how much weight are you actually going to save for the ROI going foam and all you need to do to make it work? IMHO.. not worth the effort.

[dbhosttexas]

@RJHowell the issue is the van is a 3/4 ton not a 1 ton, so payload is lower. 3550lbs vs 4340lb for the E350. The conversion that was done used MDF which is awful for weight I know.

The method I have seen for foamie cabinets is to basically create a wood reinformcement for anywhere hinges or hardware needs to be attached, dowelled into the foam.

Not really looking at financial ROI on this as I know this is a sunk cost issue 100%. I am working with updating a 1993 conversion after all. But that is because even going only to a 2003 quadruples the cost for this particular conversion... (Sportsmobile Penthouse roof model with the RB11 / rear dinette interior).

Part of my issue, and no small part mind you, is I have a tendency to bring with me cast iron cookware for proper camp cooking. And am planning on doing a 4x4 conversion to the van, all of which add to the weight.

I am looking to basically cut out about 200lbs from the interior build / rebuild. So my first thought was foam.

However look at it this way.

For those panels only needing cosmetic cover not structural, I could use 1/4" beaded ply which is 22lbs for a 4x8 sheet.
For structural I could go with 1/2" birch cabinet grade ply at ~40lbs / sheet.
By comparison 1/2" MDF weighs in at ~70lbs / sheet.

Compare that to 1/2" XPS foam at 2.7lbs for a 4x8 sheet...

What needs to be added to that figure of course if fiberglass cloth and epoxy resin weight...

I would think having to reinforce the foam panels for hardware would be no different than say having to reinforce for door hinges and windows on a foamie trailer...