Mixing Foam and Plywood in Teardrop Foamie Builds: Galley Design Challenges

[RobinR]

I am considering building a foamie in a classic teardrop shape but considering building the galley section with plywood. My logic is that the galley doesn't need insulation and plywood makes it easier to install cabinets etcetera, including the hurricane hinge for the hatch. I am intending to use PMF for the exterior and clear finish on the interior of the galley. I would insulate the cabin side of the galley wall.
If the change in material on the exterior would create a visible line in the PMF, I could glue 1/2" foam to it.

 

[Pmullen503]

If you have a seam between wood and foam, it will eventually show through PMF due to the different thermal expansion rates.

You could build the interior counter and cabinets from wood and after installation, cover any exposed PMF side walls with thin plywood. You could finish that to match the cabinets. The exterior could then be uninterrupted foam/PMF.

 

[KCStudly]

On my build I used 1-1/2 thk foam with 5mm okume inner skin and 2 plies of 6oz weave in epoxy on the outside. On the edges of the galley walls I laminated several strips of fir ripped down to about 1/8 inch thk over a form resembling the galley profile. These laminated arches of wood cap the walls and extend up past the hinge spar. Even with these wood caps, each about 1-1/2×1-1/2 in sections, I still have some movement in the humps of the walls that is farthest away from any other support. Whether it is temperature or humidity changes, the "tips" of the walls that are farthest from the hinge spar and floor will pinch in toward the hatch at times, and be fine other times. Adding the under counter support at the rear up off the floor helped some but didn't stop this pinching completely.

I think I have it stable enough to effect a good seal. Just saying, make sure to make your galley walls as rigid as you reasonably can in order to help ensure a good stable hatch seal.

 

[heyheyfifi]

Have you seen this video?

I made a “copy” of it in sketchup and uploaded it to the 3D warehouse if you search for “foamie camper”

 

[RobinR]

Have you seen this video?

I made a “copy” of it in sketchup and uploaded it to the 3D warehouse if you search for “foamie camper”

Thanks. I hadn't watched the full video. Intriguing that the shelves and countertop are foam.