Lightweight Cabinets

[cthayn]

I am at the point to decide the material to build the cabinets. I will not use MDF or particle board, due to weight and the issue with swelling from moisture.

I could use hardwood plywood, but at 65-70 lbs a sheet, it would add ~400 lbs to the van.

So I am considering making composite panels using a wood and foam panel, covered with laminate sheets. This would all be joined with water-based contact cement.

I built a test panel with 1/2” foam and some scrap laminate that I had. I used some fir to build a 1-1/2” frame and cut the foam to fit inside. I just used staples to hold the frame together until I glued the laminate in. The wood frame would add strength and give me something solid to attach the panels together and screw in the hinges.





I didn’t have any real contact cement so I used some strong spray adhesive.



After the adhesive dried I trimmed the laminate with a router. The panel was pretty lightweight and stiff. It felt plenty strong, just at 1/2”, I would likely use 1”foam for the cabinets and I estimate it would be less than half the weight of 3/4”plywood. It would save over 200 lbs of dead weight. I also expect it would be close in cost, but probable a little more work.





I am not concerned as to the strength of the panels, but I am worried about adhesive failure. I have never seen contact cement fail, but I have only used it to attach laminate to countertops. How will it hold up to heat/cold cycles, or to the vibrations of many miles on a washboarded road?

I don’t want to build the cabinet and have them fail after a few years. I would join the wood frame with half-lap joints to add more strength, but the glued skin is what adds most of the strength.

So what does everyone think? Is there a better water based glue to use? I don’t have a vacuum press, so some type of contact glue would be needed. I know there are commercially available composite panel available, but they are out of my price range.

Thanks for the help.

[maptester]

I would suggest using a paint roller (perhaps a shorter foam roller) to apply the contact cement to the skin and the foam--and make sure the cement doesn't react & eat the foam. You want the best coverage you can make. I assume these panels would be for cabinets and doors--would you use these for bed supports? You might want to use strips of birch ply instead of fir in the panels--it would be stronger. Good luck.

[larrie]

I agree with the above about using plywood for the frame and a roller for the contact cement. You may also want to screw the frame together rather than staple it. Foam and plywood may not be the same thickness. You will want to verify that.

You also should think about how and where the cabinets will the attached to the floor, walls and each other. Also how will the shelving and drawers be attached? Additional framing may be needed in those locations.

[cthayn]

Thanks for the input and ideas. The plan is to use water based contact cement to avoid the issue of the solvent eating the foam. I will also use half-lap joints to make the frame.

The frame will be strong enough, I am worried about adhesive failure with the vibration and thermal cycles that a campervan will see.

For now I am leaning towards building the cabinet carcasses with traditional plywood construction using 3/4 and 1/2 Baltic Birch plywood, but building the cabinet doors with the foam and skin method. That will cut a lot of weight, and they will not be structural parts. And if they fail, I can just build new doors.

I will document the construction in my build thread.

[maptester]

I used 1/2" birch for the shelves, 3/4" for the upright supports, and 1/4" for the backs with every joint glued and screwed. I never weighted my kitchen cabinet but it seemed light enough.

[saline]

I used the same materials that maptester did and it has worked well. No MDF, particle board or OSB.