Remounting Cabinets

[DanPatWork]

I was wondering if anyone has tried mounting the cabinets directly to the walls without the insullation, and "rat fur" using panel bonding adhesive. I've worked with some products in the auto industry that are used structurally to repair metal laminates, and this stuff really works. I'm considering this as an alternative to re-riveting, and then insulating and covering the inside, and walls after the cabs are re-attached. I've allready decided to re-glass the holes due to the amount of water leakage, and cracking in the gel. I'm going to have to replace the insulation and covering anyways, so I'm considering this route.

Advantage : no holes in the hull with the small exception of elec. hookup, water, and wiring. I'll probably butyl these and the windows anyways.

Anyone tried something like this yet? Any thoughts against?

Here's a link to the stuff we use at the shop.

3m automix

[Byron Kinnaman]

Mounting the cabinets directly to shell I would think you have a good thermal conduction where the cabinets are in contect with the shell. Condensation might be a problem.
That might be avoided by using 3M VHB for bonding the cabinets to the shell. It comes in various thicknesses. A .060 thick might provide enough insulation to reduce the chance condensation.
Boing uses 3M VHB to hold their airplanes together, strong stuff.

[Donna D.]

I was wondering if anyone has tried mounting the cabinets directly to the walls without the insullation, and "rat fur" using panel bonding adhesive.

Yep, check out Gary Little's 1986 Scamp Restoration. What a beautiful smooth trailer!

[Capt Ron]

I've thought about eliminating the rivet holes too.

On my Scamp, I could epoxy or fiberglass a wood 1x1 or 3/4 x 3/4 cleat inside the cabinets along the outer edge where the cabinet joins the body. Then I could put screws or bolts sideways through the cabinet wall into the cleat from the outer edge of the cabinet. The old flange could be trimmed off the cabinet or the holes filled with white epoxy putty or just glue a screw cap over them. If I trim the flange off, I would put some pinch welt trim on the cabinet or maybe just a split tube on the edge before finally screwing it in place.

Glassing cleats in like this would also serve to stiffen the shell some although it would likely add weight.

There must be a hundred rivets through the hull of my Scamp. It sure would be nice to eliminate most of them before I paint the exterior. Maybe after I fix the window leaks.

[Loren G. Hedahl]

I was concerned about introducing stress points by bonding wood members to curved areas of the fiberglass skin.

So I bonded rubber hose to the inside of the skin, then screwed my added shelving into the rubber hose. To make a bond successful it is important to give the surfaces some "teeth". This was done to both the rubber and the resin of the fiberglass laminate.

I am again making some changes and ripping out some of my previous work has convinced me this is a good construction process.

[Bonnie]

I was concerned about introducing stress points by bonding wood members to curved areas of the fiberglass skin.

So I bonded rubber hose to the inside of the skin, then screwed my added shelving into the rubber hose. To make a bond successful it is important to give the surfaces some "teeth". This was done to both the rubber and the resin of the fiberglass laminate.

I am again making some changes and ripping out some of my previous work has convinced me this is a good construction process.

Would you happen to have a picture of that?

Bonnie

[james kent]

In our Boler ALL of the cabinets, closet, kitchen unit, seating, and overhead cupboards are attached and held in place with a wide strip of fiberglass and polyester. Seems to have held up pretty good for the last twenty-three years. I don't see why it wouldn't work for you too.

[peterh]

This should work really well. There are a couple of things you'll want to consider/remember if you bond the cabinets to the shell.

The first is that a bond is only as strong as the stuff you're bonding to. If you simply bond the cabinet flange to the shell with epoxy, all the epoxy has to bond to is the polyester resin on the topmost surfaces of the fiberglass, and that's probably quite sufficient as long as the whole cabinet flange has an epoxy bond to the shell and not just a thin line where the two surfaces come into contact.

My suggestion: make a 50/50 paste of 60 minute epoxy and glass "microspheres," available at most plastics places that sell fiberglassing supplies, and apply a thick layer paste to the cabinet flange before (temporarily) securing it into the hull using the old screw holes. Doing it this way will squish the epoxy paste into the uneven surfaces. You can clean up the edges where the epoxy mix squishes out using denatured alcohol, which can also be used to thin the paste if you wind up making it a bit too thick.

Epoxy-microsphere paste makes for a very strong & lightweight adhesive, but be careful to wear a quality NIOSH dust mask when handling dry microspheres. Microspheres loft into the air very readily and are a respiratory hazard. Disposable gloves and goggles are a good idea, too, as the microspheres will coat your skin and break into a fine glass dust that can make you itch.

Whatever method you do use to bond the two surfaces together, make sure they come into good contact and the bonding material can transmit heat from the shell to the cabinet so they both expand and contract at the same rate, otherwise either the adhesive or the surfaces of the shell and cabinet will crack and the bond will fail.

Another thought on and alternative to directly bonding the cabinets to the shell: you might consider epoxying carriage bolts into 2" square punched metal sheets and fiberglass those to the shell where the old rivet holes are. That would allow you to use the same Reflectix/Rat Fur insulation treatment modern Scamps use and you'd still be able to remove the cabinets if you wanted to paint or replace them.

--Peter