1977 FWC Fleet Complete Overhaul

[pods8]

Epoxy and cloth strips (not polyester resin or mat) over just the joints isn't too complicated (compared to glassing the whole thing). If you want to talk details let me know.

 

[Vic Harder]

I have a contrary thought about the strategy of making our campers "bombproof". One of the things I like about them is that they stand up well to time/abuse, and can be diss/reassembled. Hence I used NO glue when I re-built my camper(s).

Maybe of combo of approaches is best, making somethings that never should have to come apart more bombproof than other parts?

 

[pods8]

I have a contrary thought about the strategy of making our campers "bombproof". One of the things I like about them is that they stand up well to time/abuse, and can be diss/reassembled. Hence I used NO glue when I re-built my camper(s).

Maybe of combo of approaches is best, making somethings that never should have to come apart more bombproof than other parts?

I've been talking strictly about the floorpack, not the cabinets (someone else mentioned cabinets). For the cabinets yes allowing for disassembly/changes is a wise approach, you don't want those one piece all glued together permanently imho.

For the floorpack I don't want it rotting and I don't want it coming apart. I've seen rotting and coming apart in multiple older campers, usually starting with the edges of the plywood wicking in water/rotting/taking damage which is why I want those edges sealed up well.

 

[Vic Harder]

Makes sense to me!

 

[rtpvibes]

Looks like a great bill

 

[Bailey77FWC]

That all makes sense to me - I think for the interior we want everything as modular and reworkable as possible. I guess the floorpack is more permanent though.

Well we finally got some plywood - I did end up using baltic birch since Front Range Lumber didn't have any 1/2" or 5/8" marine grade. They only had 5/8" baltic birch in 5'x5' sheets, so I went with my hybrid thickness plan and bought 1/2" for the vertical surfaces and 3/4" for the horizontal ones. We cut about a third of the panels out tonight with help from my dad, while my sister cleaned up the frame and pulled out the remaining staples.
What do people typically do to seal up the plywood? I was going to use spar varnish, but I wonder if some kind of epoxy would be longer-lasting. @pods8 I've been thinking more about your fiberglassing idea... maybe coating the whole thing in a good West System epoxy and embedding glass cloth just around the joints is the way to really do it right?

 

[JaSAn]

I just used spar varnish, 3 coats and double on the edges. It shouldn't be getting wet inside.

My build is modular but each module is made to not come apart. It has withstood 8 years of offroad pounding.

I did a lot of alternate designs in SolidWorks before I started building and the setup has worked well enough to not want to change very much. I did rebuild my refrigerator housing when I replaced my fridge but I wouldn't have used the old cabinet parts anyway (went thinner and lighter).

 

[pods8]

What do people typically do to seal up the plywood? I was going to use spar varnish, but I wonder if some kind of epoxy would be longer-lasting. @pods8 I've been thinking more about your fiberglassing idea... maybe coating the whole thing in a good West System epoxy and embedding glass cloth just around the joints is the way to really do it right?

The original ones were just coated in a single part paint, originally oil based iirc. If you want to go that route the homedepot in Arvada carries glidden floor and porch gloss polyurethane OIL based which is decent esp. in our climate but I'd consider that a bare minimum. The other stores in the area didn't have it when I bought some for a different project recently.

There are magnitudes to doing it better and where you feel you want to step off the overkill train (esp. in the CO climate).
-IMHO since we aren't in a production environment skim coating it in epoxy seems a wise and easy move because it'll soak into the wood fibers bonding them together better against damage and water intrusion. Other than some cost its not difficult to paint epoxy onto a surface and let it soak in, you'll need to scuff sand it once cured to prepare for painting afterwards.
-Adding some glass cloth over the joints would be an upgrade and help those more prone areas hold up better (you'll need to put a smaller fillet on the inside corners with thickened epoxy to get the glass to lay into those). This doesn't add too much difficulty.
-Doing a thin layer of glass over the whole thing would be best to really add a layer over all the wood fibers to resist against the wood checking and add further waterproofing. This part is more time consuming and finicky.

You will still have to paint for UV protection. A bedliner material (esp. a two part one) would be a great tough coating over it all imho.

Yes west system is a major brand. System 3 and some others are out there too like uscomposites.

I just used spar varnish, 3 coats and double on the edges. It shouldn't be getting wet inside.

He is talking about rebuilding the floorpack, not the cabinets (yet), it will absolutely get wet on the exterior.

 

[Bailey77FWC]

@JaSAn that's just what I am going for - I hope to be able to push this thing pretty hard off road! I haven't even gotten beyond the daydreaming stage as far as interior layouts go, though. I hope to also keep it light and simple... We're used to tent camping so the goal with this build is nothing more than a structure I can stand up in with a furnace and some lighting for winter use.

Pods - I really appreciate the advice here, you clearly have some great experience with fiberglass and the different matrix systems! I was trying to brush up on all that after work this week; I worked with composites a bunch on college but that was like a decade ago now haha. I think I'll order a kit of MAS epoxy from Chesapeake Light Craft to do the bulk of the sealing. I also ordered threaded inserts for the aluminum and a bunch of hex head 8-32s...

I'm hoping to be able to create a stronger connection between the upper frame and plywood structure with these inserts... they mount with tiny 2-56 self tapping sheet metal screws... This is probably overthinking things, but I didn't like the weight of everything in the camper riding on .0625" aluminum "threads".

I have most of the plywood cut, and the plan is:

1) Assemble the plywood panels to the frame temporarily with clamps, and glue/screw the plywood joints together... Currently thinking I'll do each side seperately and install the floor last.
2) Pilot-drill the locations for the threaded inserts through the plywood and into the aluminum frame (to guarantee they will line up)
3) Remove the wood structure and install the threaded inserts in the frame
4) With each plywood assembly seperated from the frame, seal them up with the MAS epoxy - possibly add some glass tape to the joints (haven't decided on this yet)
5) Final install the plywood subassemblies to the frame and seal up the two joints between the floor and side subassemblies with epoxy.

 

[Bailey77FWC]

I've built up both sides of the floorpack, with just the bottom floor to cut out still:

The plan is to assemble the floor in three parts, the right/left sides and bottom. We assembled the plywood with Gorilla Glue and wood screws every 6"... the pieces line up so that the screws are always going through the 1/2" pieces and into the 3/4" ones in an effort to reduce the risk of splits. I also predrilled all the holes and ran the screws in before the glue cured. The wood was all clamped to the frame while we were putting it together, so hopefully the finished product should fit nice and tight!

The left side of the aluminum frame has the threaded inserts installed, and the plywood subassembly is bolted to the frame through them using 2" long 8-32 hex head screws:

Each one of the inserts has #2 self tapping screws to keep it from spinning:

I also put huge washers on the screws (on the wood side) to distribute the load some. There are about 30 bolt/insert pairs on the left side of the camper (not counting the "bottom" floor), so I'm hoping this setup will make for a stronger joint than the original had!

After getting all the plywood assembled, I unbolted the left side as a subassembly to prepare it for epoxy:

We added some more glue fillets and enlarged the bolt holes some, to hopefully make it easier to find those inserts again after the plywood gets epoxied. In the morning I'm planning to sand it all and radius the outside edges so the glass cloth can conform to them better.

 

[Bailey77FWC]

We intentionally haven't installed the threaded inserts to the right side of the camper yet - my fear is that the epoxy and fiberglass will warp the plywood subassembly just enough to make it tough to realign the holes with the inserts. I couldn't decide if it would be better to install them before or after fiberglassing, so I figured I'd try it one one side first. If it's a nightmare I know to switch the order of operations on the other side!

I'm terrified to apply the fiberglass and epoxy - scared to ruin the good work we've done! We have several yards of lightweight 4oz cloth to work with and MAS low-viscosity epoxy. I sprung for the kit that includes the metering pumps, mixing cups, rollers and spreaders so hopefully that makes things easier. We'll try to coat the outside of the subassembly, let that cure and then fip it to repeat on the inside. I am still wondering if the fiberglass itself is really worth it, vs. just coating the plywood in epoxy. I bought it, so I'll try to include it on this side at least!

 

[pods8]

What speed hardener do you have, I passed on doing a layup this weekend to finish glassing my floor pack due to the temps, I just didn't want to race the setup time with the elevated temps speeding it up. If you're worried work in smaller sections.

Glass probably is overkill as I mentioned before but I have it so I chose to do it.