Ski Shack "The Baker Bunker"

[simple]

This will be my first trailer buildout. I want something for my family and dogs to camp in at the local ski hill. Last season we camped in the Spacekap which worked great and now I'm thinking of trying something a little bigger this year.

Design goals:
As light as possible
Warm and dry
Room to chill
Sleeps 4
Dries gear
4 season that can withstand a freeze
Galley kitchen
Bathroom / mudroom with shower and compost toilet

The subject at hand is an all aluminum 20'x8.5' enclosed trailer. Amazon Scout dispenser #315. Amazon cancelled their scout robotics program and liquidated a ton of charging station trailers. This one is a 2022 and has almost no miles on it. It also has rear barn doors which I prefer over a ramp for this application.




Here is the inside with the charging bits



240 volt disconnect and main panel



After removing the charging platforms I found all this 8020 welded to the floor. Ugg




6 fillet welds per piece. I tried a few things like a router to cut the welds out but it came down to cutting them all with a circular saw and then breaking the last bit with a chisel. Kind of a PITA but got it done.



Now there is a mile of wire and conduit sitting on the garage floor and a huge pile of aluminum pieces in the yard. I'll save some and take the rest to the scrap yard.

 

[simple]

I plan to place EPS between the ribs in the ceiling and walls and then another layer of 1" EPS over that and then skin with some type of paneling.

I'm not sure what the best thing to do for floor is. Maybe high density XPS with a layer of ply and then coin mat. I think the performance would be good but I'm not sure it it's worth the weight penalty.

Is there something readily available that is lighter than plywood that bonds well and would protect the foam from point loads? I don't think I'm up for a wet fiberglass layup.

Is there a better insulation material for the floor? I've read about some people using the interlocking foam squares but this floor is going to see a lot of water on it and I think something like foam squares would be eternally damp underneath.

 

[Pacific Northwest yetti]

Thanks for the post, I look forward to following along.

 

[simple]

I looked at marine plywood for the floor today. 3/8"thick sheets are 5@40lbs. 1"XPS sheets are 5@4.5lbs. 20' of coin mat is around 60lbs. 1gal bucket of adhesive 2@8lbs.

Total added weight for floor approximately 300lbs. Cost estimate $1200

I assume the trailer is around 1800 empty but I still need to weigh it. My goal is to stay 3000lbs or less. I think it's possible but 300lbs of floor would be a bit of a hit.

 

[simple]

I'm finally getting to this project and now it's a race to get it far enough along to camp in for NY's.

Here's a pic showing 1" EPS fitted in between the vertical wall ribs. The EPS is not bonded in and any gaps around the edges will be filled with expanding foam. There will be a layer of 0.5" XPS over the top of the EPS and ribs for a thermal break.





I had to cut through a vertical rib to use some AT windows that I already had on the shelf. The area around the cutout was floppy and the window needs a solid surface for the clamp ring to squeeze down on. I decided to add some rectangular AL tube for part of the wall build out. The tube on the right side is added along with the horizontal pieces. Running a continuous horizontal piece would have been nice but I didn't feel like surgically cutting the existing vertical pieces shorter while trying not to cut the skin. I think this arrangement will work fine considering the window has a rigid aluminum frame and inner clamp ring.

I am using 3M VHB tape to match the thickness of the existing construction. It is also holding the tube in place to be welded in.



Tube installed and bonded with the tape.



Tube welded in.



I'll make some radiused spacers for the corners and bond them in with the same tape. On top of the frame around the cutout will get a 0.5" thick plastic spacer for the window clamp ring to press against.

 

[simple]

R10 2" EPS in the ceiling and 1"EPS in the walls. The gaps have been filled with expanding foam and the wire looms have been foamed over.



I cut the 1"foam with a break away blade knife. The 2" is a whiz with this Bosch foam cutting blade. The blade doesn't make any foam dust and cuts pretty vertically. I'm excited to see how it does on the XPS. I started with the jigsaw on the normal setting for a few inches before switching to orbital. It cut a lot better in orbital mode.

 

[simple]

Here's a boring update showing boring work. The part of the project that wasn't anticipated to drag on. 4 weeks of work.

I will say working in the shop listening to music while it's getting dark at 4:30 pm is not a bad way to spend time.

1.5" foam between the extruded aluminum floor and 1/2" marine plywood.




Recpro coin mat floor. I had to weight the edges. The adhesive they supply isn't very tacky.



Covering all of the interior aluminum framing with insulation.





I looked forever to find these clamps and then a neighbor told me that they are called Haul Master 2 in 1 support / cargo bars. "Extending clamp" searches yield no such results. Doh!



Can't wait to be done with insulation.

 

[ITTOG]

I am using the same foam, but 2" on my slide in camper build. How do you plan to attach the skin to the foam? I want my skin removable so I am thinking of Luan with velcro but wish I had a better attachment than velcro because it will make the rest of the panel stick out from the foam and it won't be as firm.

 

[SDDiver5]

Well this looks like it will be very warm lol. Nice work. Cant wait to see the progress.

 

[simple]

I am using the same foam, but 2" on my slide in camper build. How do you plan to attach the skin to the foam? I want my skin removable so I am thinking of Luan with velcro but wish I had a better attachment than velcro because it will make the rest of the panel stick out from the foam and it won't be as firm.

I'm going to use some stainless self tapping screws through the foam into the aluminum framing. The interior skins are going to be 4mm coroplast polyethylene. I'm still scratching my head on the seam details but I think I'll use 10mil greenhouse tape.
The interior may look a little like a space capsule but I'm serious about keeping it light weight.

My interior 1/2" layer of foam is only bonded to the aluminum ribs. If it was fully bonded and flat, I'd try some 3M double sided tape that is formulated for polyethylene to hold the coroplast on.

 

[ITTOG]

I like the 4mm coroplast polyethylene idea. Always good to save weight. I may look into that as well. Eventually I plan to cover all the walls with maps, topo and road, and pictures of places I visit. It won't really matter what is behind the maps and pictures.

 

[simple]

I like the 4mm coroplast polyethylene idea. Always good to save weight. I may look into that as well. Eventually I plan to cover all the walls with maps, topo and road, and pictures of places I visit. It won't really matter what is behind the maps and pictures.

I found a wholesale supplier and it was $14/sheet. There is a similar product for $11/sheet but they didn't have any in stock. It's all sign making material but the difference being, the more expensive stuff has coating that can be printed on.

I'm going to order a big peel and stick wall paper mural for the inside of the back doors. Fingers crossed the adhesive sticks to polyethylene.

 

[dstefan]

I like the 4mm coroplast polyethylene idea. Always good to save weight. I may look into that as well. Eventually I plan to cover all the walls with maps, topo and road, and pictures of places I visit. It won't really matter what is behind the maps and pictures.

I used 4mm Coroplast extensively in my camper build-out. All my walls are covered with it. I also made lightweight drawers out of it. VHB sticks well (sometimes too well if you prep it well and need to remove it). It’s sturdy enough that I have stuck velcro to it for BROG bags that are constantly being pulled on and off. I’ve also run small wires through the channels, and it’s heat bendable for corners if you want.

If you don’t want color, Home Depot carries white 4’x8’ sheets. It’s also mildly insulating. Durable and cleans up well. I covered the seams with 2” white Gaffer tape, which has held up well, but I’m curious about the greenhouse tape. May try that as needed.

I have also used 3/4” SS self tapping lathe screws drilled through into my 1/8” framing to hold corners or edges in some places where I couldn’t VHB. Just don’t drill in too tight as you can distort the face of the Coroplast. Might consider velcro mounting too for areas you may need to get back into.

Cuts easily with a utility knife (perpendicular to the flutes). For cuts along the flutes use one of these:

Edit: Sorry, but Amazon links are no longer working on EP like they used to for me. DK if it’s Amazon, EP or Apple, but I’ve tried 2 browsers and three different ways to post a live link 😤. Replace the XXXXXX below with amazon and it should get you there
“https://www.XXXXXX.com/gp/product/B00DTNNTTY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1”

 

[simple]

I tested greenhouse tape and it stuck well. It's some heavy duty stuff from greenhouse megastore that we already had. The tape on Amazon looks to be questionable quality.
The clear tape looked fine on the white Coroplast but I think white might look better.

I picked up some 2" wide white hull tape. It's what they use for shrink wrapping boats. It also sticks really well and I'm going to give it a go.

There is also tape for crawl space vapor barriers but it is mostly 4" wide.

 

[simple]

I burned out on this project last Feb and stepped away from it. Kind of a rough ski season with all the rain. This summer/fall I built a 600 sqft art studio (gray building) for my wife and have been fixing up a rental house so didn't have time for the trailer project.




Ready to get back to this trailer project. Here are a few pics from where I left off.


Clamping and bonding insulation over the wall and ceiling ribs. The clamps are Harbor Freight load clamps and have been really handy for other things as well.





Lots of coroplast paneling install




Testing sconce lighting. Also a view of the awning window.





Testing puck lighting and sconces.





This is a formed aluminum drain pan. It will be the bathroom / drying room closet and will have a dedicated diesel heater firing into it. Going to test out this new Joolca separator toilet.