Pop-Up Trailer Standy Foamie Conversion

[daveo132000]

Hello all,

I posted to the Newbie form where I discussed embarking on a ‘foamie standy’ build. Due to our weather and my work schedule, I won’t see much progress in the winter months, since I need the garage for our cars.

Since I’ve learned lots from reading about others’ projects, I thought I’d document mine here as well, starting with the demo since everyone loves doing that.

Part 1 (Demolition) begins:

In late October 2024, I purchased a 1996 Dutchmen pop up trailer (model 1001) for $800. It was in pretty rough shape, but with new safety chains and re-lubed bearings, it passed inspection, and it was then brought back home where I had 3 days to cover it with a tarp before the first snowfall. It sat till the May 2025 long weekend when I opened it fully for the first time. No critters, but there was a 'je ne sais quois' in the air from being closed up for years.

I began a notebook where I kept all my info, including existing measurements of the original dimensions for later reference. As I found parts, I wrote their specs and sizes there as well, making it easier to plan out the design.

I quickly learned that a pop up trailer is basically held together by staples and a thousand Robertson square drive screws. A drill, knife, hammer and pry bar made short work of the insides within 6 hours. I scraped the roof’s interior Styrofoam layer from the fiberglass roof, bagging up all the debris, then moved the shell into the garage so the rest could be done in dry (and warmer) conditions.

The roof was cut into strips and then panels with a reciprocating saw, then all the wall panels were cut down to fit into our utility trailer for a trip to the landfill. The floor sheeting was cut into chunks with a circular saw and pried off with a crowbar since it was well glued and screwed to the frame. I salvaged the plastic wheel wells, and tackled the underframe prep.

The lifting mechanism mounts needed to be unscrewed, and some creative grinder work was able to cut the cables and springs so I could have manageable sizes of scrap metal. The old copper gas pipes, bushings, original steps, 12V lights and wiring was held on with a ton of self tapping screws that were all removed or ground flat.

At this point, I decided a couple of runs to the landfill were needed. A load of wood debris, a load of nasty cushions, tent walls, and miscellaneous debris made the yard look presentable again. I kept all the scrapped metal for now, since I didn’t know if it could be useful later in the build.

This ends part 1. Stay tuned for Part 2!

 

[Camping Cur]

Impressive amount of de-construction! You are well on your way to a really neat framework for a build. Having owned several pop-ups, you are so right in describing their construction. It will be a challenge but it seems you are up for it! Please keep us posted. Most of what you see with these are remakes and rebuilds using quite a lot of the original pieces. This is like a fresh build with a ready-made frame. Well done on getting it to that point!

 

[daveo132000]

Part 2 (Frame Preparation) begins:

Mother nature rained every weekend from March through May, then decided to stop in June. At this point in the build process, I needed to do dirty work outside, crawling around under the frame so I was happy to get some dry weather.

I rolled the frame back outside, then spent several hours using a wire grinding wheel on the frame to remove the scale and heavy rust, following up with a smaller drill wire brush for smaller spots. I needed to grind off two original flip-down front support legs that were beyond repair, but could re-use two rear support legs. I rinsed off the loose dust and paint, and allowed things to dry to check for any last spots to grind.

I then liberally applied a TSP spray over the whole frame and followed up with a pressure washer to remove any grease, rust or debris to prepare for painting. It was now late June, so things dried quickly, but I left the frame inside for a week to ensure it was ready for paint.

I purchased three cans of automotive rust reformer spray paint and a spray can plastic handle at Canadian Tire, and essentially sprayed the entire frame then let it dry for a week. Next, I brushed and rolled on about a litre of Tremclad black rust paint on all frame surfaces. Once the trailer is built, I definitely won’t be crawling underneath to paint!

After a ton of research Googling though June, I finally ordered a grey-water tank that would fit under the trailer, as close as possible to the axle for weight distribution, yet give ground clearance and room for the drain piping. Again, Canadian Tire came to the rescue. They sell a special-order Icon Holding Tank with 3” End Drain and tank sensors that fit. I ordered it in July, and work took a pause as we went on a vacation.

While I waited for the grey tank delivery, I tackled the lift jack which scraped and squealed like nails on a blackboard. I drilled out the original handle rivet and removed the mechanism. New rubber washers, wire brushing and Tremclad spray paint followed, then a liberal amount of grease. A short bolt and lock nut replaced the rivet, and now the lift jack now moves like it did from the factory.

The grey tank arrived, so I was ready to get it mounted, which would require fabricating supports. I briefly toyed with the idea of learning welding, and quickly decided I needed a professional to do the modifications I needed on the frame: 1) moving an existing angle iron support to the centreline of the trailer to support floor decking, 2) attaching two new flip-down front support legs, 3) adding removeable brackets for the grey-water tank (so if I ever need to replace the tank I could remove it from under the trailer), 4) adding a spare tire mount on the tongue, 5) adding some diamond plate to fill the gap in front of what will become the trailer’s rear door opening, and 6) fabricating a removeable step from scratch to enter the trailer.

I found a welder 10 km from home that was able to do the modifications I needed, however, a bare trailer frame isn’t road legal! So, I crafted some temporary platforms out of some salvaged plywood from the original bed slide outs and mounted the original wheel wells. I simply zip tied the platforms to the frame. I used a new trailer wiring harness I had to connect up the original tail lights, tested them, and then mounted them on wood blocks and zip tied them to the trailer frame as well. I figured with working lights and wheel covers, my trailer was now better than most of the trailers I drive behind, so off to the welder I went.

Two weeks later, I returned home with a lighter wallet, and a newly modified trailer frame. Definitely worth the money, as the welder thought of ways to do the work I didn’t consider. The grey tank was supported by 2 U-shaped flat supports that bolt up through the plastic flange and into nuts welded onto new angle iron supports stretching from left to right. I supplied him a U-shaped bolt-on spare tire carrier that he cut apart and welded the threaded rods vertically on new angle iron on the tongue, which is a better idea than bolting on the frame side. I was impressed with the removeable step, in that it doesn’t flex or rotate, and simply drops on to the rear bumper for when the trailer is parked.

I did some light wire brushing where the welding occurred, then primed and painted the new steel and welded areas. I then moved the trailer frame into the garage, and removed the tires so I could begin the building process indoors.

I think its important for new builders like myself to realize that planning and researching takes a lot of time, particularly as you try to find parts that will work in a non-standard application, or in a custom build. You need to consider how one part will impact on another, etc.

Just deciding on the grey-water tank took a few weeks as I searched the internet for appropriate suppliers, tank sizes that would fit, figured out how the drain could be routed, how the tank could be vented, and how the fixture drains would be plumbed to the tank. Thank goodness I found a welder who took my sketches and was able to create a solution to both hold the tank and allow the wide support bands to be unscrewed from underneath using bolts. It was well worth the money I paid.

This ends part 2. Stay tuned for Part 3!

 

[daveo132000]

Part 3 (Floor) begins:

Finally, new work could begin! I purchased three sheets of ¾” tongue & groove plywood for the floor and began laying them out on the frame starting on the passenger side. The groove edge was run down the (now fully supported) centreline angle iron, and I routered out a notch on the short end to allow an overlap with the next piece. I weighted down this half, and clamped it into place. I placed the driver side plywood next tapping tongue into groove, and staggered the joints to landing them all on frame steel. Once I was happy with the placement, I cut some 2x2 scraps and attached them under the wood, butting them up against the steel frame, around all sides to act as placement guides since I needed to remove the plywood to paint.

I traced the position of the wheel cutouts, then flipped the plywood pieces. I wanted to leave a consistent two-inch overhang around the frame to allow my PMF to glue later in the process, but since things were shifting a lot, I decided to trim the plywood only after it was secured to the frame. I cut out the notches for the wheel wells, planning to later attach the original wheel wells from the underside.

Once flipped, I taped off what would be later the exposed underside for gluing, and applied a primer coat. I followed this with a heavy coat of outdoor porch paint, and removed the tape while wet.

After thoroughly drying, I applied construction adhesive to the frame members, and placed the plywood panels, starting in the rear on the passenger side. The 2x2 blocks worked well to keep things aligned, so I used some self-drilling screws to attach it. I glued the notch, attached the front piece, then glued the entire groove and attached the next pieces on the driver’s side, tapping in the wood till the 2x2s contacted the frame. This left a slight groove down the centreline of the wood I will need to fill later. I then drilled holes for 5/16 diameter 1-3/4” carriage bolts I found at the Habitat ReStore, and bolted each piece of plywood with at least 3 bolts each. I loaded the surface with heavy weight and left it to dry.

Once the adhesive dried, I traced out the final outer edges of the floor. I discovered my frame wasn’t perfectly square, so I did my best getting the walls to be parallel and square to the front, but the best I could get was 3/8” out of square. After multiple attempts, I decided this was within my “acceptable” margin of error, so I trimmed the rear and long edges to their final dimension.

The front of the trailer will be a wedge, with a 2-foot-wide piece of foam extending up at a 45-degree angle, so I trimmed the leading edge of the plywood to length at the same angle. I ripped a 45-degree notch out of the foam on my table saw. Here is where my first mistake occurred. I ripped a 2x4 with a 45-degree notch to be able to lock the foam board down to the plywood, however I ended up gluing and screwing the board to the plywood flush to the edge. By the time I realized this error, it was impossible to remove, so I ripped a 2x3 with a 45-degree notch, and now this board will lock the foam board onto the top of the 2x4. The PMF will eventually get glued to bare wood equal to 2” plywood plus the diagonal of the 2x4. Oh well, it will add more wind resistance strength.

I then marked out the rear shower area and kitchen cabinet placement with tape so I could determine where my used RV entry door would need to be positioned. I was thrilled to find out the measurements I provided to the welder worked out, and my temporary step lined up well to the door opening.

I then built a 2x3 frame for the used RV door, with a temporary bottom member to keep it square, that will be inset into the rear wall. I wanted to have a sturdy frame to support the door, which I expect will see lots of hard use.

I've reached the forum posing max, so this ends part 3. Stay tuned for Part 4!

 

[daveo132000]

Part 4 (Foam Walls) begins:

After having watched a number of videos on foamie builds, I previously purchased a 16 oz bottle of Foam Fusion, which seemed to be the best rated glue to join foam. I took a trip to Home Depot to purchase 1-1/2 thick 4x8 sheets of wall foam, and began to join them up. I cut some strips of plastic vapour barrier I had in the shed, and laid them out on the trailer floor so the newly glued foam wouldn’t stick.

I needed to leave for a work trip for a few days, so I worked late the night before to glue the foam sheets to give them time to dry while I was away. Here is mistake number 2, although it really wasn’t clear before I started. Foam Fusion needs air to cure properly. I applied the glue to the notched edges of the foam sheets with a small brush, and taped the edges to keep them in place while drying. Three full sheets to a side and two for the rear wall were glued and laid out on the frame, with weights added to keep things in place. When I returned, I discovered the glue was still wet, so I propped each wall section vertically around the garage to let air reach both sides of the seams. Finally, after 2 more days, I felt comfortable calling them glued.

Wall construction could now begin. First off, I need to be able to get the thing out of the garage. With the wheels off, I could use furniture moving carts to move it, so using the current floor height, my garage door height, the RV door height, and my height, I settled on a 78” wall height. This will allow me to stand up straight with enough space to not feel closed in, and allow roof rafters with exterior foam to be applied while still in the garage. My first attempt at cutting the foam to height with a hot foam knife was a dismal failure so I decided the circular saw was the tool to use as it maintained a clean straight line.

I made two temporary supports, screwing them to the floor, and lifted the driver’s side wall in place. New discovery! My trailer floor isn’t level from front to back along the edge. Grr. So, I needed to scribe the bottom edge of the panels to the wood floor, then trim the excess with a knife and a sanding block. Once the wall bottom made good contact with the plywood over the entire length, I proceeded to build a 2x2 reinforcement to which my wheel wells will later be attached to the walls. I marked out where the wheel well blocking would be inserted, and glued it in with PL300. I repeated this entire process with the passenger side wall.

I cut out and inserted the rear door 2x3 frame, gluing it into place with PL300, and lots of tape. It didn’t hold well on one side, so the next morning, I scraped out the glue, widened the gap, re-glued the joint, and used a ratchet strap to keep the pieces joined while curing. Temps were falling at this point, as it was late September, and the glue was taking long to dry.

Rather than rushing things, I decided it was time to pause the project since work was picking up, and more importantly, the boss needed her side of the garage to park her car.

I purchased some furniture wrapping plastic, judiciously stacked the wall panels and RV door onto the trailer, and wrapped it like a burrito to protect the bare wood floor for the winter. I covered it with a piece of vapor barrier and then a tarp, tying it all to the frame with rope. It was moved back outside by mid-October.

Sharp eyes will note that I still need to add on a short piece of foam panel where the leading edge of the angled panel falls at the front of the trailer, but that step will need to wait till construction continues in the spring. I need to get some exact measurements for the windows and interior walls planned out before I know the exact angle I will cut.

Some notes for people cutting this type of foam:

The hot knife works OK, but I found it hard to control the heat so it wouldn’t smoke, and after it did cut, the edges receded from the marked line. The circular saw (or jig saw) works much better. However, as I made multiple cuts, I discovered an issue using the circular saw…. After making long cuts, the blade began to build up residue from the foam plastic, which caused the cuts to become more jagged or rough. I needed to remove the blade and clean it off with paint thinner periodically. While not readily visible, I could feel the difference between the cleaned and gummed up blade.

This brings my construction phase to a winter break. We already have had three snowfalls, and the trailer is buried under 6 inches of snow, so for the next few months I will be working on planning out the exact placement of my (now stockpiled) components: shower pan, 2 windows, a mini-fridge, and kitchenette. Canadian Tire had a good sale with a bonus point offer so I picked up the fridge and two new tires (the old ones were from 2016) in September, and I ordered some other parts like an electric inlet, water inlet, and exhaust vent during Amazon Black Friday sales.

I have also built an Excel spreadsheet to calculate axle and tongue weights, and overall trailer weight, so I can keep to my target of <300 lbs at the hitch. The trailer has a relatively long moment arm from the axle to the rear, so I need to watch the weight of any materials that are placed behind this point.

This ends part 4. Stay tuned for Part 5 (ETA May 2026)

 

[daveo132000]

Part 5 (Winter Projects & Spring Revival):

With the burrito-wrapped trailer outside buried under snow, the winter period allowed some more planning. I developed some drawings with LibreCAD that provided accurate dimensions to place everything along the two side walls. This also allowed me to calculate the convertible bench/beds to be built, and do an estimate of the overall weight of the completed trailer. If my math holds, I’m estimating about 1750 pounds gross, with 128 pounds hitch weight, a bit light. My research suggests approximately 10% of the trailer weight should be at the tongue, so I might use some heavier wood on the front half as I continue the build in the spring.

A couple of small projects moved ahead. I constructed my 30A shore power plug end to a 25-foot cord I acquired, and tested its weather tight connection.

I am thinking I will likely add trailer brakes to the trailer, so I bought a trailer brake controller and the required adapter for my vehicle, and installed it. I used lever connectors so when I eventually get to test the controller, I can easily redo the wiring if I got my wiring criss-crossed.

The original plastic trailer wheels must have scuffed the side of the trailer tires some time in the past 20 years, since there were actually 2 thin cracks in the side wall where the plastic cracked. This would have allowed water to enter the trailer cupboards when travelling in the rain. So, I bought 2 cans of black Flex Paste at Canadian Tire and applied a coat across the inside and outside of the wheel well walls. I embedded some nylon screen mesh into the Flex Paste to give it some strength resistance. Overall, this solution worked well, and the repairs are very well bonded to the plastic. Water tight!

My wife and I attended a spring trailer show in town, and we got some ideas for colour schemes, and some other layout or features to tweak in the interior design. Greys and blacks seem popular now!

After the Victoria Day long weekend, things slowed down at work, so I was able to bring the burrito into the garage to begin working on the project again. The tarping and vapour barrier over my plastic wrap protected the bare wood floor perfectly over the winter months, with no water damage. As I unwrapped the pieces, I double checked no critters had decided to gnaw on anything, and am happy to report all was well.

This ends part 5. More updates soon, as construction has continued!

 

[daveo132000]

Part 6 (Grey Water Plumbing Layout):

With the start of work, I needed to determine if my rear wall door location would permit the depth pf kitchen counter I needed, which itself needs to hide the drain pipe going into the grey water tank. If the drain location would be too far inboard, now was the time to redo the back wall with a wider passenger side panel.

With the tires still mounted, I dropped the tongue low and crawled under the trailer to estimate the tank location’s measurements. On the top floor surface I marked out the edge of the planned cabinet edges, so that the drain pipe would be near a cabinet wall and not in the centre of the storage space. I drilled a pilot hole in the floor, and dropped down a rod marked with grease pencil till it touched the tank.

I then crawled under again, unbolted the grey water tank (last summer, my welder fabricated support straps held up by 4 bolts accessible under the trailer) and noted where the mark landed.

I previously bought a rubber fitting to insert into the tank that will accept a 1-1/2” ABS pipe (Icon Direct Holding Tank Fitting 1 1/2" Rubber Grommet SKU:12483), so I measured how far I could move the centre of the drain hole towards the outer edge of the trailer, then re-installed the tank.

From above, I drilled a new pilot hole through the floor and into the tank. Once again, I removed the tank, and double checked the rubber fitting centred on the pilot hole would seal but be as close as possible to the tank end wall.

I marked out the required hole on the floor, and measured to the passenger side wall to confirm if my rear wall could accommodate the cabinet to hide the pipe. It does, but only barely, and I won’t be able to have a toe kick at that spot, but I’m fine with it.

So, I drilled out a hole in the tank, and inserted the rubber fitting. I then drilled out a hole in the floor, reinstalled the grey water tank for the final time, and cut a stub of pipe to test out the connection. Everything worked well, so I taped over the hole for now to give me a level surface to work on the wall panels.

This ends part 6. Wall panel work is next!

 

[daveo132000]

Part 7 (Wall Panel Work):

With the original side walls propped up, I used two cut offs to extend the front of the walls where the trailer’s front 45-degree shape will extend to. As this glue dried, I did some of the other steps previously posted.

I placed the driver’s side wall panel in place onto the floor, with a temporary brace. Then, I used the lower half of the angled front wall to mark out where the wall panel needed to be cut, and where the top half of the front wall will begin to angle back towards the roof.

I then placed the passenger side wall panel in place onto the floor, with a temporary brace. I again used the lower half of the angled front wall, sliding it flush under the driver’s side angle cut to then allow me to mark out where the passenger side wall panel needed to be cut, and where the top half of the front wall will begin to angle back to the roof. The lower half of the angled front wall is still wider than the trailer, so I can cut the final width once the wall panel placement is permanent.

I then laid the passenger side wall panel on the floor, and used a string line to so that the angle of the top portion of the front wall would be 90 degrees at the tip, and meet the roof at 45 degrees. Once laid out, I snapped a chalk line, and cut the panel to shape with a circular saw.

On this wall panel, I then marked out the various items that needed to land against it, such as a length of top cabinets, the mid-cabin shear wall, lower kitchen cabinets, a convertible seat/bunk and finally the egress window. All items fit according to my CAD plan! These marked lines will eventually be covered by an interior panel skin, but this step permits me to lay out the plywood inserts I will need to make next.

With passenger side wall panel cut and marked up, I used it as a template for the driver’s side wall panel, and also cut the front wall angles. I flipped it and also marked out the various items that needed to land against this wall.

This ends part 7. Wall panel inserts are next!

 

[daveo132000]

Part 8 (Wall Panel Exterior Light Inserts):

With the wall panels cut to size, I planned out where my exterior lights needed to be placed for the trailer to be road legal. Princess Auto had LED tail lights and red and amber marker lights on sale a while back, so I purchased a complete set. They are all surface mounted, so I decided I wanted a bit of meat to screw into after the exterior skin was in place.

I found a 2’x2’ ¼” birch plywood panel at Home Depot, and cut the various inserts needed for the lights.

I did a test plunge of my router with a rabbiting bit to measure the cut to the edge of the base, which then allowed me to measure and tape on temporary stop blocks to guide the cuts. Then I set my depth, attached a vacuum, and cut out the various clearance light holes.

On the rear wall panel, I marked out for the tail lights and license plate, as well as the top and centre marker lights and an exterior door light. With the stop blocks in place, it went fairly well. Any round corners were simply trimmed square with a razor knife.

I spread a thin coat of PL Premium onto each of the wood inserts, and adhered them into the wall panels till dry. A bit of sanding might be needed to ensure they are plush to the foam surface before I skin the outside.

This work was quite exacting, and took a few evenings to measure out and cut the holes. I definitely needed the vacuum to remove the foam router shavings…. With ear defenders on, I once forgot to turn on the Shop Vac and immediately the foam bits blocked my view and clogged up the cutting area!

This ends part 8. Wall panel Interior inserts are next!