I think a rebuild is in order.

Discussion in 'Camper Restoration Projects' started by mckeapc67, Jul 16, 2015.

  1. mckeapc67

    mckeapc67 New Member

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    Feb 22, 2011
    My PUP is showing her age and the effects of the humid southern climate.

    I already had to replace a section of the floor and now another spot is getting pretty soft.

    I also have several wall sections that have come loose from the floor & I suspect that rot is part of the culprit. The short sections of wall, front driver side & rear passenger side are loose. The front one isn't really affecting too much because the bunk is well supported by the brace poles. But, the rear one, which borders the door, is allowing the bed to sag a bit and the door not to align properly.

    In addition, because of the common cracking of the corners on the Flagstaff roof, I have a bad piece of wood in the leading edge of the roof.

    Given all of these issues, I think that I'm going to attempt a complete floor-up rebuild soon (maybe this winter).

    I'm thinking that I can certainly do the rebuild for less expense than replacing the entire PUP. While I'm at it, I'll probably do some mods in the interior by replacing some cabinets and possibly removing the shower unit and hot water heater which I never use.

    Here are a few thoughts & questions on the project that I'm looking at:
    • I'm thinking of going for rugged construction within the limits of my frame and axles. So, I'm looking at materials that should hold up better than the stock stuff.
    • What are suggestions for floor materials? I see many use exterior plywood rather than OSB.
    • Has anyone used 3/4 or 5/8 plywood for the walls?
    • I'm considering adding additional exterior access doors to be able to load/restock supplies without having to pop up.
    • I'm also considering adding a bit more depth to the roof sides to allow for thicker mattress pads or toppers. Has anyone done this?
    • Obviously, I would like to reuse the exterior siding & diamond plate. I'm thinking that contact cement is what is used to reattach?

    I'll keep an eye on this thread and be reading all of the other rebuild threads. Once I start the project, post a thread on the progress.
  2. edh

    edh Active Member

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    Jun 2, 2008
    Just a couple thoughts in response to some of your ideas:

    1. Re: your floor and walls: If you go with 5/8 or 3/4 plywood, or treated wood instead of untreated wood, you're going to add considerable weight. So you'll need to be sure that your popup chassis (axle, frame, tires, etc) can handle the additional weight. Same for your tow vehicle, esp. if you are operating near its limits now. Tongue weight could be an issue as well as total camper weight.
    2. Instead, I suggest checking into which materials best resist rot, other than treated plywood. Floors usually fail from water leaking in and sitting inside, not because of getting wet underneath. That's why OSB floors usually work out OK if there are no leaks. The resins binding them together make them less likely to wick up water and remain damp, making them generally more resistant to decay than dimensional lumber and regular plywood. Note that I am talking strictly about OSB, and not about any kind of MDF (which swells and falls apart when soaked). An exterior grade OSB might be your best bet.
    3. Also, if you use treated wood against steel it will react to a degree and corrode the steel. This includes your frame and any metal hardware that touches or is inserted into the treated wood. I am not sure how much of an issue this will be, but corrosion will happen faster when regular steel is in contact with treated wood. The way around it is to use stainless or specially coated fasteners designed for use with treated wood, though this won't help with things like your frame.
    4. Re: walls of plywood: again, think about weight. Also, compared to heavier solid wood or plywood, you can get usually get equal strength and better dimensional stability from panelized construction, i.e. a lightweight internal frame with a thin layer of plywood glued and screwed on both sides. You can check this out by going to Home Depot or whatever and looking at their hollow slab doors; they are very light yet resist deformation very well. Your camper manufacturer likely used this principle to make your camper lighter yet still strong enough. Whether going to bigger framing (e.g. 2x4's) will be enough stronger to be worth the extra weight is a question you'll have to answer. I gutted mine and am rebuilding cabinets, etc. with the panelized approach, using 1/4 inch plywood over 1x4 framing. Framing interior structure with aluminum channel is another option, but much pricier.
    5. Also, if you use plywood, you'll lose the insulation that's now inside your wall panels. You can insulate it by gluing foam to the inside and then gluing paneling to that, but you'll have a pretty thick wall that way, and that could prevent reusing all the aluminum channel that now covers the edges of your walls..
    6. You can increase the height of your roof's sideboards, but note that this will make your camper taller and harder to see over when driving or backing it up. I increased my 4 inch sideboards to 6.5 inches, a reasonable compromise for me.
    7. Extra doors so you can access the interior without raising the top would be handy, but keep in mind that each entry point is another hole. Every hole has to be very carefully engineered and sealed to assure that rain (and splashed water from the road when towing it) can't enter. Also, holes will affect structural integrity, so again, engineering it carefully to assure that your box remains structurally sound will be important.
    8. The real issue with camper design and durability is insuring that water is not allowed to penetrate to the interior; that's the cause of most camper box failures. You have even more of an issue down south with the higher humidity for more of the year. The fewer seams you have, and the more water resistant and long-lasting your sealing efforts, the better. To these ends I am going with eternabond doublestick tape to seal the entire edge of my FRP to my wood frame, and another layer of eternabond single-sided tape over the outside of all seams. I will then be caulking the edges of the eternabond. A couple coats of a good roll on bedliner (grizzly grip, monstaliner, etc) is expensive but adds insurance against leaks. And you have to paint FRP anyway as it yellows if you don't.
    9. You should be able to reuse about anything that's still in good shape, including the aluminum skins and extrusions. It's a lot of work to scrape the foam and adhesive down to the aluminum skin, but it can be done. I would opt for new, stainless steel screws and other fasteners; won't cost that much more and will resist corrosion much better.
    10. As for adhesives, many will dissolve the foam so find something specifically designed to bond your kind of foam to wood and aluminum. FRP is similarly fussy about the adhesive you use. I am not an expert on adhesives so am not sure if contact cement will do the job or if more modern adhesives might be better. I know contact cement is still pretty much the go-to adhesive for things like rubber roofs and laminate counter material. It's tricky to work with compared to adhesives in a tube like liquid nails and such.
    11.Finally, The cost of materials will add up surprisingly quickly. It sounds like you need to rebuild from the frame up, and that is a lot of material to buy retail. You might be able to get another camper you like that is in better condition for less money. Even if you spend the same money on another camper that doesn't need so much work, you'll be at least be saving a lot of the time and effort you'd otherwise spend on your rebuild. On the plus side, a total rebuild lets you make it the way you want, from layout to colors and materials, and lets you be as fussy and thorough as you want to be.

    I went with rebuilding mine from the shell up--floor and walls have been wet from roof leaks and I had to expose them so they will dry thoroughly so removed all the paneling down to the foam. Only a few small areas need repair due to rot so am not really replacing wood except for the cabinets I've designed. I had ideas about layout and design that I cannot find on the market, at least not at a cost I can afford. And also, I like tearing stuff apart, and like the challenges of designing something and making it work. As a teacher I also have time to work on it in the summer. So for me it was a good plan, though it's taking a lot longer than I thought it would (esp. to scrape out all the crappy paneling to expose and dry the wood and foam).

    So if you are handy, have lots of time, and love a challenge, you can rebuild from the frame up and, if well-planned, end up with something way better for your particular needs. Some have documented crazy-complex rebuilds in this forum. Whatever you decide, good luck, and do post pics of what you end up doing and keep us up to date.
  3. money pit

    money pit What could be so bad??? We are camping!!!

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    Oct 5, 2014
    [:)C] my 1983 viking which I took down to the frame and did (still doing) a frame up rebuild...my floor was a 1/2 non treated plywood....(from factory). I took black oil based paint and painted the plywood on the frame down side after wheel wells were cut and installed. My wall construction was 3/4 inch by 3/4 inch pine.....most were pretty rotted so I used them as a pattern and remade them using same side cedar that I cut down, paneling walls inside, foam board then skin..

    As for my roof rebuild that is where I am at right now...side walls are 1/2 inch plywood attached to the same 3/4 by 3/4 frame work with foam board....I will prolly leave it the same for weight. Only thing I might change is add some more cross bracing for support across the top.

    as for ur skin is it alum or abs plastic? most alum skins are attached with staples across the hidden lines and clear caulk or the putty from the factory at the corners.... as for the plastic skin I would think something like a spray on can style like 77 should do the job.....

    Keep us posted and share some photos of your progress....

  4. mckeapc67

    mckeapc67 New Member

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    Feb 22, 2011
    Thanks for the replies and ideas. I'll certainly do a thread on here if/when I start the project. I am leaning toward doing this project for a couple reasons. First, I love the PUP and would love to have the opportunity to do the mods that I would like and end up with the "perfect for me" PUP. Second, I would like the challenge since I enjoy building things anyway.

    If I decide that it would be too expensive or just opt for getting a new trailer, I may look into a hybrid design.

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