What is the best skin to put under canvas?

[GPW]

1/8” around here , and it feels thicker than that ... Just measured @ 5/32”

[TheOtherSean]

If you used Masonite or plywood , both would be a bit heavy for under a canvas skin . Surely a bit of overkill ... Strong for sure , but ...

Remember the Old Timers skinned their trailers with Masonite , worked for them ...

The 4' x 8' sheets of 2.7mm plywood (denoted as "utility panels") at the local HD are under 1/8" thick, and felt fairly light when I picked one up. References give an average weight of 11 pounds for a 4 x 8 sheet of 1/8" ply, so this may be marginally lighter - maybe 10 pounds? For a 6.5 wide x 12 long x 6.5 high foamie canned ham, given 10 pounds per panel, it'd add from 50 pounds if adding the panels to interior or exterior of the sides, to 211 for skinning interior and exterior of roof and sides. That's assuming a rectangular box - the curved shape will reduce that somewhat.

I'm finalizing plans for a somewhat smaller trailer myself and anticipating a semi-conventional build - 3/4" foam sandwiched between 2.7mm skins with some 1x at overall edges and for blocking. Accounting for foam and skins, but NOT the 1x edges and blocking, windows, doors, spars, etc. I was looking at about 50 pounds for each side and 111 for the roof, for a total of around 211 pounds. Dropping the outer 2.7mm layer from the roof would remove about 45 pounds of that weight. Obviously, adding that other stuff in will add a bunch more weight, but that's a nice back-of-the-envelope calculation.

[GPW]

" maybe 10 pounds? “ ... Maybe more ...??? if you covered everything with “utility panels ” you wouldn’t need an fabric skin on the outside ... Just give it a couple coats of Aluminum paint, like the old timers did ...

At the HD yesterday ( buying lawnmower parts and generally just looking around ) we noticed a couple rolls pf protective brown paper ... one was thick paper , the other , was really Thick paper ... http://www.homedepot.com/p/Ram-Board-38 ... /202823781

[KCStudly]

TOS, Point of reference, my walls are about 9ft 8in long at the floor, 1-1/2 thk foam; 5mm (3/16) thk inner ply skin; with a 2x2 cedar sill and door surround; laminated fir hard edge along the galley wall edges (about equivalent to a bent 1-1/2 x 1-1/2 actual); numerous embedded 1x pine blocks, both inside and out, including 1x4's for the fender, side table and bulkhead wall blocking; and with the door made of similar construction (but not the window or hardware) they only weighed 45 lbs each. This was prior to adding the outer FG skin. With the foam wall core sitting on top of the sill the overall wall height at the crest is about 49-3/8 inches (IIRC). Being close to a Benroy profile (less curves cut away than a more traditional TD shape) and taller than most 48 inch walls, this would be a fairly conservative comparison for what you are proposing in a 3/4 inch thk core, so I think your 50 lb estimate is high, unless your walls are to be significantly larger.

[TheOtherSean]

Thanks for the point of reference, KC. It wouldn't surprise me if my estimates were significantly higher than reality. I do expect the reality of building a 12' canned ham as I described would come out heavier than you've experienced with the Poet Creek Express. OTOH, I could be wrong. I'll have some experiential data (though for a smaller design) in a few weeks, weather and work permitting.

[KCStudly]

Ah, it was the 12 ft nugget of info that I had lost track of. Got thrown off by the reference to 4x8 sheets.

[Alan_H]

" maybe 10 pounds? “ ... Maybe more ...??? if you covered everything with “utility panels ” you wouldn’t need an fabric skin on the outside ... Just give it a couple coats of Aluminum paint, like the old timers did ...

At the HD yesterday ( buying lawnmower parts and generally just looking around ) we noticed a couple rolls pf protective brown paper ... one was thick paper , the other , was really Thick paper ... http://www.homedepot.com/p/Ram-Board-38 ... /202823781

That Ramboard looks interesting. Wonder how well adhesives stick to it, since it has the spill-guard to protect from paint spills.

If we could find something that would adhere to it, then tape the seams, it could be a great skin for under canvas.

[GPW]

Alan , as some reviewers reported liquids will seep through it eventually ,so it must be permeable to an extent ( a paper product, and paint is rather thick anyway ) ... That and you wouldn’t need much to glue it to the foam , that’s not a big bond anyway , and in reality , the Canvas outer skin shrinks and compresses everything tight like a sock holding it all together ... Naturally it needs to be tested by one or more of us ... I think it was fairly cheap for 50 ‘ long ... Common reinforced paper packaging tape would suffice to cover any seams . all under the canvas anyway eh ?

And then ,after a quick check of the FoamStream outer skin this AM ( planning the Cleaning and updating ) ... 18 oz. canvas over 3.5” EPS (beaded foam) ... After several years outside now , the surface is quite HARD ... almost feels as if something is under it already , so we can only imagine any underlayment under the canvas would add a tremendous amount of strength and hardness to the surface of the foamie ... Or at least reinforce suspected high stress areas , like the floor wall join ...

[GPW]

You know , just thinking about it .... If it’s already waterproof , then it doesn’t need anything, but glued on ... That’s a time saver... Needs TESTING !!! Question now is, who has 30 bucks to spare ...

[Talia62]

This might sound crazy, but what about cork? You can get it in really large sheets, and pretty damned thin.

[JaggedEdges]

Cork is natures expanded polystyrene..... meaning that thin sliced cork has the same kinda strength as thin sliced EPS... i.e. none, tensile strength of wet tissue kinda thing. It's okay glued to a solid surface, but if you're gonna have to have a sheet of plywood to glue your cork onto, you just do it with the plywood, if it's not the properties of the cork that are special to you. I think handling larger pieces of it, you'd tend to put your fingesr through it or tear it under it's own weight.

[GPW]

Talla, Cork sheet , although attractive , has no "tear strength" , and is certainly not smooth ... BUT , think how nice Cork sheet would look on the Inside , and you could pin stuff up on it too ( Maps , posters ,pictures , lists , reminders to self) ...


EDIT: But you have given me an idea for the 10,000 + wine corks I’ve collected.

[greygoos]

Hi I brought this up in an earlier thread regarding new skins for Foamies and it wasnt well received but I am going to suggest it again and would appreciate comments. How about Expanded PVC foam? It is lighweight and inexpensive. I have thought about using it for an outside skin and or under canvas.

[GPW]

Goos , I believe some are looking for something that would add great Strength too , or make it smooth for the canvas .. which was never intended to be anything other than canvas anyway , but that’s how things go eh ???

Note: JMHO , I think I’m going to stay with canvas over foam as originally proposed, only because we know it works so well ( as intended originally) and we’re NOT putting our trailer in a Car Show or subjecting it to unusual stresses other than making it live outside ... ... so basically the outer paint job does Not have to be mirror smooth ... It’s a Camper .... a Foamie' Camper ...

[mikeschn]

Hi I brought this up in an earlier thread regarding new skins for Foamies and it wasnt well received but I am going to suggest it again and would appreciate comments. How about Expanded PVC foam? It is lighweight and inexpensive. I have thought about using it for an outside skin and or under canvas.

You need to tell me more about this...

How thick would it be?
Can you get 5' x 10' sheets
Would it just be a sub-layer between the Foamular and the canvas?
How heavy is it?
How flexible is it?
How well does glue stick to it?

Mike...