Alternate skins ....

[dales133]

Ive been pretty impressed with the 3mm ply over foam with pmf onto.
Its easy to get a super straight finish as you can patch and sand the ply true and i recon your chipboard would be just as good

[Ned B]

Bears ... Cute as Teddy , Scary in the flesh ( fur) ... hahahaha
Naa, no worries eh , with no rules , nobody gets offended , even at the bear jokes ....

Interesting thread. As I'm about to start my build of my sleeping car 'soon' I'm pondering covering. One reason I'm drawn to foamies is the PMF , doubly so now that KC has chosen to glass TPCE. There's no way I would ever consider personally glassing a trailer. I do have a son who is a body man though. I have no qualms though with a tb2 over duck cloth covering. I'm going to take a new path however for the top coat/ coloring & go with PlastiDip. Easy to apply, easily renewable & just wait til you see the colors!

Tony, clever with the bear!
I'd have thought that a long time Foamie supporter would've known the true Foamie nemesis however:

ImageUploadedByTapatalk1451565468.242721.jpg (177.39 KiB) Viewed 1071 times

[KCStudly]

The decision to do glass/epoxy instead of canvas/glue was a long and hard one for me. The canvas/glue is very impressive and I would not discount or discourage anyone from using it. It has a lot of good things going for it, and very few detractions.

I have always said that TPCE is as much a personal challenge to push myself and my craftsmanship abilities. To that end, and the expected durability and longevity that the FG will bring, I decided to go to the extra effort (... and expense) needed to do the glass. Like so many things (canvas and glue included) it just takes proper setup (including PPE), planning, practice, patience and a lot of work to make it the best that you can. I expect that I would have given PMF the same love and attention to detail that I am giving the glass; so if using me as an example, consider my anally retentive nature and compare it to your own "level of pain" on sweating the details as a factor before deciding which is easier.

For comparison look at atahoekids Road Foamie as an example of a faster built but perfectly presentable glass over foam TD. Atomic's Astroliner uses a lot of composite construction and is a good example of a professional grade masterpiece that is also coming together much quicker than TPCE. The point is that everything has its own level of difficulty vs. time vs. cost vs. outcome vs. experience factor. The end result is all relative to the individual person's experience and willingness to go through the effort.

Remember, too, that some people don't glorify all of the gory details, making the outcome seem that much more easy to achieve; whereas I "spill my guts out" frequently sharing all of the trials and tribulations.

I still have a big roll of canvas and the Charcoal Briquette UT. You never know, there may be a canvas covered/hard sided/standy/trolley top/slide-in in my future.

If I do another one, I just might do canvas over ply, or even canvas over chip board; not because FG is too difficult or expensive (... it is), but because I will have already done a FG camper at that point and enjoy all of life's varied opportunities to experiment and learn. Dare to be different.

[Ned B]

KC your build is an inspiration! I am fascinated by the process itself. I simply know my own abilities and tendencies. FG would drive me to drink... I *think* I can pull it together and manage PMF.

As a woodworker I am jones-Ing to build a traditional woody/plywood as the second or third project behind my sleep trailer this year, then my bigger wanderer eventually.

[GPW]

As much as we love woodworking ( making guitars ) , our first trailer (wood) came out exactly what I wanted , but just didn’t last ... plywood de-lamination due to splitting on the outer curved surfaces ...canvas skin on top would have fixed that .. The foamie was a compromise between a traditional trailer , and a tent ... The canvas skin flexing with the foam , allowing such things as self healing and super easy repair ( patching) ... besides the easy , and Thrifty building method ... A simple camper , to go camping in ...
We felt to really take advantage of a good solid fiberglass skin over foam , it should be like a Boat , the Fiberglass skin rather thick and solid , the foam merely becoming mould and insulation ... The fiberglass itself becomes the structure ... and can be filled and sanded in traditional auto body methods to produce a smooth shiny finish , just like on a car ... We’ve had friends in the past in the boat manufacturing business , making everything from pirogues to large Lafitte skiffs , using traditional fiberglass methods... That and my Brother ’s body shop specialized in Corvettes ... fiberglass for obsessives ... everything had to be "better than perfect" ...

What we have here is a choice of various degrees of skin “hardness” possible ... from plain fabric , to chipboard , to fiberglass, or even metal ( yet to be fully explored) ... remembering if the Foam is to be the structural element , the skin must follow that ... If the skin is to be the structural element , then the foam becomes less significant.
It’s all a Compromise .... What You choose to do !!! what you Need !!!

The BEST thing is for those in doubt , you can conduct some small tests on your own to see which way you want to build ,and which skin choice to use ...

[vigilant1]

We felt to really take advantage of a good solid fiberglass skin over foam , it should be like a Boat , the Fiberglass skin rather thick and solid , the foam merely becoming mould and insulation ... The fiberglass itself becomes the structure ... and can be filled and sanded in traditional auto body methods to produce a smooth shiny finish , just like on a car

And I think the glass/epoxy would probably do really well, but dang--the cost. I'm not an expert, but I've heard folks who build boats and airplanes often fo with about 17 oz/sq yd of fiberglass, which requires quite a bit of epoxy to lay up/fill. And that thickness is driven almost exclusively by the need for local "toughness" to survive the bumps and dings of life, they could get by with much less if all they needed was to provide actual strength/stiffness.
If we could get a cheap, tough, entirely waterproof, light, gluable with epoxy skin to go over the foam (to supply toughness by spreading out local pressure over more foam), we could get by with probably 6 oz/sq yd of fabric, and much less epoxy. But I don't know what that would be. The closest I can think of is very thin plywood drenched through with "the mix" (25% PU/75% mineral spirits).

GPW, from your OP here, it seems you're optimistic about chipboard holding up to the elements (if protected) better than plywood. Have I got that right? Seems backward from what I'd have thought.

Mark (who knows almost nothing about anything)

[GPW]

We just feel that since chipboard is made of the same material as plywood ,cellulose , just arranged differently , that it would also be able to be waterproofed in the same way (better actually) ... BTW, my test samples in the FS are working just fine ... Some were exposed to moisture and didn’t swell or deform ...

So far , you can use T2 to glue chipboard to foam ...then once that’s dry , you can add "the mix" on the exposed chipboard side and it will sink in all the way through to the T2 areas... then painted on top of that , produces a more “plastic-cellulose hybrid “ material much more durable than just cardboard alone ... Possessing a similar density , we can expect it to behave similar to plywood, strength-wise , except doesn’t de-laminate or split with the grain ...
For a really sturdy build , I’d suggest canvas over chipboard , over foam ... That would be really STRONG ... not as brittle as fiberglass ,and not as expensive to do ...

Just a thought ... The chipboard , no matter what , must be waterproofed , otherwise it’s no better than surface painted plywood ... For those with doubts , take the test .... properly waterproof a piece of chipboard , let it dry/cure , then soak it in a bucket of water and see what happens ... Prove it to yourself ...

[tony.latham]

GPW:

that since chipboard is made of the same material as plywood

Just to be clear, when you say chipboard, are you using that generic term for particle board or OSB (oriented strand board) or something else that I'm not familiar with?

Tony

[GPW]

Chipboard . like the kind found on the back of writing tablets ,legal pads , etc. only Thicker ~ .120” ... essentially a Very thick paper , which as you know is made from wood ... same as plywood ...

http://www.utrechtart.com/Chipboard-Sca ... ng.utrecht Here’s a place I got mine from ... good prices ... the locals were twice as much ...

[tony.latham]

Chipboard . like the kind found on the back of writing tablets ,legal pads , etc. only Thicker ~ .120” ... essentially a Very thick paper , which as you know is made from wood ... same as plywood ...

http://www.utrechtart.com/Chipboard-Sca ... ng.utrecht Here’s a place I got mine from ... good prices ... the locals were twice as much ...

It sounds like you are talking about what we might call non-corrugated cardboard up here at 45º north. Bear with me, I'm a little down on my coffee so far...

Tony

[GPW]

Yep, that’s it ... !!! I’m just now on my second cup ...
The non corrugated (shipping box) type cardboard ... Gray looking , dense, same stuff a cereal box is made of ... Great stuff, easy to work with common tools , but the trick is waterproofing it .... that makes it into a Much better product for our needs , and is easy since it soaks up the mix like a sponge ... As I might have mentioned before , it’s best to glue the chipboard to the foam First with something like TB2, because the chipboard is absorbent ... and after that is dry /cured , then liberally soak the rest of the chipboard with the waterproofing mixture ...

Ps. We have used the brown corrugated cardboard before for making model planes , but would Not consider it for trailer building ... and we used the same glues and waterproofing mixture on that too .

Here’s where we learned about cardboard construction , and what is possible ... and where “the mix” comes from ... http://www.feltondesignanddata.com

[vigilant1]

Chipboard . like the kind found on the back of writing tablets ,legal pads , etc. only Thicker ~ .120” ... essentially a Very thick paper , which as you know is made from wood ... same as plywood ...

http://www.utrechtart.com/Chipboard-Sca ... ng.utrecht Here’s a place I got mine from ... good prices ... the locals were twice as much ...

It sounds like you are talking about what we might call non-corrugated cardboard up here at 45º north. Bear with me, I'm a little down on my coffee so far...

Tony

Tony, I'm so glad you asked that. I've never heard of thick, un-corrugated cardboard referred to as "chipboard" before, but apparently it is common. I thought we were talking about thin (1/4" or so) OSB. Everything makes a lot more sense now.

Cellulose-- what makes it cheap ("It grows on trees") is its Achilles heal (food for mold, etc when wet). But, probably okay if we recognize its limitations and deal with them.
Mark

[GPW]

"(food for mold, etc when wet) “ .... Hence the need for the waterproofing .... OK ???

[vigilant1]

"(food for mold, etc when wet) “ .... Hence the need for the waterproofing .... OK ???

Okay!!! Waterproofing is certainly important.
Observation: Almost every wood-framed factory trailer leaving the showroom is 100% waterproof. Many of them have rotted through after a few short years.
What would belt and suspenders look like?
- Keep the water out (protects the contents and the structure of the trailer)
- Design and build so the trailer can dry quickly when water does get in (no materials or assemblies that trap liquid or vaporous water)
- Avoid materials that fail when wet.

But, that's admittedly an ideal approach. In real life, compromises are usually required if we want to make progress.

Mark

[GPW]

Quote: “ Almost every wood-framed factory trailer leaving the showroom is 100% waterproof “ ... So they say ... ... My RV dealer lied more than an Army Enlistment officer ...

The three rules ^ .... Good ones !!!