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daveo12345 12-08-2020 08:14 AM

Stick Built Conversion to Molded
 
ok - not really but let me explain

I have a keystone outback stick built. Original owner and I understand that all campers leak.

I also own a swimming pool. 25 years ago the interior suface was converted to fiberglass. 10 years ago I had the company apply a second layer of fiberglass.

So.....

Lets say you had a stick built rv. Could you:

1. remove all moldings from edges.
2. Wrap the entire rig in fiberglass, roof to bottom

you would eliminate almost all seams

Wonder why not even 1 stick rv manufacturer has done this. Of course it is not as good as a moulded fiberglass, but it seems close?

Dave

Jim Bennett 12-08-2020 08:38 AM

Quote:

Originally Posted by daveo12345 (Post 800227)

Wonder why not even 1 stick rv manufacturer has done this. Of course it is not as good as a moulded fiberglass, but it seems close?

Dave

Because it is simpler to just build a fibreglass shell in a mould to get a superior product to glassing over a stick built shell.

There are lots of fibreglass built-up panels that in themselves are a good thing. The problem is in the fact they have a long joint around the roof and on the corners.

daveo12345 12-08-2020 08:45 AM

followup
 
I am aware of the joints in a stick built, believe me. I think we are all (us stickys) are all aware.


I do agree that molded makes sense. But the cost difference is amazing.


15k for a sticky which lasts 10 years vs. 40k for a molded. There's only a couple options for molded 20ft.


I'm just thinking a wrapped sticky could be done much cheaper.



I watched the guy do my swimming pool. He did epoxy with a roller, then glass, then epoxy the gel coat. 1.5 days for 1 guy. He lightly sanded between coats.


So if i had a sticky with no decals, few holes in roof, no rubber roof, i would think 1-2 days extra. Maybe a 2k added and might just double the life of the camper?


I figure the tooling costs for the fuberglass molds are 250k.


I wonder how boat manufacturers do it?

Rzrbrn 12-08-2020 10:40 AM

The molded fiberglass folks make their product the same way as the fiberglass boat mfg's do. Both use female molds, gel coat then either chopped fiberglass or fiberglass mat, then resin.

But...there are also wooden boat builders that basically have a wooden boat and apply a layer of fiberglass over the wood. This seems to be the method you are suggesting. This website gives a basic idea of how to do that:https: //www.diy-wood-boat.com/applying_glass_cloth.html

daveo12345 12-08-2020 10:51 AM

This is exactly what i am talking about.


I think it would be easier to start with a rig with a fiberglass roof rather than trying to remove or fiber over a rubber epdm roof.


I am thinking of doing a trial on by worthless sticky.



I cant imaging doing this is alot more labor intense than applying and sealing all that molding?


I'm betting the stick rv manufacturers know this is a good idea, but want their rigs to fall apart so folks keep buying?


This would be a great aftermarket business.

Cliff Hotchkiss 12-08-2020 10:54 AM

I think you would wind up with more than a few cracks in your new fiberglass shell. The shape of your camper probably wouldn’t allow for large radius corners, the stick frame would probably flex quite a bit too. Don’t forget your fiberglass coat is just adding weight to the structure, not support. Your swimming pool is not going down the road at 70 mph and the water in the pool is actually keeping it in place.
That said if you had a leaky trailer that you’re willing to experiment on, you should try it, maybe start your self a whole new business venture. I know there’s a lot of leaky stickies out there😎

Tom Y 12-08-2020 11:00 AM

Stick built is just that, typically balsa wood or another light wood framing flat sides, cast fiberglass incorporates
the shape to form the structure instead of framing. Our bodies have no framing required, they just sit on top of a metal frame. That's how we get away with the heavier weight of the fiberglass.
If you added a shell of fiberglass you would probably exceed the gvw of the stick built.
A stick built tends to work and loosen at those hard seams, along with expansion/ contraction it's just a matter of time before their leaking. Not so sure glassing over would stop the flexing.
If your going to use a camper alot migrate away from the stick built, they depreciate much faster for the above mentioned reasons compared to a cast fiberglass unit.
Just my 2c.

daveo12345 12-08-2020 11:29 AM

So i get the points about flex and weight. Probably could calculate the weight added for resin and glass matting. Could remove the epdm to save some weight.


Regarding strength, a boat slamming down on water and waves i would think causes more flex? Only on way to find out if it would crack. Ill look for my MEMS engineering books and calc the tensile and flex for fiberglass and see.


If i were to do this on my sticky i think i would try a checkboard layout of the glass and of course wrap the corners both lengthwise and horizontally.


When they did my pool if was 2-3 5 gallon buckets of epoxy, so wtih the matting im guessing +300 lbs? minues the rubber roof maybe +250?


Of course there would be no way to get the same strength as molded,



Probably alot of sanding and buffing at the end.


Still i am very curious if this could be done. There is one youtube video of a guy doing it on a small tool trailer made out of stirafoam

Cliff Hotchkiss 12-08-2020 11:44 AM

Quote:

Originally Posted by daveo12345 (Post 800248)
So i get the points about flex and weight. Probably could calculate the weight added for resin and glass matting. Could remove the epdm to save some weight.


Regarding strength, a boat slamming down on water and waves i would think causes more flex? Only on way to find out if it would crack. Ill look for my MEMS engineering books and calc the tensile and flex for fiberglass and see.


If i were to do this on my sticky i think i would try a checkboard layout of the glass and of course wrap the corners both lengthwise and horizontally.


When they did my pool if was 2-3 5 gallon buckets of epoxy, so wtih the matting im guessing +300 lbs? minues the rubber roof maybe +250?


Of course there would be no way to get the same strength as molded,



Probably alot of sanding and buffing at the end.


Still i am very curious if this could be done. There is one youtube video of a guy doing it on a small tool trailer made out of stirafoam

🤔No doubt you can do it, but I think you're gonna have to try it to see if the results are worth the effort. Don't think your boat analogy works though.

vintageracer 12-08-2020 11:52 AM

Weight is you enemy with any RV.

Fiberglass is HEAVY!

Fiberglassing over any wood structure that would have any rigidity at all against over the road cracking, fracturing or outright failure of the joints means lot's of additional weight added to the RV trying to band aid repair a water leak problem.

Not a good solution.

This is why lightweight composite construction RV trailers is the next "Big Thing". Lightweight, lots of strength, no leaks, insulation factor and more. Yes it's expensive at this time however prices will continue to fall as the benefits and scale up of builds by the big manufacturers drive's down prices.

You looking for a solution to a problem that nobody has yet solved at any reasonable expenditure level. This is exactly why newer, better and cheaper build materials and methods replacing wood all together in any RV build the solution to the leaky RV issue.


Here are a couple of threads concerning DIY composite camper builds for your enjoyment:

https://expeditionportal.com/forum/t...-build.184366/

https://expeditionportal.com/forum/t...osites.219163/

https://expeditionportal.com/forum/t...camper.220166/

daveo12345 12-08-2020 12:06 PM

interesting on the composites.


As for weight, my calculation using 2 ounces of fiberglass per sq. ft means only about 200lbs to completely encapsulate 5 sides of a camper.


I still cant believe no rv manufacturers dothis


maybe its the cracking. ong stretches of fiberglass might break? But why not fiberglass over plywood boats?

Mary Ann in NC 12-08-2020 12:31 PM

Glassing over an RV
 
I built 12 small boats. All were wooden with glass matting and thickened epoxy at the seems. Then several coats of thin epoxy over everything else. You have to sand everything each time you apply the next coat of epoxy. Then, it has to be painted because epoxy will submit to UV. I would call the Escape or Casita folks and buy a good trailer.

daveo12345 12-08-2020 12:33 PM

ahh, so its a labor intense thing. that makes sense. Doable just labor intense


probably alot easier to just buy one already well made


its just my stick experience has been so bad and those rigs are so expensive

Jon in AZ 12-08-2020 12:47 PM

It would still have all the sticks inside. The thing I like best about my Scamp is the simple, self-supporting shell, as well as the modular fiberglass interior. All the main structure (shell and interior) is largely impervious to rot*.

Compared to a stick-built frame and cabinetry, the whole thing is also relatively easy to disassemble for repair, modification, or restoration.

* Except the floor, of course, but that would be no different than a glassed-in stickie. And some manufacturers have developed all-composite floors (for a price).

Tom Y 12-08-2020 01:04 PM

As an alternative to glassing the unit, or buying a cherry fiberglass unit, I would recommend looking for a used in need of repairs fg unit.
I purchased my Bigfoot tf20 5th wheel out of Canada in need of repairs for 1500.00, added another 2k during the rebuild, have put many miles on since and could sell for twice my dollar investment!
And I have a conversation piece everywhere I go!
Good luck

Glenn Baglo 12-08-2020 01:21 PM

I had a fibreglass over wood boat. I drilled into the transom to attach an auxiliary motor mount and steam came out. Had a friend's father ( a professor of wood, really ) come check it out, and then I towed it to the dump.

vintageracer 12-08-2020 01:23 PM

Quote:

Originally Posted by daveo12345 (Post 800254)
interesting on the composites.


As for weight, my calculation using 2 ounces of fiberglass per sq. ft means only about 200lbs to completely encapsulate 5 sides of a camper.


I still cant believe no rv manufacturers dothis


maybe its the cracking. ong stretches of fiberglass might break? But why not fiberglass over plywood boats?


That resin loading will git you about 1/16 inch to 1/8 inch thickness IF you are lucky! Virtually no structural support at all will be provided. You will need to upwards of a 1/4 inch thickness to survive the wear and tear the road will exert trying to make fiberglass support the wood and survive not cracking or flaking.

Here comes the additional weight, the time to do all this glass work, the fumes, the smell, the labor, the expense, the needed repair and the repeat again once your done trying to keep your monstrosity together in one piece on the road.

Not worth the effort or expense!

Darwin Maring 12-08-2020 01:24 PM

Just take it to one of those companies that coat beds of pickups and have it sprayed in any color you want. I once saw a whole pickup sprayed in that stuff.

Darwin Maring 12-08-2020 01:25 PM

I had a fibreglass over wood boat. I drilled into the transom to attach an auxiliary motor mount and steam came out. Had a friend's father ( a professor of wood, really ) come check it out, and then I towed it to the dump.

Glenn, You had one of the good ones, years ago they use to use cardboard as stifiners.

Darwin Maring 12-08-2020 01:26 PM

And you think fiberglass rvs dont leak - Stick around and find out.


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