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Re: Alternative to canvas …. a thought

PostPosted: Fri Sep 11, 2020 5:27 am
by GPW
RJ, a Lot of us don’t have much money right now , but newspaper is easily obtained/recycled ( likely free ) . And it’s so easy and safe even the kiddies can get involved ( family project ) … TB2 , newspaper , nothing toxic or offensive , save the news … :R :lol:

You know , with 99% of us not being Rich , Thrifty always seems a good idea … :thinking: :thumbsup:

Re: Alternative to canvas …. a thought

PostPosted: Fri Sep 11, 2020 5:30 am
by GPW
… and for those who like SMOOTH finishes , we’ve seen statues made of paper with smooth glossy finishes … 8)

Re: Alternative to canvas …. a thought

PostPosted: Fri Sep 11, 2020 7:00 am
by aggie79
I saw online about a paper mache glue that was made from 60% PVA glue and 40% methyl cellulose. The latter was comparatively inexpensive and helped “stretch” the PVA glue.

I’m retiring at the end of the year so I’ll have some time to experiment.


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Re: Alternative to canvas …. a thought

PostPosted: Fri Sep 11, 2020 4:05 pm
by KCStudly
The problem with history is that people forget and it tends to repeat itself.

Remember the guy who built his whole camper out of large format corrugated cardboard? I seem to recall he lived in a dry climate and wanted something to take his family of 4 (2 youngsters) out and about for a summer. And that's all he got. Despite his best efforts to seal, a year later (or so) it was mush.

Now I'm living in the proverbial "glass house" (my build has not been thrifty, and is nowhere near capable after a long slog... and a long layup), but regardless of how low buck and simple you build, in the end it will be a considerable investment in your time... longer and more difficult than considered, at least for us first time builders. So my 2 cts says, "Build with the best materials you can. The cost will be forgotten long before the... ". You know the rest.

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 4:31 am
by GPW
Aggie79, We look forward to your experiments … 8)

KC , although cardboard was a fail , the paper covering over foam would be some thing quite different … Paper mixed with TB2 would be pretty waterproof , especially painted on top … Naturally , more “testing” is indicated !!! :thinking:

Cotton canvas or newspaper , It’s all natural cellulose fibers … ;) One we buy on a roll , the other we recycle … It’s easy to find a free stack of newspapers … ;)

Ps. Heavy brown Kraft paper works well too…. we covered foam wings with that and white glue for years , cheap , strong , easy to paint, and even shrinks tight just like canvas does … :o

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 8:32 am
by Wolfgang92025
For what it worth.............
Paper on the inside I think is not an issue. Not a lot exposure to sun, rain or other harsh damaging elements.
For the outside, I would not use paper even after glue and paint to protect it. Sun, heat and water will eventually get through the finish.
Cloth fibers will break down under those circumstances also, but it a lot longer.
Think about this, you wash your clothes in hot water, let it dry and it"s ok again. Try that with your newspaper.
Like KC said, for the amount of effort, the savings are just not worth the risk of failure.
It's one thing when you talk about an model airplane what might be a few hundred dollars and 50 or 100 hours of labor.
Trailers, when its all said and done, usually run into the thousands of dollars and hundreds of hours.

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 8:58 am
by tony.latham
rjgimp wrote:
tony.latham wrote:Alternative to canvass...

Somebody invented fiberglass last year. I have yet to see a peel test on it though. ;)

Tony


Fiberglass costs money though. You know Glen... THRIFTY!!! $> In days of yore it might be said that he tends to squeeze his nickels until the Indian is riding the buffalo! :R
Image




Seriously GPW, interesting idea... particularly in light of the above article about the fenders made during WW2. I wonder how durable those ended up being? I have some foam scraps out in the garage and a fair amount of newsprint on hand. I might see about a ...TEST!!! :thumbsup:
The fiberglass I used on my walls was $3.50/yard. It’s cheap.

How much is canvass?

Tony


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Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 11:13 am
by IrrationalExhuberous
tony.latham wrote:\The fiberglass I used on my walls was $3.50/yard. It’s cheap.
How much is canvass?


A tiny bit cheaper but not by much. I haven't done any project with it yet but I assumed the bigger cost savings came from not needing the resin and getting to use cheaper glue and paint?

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 11:29 am
by tony.latham
IrrationalExhuberous wrote:
tony.latham wrote:\The fiberglass I used on my walls was $3.50/yard. It’s cheap.
How much is canvass?


A tiny bit cheaper but not by much. I haven't done any project with it yet but I assumed the bigger cost savings came from not needing the resin and getting to use cheaper glue and paint?
A six quart kit of epoxy costs $100. You need at least two gallons of TB2 for PMF. I think that’s probably $60.

Tony

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 12:10 pm
by rjgimp
Tony-
Not to get off topic but my understanding of the original advent (and the greatest cost benefit) of PMF was that you just used whatever leftover paint was lying around in the garage. Hasn't it been only in the last 10-15 years or so that it is being accomplished with new materials specifically purchased for the project?

Re: Alternative to canvas …. a thought

PostPosted: Sat Sep 12, 2020 2:13 pm
by Pmullen503
The other big benefit to the system was that you could use foam for the structure. Lightweight, easy to work with, and strong enough when covered with canvas, and well insulated.

I still think there are shapes (compound curves) that are possible with foam that are hard to do in wood. The PMF system is not great with those kind of curves. Epoxy/glass can handle that but it's intimidating for some if they've never used it before and it does cost a little more than PMF. I can see where paper mache would work on a compound curve if you didn't want to tackle it with epoxy/glass.

Re: Alternative to canvas …. a thought

PostPosted: Sun Sep 13, 2020 4:35 am
by GPW
Now George makes a good point … “ Once there is a failure in the paper it rips pretty easy and it certainly does not give the canvas protection against pokes and cuts like the canvas does. “ …
The question is how many Fails we have ??? Not a big history of foamie failures … one got blown over and one hit a deer :o ( but those were canvas covered … ) :thinking:

Since this was a hypothetical question , it’s given us a great and interesting conversation.. And the possibility of experimenting with a commonly available material ( and recycling that benefits us and not some paper mill who profits from our efforts , not that I’m against that at all ;) ) … In other words , what we Foamie Guys ( and girls ) do best …. TEST Everything !!! and discuss it !!! :D :thumbsup:

Since these strange times affect us all, few have a lot of extra money to spend ( if at all ) , we get back to the idea of "Thrifty Alternatives” , or how all this got started years ago …. :lol:

Another Thrifty alternative covering that now presents itself is recycled coffee bean bags … It’s Not pretty, It’s STRONG as heck , and we can find them free for the asking down at the coffee co. ;) Old Paint would probably stick it down fine ? :thinking:
Just a Thought !!! Why we’re here eh ? 8)

Ps. EVERYONE , Please stay Well and Safe !!! These are tough times for everybody , but we’ll get through it !!! Eventually !!! :NC

Re: Alternative to canvas …. a thought

PostPosted: Sun Sep 13, 2020 7:04 am
by greygoos
Here is a paper mache camper that you might be interested in. https://www.doityourselfrv.com/rocket-i ... ic-camper/

Re: Alternative to canvas …. a thought

PostPosted: Sun Sep 13, 2020 9:06 am
by tony.latham
Hasn't it been only in the last 10-15 years or so...


I don't know what was first used for the PMF system for teardrops. I think it may have been Glidden Gripper. That stuff seems to have dropped by the wayside for an unknown reason (to me). Maybe Glen can chip in on the histroy of PMF. I don't think the system is a take-off from canvass covered canoes since that method used aircraft (nitrate and butyrate) dope for adhesion. I covered an aircraft using that method and dacron cloth, by the way.

There seems to be two PMF systems. One for foam and another for plywood. Or am I confused on that? TB2? Primer?

The reason I threw my hat in on the mix was the subject line since PMF is an alternative to fiberglass. And I'll stick to my guns that since epoxy has come down in cost, it's not much cheaper and thus the P-word is a misnomer. Unless one scrounges and then it's truly PMF.

There's obviously a niche for the stuff. :thumbsup:

And I'll apologize for pointing this post off and down a rabbit hole. :thumbdown:

Tony

P.S. By the way, the first mention of using PMF on here that I can find was in 2015 by davesl77. He used it over wood using TB2.

Re: Alternative to canvas …. a thought

PostPosted: Sun Sep 13, 2020 10:08 am
by Terra6
Luv the informative, retro references, Thx Aggie and Grey. :thumbsup: :applause:
And to add to that, Amazon Prime has the Kon Tiki documentary which I recently watched. Of note, they had cardboard boxes of rations rolled in asphalt and covered in sand stored under the raft, submerged in sea water. Stayed dry and intact during their 120 day sea voyage. Unbelievable.
[quote][/quote]
GPW, appreciate looking for alternatives. Brainstorming and seeking new ways is the history of the evolution of man.
And foamies. :thumbsup:

Some thoughts from past experience and lives.
Kraft paper and cardboard would give much stronger results.
Repulped and formed to shape readily done with water.
Key would be finding an impregnation solution and technique that is cost effective and durable. :thinking:
Tar paper technique?

Simply painting or surface coating of paper would not seem to be durable over a large, exposed surface with seams and corners. Potential for cracks and seepage over time, weather and temperature cycles of expansion, contraction, water exposure.

And as Tony says, can it be accomplished cost effectively over present methods such as fiberglass?

And while we're at it, any other surface coating materials and methods possible which could be cost effective?
Problem is most (all?) chemical solution coatings tend to be expensive. Simply reducing the cost of a bulk filler material might not be enough if you still need an expensive binder coating for good impermeability and UV resistance.
Collecting pine tar in the forest? :lol:
Homemade binder?

PMF over wood as a protective layer works. Necessary over xps foam? Thinking a surface coating for UV resistance would be sufficient. Cheaper rhinoliner type coating?

But if one looks at the cost of the skinning materials vs the overall build time and cost, how much of a gain would it be?
Food for thought.


Aggies article shows it can be done in war time as replacement. How cost effective today and the materials + method are the questions of the challenge initiated by GPW?