Foam Outer Finish Material

[stomperxj]

Let's talk foam coverings. I posed this question in Mike's Foamie Standie thread but thought it would be a good subject to cover by itself...

I see that a few of you that are working on your foamies are using canvas to cover the outside with some kind of glue like Titebond for adhesion. Here are a couple questions for discussion:

1. What are the advantages/disadvantages of using canvas over fiberglass cloth?

2. How waterproof is canvas?

3. Is using canvas over glass strictly cost related?

4. Is there another covering material besides glass and canvas that would work?

Discuss-

Jess

[Ratkity]

Let's talk foam coverings. I posed this question in Mike's Foamie Standie thread but thought it would be a good subject to cover by itself...

I see that a few of you that are working on your foamies are using canvas to cover the outside with some kind of glue like Titebond for adhesion. Here are a couple questions for discussion:

1. What are the advantages/disadvantages of using canvas over fiberglass cloth?

2. How waterproof is canvas?

3. Is using canvas over glass strictly cost related?

4. Is there another covering material besides glass and canvas that would work?

Discuss-

Jess

1. cheaper
2. Totally
3. Cost and skill
4. Any other fabric-type material or materials in general?

There's aluminum, plywood with various treatments, cedar, etc.

The canvas used was originally a painter's drop cloth because of thriftiness. GPW is using old bedding sheets inside his foamie. I used duck cloth (had an old and big enough scrap laying around) and cotton fabric on my solar panel cover.

Hugs,
Ratkity

[GPW]

Stomp, Fiberglass is really Great stuff.. But unless you have a shop to do it right , its a LOT of Work !!! Most people who do a glass job want a shiny smooth finish , like a car ... that takes a lot of filling , and many hours of block sanding / primer .. air tools help ... Now if you want a really great paint job on top of all that you have to have the necessary spray equipment , and a booth , and the skill to use it ... Beautiful results can be had ... but it's expensive , messy , and hours and hours of work ... My brother owned a body shop that specialized in Vettes'...
Our canvased Foamies are a way for the average guy like me (or Lady) to make their own , in their garage , or backyard , no fancy tools, no advanced skills , nothing too messy (save the foam dust and peeling the T2 off your hands ... somewhat therapeutic...) and a Lot cheaper than many "alternatives"... Light too ... Glassed would be much Heavier ... (it's the resin weight) Our paint jobs may be rough, but there's still the potential for a good looking trailer ... (like Eagles, which matches her TV)
As this Foamie thing develops , we expect to see many innovations ... so stay tuned , there's more good things to come ...

[swampjeep]

1- I'm thinking teh canvas will be MUCH cheaper, and easier to work with (cut, stretch, get a smoother finish then glass mat)

2- the canvas isn't what's waterproof, it's the layer of titebond or paint that is put over teh canvas that becomes waterproof when dry. There's a post talking about TB II compared to TB III, the makers of it say II is only water "resistent" but GPW said his gutar made with II was under water for weeks and is fine today (maybe it could come apart when it is saturated, but dries fine ??)

3- also easier to get a smoother finish, teh tighter the weeve the smoother the finish I believe, so even bed sheets will have a better finish the canvas, or canvas for art over canvas for house painting...

4- my understanding is any cloth type material can be used for this method.

[eaglesdare]

another question about this. can you use that glass cloth with glue? leave the smoothness out of the equation. just wondering if you could use glue, and if so would the glass cloth be strong?

i know nothing about that stuff, so i am interested in the answer.



i used the canvas/glue method, because when i first read about it, it was exactly like gpw stated above. it was cheap enough, i could buy it locally, i could do it without any special tools. and it works. it is lightweight (enough). thanks for the compliment on mine gpw, but mine really isn't that great looking. it really only matches the car. but a person with a bit of time, and does it right can make a really nice looking one. hopefully my second one will look much better. gpw's with the round edge looks great, and i have the feeling that mike's is going to be another great build.

[stomperxj]

Great answers guys... Keep em coming-

How about a strength comparison between the two?

How would a canvas covered shell take a limb strike from a tree on a logging road vs a glass covered one?

[GPW]

Depends on the size of the limb eh ? But you can be assured the damage would be localized to that area only , simple repair with a Foamie first aid Kit ... if a Log falls on it (tree) then think about a pancake ... But then a wooden or FG TD would be no better off , right !!!

[swampjeep]

another question about this. can you use that glass cloth with glue? leave the smoothness out of the equation. just wondering if you could use glue, and if so would the glass cloth be strong?

i know nothing about that stuff, so i am interested in the answer.



i used the canvas/glue method, because when i first read about it, it was exactly like gpw stated above. it was cheap enough, i could buy it locally, i could do it without any special tools. and it works. it is lightweight (enough). thanks for the compliment on mine gpw, but mine really isn't that great looking. it really only matches the car. but a person with a bit of time, and does it right can make a really nice looking one. hopefully my second one will look much better. gpw's with the round edge looks great, and i have the feeling that mike's is going to be another great build.

I do believe you could use the glue with glass matting

Great answers guys... Keep em coming-

How about a strength comparison between the two?

How would a canvas covered shell take a limb strike from a tree on a logging road vs a glass covered one?

when you say glass in this compare, are you stating glass w/resin, or just titebond?

To keep this a simple type contruction, I would be curious of the testing done using titebond with the 2 materials, if I'm going the route of a foamy, I ighly doubt I would do glass/resin, I just don't have the skills and/or tools for working with glass/resin.

[stomperxj]

when you say glass in this compare, are you stating glass w/resin, or just titebond?

I'm talking with resin, not Titebond.

Just was curious if anyone had done a durability test with the canvas. Like make up a test square, let it cure and then hit it with a hammer to see what kind of impact it could take or if there was any kind of failure...

[swampjeep]

when you say glass in this compare, are you stating glass w/resin, or just titebond?

I'm talking with resin, not Titebond.

Just was curious if anyone had done a durability test with the canvas. Like make up a test square, let it cure and then hit it with a hammer to see what kind of impact it could take or if there was any kind of failure...

should probably compare it to every other construction method to, like the roof on this manufactured camper

[Conedodger]

I think you may need to look at this in a bit more technical on how these products work

Epoxy is a chemical cure where you add an activator to start the curing process and as such it will cure (And stick) to almost any solid object, It does not have to penetrate to stick and will stick to non-porous materials.

Metal to Metal (Both non-porous) is a good example can be stuck with epoxy but the slightest movement and the bond strength is gone

PVA (T2/T3) will only work on a porous material and my understanding is it once applied the water inside soaks into the porous material and so dries.

Metal to Metal (Both non-porous) will no stick and the center area will stay wet.

However if you had 2 perforated metal pieces with tiny holes in I think they will stick as the PVA fills up the holes and over time the water can evaporate.

Cloth is Porous so PVA will stick and we are told foam is non-porous so they should not stick, however if you read the specs of your foam they give a measurement of how much water it will soak up. Metal is 0 and Foam is +or- .02. Also foam is full of tiny holes and this is why i think this is working.

I have now done some testing myself with scrap stuff and its my findings that the cloth has to breathe for this to work.

I tried several different cloths and find man made fibers hold the best as they soak up the PVA. Polyester cloth is non porous so should not work but thin polyester cloth sticks very well if stretched. But thick heavy duty polyester does not stick very well at all. I think this is because the thick cloth just does not have enough holes so acts like a solid. I also tried some waterproof cloth (Coated sportswear) and it did not stick very well.

Cloth backed plastic (leather look) also did not stick other than at the edge.

As to strength, well i use thin mdf and glass fiber as joints to make speaker boxes and in my testing I tried one with thin ployester cloth and PVA and i would say its plenty strong enough and will be using this in the future.

One thing is very clear the more cloth layers the stronger it is and 3 thin layers of cloth is much stronger than on layer using thick cloth.

My findings:

I am amazed at PVA/Cloth/Foam strength but will say once it cracks at a joint the strength has gone.
Plus points, No mixing, clean up with water. Smell nothing like epoxy.

IMHO Glass Fiber / Epoxy is stronger but its also heavier and thicker and much harder to work with, if you get the mix wrong it can be a disaster.
Plus points, getting high on the fumes.......

Finally one thing i have yet to test is strength against thickness.

Remember foam has no strength so its the hardness of the outer covering that gives it strength.

Glass Fiber gets stronger and stronger with each layer and you can keep going and make very solid structural joints where the glass matting stops the joint from cracking, and this can be done all at once and the results will be cured and moveable in a few hours and fully cured in 24 hours

I get the feeling that adding more and more cloth layers with PVA will not be the same but as PVA takes a while to dry. I also have yet to test adding layers of cloth after a week or so but cant see why it would not work.

[GPW]

Er, actually the foam does have some strength ,a good bit , we've used it for many years to great acclaim ... and while we're not on a quest for the ultimate TD here, building to the parameters stated produces a camp able structure that is affordable and can be built by most anyone... with little to Rot...
Better than a tent , not as strong as a Tank...
Someone please remind me to bring a hammer to a TD gathering , so I can test the strength of others trailer materials... May not be popular , but we'd gain some empirical evidence...
And although there's much speculation by some as to "what if", the same may be said for most any of the other TD construction methods ...

[Ratkity]

In addition to the above information:

Scuffing the foam surface lightly with a hand or orbital sander helps in the adhesion process. Basically making the surface of the foam more porous for glue to adhere.

Hugs,
Ratkity

[eaglesdare]

Er, actually the foam does have some strength ,a good bit , we've used it for many years to great acclaim ... and while we're not on a quest for the ultimate TD here, building to the parameters stated produces a camp able structure that is affordable and can be built by most anyone... with little to Rot...
Better than a tent , not as strong as a Tank...
Someone please remind me to bring a hammer to a TD gathering , so I can test the strength of others trailer materials... May not be popular , but we'd gain some empirical evidence...
And although there's much speculation by some as to "what if", the same may be said for most any of the other TD construction methods ...

[swampjeep]

Er, actually the foam does have some strength ,a good bit , we've used it for many years to great acclaim ... and while we're not on a quest for the ultimate TD here, building to the parameters stated produces a camp able structure that is affordable and can be built by most anyone... with little to Rot...
Better than a tent , not as strong as a Tank...
Someone please remind me to bring a hammer to a TD gathering , so I can test the strength of others trailer materials... May not be popular , but we'd gain some empirical evidence...
And although there's much speculation by some as to "what if", the same may be said for most any of the other TD construction methods ...

Hey Bear, don't forget to take a hammer to the next TD gathering...





I might to remind you later, so I figured I better do so now