Cheaper PMF Landscape Fabric Test

[leblanda]

Hello guys

I saw on youtube one guy that used landscape fabric instead of canvas.
I did some test on foam and wood
Here is the test for bending on foam.
I did put some brick on the 1 inch Foam to test the strenght of it
Each brick weight 1.5 Kg
For foam covering, Canvas is the way to go as it add more rigidity but more weight
For wood covering Landscape fabric add less weight and do not need ironing.

I did some tear test glued on wood for both canvas and landscape fabric and they seem equaly glued.

 

[Pmullen503]

What does it look like after paint? If you were to drop a golf ball from several feet high onto each, which would dent more?

 

[KCStudly]

I seem to recall this being discussed very early on in the big thrifty thread. Theory was that the plastic fibers of the landscape fabric would not be expected to be able to form as strong a bond with the TB2 or 3 glues that were most favorable at the time. I wonder if your results were favorable due to a wet application where the glue was able to fully surround the fibers, gripping onto them and curring around them, rather than just bridging surface contact points.

 

[Chefsonora]

I might consider using it over seams to smooth it out, but wouldn't rely on it for strength. I've used it under elastomeric roofing to help cover voids, but it takes a lot of goo to encapsulate it.

 

[leblanda]

What does it look like after paint? If you were to drop a golf ball from several feet high onto each, which would dent more?

i did not paint it. i just test the strength of it. maybe a good test todo.

 

[leblanda]

I seem to recall this being discussed very early on in the big thrifty thread. Theory was that the plastic fibers of the landscape fabric would not be expected to be able to form as strong a bond with the TB2 or 3 glues that were most favorable at the time. I wonder if your results were favorable due to a wet application where the glue was able to fully surround the fibers, gripping onto them and curring around them, rather than just bridging surface contact points.

Important things. the one i grab is the one that feel like a fabric not the one that is looking like plastic tarp. Maybe that why i had good luck with it

 

[ghcoe]

I would stick to canvas. Foam expands and contracts quite a bit with temperature swings. Cavas being fabric is able to move with it (as long as you don't use prewashed canvas). Rigid/stiff fibers cannot move as easily, and I suspect delamination/wrinkles with time. I see it a lot with people who though window screen was a good option. Yes, you want strength, but sometimes strength is flexible.

If you apply canvas the way I do you don't need a iron.

 

[TimC-TNT]

Interesting experiment and good description of the technique.

I have to +1 on George's comments... "...you want strength, but sometimes strength is flexible."

I do have to mention that I've done PMF on four builds so far; the oldest born in 2016. They all remain in excellent condition. That's with 10oz cotton canvas from Big Duck. PMF on plywood and lumber and PMF on XPS foam. . I have never ironed the cloth prior to application. The amount of shrink in the first 1/2 hour pulls everything tight as long as you prepared for the work and worked uninterrupted.

 

[Chefsonora]

I like that. My mom at one point tried out a line of canvas boat clothes and I became well familiar with the shrinking potential (after wearing a brand new pair of shorts and jumping into the lake and proceeding to walk around until they dried. I believe that my voice went up an octave by the time I got back to the van, lol! But being able to utilize the effect is definitely beneficial and genius!

 

[philpom]

I would stick to canvas. Foam expands and contracts quite a bit with temperature swings. Cavas being fabric is able to move with it (as long as you don't use prewashed canvas). Rigid/stiff fibers cannot move as easily, and I suspect delamination/wrinkles with time. I see it a lot with people who though window screen was a good option. Yes, you want strength, but sometimes strength is flexible.

If you apply canvas the way I do you don't need a iron.

Curious how you do it? I use a roller to apply the glue to the surface, dampen the fabric and apply using a plastic trowl to work it down and once it nice I roll more glue over it. Finally once cured for a week I apply 3 or 4 coats of paint. Works great for me.

 

[TimC-TNT]

Curious how you do it? I use a roller to apply the glue to the surface, dampen the fabric and apply using a plastic trowl to work it down and once it nice I roll more glue over it. Finally once cured for a week I apply 3 or 4 coats of paint. Works great for me.

Much the same technique for my PMF. I use an 18" wall paper brush to help smooth out the canvas and help bed it into the glue. I don't worry about perfection since the shrinkage pulls all the old folds and wrinkles out.

 

[ghcoe]

Curious how you do it? I use a roller to apply the glue to the surface, dampen the fabric and apply using a plastic trowl to work it down and once it nice I roll more glue over it. Finally once cured for a week I apply 3 or 4 coats of paint. Works great for me.

In this video I did not use bonding primer on the surface. Now I use bonding primer, but the canvas application is still the same. If you don't fill the canvas weave completely with glue and paint you run into a risk of that canvas rotting later.