Curious mind on system..

[RJ Howell]

GPW,
John wants to know if what he makes is water tight. Those cheap coolers are already water tight so he wouldn't be answering his question by using those. However, he can graduate to a cheap cooler after he finds out that PMF, if made correctly, is water tight.

Fun experiment would be to line the cheapie cooler with wax paper first, then go for it. The cloth bucket should then just slip out!

[RJ Howell]

Back on topic..

I did a bit of fairing after enforcing the seams and openings. This lead me to using primer vs. TB2. Seems to me, new at all this, that once you start with primer it's best to stay with primer. I tried again to use the TB2 and ended up just tearing it off and redoing with primer.

Now comes the dreaded question of: Is it better to size, or not?

On my build I have two areas that concern me and felt sizing was needed. Minimal shrinkage was required. Angles going into the window openings and the front underside of the overhang I wanted as one piece. The balance I don't see sizing required and want the extra pul/stretch from not doing so.

One thing I do like.. Is ironing the fabric and getting most all wrinkles out! My wife is laughing that know I have learned not only to sew, but now ironing.. Life is going to get a bit weird for me from here out..

[RJ Howell]

Next comes to top coat or not when applying the canvas..

I'm lost on this one. I've done both so far and really undecided..
On the sample board I see no difference, yet that's only narrow strips and air can get to the most of it easily and dry. What I can say is the canvas with the top coat is stiffer (should be, it's top coated), yet can't really tell if it helped or hurt the foam to canvas bond.

What's the consensus? To top coat or not to top when applying? Better to wait, let dry, then top coat?

[pchast]

I'd let the canvas and 'glue' get well dried before adding another coat of
a paint. I didn't doing mine. It took weeks for the paint to cure/harden.

[GPW]

On our FoamStream roof repair/modification , we let the Gripper primer coat sit out in the open for 6 months before we finally painted it … No problem …

“ yet can't really tell if it helped or hurt the foam to canvas bond.” … as most of us concluded . once the canvas fully dries/cures , it shrinks Tight and forms a sock like covering on the outside ( but NOT on the inside ) , and that really holds everything together , the fabric to foam connection really is not that stressed … I can only offer my Trailer which has sat Outside for 6 + years now and is still in fine shape … just needing a good wash every year , and a paint touch up every now and then …In 6 years we’ve only repainted parts of the trailer that we “worked" on … one day we’ll have to repaint the whole thing again … Just for “Uniformity” …

[RJ Howell]

My question was mainly on applying the canvas, yet I understand what your saying.

I am constantly temped to add more primer over the canvas as I apply.

My working system to date:
No pre-sizing. I like the stretch and shrinkage that occurs and removes all the winkles.
I also like pre-priming the foam and letting that dry for a day two.
I like pinning the canvas in place as I go. I'm not seeing the shrinkage others have spoken of, well not yet anyway.. Some yes, yet not as much as folks have spoken about.
I do like the sprayer from HF and seems a 70/30 mix flows well.
I spray the canvas, then the foam, then the canvas again. Ya, that canvas drinks it so fast you need that second coat.
Floating, rubbing, stretching, rollering and pinning the canvas seems to work well.
I do go back and trim the overlaps and use a brush to add more primer there. Pinned as well.

I'm not saying this is how, just what is working for me.

I had an issue with one side and believe it's because I deviated from my system. I pre-sized and pre-primed the canvas. I'm finding pre-sizing doesn't allow for the stretching I want as does pre-priming. Is this system without flaws, heck no, but only seems to be minor so far and along the edge. Workable so far.