Teardrops n Tiny Travel Trailers

What I hope for is a simple thread of products tried to replace GG.
Maybe set a rating of 1 to 10 (10 being best), and a short description of test & result. My hope is that it could become a singular thread for basic results.
I would like to see rating of 5 (average) being something that could be used or expanded upon.

My first two entries to this will follow.

Zinseer 123 water based exterior primer

Adhesion to foam. 4
Adhesion to cloth (bedsheet) 4

Tested at full strength. Holds decent on angles, yet fairly easily torn back on the flat. Tested at 4hrs, 12hrs, 24hrs no noticeable changes to adhesion.

Recommendation: Find something else!

Kilz Premium water based exterior primer

Adhesion to foam 5 (pushing a 6)
Adhesion to cloth (bedsheet) 5 (pushing a 6)

Tested at full strength. Holds pretty well on angle (hard to break apart). On the flats does pull some foam off & holds well to the cloth. Noticeable difference as it cures.

Recommendation: Decent yet still would like something much better!

Since you feel like experimenting... I've got one for you.

When building my first camper, I didn't know about Glidden Gripper. I didn't use any canvas on the outside, but I did use some bed sheets to cover a part of the ceiling. I used Great Stuff for Windows to glue the sheets to the foam and it turned out really nice.
I sprayed the great stuff to the foam.

Smeared it and kept smearing it with a piece of scrap wood till it wasn't making any bubbles at all and it was like spreading bubble gum.

Then put the sheet on it and used a roller to make sure it laid flat.


Since you're going to be covering small areas, one at a time, this might work for you.

Since I already had the material to do the experiment, I decided to have some fun and do it myself.

First I prepped the foam by sanding it and then putting some dimples in it.

Then I put down enough Great Stuff for windows to cover the area.

Then using some scrap wood I worked the spray foam and spread it out for about a minute or more to make sure it wouldn't bubble.

Then I laid the canvas on it.


It's been about 5 - 7 minutes since I put the canvas down. I'm now going to rub it again to make sure no bubbles are rising up under it. This method takes work, but if it holds as well as I hope it will, then it will be worth the effort.

And then to mention our old favorite … We used some Titebond 2 on a recent house project and accidentally allowed the glue to cure on the brush ( ruined ) So we soaked it for days hoping the T2 would loosen up in the water , and after a week of immersion in water , the T2 was still solid !!! For “ normal uses “ this might be as good as everything else …
As we mentioned before , the T2 failed under the flooring /covering on our Foamstream only after a couple years of daily wetting ( dew) … So basically if your trailer spends a couple weeks underwater , it “should” be OK …” drip edges “ prevent long term absorption…

Easily obtainable in it’s original form , and lots cheaper than the old Gripper … And , in case of bubbles , it’s easier to “Iron “ the bubble and make it go away … Gripper is not so cooperative !!!

The lesson I learned about TB2 from my first camper was that if it is used in a place that air can not get to, then it won't dry right and it will fail. I tried gluing, with TB2, two large pieces of foam board. It was full strength *(Not Mixed) TB2 but after 3 days the water that is in TB2 separated out and dripped out of the foam. It left a mess.
If you still have that brush, use boiling water and the TB2 will come out.

Results of using Great Stuff to hold canvas.


No Bubbles came up.

I pulled up half of it.

It held very tight.

However, I'm not sold on it yet because of the next step. The canvas has to be made rot-resistant, which means TB2 (80-20 mix). The water could make the Great Stuff weak.
So, on the half of canvas I didn't pull up, it's time to use the anti rot formula.
This will take a couple of days to dry. I'll get back to you.

Postal_Dave wrote:Results of using Great Stuff to hold canvas.
This will take a couple of days to dry. I'll get back to you.

How would you rate the practicality of it to cover the entire trailer?

If I did try to cover an entire trailer...

First know that I used pre-washed canvas, so it is already shrunk. Some people like for the canvas to shrink after it has been applied to the foam. I don't because it can warp the foam if both sides aren't done at the same time. With this application, it might be difficult to put Great Stuff on both sides of the foam at the same time.

With that said, I wouldn't try to cover more than an area of one side, of a full sized sheet of foam in one shot. I would first get several plastic scrapers, several cans of Great Stuff Blue, disposable gloves, and a few friends to help. A full sized sheet of foam might take one or two cans to cover and then you and your friends would have to start scrapping the spray foam. It takes time to work it down so it won't bubble up too much. Then some help putting the canvas on working it and making sure the canvas lays flat and it has good contact. I'd then rub it down a couple of times over the next 30 minutes to make sure it doesn't bubble up in any places.

I'd say it's doable with help.

Be sure to test it out yourself on a small scale before applying it to your trailer. You want to become very familiar with this method before taking that final step.

Right now though, I'm still waiting to see how the canvas filling TB2 and water mix affects the great stuff. It might ruin it. I don't know.

Gripper was an acrylic primer. Almost all primers are now latex based.

Sherwin Williams makes an acrlic primer called Pro-Crylic. Gallons only.

theoldwizard1 wrote:Gripper was an acrylic primer. Almost all primers are now latex based.

Sherwin Williams makes an acrlic primer called Pro-Crylic. Gallons only.

Thank you! I heading out to buy a gallon and give it a go.. $39 a gallon, II can work with that!

Edit: Retail is $80 a gallon. $50 with a Pro account

Has anyone tried polyurethane varnish? I see water based coatings but not solvent based.

Another question. Has anyone used canvass over wood? Seems like a great way to strengthen and waterproof those thin ply roofs.

Tt

Tomterrific wrote:Has anyone tried polyurethane varnish? I see water based coatings but not solvent based.
Tt

This is what a solvent based coating will do to foam. Use it very carefully!



I personally have had zero luck with any polyurethane/varnish/spars/.. on exterior usage.
You have something in mind and wish to sample it, please do!

This is very early results for the SW Pro Cryl.

Left to right: Full strength on both pieces / Full strength and 50/50 TB2 / 75/25 PC (PC/Water).

Full strength rates a 3. Does not saturate the cloth nor stick well to the foam.

Full strength and 50/50 TB2. I'm going a strong 8. The bonded well to the foam and the TB2 just stiffened the cloth. That is nice to me.

75/25 mix. Interesting how well it bonded to the foam and the cloth. Cloth is still pliable.. Good or bad thing, you decide.

Again very early returns.. We'll see what each day brings from here. Plenty of sample left to continue the test.



Now the second test happening is unfair as a alternative, yet like the system. This is testing pre-priming and only dealing with the cloth.
I like only doing the TB2 in this instance. Seems adding more primer reduced the bond to the foam..

Left being only 50/50 TB2 on the cloth and Right being priming and doing TB2 to the cloth. Right came off way too easy.. This test is now 24hrs in.



My sample board has room to re-do this test with the PC from SW (purposely).