Glidden Gripper vs PPG gripper

[JagLite]

price is irrelevant but is there a big weight difference?

Only 1/2 pound per 4'x8' sheet so for the 9 sheets I need it only adds up to 4.5 lbs.

Epoxy must be a lot cheaper down there than it is up here in the Great Land.
A few years ago when I bought a gallon of resin and a half gallon of hardener it was almost $200.

It is interesting to consider polyurethane varnish as an alternative to paint.
I have some so I will make a test patch and compare it with the TBIII I've been playing with.

I'm not concerned with weight as much as cost.
And comfort with construction.
I detest working with fiberglass.
I built a couple sailboats with it and learned how to do it nicely but can't stand the itch from sanding it.
A few years ago we rebuilt a totaled Class A motorhome and I fiberglassed the new plywood roof.
UGH!

I agree that an epoxy/glass foamie is the best and will last the longest.
But I view my trailer as more of a throw-away project to keep as low cost as reasonably possible.
Even PMF will outlast me...

[tony.latham]

Epoxy must be a lot cheaper down there than it is up here in the Great Land.

Isn't everything cheaper down here?

I did my 5 x 10' teardrop with Raka's $98 6-quart kit (plus $20 shipping). Two gallons of Minwax Polyurethane (down here) will easily bust a hundred bucks.

I detest working with fiberglass.

Why? I find it not much different than varnishing.





Tony

[John61CT]

There are all kinds of high tech PU sealants / paints / primers / adhesive etc coatings, the term "varnish" seems to me would be designed for wood?

Apparently this is a reasonable source for glass-epoxy?
https://fiberglasssource.com/collections/epoxy-resin

But low fumes, less itching for those who are sensitive

and water cleanup

to me are well worth exploring other options even if the cost issue is moot.

[JagLite]

There are all kinds of high tech PU sealants / paints / primers / adhesive etc coatings, the term "varnish" seems to me would be designed for wood?

Apparently this is a reasonable source for glass-epoxy?
https://fiberglasssource.com/collections/epoxy-resin

But low fumes, less itching for those who are sensitive

and water cleanup

to me are well worth exploring other options even if the cost issue is moot.

I used Verathane (poly varnish) for 10 years over fiberglass covered wood on my boat, no problems other than the need to do it regularly because the sun eats up everything in Hawaii. Multiple coats each time of course, three coats as a base, then one more coat for each month I wanted it to last. Usually I did 7 coats, three times a year.

The epoxy prices at fiberglasssource.com are great.

I just checked and to no surprise, they do not ship to Alaska.

[JagLite]

Epoxy must be a lot cheaper down there than it is up here in the Great Land.

Isn't everything cheaper down here?

I did my 5 x 10' teardrop with Raka's $98 6-quart kit (plus $20 shipping). Two gallons of Minwax Polyurethane (down here) will easily bust a hundred bucks.

I detest working with fiberglass.

Why? I find it not much different than varnishing.





Tony

Why do I detest working with glass you ask?
Let me count the ways....

Kidding.
After working with it daily for years my body reacts badly to it.
Not putting it on, sanding it and finishing it is what gets me.
If I could just let it be and not finish it smooth with perfect joints and corners I could do it but I have this dumb need to make things as good as I can which means a lot of sanding, filling, shaping, recoating, more sanding, etc. until it looks like it was all one piece. I've spent way too many hours with a grinder throwing fiberglass all over everything.

Like this gas tank I made for one of my bikes:













Finally with paint and stripes:






With paint/glue and fabric I won't be tempted to make it look perfect, I can just paint it on and be done with it.
I hope....

[John61CT]

In fact I like the bumpy papier-mâché / coarse weave aesthetic, more suited to roughing it.

Shiny fancy gets beat up soon enough, and then becomes a lot more noticeable.

That tank's some sweet handiwork though!

[John61CT]

Potential new candidate, ghcoe might be testing

Valspar Bonding primer https://www.lowes.com/pd/Valspar-Interi ... 1000381269

http://tnttt.com/viewtopic.php?p=1261472#p1261472

[vtx1029]

Has any one here tried to use PL Premium adhesive to attach the cloth to foam? I've used this stuff a ton and it bond is very impressive. Its wood to foam bond is really well! I put it on with a small v-notch trowel.

[GPW]

The big problem all along has been the adherence to Foam … Which is just about one of the worst substrates to stick things to , for the very reason that the Foam always FAILS (the tear away test) first no matter what ... No matter what you use , even Fiberglass , it will peel easily away from the foam …
Given that the ”Sock” effect holds it all together , The real long term concern with PMF is waterproofing the canvas (total fiber encapsulation) to keep it from rotting … not actually the adherence issue ( we know how that works by now eh ) . I think that’s the issue we should be concerned with . TB2 failed on the FS due to the morning dew keeping the painted canvas (under the floor wall join) saturated daily , eventually ( years ) leading to a breakdown in the glue ( only water resistant ) . Drip edges solved that pesky problem . The original Gripper was durable and waterproof … There’s probably plenty of good things that will work , we just haven’t tested them yet !!! Foamies have always been an ongoing theme … an Evolution !!! A Trailer Revolution ... We are a “community" , growing and learning as we go …

Tony , no offense Dude , You look a LOT like my Dad … ( ~ 40 years ago) He’s 97 now … Handsome guy !!!

[ghcoe]

It is not really what we use to glue the canvas onto the foam that fails it is the foam. The foam basically fails right at the glue line.

[John61CT]

I don't understand "glue line" in this context.

Isn't every square inch covered in adhesive and fabric?

My plan is to encapsulate the six sides of the foam sheet to create a laminated panel before assembly.

But even if the assembly done with raw foam then skinned, I figured the continuous surfaces all covered, with especial care at the vertices join edges.

[ghcoe]

Glue line is where the glue comes in contact with the surfaces it is bonding together. In a foamies case the glue penetrates the canvas fine it, however, does not penetrate very far into the foam. In most cases when I look at a failure you can see a very thin layer of foam still attached to the glue. It is the foam that failed at the glue line not the glue.

Not really understanding your build description, but if you do not have canvas/fabric folding over the corners you will have problems. fabric overlap is really where the foamie gets it's strength. Don't just rely on a foam to foam joint it will fail.

[John61CT]

Aha, so more the "glue plane" or layer, I was thinking a one dimensional line, like a border or bead.

Yes of course the lightweight granular nature of foam is what makes everyone think it is weak, no real cohesion under certain stress vectors.

Therefore adhesion bonding is to the outer surface only,

unless you use a good spike / roller tool to create punctured "stalactites" of the adhesive's 3D penetration deep into the slab.

Once all the edges have been wrapped contiguously with the large-area surface sheeting, that combines with the "sock effect" so you end up with a panel with a high level of overall cohesion and integrity, much higher tensile strength, puncture resistance etc.

Of course if you try a forceful "peel test" it will fail, but that is not much of a stress vector in normal use.

Not really understanding your build description, but if you do not have canvas/fabric folding over the corners you will have problems. fabric overlap is really where the foamie gets it's strength. Don't just rely on a foam to foam joint it will fail.

No, one method I've been noodling with requires a strong steel support frame for 4-600 lbs of load up top on a roof rack.

So standalone composite panels just provide walls / roof insulation + skinning, not load-bearing structural strength at the edge and corner joins.

So yes every edge gets overlapping fabric + adhesive, but not necessarily between slabs, when repeated dis/assembly is desired.

I realize not a Foamie concept overall, if I were doing one of those more "purely", then the foam box gets glued / braced etc to be very strong and the overall assembly then "sheet-skinned and glued" as a whole, as you say overlapping at all the transition edges and vertices.

[Merv]

So if you were building a fomie, covered with PMF. with what you know today, what primers, glues, paints, etc. would you use?

[John61CT]

I would test until I identified one coating to do it all.

And report back annually on the longevity results, which takes at least five years.

I would love it if Aluthane metallic paint panned out.