Teardrops n Tiny Travel Trailers

I spent years in the upholstery business. I put on an awful lot of vinyl tops. Any and all gluing work was done by spraying a substantially stickier glue than tightbond through regular siphon type spray guns. I currently have an old automotive gun sitting full of weldwood contact adhesive for any project that comes along. They never really clog up because of the continuous fumes. Can't imagine not having one handy!

I've seen so many people wrestle with ROLLING titebond2 onto their PMF builds, I'm really curious if anyone ever tried spraying it ? I dont know why it wouldn't work just fine. I want to attempt a minimal framed foamie Truck Camper project this next year, but the pain of watching people roll tightbond is just awful.

I have sprayed many, many gallons of fiberglass resin thru a regular paint gun for high end wood projects. Yes, you have to clean that gun well with acetone every time, so tightbond surely wouldn't be more difficult than resin !

Anyone ?? I just have not seen it yet. Thanks!

Not seen anyone spray TB2 or 3, perhaps because it might dry too quickly... it is not a contact type of glue, so the window of opportunity on assembly is when it is wet.
Solvent based contact glues are avoided when using foam board insulation because most will dissolve the foam without some other form of barrier. I did try the water based 3M contact glue and was not impressed with its performance. I think it wants a higher psi or roller weight than I was able to apply. My guess is that it is tailored for plastic laminate, not wood and foam. But I'm no expert. At least one member here really loves the stuff.

>>>>the window of opportunity on assembly is when it is wet.

Interesting thought.... I however was thinking it would have less open time than I have been seeing in videos with people rolling. I've seen what appears to take quite a bit of time trying to get the stuff on, and certainly they can't get it on as even with a roller as if sprayed.

Then you have the concept of thinning it, which, as long as it was not 90 degrees, in the sun, should allow for more open time. In any event, I certainly will be trying to spray it on some samples down the road.

Other related questions come down to what other adhesives might be an advantage over just the TB2 ? Titebond also has a water based product they call "advanced polymer". I see people using that for Filon adhesion.

Regarding solvent adhesion, primarily when speaking of foam to foam, there are surfboard builders who claim to use solvent based, sprayed on in numerous really fine coats, then stuck together. The fine coats do not eat the foam like it does when put on heavily, and I would assume that when they are pressed together, whatever "melt" there is, just increases the actual bond. I have sometimes wondered if two foam panels were sprayed with an even coat of lacquer thinner or acetone, then stuck together and weighted... perhaps the "melt" of the two panels could make the strongest joint as the same materials are essentially melted.

I've spent all my time in the cargo trailer forum here, but I suppose I will be digging thru more of the foam construction messages over the winter.
Thanks !

Grummy wrote:...

I've seen so many people wrestle with ROLLING titebond2 onto their PMF builds...

...but the pain of watching people roll tightbond is just awful...

You do you Grummy.

Four TD builds using TBII rolled on and I haven't experienced the "pain" you refer to. Give your method a go and let us know how it goes. It's called proof of concept. Maybe you are on to a new improved method but coming out of the gate poo pooing a method used by a large number of folks here is a little rich.

I just canvas'd my diesel heater box last night, and had no problems rolling it on. Pour it out of the just onto the wood, and use a cheap roller. Took me an hour to glue and cut the canvas. I'm laying the first layer of paint tomorrow. If it can be sprayed, I'd be interested in hearing about it, but rolling works just fine for me.

>> poo pooing a method used by a large number of folks here is a little rich.

I'm not poo pooing anything !

I just know that I could probably spray a 4' x 12' area twice (once on the build, once on the canvas) in less than a 2 minute period. I'm fairly sure it would still be wet when I drape the project. I really despise painting to start with if it involves rollers and brushes.

So, It's not you... it's me!

When I have something to PMF, trust me, I will be trying it.

It also comes down to what equipment you have. The whole PMF/foamy Ethos is about simple tools and techniques.

Now, if I had a big CNC router ...

>>> Now, if I had a big CNC router ...

EXACTLY! I had a 6'x12' available for 18 years at my last job. Always planned on cutting "dogbone" framework for a teardrop (there are drawings for the concept somewhere on tnttt). Just never did it. Cutting various foam plugs out of pink foam is what we mostly did. And, It cuts with perfection, so you really could make absolutely perfect joints. The parts I cut would be "flashed" with high heat for a few seconds and the foam gets a rigid shell of it's own... turns real smooth. People can achieve similar with a heat gun.

My personal CNC Router is only 30" x 50". I don't see a way it could be helpful with what I want to do.

Always planned on cutting "dogbone" framework for a teardrop (there are drawings for the concept somewhere on tnttt).

Dogbone? I think you may be talking about sandwich wall construction?



My website has (free) CNC files for a 10' teardrop cut from 4 x 8' sheets.

https://www.tonylatham.net/teardrop-cnc-files.html

Here's my CNC cutting a test piece:

https://youtu.be/0UidRSQWz0w?si=i6A9Tn0Q8mtAFSQB

Tony

No, "Dogbone" on the primary assembly method, but THEN yes, sandwich.

A method to maximize the use of plywood, rather than just cutting the shape out. The intent was to make a "Flatpack" Kit, that could be shipped on a pallet cheaply via Fastenal, then assembled by others using either or both pocket screws and Biscuits. I posted the concept in a rendering here:

download/file.php?id=1709

The intent was to make a "Flatpack" Kit, that could be shipped

Interesting. Someone was sure designing for a high snow load and heavy hatches.

Tony

So yes, if applied sparingly you can get away with solvents on foam. I did some guide coats with spray bomb aerosol paint while fairing and didn't have any issues, especially after the foam was mostly covered up with epoxy. But if you get a big drip of "high test" solvent directly on the foam it will eat it's way to China in an instant. Something to be very leery of after hours of fabrication on a part. Just saying. Yes please, experiment, I have done a lot on my build.

Another thing to be mindful of is using water based products to glue to foam when the path to evaporate to atmosphere is less than direct. Heavy coats of TB2 between foam and ply (or plain wood) won't set well, but light coats where the wood can absorb all of the moisture work great. That's also why it is important to make sure your canvas bond coat is fully dried before top coating, you don't want to seal in moisture and get bubbling later on down the road (not sure the bubbling phenomena is fully understood yet, but seems to happen with foamboard regardless of media used).

The PL300 marketed for gluing foam works okay if you follow the instructions and only put large beads 12 inches apart vertically on a large panel, so that when you press a panel of foam to the wall it grabs. Great for hanging wall board that the finished surface is going to be fastened through anyway, because this leaves big voids, or chimneys for the moisture to rise out of, but is not a structurally sound laminating technique. Try to spread it with a notched trowel for proper laminating, and it won't cure. Had to cut shallow kerfs in foam to make sure there was enough chimney effect for venting.

Absolutely experiment, test and report back. I tried and found I have to thin it too much and found the additional water (moisture) didn't agree with bonding to my foam test pieces. I did thin my TB glue to roll easier but not near what I needed to do to spray. I also tried just spraying the cloth and applying thinking the absorption of the cloth would offset the non-absorption of the foam. Still seemed too wet.

I went FG for the last two builds and find it easier for me.

Safe Travels

If you have an undercoating spray gun, one that is used to spray on bedliner and the like, TB2 works perfectly. No need to thin it down, and it gives a uniform coverage. I used it to make my PMF when i did a home made tonneau cover for the bed of my pickup using a wood frame and foam panels. I sprayed the panels and the inside of the canvas, then applied canvas with a roller, and sprayed the outside of the canvas to finish.
I would think if you had to thin it down enough to get it to spray in a regular paint gun, the water will make the glue lose its gluing capabilities.

YJlover63 wrote:If you have an undercoating spray gun, one that is used to spray on bedliner and the like, TB2 works perfectly.

Nice! I knew someone must be spraying it. I often use a hand held sandblast cup for spraying latex paint on hard to roll or brush surfaces (like T111). I don't think there is much difference between Undercoating gun and sand blast gun now that I think about it. I spray Fluid film in an undercoat gun.

I bet it was faster than rolling, and at least my experience with contact adhesives in Auto Guns, certainly one is able to create a nice even coat. You'd probably be surprised how well an auto gun actually works... I dont think Weldwood contact is thinner or thicker than TB2. For now, I bught a popup truck camper, but I still think I will be building a foamie one anyhow.