I realized I’ve never sprayed with a proper spray gun before, only with rattle cans. I’ve also never worn a NIOSH organic vapor mask before. Wow. What a difference!
We used DAP Weldwood HHR Landau Top contact adhesive. It’s pretty powerful stuff. I bought a cheap spray gun along with the adhesive. It worked fine with our 4 gallon air compressor. Once you get the pressure dialed, it works really well to create the “web” of glue that you want on the surfaces. Of course, we missed the 80 degree days of September so we had to spray inside the garage to make sure the glue had a chance to flash off.
That meant wearing respirator masks to protect us from the vapors. I haven’t used a NIOSH-approved mask before, and now I think I’ll wear one even if I’m just spraying a small item with a rattle can. It wasn’t until I took the mask off outside the garage that I realized how much the whole place stank of the adhesive. Through the mask, I was just breathing “fresh” air.
The instructions said to “apply pressure” to the items after they had been joined. We have a 4″ roller that worked well for the smaller panels, but it would have taken all day to roll the larger ones, so we improvised.
Update: If you don’t want to spend the money on a full spray gun kit, 3M 90 adhesive works really well for the same job. We used it for a couple of smaller panels that we did later on. Just be sure to start spraying before you hit the fabric, and keep the spray can moving. If you get too much adhesive in one place, it’ll soak through and cause dark spots on the fabric.