After a whole lot of time prepping the boat for spray foam insulation, I decided DIY Tiger Foam was the best bang for the buck. I initially intended to have a pro come out and do it, but I couldn’t find one who had experience foaming a boat. There was also a wide gap between estimates: $2,000 from one contractor vs $3,500 from the other. Tiger Foam was $1,350 for two 600 board feet kits, including shipping, and its E-84 fire rating is better than what the pros were offering. Plus, I like the challenge of DIY so…
After moving the plywood stack up against the galley bulkhead and the track saw table to the center of the salon, I started taping the place up the 3M hand masking film.
I taped off the vent hole up above before spraying began.
Having read all sorts of comments, seen tons of youtube videos, and read the manual front-to-back several times, I knew for a fact that spray foam is temperature sensitive. There are all sorts of warnings about application when it’s too cold, which yields a foam mix that may not rise at all. But there are no warnings at all about application when it’s too hot…which pretty much describes this whole year since two days after winter ended. I mean, we went straight from snow to hot–it was 75 degrees two days after the last snowfall, and it’s been over 85 on many days pretty much since late April.
So, on the day I sprayed foam, overnight temps never went below 79. That’s good, because 70 degrees is the minimum recommended tank temp for the foam. But by 10am, it was over 100 inside the tent up topside. The tanks were on the warm side when I finally brought them inside the boat, suited up, and started spraying. What they don’t show you in all of the videos is the amount of foam that rains down from above–what a mess!
That said, the first tank didn’t quite get the coverage I expected. But I attribute that mostly to the tank being too warm. There’s a bit of a learning curve, too, with respect to petroleum jelly you use on the nozzles (hint: use lots, and keep reapplying it or the foam doesn’t exit the nozzle smoothly). It also takes a bit to figure out which nozzle to use and how hard to pull the trigger (hint: use round nozzles and a very low application rate to frame out the perimeter of very box section between frames, then the fan nozzle and a higher application rate to fill in the middle). There’s also the eye protection problem.
It was 90+ in the boat and sweat running in my eyes made the job that much harder. The goggles I used kept fogging up on the inside, and the spray foam was coating the outside. After ten minutes, I was basically spraying blind. Swapping out the old goggle lenses for new, the same pattern repeated. And unlike spraying in a house, like they show on all the videos, all of the nooks and crannies of the hull and deck framing make it especially important to be able to see what you’re doing.
But it worked. It’s not perfect, but I got foam!
This locker has the new aluminum deck outboard, so that aluminum didn’t have any of the OEM bitumastic. I laid the foam on heavy in here, in three layers yielding 2″ thickness minimum.
Note the slightly yellow foam at the center of the overhead above–that’s from the first tank that was a bit too warm. It expanded well, but perhaps not 100%.
When I finally wrapped up, it was late after a looong day.
Next up in our 1969 Chris Craft Roamer 46 Refit: 1st Galley Plywood Install