Although our plans don’t always work out, we are planners. We plan our meals, we plan where we are going to hike the coming weekend, we plan what we are going to do a month from now, and we even plan to make plans.
Naturally, when we decided to spray foam our bus we were already planning on how to trim it. There were a lot of options as far as tools went and some were more expensive than others. We purchased a 36″ manual hand saw but it kept getting pinched between the foam after it got a few inches deep. More searching led us to Milwaukee’s products in the FoamZall line that range from $450-$700. While this may be a good option if you’re in the foam biz, it’s not a good option if you are looking for a single serving tool. (Anyone? Anyone?) (Fight Club)
36” Open Cell Blade for Milwaukee FoamZall (or other foam blade)
The Nitty Gritty:
We did this modification with the 36″ hand saw we purchased since we already had it but it will also work with other foam blades. Using a regular reciprocating saw blade, trace the pattern on to the foam blade. If you purchased the hand saw, trace the pattern onto the side opposite of the handle so the screw holes where the handle was will not make the blade weaker. Once you are done with this mod, you will also have the option to reinstall the handle.
Use a Dremel to cut out the shape of the blade. We had to use a Dremel stone wheel to VERY slightly thin the blade because it was too thick to go into the reciprocating saw. After it slides into the saw you’re ready to cut. It’s that easy.
There was a slight learning curve in getting it to cut good. We ended up going at it from every angle until we found a method that worked. The tool worked best when we started vertically on one side, and use a see-saw motion to work the blade through the foam panel. After about half way through the panel we started vertically again from the other end. When you are nearly through, let off the saw. When the blade is not being held tight and straight by the foam, it starts to wobble hard.
The blade eventually breaks because of some of the harder angles used while cutting. All you have to do is trace out the end of the blade again and re-cut it. Our blade only broke 3 times while trimming the 27′ bus.
If you followed our tip on our Spray Foam Insulation post, then trimming your ceiling will go much smoother for you than us.
Good luck and be safe. 😁