Caulking & Spray Foam

[Mako_Kupo]

he everyone! two questions here, fully rebuilding a '79 Ford Class C (Coachmen). anyway;

there is an absolutely ridiculous amount of caulking on both sides of every metal outside panel. I have managed to get the gray, almond, and most of the white caulking off with mineral spirits, paint thinner, and general caulk remover from Home Depot unknown brand. there are two types of caulking on here that nothing touches, one of them is silicone and the other seems to be some kind of rubber or glue. the roof especially, it seems to have been glued down(not caulked) to the wooden part of the roof.

how do I get rid of these? I do not care about the paint, for the most part. to remove the silicone, iu have already stripped a ton of paint off right down to the metal, and I've only just begun not he silicone. oftentimes I get through the pain before the silicone STARTS to come off.

so, I'm going to get a Dremel with a wire brush scrubber on the end. for the silicone, I've been using my Oscillating multitool and for the tough stuff, a power drill with wire brush. a Dremel would work MUCH better for this, since the wire brush keeps sliding out of the drill and are actually designed for the Dremel rotary tool. will this work for that? the rubber stuff refuses to come off with anything less than the power drill + wire brush + pushing down really hard + 10 seconds per inch, if not more. I am hoping it will work for both of these types of caulking(praying, and I am not religious).

second, I am doing spray foam myself. I do not know which brand to get, if any of them stand out as the best I will go for it. I need about 600 ft, which luckily is what the good size ones are rated for. I want to swing for a little bit more, so I can do two coats in spots that allows it. thank you everyone!

[MEXICOWANDERER]

IMHO No matter what heater I use (even electric) I have not one but two (different brand) detectors. One 2' astride the heater the 2nd at the bedroom door.

[westend]

pianotuna wrote:
Do not use an unvented combustion heater. There are many through the wall units that do not require power.

X2, don't become a victim.

There are also many inexpensive standalone propane heaters that are vented. I have one that is in it's third RV. It is rated at 20K BTU and has a 3" class B vent going through the roof.

[westend]

I remove silicone with 3M caulk remover. I put it on with a brush and let it sit, overnight, under Saran Wrap.
For stubborn, dried acrylic or very sticky butyl and urethane caulks, I remove them mechanically. I use anything from a putty knife to a 4" grinder with fine wire cup wheel. The 4" grinder and wheel is so far superior to a drill and wire wheel that there is no comparison.

I contemplated spray foam walls but there are issues with spray foam and a thin frame that has aluminum siding attached. The heat and movement will mean possible foam shrinkage. I decided a 1" thickness of fiberglass batt compressed against the siding and a 1" foam board, cut to friction fit wall studs and ceiling rafters was a cheaper and possibly better insulation schedule than spray foam. YMMV. Cutting all the foam board in a 22' trailer is an intensive project. The insulation took me two weeks to complete.

[MEXICOWANDERER]

VERY carefully, dip a Q-Tip and apply it to stubborn residue. It eats paint.

Or

Mix flour and water to a thick paste consistency. Apply thick over silicone. Allow to dry thoroughly. Lift off.

[pianotuna]

Do not use an unvented combustion heater. There are many through the wall units that do not require power.

[Mako_Kupo]

the idea behind the spray foam is pretty much what you said, it just makes for a better build and better insulation. since we are doing a total rebuild, any future plans are already being planned for like a solar setup; places are being setup and reframed for future upgrades, all of which are planned. the only upgrade I don't have now is the solar, everything else will be installed as soon as possible(already piled in kitchen lol)

the plan is this; right now its a flatbed truck with the walls, floor, and roof all in their single respective pieces in the yard, rotten wood being replaced. as soon as its done, the floor, walls, and roof go one and then the metal panels. from there, I do plumbing(only sinks and shower, using compost toilet), and electrical. I have a wave 8 heater so no ventilation needed, and a domestic cool freeze fridge so no venting there either.

I'm already looking at plumbing and electric options, but am unsure of what brand insulation to use. I probably will use a professional, I've heard the foam is around 600-700$, the mask & suit another 150$, and the pro would do it for a total of 900$ including cleanup. if thats the case, I will go with the pro as soon as everything else is done.

thank you so much!

[DrewE]

Do you have the electrical, plumbing, and gas lines all run and in place? Surely you'd be best to do that before spraying foam everywhere, at least for the runs in the outside walls.

I tend to agree with SidecarFlip that sheet foam would be an easier and probably more practical way to work. I have next to no experience with spray foam, just used Great Stuff a couple of times, but I do know that it's messy stuff and not always the easiest to control. I personally would investigate what it would cost to hire it out to a spray foam insulation company, and enquire if it might be possible to "piggyback" on some other job while they had the equipment and materials out.

Sprayed foam will seal better than sheets or batts, generally, and so provide a bit better insulation in the end. Any future major repair work would probably be a bit harder with it than with the other options.

[Mako_Kupo]

thanks for the quick reply! from what I've seen/read, the newer spray foam cures in 60 seconds - two minutes. mainly, the entire frame is done with 1 1/2" x 1 1/2" beams, so for the most part I could only go over it once but the floor and roof are different, also the bed over cab. I haven't bought anything yet, but the situation here is - time is critical. I can't have this here for much longer, it needs to be moveable is less than two weeks. she runs, but is currently a flatbed truck. I have one friend building the frame while I slave over this caulking, lol...

[SidecarFlip]

Be careful with spray foam because it expands as it cures. You could easily wind up with a 'pregnant' unit... not good... Much better alternative is pink foam sheets cut to size and installed.