Used Spray Foam Insulation?

[Zeus51]

Has anyone used expanding spray foam insulation to close air gaps in the cab? If so, what did you use? Did you spray foam the bottom portions of the driver and passenger side air vents?

 

[cucvrus]

You are asking for a rust haven. Use a seam sealer and clean the area really well before you apply the sealer. The original sealers at this point in time are doing nothing. I would remove all the cowling and clean that area under the cowl screen really well. Lube the wiper transmission and reseal every joint you can get to. Removing the cluster and glove box will help gain access and visibility to problem areas. If you can remove the heater box and go to town cleaning sealing and painting. Fun Times. Good Luck.

 

[richingalveston]

there should not be any air gaps. Gaps mean the gasket or seal is bad or missing.
You can get all the gaskets at several different online places like LMC.
Spray foam is a bad idea because it will absorb moisture and just make it rust faster.

What particular gaps do you have and maybe we can identify a missing gasket.

 

[Zeus51]

I see both of your points. I didn’t think of the foam absorbing the water. Honestly, it was a thought I had to dampen sound and possibly help with heat. While my truck is torn apart and getting ready for paint, I thought now would be the time to do it.
The locations I was thinking is: in the head liner between the inner and outer layers of metal, in the rear cab corners down through the rockers, and maybe in the lower sections of the air vents on both sides. I have new air vents and gaskets. I guess my thought was an attempt to get rid of dead space.
I think your point of retaining moisture is a big point. It’s probably best to just leave it as is.

 

[richingalveston]

The lower sections of the air vents between the inner and outer fender is where the water drains from the cowl. (The slotted metal in front of the windshield.)

The roof metal has a very small cavity between the two metals. There is more space around the edges but most of the center has only about an 1/8 to 3/16 of space. The metal is thin there and foam would probably distort it. Also it would take a lot of holes to get the foam to spread and let the trapped air out.
About the only viable option is to put a civy head liner in it.

insulating the floor and fire wall with the many available products does help a lot with noise. I have double fire wall insulation and 3 layers on the floor and my truck is pretty quiet.

one place to make sure is pluged is where the ICE port comes through the fire wall. it is a 2 inch hole with a rubber plug and the plug comes out very easy. A lot of noise and wind can come through this hole and gets into the cab from under the dash.

 

[cucvrus]

It's a CUCV it is supposed to be noisy and have road noise. Want quiet buy a new truck. Anything you add is going to add a moisture trap. I always fight rust and corrosion here in Pennsylvania. I have found that a professional sprayed in liner like my favorite Line X does a great job and seals the floor and any other areas. Big Red was sprayed back in 2005 by a local Rhino liner dealer. I plowed snow with it for 14 years and never wore spot below the gas pedal even close to thru. I tried self applied liners and they were rust causers. I had rust starting under them where a scratch from a stone of metal broke thru. One <1009 was so bad under the DuraBak liner I ended up parting it out. Do as you wish. Steel rusts when it is damp or wet. If you stop it on the top side with an impregnable chemical coating you are assured that rust has been put at bay. I sprayed several M1009's and a few CUCV pick up cabs inside. Costly yes. But try fixing rust. That is my experience here in a very rusty area of the country. Looks great also and can be applied in colors other than Black. Good Luck. If you are serious about painting and redoing it. remove the frame and go over the entire underside of the body. Once and done. Always time to do it right. Not so much when having to do it over.

 

[MarcusOReallyus]

The roof metal has a very small cavity between the two metals. There is more space around the edges but most of the center has only about an 1/8 to 3/16 of space. The metal is thin there and foam would probably distort it. Also it would take a lot of holes to get the foam to spread and let the trapped air out.

I've seen it done. It's not pretty. If you can get enough in there to make a difference, it caves in the inner (lower) skin.

 

[dependable]

On several of my CUCVs I've taken the trouble to quiet them down. I usually used a combination of stick on product like Raamat or Duramat, then spray coated interior with a product called Lizard Skin. It helps lower both volume and tone of noise. This is all on inside of cab and doors and does not hold moisture.

Since my first three 6.2 diesel chevy trucks were civilian, I was not as ready to accept CUCVs are noisy, and some of us are unwilling or unable to spend what new trucks cost these days.

Spray foam will defiantly hold water and promote rust, I've scrapped a couple of cars this was done to, and it is not pretty.

 

[ssdvc]

Had an M1009 I bought from a guy who did use that expanding spray foam on the truck when he "restored" it. Rusted pretty bad, especially in the areas that had the foam sprayed in. What a nightmare.

And like Rick said, get your truck down to the Line X dealer and have it done professionally, you will not regret spending the money. On the first M1009 I bought, the "restorer" did the liner coating in his garage. It didn't last. On the last M1009 I bought, restored by Rick, it had the Line X done. After 4 years it shows ZERO signs of wear.