Heater box caulk

[legendman]

As you can see my cab as been completely redone and now it's time to put the heater box back, I need to know what I should use as a sealer between the heater box and the firewall, both inside the cab and outside.

Thanks

[chengny]

GM used 3M Strip Calk (thats how they spell it) at the factory but that was on the engine side of the firewall.



There was no sealant between the heater box and the cab side of the firewall - the sound dampening material provided the seal. But if your insulation blanket is long gone, the 3M Calk works good. Only problem is - the smallest box they sell contains 60 feet of the stuff (60 X one foot strips) - about 15 dollars.

[legendman]

Originally Posted by chengny

GM used 3M Strip Calk (thats how they spell it) at the factory but that was on the engine side of the firewall.



There was no sealant between the heater box and the cab side of the firewall - the sound dampening material provided the seal. But if your insulation blanket is long gone, the 3M Calk works good. Only problem is - the smallest box they sell contains 60 feet of the stuff (60 X one foot strips) - about 15 dollars.

Thanks, I want to put it on both sides, I have the sound dampening that was on the inside but it stinks of mouse crap so it has to go.
I will get some of the 3m Strip Calk.

[nheller76]

Originally Posted by chengny

GM used 3M Strip Calk (thats how they spell it) at the factory but that was on the engine side of the firewall.



There was no sealant between the heater box and the cab side of the firewall - the sound dampening material provided the seal. But if your insulation blanket is long gone, the 3M Calk works good. Only problem is - the smallest box they sell contains 60 feet of the stuff (60 X one foot strips) - about 15 dollars.

Im sorry i have to do it!!!!! you said "calk"

[gmclowsierra]

I just did mine and used plumbers putty. Never dries out and you make it ad thick as you need it. Tighten up and remove the excess.
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[NC_John]

Originally Posted by gmclowsierra

I just did mine and used plumbers putty. Never dries out and you make it ad thick as you need it. Tighten up and remove the excess.
Posted via Mobile Device

I was just searching what to use (I have mine off this morning). Good idea- off to ACE Hardware I go!

[legendman]

I ended up getting some from Eastwood, nice stuff.
Should work well

[NC_John]

Originally Posted by legendman

I ended up getting some from Eastwood, nice stuff.
Should work well

I stopped by NAPA on my way to ACE this afternoon and got a roll of windshield seal. Worked perfect.....

[hatzie]

Originally Posted by NC_John

I stopped by NAPA on my way to ACE this afternoon and got a roll of windshield seal. Worked perfect.....

Yup!! The strip caulk is already pre-formed but the old fashioned windshield seal will do the job nicely.

[NC_John]

Originally Posted by hatzie

Yup!! The strip caulk is already pre-formed but the old fashioned windshield seal will do the job nicely.

Until you have to take it off. It sticks so good you risk breaking the heater box...

[tucsonjwt]

The heater gets very warm, but it is not fire starting hot. I can't imagine that it would get hot enough to melt or set on fire regular foam weatherstripping.

[mrpaintstick]

I am getting ready to reinstall my heater box would Dap roof caulk be a suitable substitute? It seems to stay plyable and would be resistant to oil. just a thought I know a roofer so it is easy to get.

[tucsonjwt]

I would stay away from plumbers putty and tube caulking. When you need to replace your heater core you will have a gooy mess.

[NC_John]

Originally Posted by tucsonjwt

I would stay away from plumbers putty and tube caulking. When you need to replace your heater core you will have a gooy mess.

what he said. I had to remove my heater box right after installing it with the windshield seal and it was terrible. Just buy a gasket set- it'll come with the foam seal for the box.

[mrpaintstick]

I was wondering about the foam seal

[Axle]

The calk you may find on the shelf or hanging on the rack at your local hardware store. May not be under the 3M name. Looks like a thin package of kids plasticene. You even have (had?) a choice of colors. We often used what was boxed as "Crack Seal".

We used to use that stuff when cabling to seal holes. The exposed side will skin over, but it will remain pliant, I've removed some that I jammed in a hole some 20 years ago and could still work it.

Alex.

[Skunksmash]

Originally Posted by tucsonjwt

I would stay away from plumbers putty and tube caulking. When you need to replace your heater core you will have a gooy mess.

Don't they sell some kind of high temp tube caulking? Think they use it for stucco repair that's going to be out in the sun.

[andrewmp6]

You have seam sealer which is like caulk but for cars,Or you have 3m window putty no clue on how that one handles heat tho.

[tucsonjwt]

I just used strips of self-adhesive urethane foam window and door stripping from Home Depot. It looked like what I had in there originally when I removed the heater box. I like the 3M strip caulk idea also, but I have never seen it in person.