Firewall Heater Install

Finally getting back to getting the heater put back together. Willie didn't come with a heater originally but I was able buy one and restore it. When I attach it to the firewall, what should I use for a gasket or sealer between the case and the firewall? Seems like I recall form my youth that most car manufactures used some sort of sticky stuff. Suggestions?

 

There's a white caulk of sorts on mine. I pulled mine last spring to put a gm blower on, cleaned it and added a recirculate baffle. That stuff was still pliable.

 

Use the closed cell foam gasket, the one with one sticky side. 1/2” works or you can go wider.

 

Check with Timgr. He has the name of the stuff used originally or a close replacement iirc. It was a sticky ribbon sealer that I’ve seen. Kind of a mastic type material.

 

It's butyl strip caulk, sold at the home center as "Mortite" ... used for sealing window cracks and such. Lots of brands out there.

 

Great stuff, a classic.

Are you sure it is butyl? The primary ingredient is titanium dioxide.

In my experience butyl sealants are much more adhesive. Mortite seems more like a putty, and is easily removed.

 

Don't know specifically. I was told it's a butyl product, but I had previously thought the bulk of it was clay. This would go along with the TiO2 ingredient. Clay matrix and butyl binder?

 

Butyl is what they call it for sealing RV roof vents. Home Depot has rope caulk that works well I used that around my wiper motor. It's about 1.5" wide but easily tears off to the width you need. It smashes and seals very well.

 

Seems to me it should be black originally, but maybe not.