Glue for C2 Upper Firewall Insulation

[Patrick B.]

What kind of adhesive can you recommend for sticking the jute insulation to the upper firewall below the dash? Should this go in before or after the windshield wiper motor?

[Richard M.]

Re: Glue for C2 Upper Firewall Insulation

Patrick, I use 3M Spray adhesive, just on the fiberglass. Make sure it kicks-off a bit so it's tacky. I was able to install it with the wiper arms installed, but no wiper motor so I could move the arms around as needed. IIRC, the trickiest part was lining up the holes for the motor though.

It's a bit of a pain as you only have one shot at it.

Rich

[Ed S.]

Re: Glue for C2 Upper Firewall Insulation

Patrick,
Wear disposable gloves and put 2 inch blue painters tape over anything you don't want the adhesive to come in contact with up under the dash. Then when the insulation is in place remove the blue tape, along with any stickyness that it collected during the installation. A bit of a pain but worth the process if you don't want sticky stuff in a lot of places it should not be.

[Patrick B.]

Re: Glue for C2 Upper Firewall Insulation

Thanks Richard and Ed. I wonder if the 3M adhesive or something like it is available in a form that can be brushed on to eliminate the overspray and masking problems?

[Keith B.]

Re: Glue for C2 Upper Firewall Insulation

you could always use contact cement

[Ed S.]

Re: Glue for C2 Upper Firewall Insulation

Contact cement would definitely hold very well. But.... any contact cement that I have used requires the cement to be applied on both surfaces that are to be bonded. The other issue is that when two coated surfaces come in contact - they instantly cement themselves together really well - like too well to easily separate without damaging one surface or the other - I think this is why they call this stuff "contact" cement.

[Patrick B.]

Re: Glue for C2 Upper Firewall Insulation

To follow up, I used Permatex #27828 headliner and carpet adhesive, and it was an easier job than I expected. It was a spray adhesive but the spray pattern was easy to direct without making a mess. I installed the wiper motor easily after gluing in the jute insulation. The outer heater box was more difficult, and I would have been hard pressed to get it over all 7 studs had the body been on the chassis with the 427 installed.

If the photo I tried to attach shows up, you can see the body back in Goodwood green for the first time since about 1970 when a previous owner put flairs on it and painted it red enamel.

[Michael A.]

Re: Glue for C2 Upper Firewall Insulation

Patrick - thanks for the follow up. I had been looking at the 3M Super 77 but was hesitating as it’s only ready to hold up to 120F. I checked the Permatex #27828 and it’s rated up to 170F. I suspect the surface of the firewall can easily exceed 120F on a hot summer day so I think I’ll go with the Permatex. How has it been holding for you since your post from 2016? Have you had the car in operation in warm weather yet?

Cheers,

[Jim D.]

Re: Glue for C2 Upper Firewall Insulation

I've used 3M spray adhesive on several cars without issue. Once it sets up, that insulation isn't going to come loose.