Author Topic: Sealing the 2 halfs of a Heater Box  (Read 789 times)

Offline markb0729

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Sealing the 2 halfs of a Heater Box
« on: March 31, 2017, 02:45:55 PM »
I'm finishing up replacing the foam seals in the heater box of my 65 Dearborn built Fastback.  I'll be putting the 2 half's of the heater box together very soon. 

Would rope caulk be used at the factory for sealing between the 2 half's of the heater box for the early 65 through 66 Mustangs? 

I've read through several threads on this site and there are members that have used rope caulk (or the 3M 8578) to seal between the 2 half's of the heater box and some that have not.  I like the idea of a nice seal between the 2 halfs of the heater box but I'm afraid if I use the 3M stuff, I'll never be able to get it apart again if I need to. 

For those of you that did not seal between the 2 half's of the heater box, do you have noticeable air leakage between the 2 half's?

I'd like to hear both sides of the story.

65 Dearborn Built Fastback
Approximate Build Date, September 2, 1964
289 4V, C4, PS, PB, No A/C

Offline CharlesTurner

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Re: Sealing the 2 halfs of a Heater Box
« Reply #1 on: March 31, 2017, 02:55:25 PM »
There was no sealer from the factory, it's unnecessary.
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Offline MattDoscher

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Re: Sealing the 2 halfs of a Heater Box
« Reply #2 on: March 31, 2017, 06:28:24 PM »
Doesn't 1 half have a tongue and the opposite half have a groove?  Making it a tongue and groove sort of application.  No seal is really necessary.

Matt
Matt Doscher

1965 Mercury Comet Caliente Convertible
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Offline markb0729

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Re: Sealing the 2 halfs of a Heater Box
« Reply #3 on: March 31, 2017, 09:51:50 PM »
Yes, Matt.  There is a tongue and groove on the mating surfaces of the 2 half's.  Not an air tight fit by any means but the air leakage is probably minimal.
65 Dearborn Built Fastback
Approximate Build Date, September 2, 1964
289 4V, C4, PS, PB, No A/C