Heater box fiberglass repair

[71Satellite98661]

Does anyone have any tips on repairing the heater/ air conditioning plenum under the instrument panel? My damaged areas are not major but would like to patch them and attempt to match the original color and texture as much as possible. Any photos or links appreciated!

[road chicken]

Good luck, I know those are no fun because they get so brittle and flake apart just from the age. I cringe when I have to move mine.

[sdweatherman]

Could you post a picture or describe exactly what piece is broken. I have extra AC parts if you are interested. Scott.

[71Satellite98661]

Thanks guys, after disassembly and cleaning the hole is tiny and up against the firewall not to be seen. I just used black RTV with two applications. I got lucky. I was very surprised at how easily the A/C and heater box came apart. I found that 409 and diluted Castrol Super Clean took care of the grime. I steered clear of the yellow stamping and was able to retain those. I used flat aluminum paint on the actuators. They look very good but could use more a bit more gloss to look more like the original plating. A wire, then fiber brush was used to clean the actuators prior to paint. A pressure washer and brush made the fiberglass look absolutely like new, I was very pleased. Also very happy with Detroit Muscle Technologies with the gasket and seal kit. I wish I could remember who it was earlier in response to heater core testing but thank you for the great idea of using a bicycle inner tube and two clamps. Genius!

[kenny]

your welcome for the tip to test heater core yourself. i am glad it was helpful, a friend of mine that restores 69 and 70 mach 1 and boss 302 mustangs taught me that, he had a big tub and tested his radiators that way also. sounds like you did a real nice job on your box. i washed mine with dish liquid and a green scotch brite and lost the yellow stampings and the fibers in the material seemed to be more exposed and looked real white so i ended up putting some flat black paint back on mine so it would blend back into the interior better. wish i had not been as aggresive and saved the original look like you did. and i agree the kit from dmt for the heater boxes is great.