vent stovepipe sealing?

[Steve A.]

When I disassembled my firewall and removed the vent stovepipes I noticed a sealant similar to roofing tar around the edges of the flange. When I heated the bonding adhesive you could see this "tar" bubble...which the bonding adhesive does not do.When I look at the AIM, it calls for the flange to bond with a bonding connection "B" (90 degree butt joint)...but there is no mention of any further glue or sealant. The aim does show an adhesive but it looks to be the adhesive that glues the foam seal to the front edge of the stovepipe that fits to the back of the filler panel on the firewall corners.If there was tar sealer put on, how was it done and why doesn't the AIM reference it?I have my stovepipes bonded back in and I want to determine if I am done before final assembly or do I have sealer to administer...Thanks

edit, 1965 car

[Philip C.]

Re: vent stovepipe sealing?

Steve I am sorry but WHAT the He%& are you taking about??? Phil 8063

[Steve A.]

Re: vent stovepipe sealing?

Sorry, I have the vent ducts removed from my firewall in a total nut and bolt restoration. Took the car all the way down to removing the birdcage from the body to inspect/repair all aspects of this car. When I removed the ducts I found some tar like sealant around the flanges of the duct passageways (often referred to as the "stovepipes"). There has been a couple of places where this black asphalt type sealer has been used, I assume to prevent water intrusion. It is different than the rope type black sealant you see around the corners of the birdcage where it meets up with the body. I find no reference to this stovepipe sealant in the AIM, but there are a few anomalies with the AIM so just trying to see if anyone that may have built these cars at the factory recalls if this sealant was used.

Here is a picture of the area I am talking about.



You can see some remnants of the black tar like sealant still on the part. The flange has/had a strip of bonding adhesive that affixed the duct into the firewall. Looked just like bonding adhesive that was used on the panels and removed by sanding/grinding just like on panels.

I bonded the ducts back in, here you see the bead of bonding adhesive laid out with a wax paper piping funnel



So here is the duct now bonded back into the firewall per the AIM. Disregard the screw, it was only used to "pull" the duct into a seated positon during bonding. It utilized the same hole that affixes the grill cover...i nice little trick to hold the duct into place while curing.



So my question is should there be any of the black, asphalt type seam sealer applied around the flange? The AIM doesn't call that out...but I am pretty sure what I removed was original.

Sorry for all the detail, but you asked

[Wayne W.]

Re: vent stovepipe sealing?

In the body shop, items on the firewall assembly were sealed with that tar substance from the outside. That housing was part of the firewall assembly and got the sealer. It is on most of the things that are attached to and go thorough the firewall.

[Steve A.]

Re: vent stovepipe sealing?

Thanks Wayne, that is exactly what I was looking for, that explains why it appeared to be sloppily applied. Between you and John my steak dinner & beverages debt is going to be huge! (but worth it). What sealant on the market today is the best reproduction of original?