I recently removed the heater box from my '71 (yes I did it with the dash in, not the easiest but, I did it)to find that the core was no good, now that I've gotten a new core I was thinking (yeah I know mistake #1!) I should renew the foam insulation that goes around the doors, flaps and, the foam that goes around the core itself. The only problem is I've yet to see a picture of exactly where the core foam goes and, what type of foam to use on the box. If anyone has rebuilt their heater box before and/or has some insight I'm all ears.

P.S. I don't know if you guys know it or not but 32 degrees at 4:30 am without heat is getting a little old!....err or is that Friggin' COLD!!!!

I prefer Closed Cell Sticky Back Foam Tape in various widths and thicknesses. That's what I used to refurbish my Heater and it works like a charm. When you close the flapper doors, you don't get blow by, and same with Defrost or Vent.

The foam goes around the Heater Core to "snug" it into the channel. There are also a couple pieces that go around the inlet and outlet pipes for the core to also seal it there and not have air escaping out of those holes. As far as the internal flapper valves, you will need to experiment and see if you need to get a whole sheet of foam and a vinyl skin, or if you can get away with just using the tape. I didn't have to do anything but reglue my insulating skins back onto the flapper valves.

As far as whether or not you should do it now with the added expense and time, or wait, ask yourself this: When is the next time you are PLANNING on having the Heater Core and everything out of the car? If not in the near future, do yourself a favor, clean, get rid of rust, paint and re-foam the box and put it back. You'll thank yourself later.

2¢

Enrique

EScanlon, you seem to have the answers to all my "Z" questions, thanks for the imput! So if I'm following you use the clsed cell sticky back foam on the doors/flaps that had foam strips and use the foam backed vinyl on the big door that has the vinyl now?

One more question, do you know of a good source for the foam and, does it have to be heat resistant or anything special?

I checked two places for the foam strips, one was an R/V Center (for accessories and the like) and the other was a Building Supplly store that sold to not only plumbers but also to people hanging suspended ceilings.

You'll find various widths and thicknesses. What I liked was that I also found different "squeeze" or firmness levels. I picked a fairly soft but resilient foam, grayish black if I recall.

You have it right.

Remember, the main thing for the foam is to SEAL around the Heater Core and to provide a seat for the edges of the doors. That way the air will go to where you want it to.

Good Luck

Enrique

Home Depot or Lowes has the sticky-backed foam. Comes in varying thicknesses on a roll. Look in the area near the door sill plates. It is used for sealing around the doors, camper shells, etc.

Another thing that you could fix with that tape is the Center Vent Bellows connector.

That's the part BEHIND the Chrome Center Vent drum. Time and heat have usually cooked the foam padding to dust.

Be careful how you build up the foam especially to the sides where the thumbwheels can rub on it. They DO rub, just not so much as to make it difficult to rotate the vent. The foam should "seal" the upper and lower edges of the bellows connector to the body of the Vent Drum Holder.

Hope this helps.

Enrique