AC heater box in bad shape

[Blk63vette]

Hello
I took a hard look at my heater box. This housed several generations of mice. The bottom to the box is rotten. The blower motor crumbled in my hands. I as thinking of making new one from parts of original. The flap is rusted bad. I don’t to use smoke wrench because of the rubber seal around flap. I thought about soaking that part of box into rust removal solution. (edited by staff) What you think?
https://67-72chevytrucks.com/vboard/...1&d=1669136691
https://67-72chevytrucks.com/vboard/...1&d=1669136691
https://67-72chevytrucks.com/vboard/...1&d=1669136691

[The Rocknrod]

You might also try calling Aspen or 4,5,6 truck parts.

[jweb]

Looks like there's one on Ebay:
https://www.ebay.com/itm/16572189706...Bk9SR56L0uKUYQ

[cgrocen]

If you want to try soaking the parts in a rust removal solution, you might want to try a mixture of water and molasses. I have used it with great success. 1 part feed grade molasses and 9 parts water. Soak the part for about 2-3 weeks, and the rust is gone. You can buy a 5 gallon pail of feed grade molasses for about 30 bucks. You will have to wash the parts thoroughly after you remove them from the mixture. The parts will flash rust when dry. After the parts are dry I spray on a coating of POR-15 Metal Prep. It contains phosphoric acid. It etches the metal preventing any flash rusting. Pros: cheap and it works. Cons: It takes a long time, weeks, and the solution reeks! Bottom line IMHO it is economical and it works great. It is not acidic and won't harm good metal. Here are some replacement panels that I bought that were covered with surface rust. I made a "container" to hold them in for about two weeks. Last photo shows clean bare metal after pressure washing them, but before coating with metal prep.

[Blk63vette]

Great ideas.
Thank you. Since chances of me finding a factory AC heater box is slim and none. I got a heater box I will try to convert to a AC heater box.

[AcampoDave]

You could try cleaning the metal with a rust remover like Naval Jelly and then patch it using fiberglass resin and cloth. It's still holding up well for me on the lower corners of my doors and a layer of Bondo over that really got it smooth. The trick is to remove the rust first and if it leaves a big hole, some metal window screen can be used to back up the fiberglass. The flapper part looks like you could save it with some Naval Jelly too. I like to scrub it in real hard using an old toothbrush. I've even wetsanded with it using 600 grit wet and dry paper. (Gonna take a few coats though). Then oil it up

[61hawk]

Originally Posted by AcampoDave

You could try cleaning the metal with a rust remover like Naval Jelly and then patch it using fiberglass resin and cloth. It's still holding up well for me on the lower corners of my doors and a layer of Bondo over that really got it smooth. The trick is to remove the rust first and if it leaves a big hole, some metal window screen can be used to back up the fiberglass. The flapper part looks like you could save it with some Naval Jelly too. I like to scrub it in real hard using an old toothbrush. I've even wetsanded with it using 600 grit wet and dry paper. (Gonna take a few coats though). Then oil it up

One thing a lot of people don't know is you can use POR-15 instead of fiberglass resin. Two or three layers of fiberglass and you'll be able to beat on it with a hammer.

[1966 K10]

Im in the same boat, burb had a ton of mice and additional damage to the core plate. Found another box to put in meanwhile since its a daily driver.

I never realized how different the regular deluxe heater and the A/C box with the re blend flap. Not sure if A/C boxes are specific or just modified from the factory. If you look close at a regular box there is almost an imprint of where to cut if you were to add the flap.

The heater core for the A/C box is HUGE compared to the standard unit.


I will pressure wash then soak in evaporust to see what is left to work with. Dont think there is any rust through, flap rods might be wasted though.

[Blk63vette]

Hello
I bought another heater box. I compared them both and mine is the same as the AC box my truck came with. However, I believe my AC was not from the factory I believe it was dealer installed the cut hole in firewall and heater box was cut crudely. I think the dealership converted my heater box with a factory parts kit. I don’t think anyone else messed with this box besides me. I’m going to try evaopo rust and see if I can’t get the flap out of the rusty box and I
Put it in the new box.

[Blk63vette]

Hello
I found a complete and from the pictures in good shape AC heater box the motor isn’t working but besides that it’s all there. I show pics when I get it.