What did you to to restore your flapper boxes?
 

To my delight, the nuts holding the flapper boxes to my 87 came off when I looked at them. A stroke of good luck.

Wondering what the best way is to go about restoring these. My biggest concern is functionality, which is sort of linked to appearance, as rust bubbles near the moving "flap" seems to overcome the return spring and prevent the box from closing, thus unwanted heat. I have the motor out and want to address these... but I'm weary about stripping and painting these with the little delrin or nylon gaskets/glides I see on there. Are those available? How to proceed?

You probably should post this in the 911 section, because there were no 87 914s. ;)

I'll move it for you.

--DD

Have a look at this link: Heater Box Restoration

Ian

I removed them and sand blasted off the surface rust. There was some moderate pitting and "deeper" surface rust in a few areas.

I had no problem blasting carefully around the areas with plastic bushings and the edges of the flappers.

I finished by blowing out the residual sand and painting the boxes with Wurth zinc rich Weld Through primer.

Nice results with smooth movement.

Cooper

carful, the do get hot and cheap paint fumes do get in the cabin, the fumes only effect one eye so you should be good to drive

I wire brushed and naval jellied the rust off and will now prime and VHT high temp paint the boxes (but not the insides which look fine).

Thanks all.

Buy new ones, easy.

for $160, I'll pass. I could probably get a blasting cabinet and compressor for less than two heat boxes.

My 10 steps program; Post 1 of http://forums.pelicanparts.com/porsche-911-technical-forum/589980-cleaning-flapper-boxes.html

Perfect! Thanks. I have VHT high temp satin black and high temp primer on order. Already stripped down most of the outside but i do want to remove the shaft to gain access to the friction surfaces, since making these close reliably (not look good) is the real goal. Did you ever find replacement parts for the plastic bushings?

No, I re-used the crack one and it still holding. I think even a broken on could be JB Welded.

Its basically an isolator between the steel body and the retentive clip to relieve friction so it would be easy to fabricate one using hight heat gasket. Thickness does not really matter as the clip can slide down further.

Have fun...