Chipped Porcelain Exhaust Manifold

[Guest dgriff8923]

This is my weekly question. My 1918 Cad has black porcelain finished exhaust manifolds that are in pretty good shape but have a couple of chips in them. Is there a good repair method or should I look at having them re-done? Thanks again for any helpful hints or ideas.

[Curti]

It is like a broken piece of glass, once it is broken, it will always be broken. Jet it refinished.

[trimacar]

Curt is correct, you can touch it up with some black manifold paint, and it will look just like porcelain that's chipped and touched up with black manifold paint.

If they're in "pretty good shape", my suggestion is to leave them alone. Porcelain is expensive, and no guarantee that it won't chip again. Also, there are horror stories of shops taking a grinder to an exhaust manifold, breaking the "surface tension" of the now heat treated cast iron, and having the manifold shatter.....

[Curti]

There is a place in Northfield Minnesota that has a good reputation. Never ever spray cold water on a porcelain coated exhaust manifold when it is hot. I did !!

[Restorer32]

Also never use braze to fill pits in a manifold you intend to have porcelainized. Braze melts at 1400 degrees F while porcelain is applied at 1400 degrees C. I didn't do it but I know a shop that did, on a Duesenberg no less. Expensive lesson to learn.

[Friartuck]

Exhaust Manifold Porcelain Service

Prairie Auto Porcelain, Inc,

17250 Cannon City Boulevard

Faribault, MN 55021

(507) 645-5325