Repainting rusted headers??

[crashz]

Since its not leaking, I'd leave it alone. If you are worried about future service and breaking bolts, you could put studs in place, but its a lot of work for marginal benefit.

For purely cosmetic solutions, why not try the cast iron manifold paste that is found in common restoration catalogs (LMC, JC Whitney, Summit, etc)? It is a paste that brings back the original finish of the cast. A quick spray of high temp clear, and it should last a long time and look good doing it.

 

[mrutkaus]

Yes I'd be very careful with the bolts, keeping them soaked for as long as you can with PB blaster, wd40 etc before you start on them. Then if there is any chance of breakage, ie tight, spray several times during removal.

When I removed some bolts from a Mercedes engine block, I built a well out of clay and a drip tube and soaked the bolts for a month or more before I started working on them.

Mike

 

[flusher]

The headers on my Kubota is getting rusted badly over the years. I tapped on it with a hammer lightly and its definitely not anywhere close to rusting through. But im concerned because the rust is causing the bolts that attach it to the block to rust. Its only about $30 for new bolts and gaskets so Im going to order them up.

My question is should I be careful removing the old bolts? Any specials precautions? I dont want to break a bolt in the block.

Are high temp paints that come in a can any good? I imagine I would need to get the header sand blasted to remove the old rust.

Everything else under the hood is in excellent shape.

Use a rust converter like Orthophos on the rust (wire brush the loose stuff, but don't remove any of the other rust) and then a high temp paint. The cheapest stuff is the black paint for barbeques.

 

[ampsucker]

since everybody has an opinion on this, i'll add mine! ;-)

agreed that cast iron manifolds rarely rust through. the most common problem is cracking - usually due to something cold like a/c condensate dripping on a hot manifold. not going to be a problem for you. if you don't have any leakage or warpage, it's unlikely the mating surface is going to corrode as it's very much insulated from oxygen penetration due to the compression of the seal between the metal parts.

if you just want to make it look better, paint it. although i've had mixed results with "high" temp paint from a can. never tried the high dollar stuff from a custom mix, though. having it powder coated or ceramic coated would most likely last longer. usually, that type of "send out" stuff is done for the insulative effect of retaining exhaust gas speed and heat out through the tailpipe in performance auto applications. it's not going to help your tractor perform any better but will probably last longer cosmetically than paint.

if you just want to make sure you can service it later, take each bolt out one at a time after soaking with penetrating oil, coat with anti-seize lube, and reinstall. make sure you torque to proper spec with a good torque wrench. that will insure an even seal where the manifold meets the block.

amp

 

[RWolf]

There is another way to remove rust from your exhaust manifold without sending it out to be sandblasted and you can do it a home fairly easy. The diagram is pretty straight forward. Use a clean piece of steel for the positive plate, Your manifold for the negative and a "trickle" charger for the power source. The liquid is a 10% solution of washing soda (sodium carbonate, soda ash) and it is available at many grocery stores in the laundry detergent aisle.

forgot to mention this process will take about 48 hours but is entirely hands off. After cleaning then a coat of barbacue paint or other high temp. paint of your favorite color.