Powder coating muffler

I powder coat a lot of parts I use when restoring or building cars, trucks, tractors, etc. I was ordering some powder a while back and saw a silver high temp. powder that was advertised. It was advertised to be good for up to 1800 degrees. I ordered some and I just tried it on a muffler that I put on a Farmall Super A that I had just restored. Ordinarily, the factory finish or even high temp. paint on a muffler will discolor after an hour or so of running. This powder coat has not changed at all after about 6 -7 hours of running time and looks great.
I have a 2N that I am starting to reassemble and I have coated the muffler, tail pipe, and exhaust manifold. If it holds up on the exhaust manifold, I will really be impressed. I purchased the powder at Columbia coatings. It has a cure time of 30 min. @ 450 degrees.
 
There used to be a powder coat shop near me, sadly they didn't take care of business and went away...

They did a lot of custom automotive work. Saw a bunch of exhaust manifolds they had done. Never saw one after it was put in use, but it must have worked as many as they had waiting to be picked up.
 

Yes, please post back about how it holds up. On another forum someone was very happy to find that type of coating but then he found out that it burned.
 
Wonder how hot of an oven would be needed to bake powder coating in place that could withstand exhaust temps (that can get to RED heat)?

Sounds like it would be in the realm of ceramic coating?
 
This particular powder is baked at 450 degrees for 30 min. This stabilizes the powder, the heat from the manifold, muffler or whatever you applied it to, finishes curing it. I have used it on a couple of carbs and distributors and it set up fine at 450 Deg.. Gasoline doesn't seem to discolor it.
 
I am saying that it is advertised to be good to 1800 degrees. I have it on a super a muffler right now and it is holding up fine so far, but the muffler is not heating up to 1800 degrees. I have not yet tried it on an exhaust manifold, which will get much hotter than a muffler. I have a 2N manifold coated and as soon as I reassemble the tractor I will see how it holds up and post the results.
 
Most of the high temperature powder coatings are advertised to hold up to a temperature of 1000F to 1200F. The weak link is not the coating, but the preparation and the composition of the part being coated. If there is any residue or chemicals on the surface of the part it will burn and leave a residue that will not allow the coating to adhere.
If the muffler is made of aluminized steel, the aluminum will melt at a little over 1200F which lets the coating turn loose.
Blasting with clean media then coating immediately without touching the part with bare hands and baking at 450F will give best results.
Don't expect the coating to remain adhered to a red hot pipe. Too much oxidation of the steel occurs at these temperatures to keep the coating attached.
 
So it would hold up on tractor that is a trailer queen or not used under heavy load but would burn of on muffler of a tractor that is worked hard and muffler runs cherry red hours on end.
 
I normally bead blast, then spray it down with phosphoric acid and let it set for a few hours. Then I lightly bead blast it again and then powder coat.
 
Bead blast. Then coat immediately. The iron phosphate that is formed when using phosphoric acid will degrade at around 600F. Silicone coatings will withstand high temperatures but will only adhere to the surface. If the surface is a layer of iron phosphate ash, you can expect it to delaminate.

There are lots of factors in successful high performance coatings. My best suggestion is to test under the conditions you expect to survive before guaranteeing anything to a customer based on a data sheet.

I have helped suppliers to Green, Blue, and Yellow tractors with this very issue. It is not easy.
 
(quoted from post at 09:29:42 12/18/15) Bead blast. Then coat immediately. The iron phosphate that is formed when using phosphoric acid will degrade at around 600F. Silicone coatings will withstand high temperatures but will only adhere to the surface. If the surface is a layer of iron phosphate ash, you can expect it to delaminate.

There are lots of factors in successful high performance coatings. My best suggestion is to test under the conditions you expect to survive before guaranteeing anything to a customer based on a data sheet.

I have helped suppliers to Green, Blue, and Yellow tractors with this very issue. It is not easy.

The iron phosphate treatment is of course to eliminate little pockets of rust that you may not even be able to see. We all know how rust thrives under powder coat, so are you saying that it is better to have a little rust than any iron phosphate residue. I don't know how iron phosphate ash gets into the picture. I never would have thought of it as combustible.
 
Applying high temperature coatings is a whole 'nother animal from typical coatings. And "ash" may be a simplification of what actually happens when an iron phosphate coating formed by phosphoric acid on steel is in effect incinerated somewhere about 600F.

For what we are doing, best results will be obtained by a blast and immediately coating and curing.
 
(quoted from post at 16:52:54 12/18/15) Applying high temperature coatings is a whole 'nother animal from typical coatings. And "ash" may be a simplification of what actually happens when an iron phosphate coating formed by phosphoric acid on steel is in effect incinerated somewhere about 600F.

For what we are doing, best results will be obtained by a blast and immediately coating and curing.

Well what do you recommend? I have some car parts that are going out to the powdercoaters soon. They media blast everything that needs it before coating, but I have parts that were professionally painted that had rust bubble up under the paint after three years. How do you know that there is no rust to come up under the powder coat. I have things that were powder coated at the factory that have large pieces peeling off due to the rapid spread of rust underneath. My concern is not so much the type of animal, but that the coating stay intact for twenty years.
 
Showcrop, A lot depends on the type of parts and what you require. For example, are these underbody parts that are exposed to rock chipping and road salt or are they engine parts exposed to oil and gas or are they exposed to lots of sunlight. Each of these applications would ultimately use different processes and or different types of powder to achieve your goal.

And the recommendations I made previously are exclusively for silicone based high temperature coatings exposed to temperatures above 600F such as muffler applications.
 
(quoted from post at 22:58:07 12/18/15) Showcrop, A lot depends on the type of parts and what you require. For example, are these underbody parts that are exposed to rock chipping and road salt or are they engine parts exposed to oil and gas or are they exposed to lots of sunlight. Each of these applications would ultimately use different processes and or different types of powder to achieve your goal.

And the recommendations I made previously are exclusively for silicone based high temperature coatings exposed to temperatures above 600F such as muffler applications.

This is on a dashboard on an old car. It will not be exposed to oil, gas, chipping, sunlight or abrasion. it had a little rust in small areas, I plan to blast those spots, but from experience I know that minute particles of rust, will grow and eventually force powdercoaters to lift.
 
This is on a dashboard on an old car. It will not be exposed to oil, gas, chipping, sunlight or abrasion. it had a little rust in small areas, I plan to blast those spots, but from experience I know that minute particles of rust, will grow and eventually force powdercoaters to lift.[/quote]

That sounds like a simple application that would warrant the typical clean with alkyline cleaner, rinse, iron phosphate, rinse, then rinse with distilled or de-ionized water if your local water has lots of minerals. Coat immediately especially if the humidity is high.

Use a TGIC polyester to provide UV resistance (sunlight stability).
 
(quoted from post at 07:43:54 12/19/15) This is on a dashboard on an old car. It will not be exposed to oil, gas, chipping, sunlight or abrasion. it had a little rust in small areas, I plan to blast those spots, but from experience I know that minute particles of rust, will grow and eventually force powdercoaters to lift.

That sounds like a simple application that would warrant the typical clean with alkyline cleaner, rinse, iron phosphate, rinse, then rinse with distilled or de-ionized water if your local water has lots of minerals. Coat immediately especially if the humidity is high.

Use a TGIC polyester to provide UV resistance (sunlight stability).[/quote]

by Iron Phosphate do you mean phosphoric acid?
 
by Iron Phosphate do you mean phosphoric acid?[/quote]

For our purposes, yes. phosphoric acid applied to iron forms an iron phosphate conversion layer that not only neutralizes rust particles but etches steel for better adhesion.

In production applications, products are used that are easier and more consistently effective that are based on phosphoric acid with additional surfactants and oxidizers or accelerators.

http://powder-coater.com/phosphating.htm
 
(quoted from post at 13:13:16 12/19/15) by Iron Phosphate do you mean phosphoric acid?

For our purposes, yes. phosphoric acid applied to iron forms an iron phosphate conversion layer that not only neutralizes rust particles but etches steel for better adhesion.

In production applications, products are used that are easier and more consistently effective that are based on phosphoric acid with additional surfactants and oxidizers or accelerators.

http://powder-coater.com/phosphating.htm[/quote]

I have been using phosphoric acid rust converters for many years. It is actually rust that it converts to iron phosphate as opposed to iron. I have used it on rusted iron but much more often on rusty steel. I am currently using one by SEM the auto body supply manufacturer. It seems to be more active than others that I have used.
 
You start seeing color by 950 F. By 1,000 F most people call it "cherry red" but the red gets brighter until about 1,400 F when it starts to pale on the way to yellow, then white. Most tractor exhausts I've seen barely get over 1,000 degrees, and a B would not be one of them. A long ways from 1,800 degrees.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top