De-trickulatatin a header coating conundrum.

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Rice Nuker

Rice Nuker

Let the Coal Roll!
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Let me preface this thread by saying that I am fairly certain this is a process failure on my part.
First I blasted these super bare with sand blaster. Then I hung them in the sun, filled my paint gun with denatured alcohol and soaked the bejesus out of the headers. Let them dry for an hour and mixed up some KBS aluminum color - extreme temp paint.

http://www.kbs-coatings.com/XTC.html

I thinned it 20 % with high quality urethane reducer and layed on 2 medium coats about 10 minutes apart.

Then let them sit in the hot *** sun for 2 days.

Then carefully installed on engine, fired it up for 5 minutes at 1800 rpms, let cool for 10, then fired up for 20 minutes at 1800 rpms. This was not engine break-in or similar, I just like to run the motor at that speed while warming it up.

After that, within one hour, all the paint fell off like bark peeling off a tree.

See images. The dog appears to think it's a preparation issue.
 

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My .02 cents was the surface temp was too hot. This is from their directions.


Ideal application temperatures of air & substrate to be coated are 50-82°F (15-28°C). KBS Xtreme Temperature Coating may be applied by conventional or HVLP spray, airless spray, brush or roller. Do not apply KBS Xtreme Temperature Coating in heavier films than specified since blistering may occur.
 
Actually, heck the surface could have been 120 being in the sun. I was also thinking I should have baked at 250 prior to running on the car.


Yea, I am interested in blasting and re-coating but needing to get this engine back in, wanting it to turn out right so I can move forward.

Also, I was thinking surface contamination because it looks to have released perfectly, leaving bare blasted metal.
 
I was not aware high temp paints were supposed to be thinned. That changes their chemical compound.

Straight from their site:

"FOLLOW ALL CAUTION & WARNING NOTICES WHEN SPRAYING. ALWAYS WEAR AN AIR SUPPLIED RESPIRATOR: NIOSH/MSHA approved organic vapor particulate respirator. Spray pressure of 35-45 psi (250-330kpa) for siphon/pot guns and 25-35psi (170-250kpa) for gravity/top container guns. Thinning is not generally required but if needed 5%-10% is normally adequate. Use KBS #1 Thinner only which is a slow evaporating solvent. Do not reduce Xtreme Temperature Coating with lacquer thinner. Also remember to clean your spray gun immediately after using Xtreme Temperature Coating."
 
Yep. I saw that. Figured I could get away with it because it was fancy high end urethane thinner. From your neck of the woods no less. Southernpolyurethanes.
 
Ricenuker, I cleaned for a living and alcohol, sprayed at that low pressure, will not adequately dislodge tightly adhered sand contamination. We would have used high pressure water and soap followed by a really good rinse and then an alcohol to help flash the water off. I know you are trying to avoid rust but not sure how you can get enough sand residue off to get great adhesion. I suspect it works a lot of time but in my business, it would not have.

I wonder too; would the urethane not burn off too and tend to flake since most of those are going to cook in the 500 degree F range and headers can see 700 to 1200 pretty easily at the port? I know the paint should have the binders that adhere but if the surface is not really clean, can they bind well enough?

Good luck with round 2. :):)
Tom
 
Rice Nuker said:
Yep. I saw that. Figured I could get away with it because it was fancy high end urethane thinner. From your neck of the woods no less. Southernpolyurethanes.
Click to expand...


Naw don't be doin all that. It ain't my fault. lol
 
"...will not adequately dislodge tightly adhered sand contamination."

wow, never thought of it like that. Imbedded micro-particles of shibullit just waiting to be a release agent.

"Naw don't be doin all that. It ain't my fault. lol"

roger that!


Thanks guys.
 
You need a good ultrasonic cleaner and you would see some serious sand residue being blasted off! :)
Tom
 
No matter what you do and no matter what you use there is still the problem of heat expansion of metals!! When metal expands (under heat) it tends to sluff off anything that is attached to it simply because all materials expand at different rates (iron, cast iron, metal, aluminum, paint, etc). The coating you use will expand at it's own rate and separate itself from the base metal as the base metal expands at a different rate. You didn't do anything wrong but if the coating doesn't expand and contract at the same rate as the base metal there will be some separation. This is true of any paint system. That's why they make high heat paints!!
Adherence can also be a problem but regardless of how well a paint adheres to a surface, expansion and contraction can still separate the base metal from the coating. Surface preparation is also be very important but heat expansion can still separate the metal from the paint/primer if they don't expand and contract at the same rate.

My two cents!!

treblig
 
The last time I did these headers, I blasted them an sprayed cold galv rustoleum rattle can on there. Lasted 4 years with very little specks of rust. Kind-of a white color after burn-in.
 
omg, now I need an ultrasonic cleaner or I'll never get paint to stick again.

I've researched them and the action and results sound fantastic. But unless they make one that'll hold a set of headers for 100 bucks, I am not going to own one. In other words, they are astronomically and exponentially expensive as the get larger than a quart.


VOETOM said:
You need a good ultrasonic cleaner and you would see some serious sand residue being blasted off! :)
Tom
Click to expand...
 
Yep, I think the concept is similar to cold galv spray. Very little resin, some anti-rust dust with a bit of color and then some lacquer solvent which evaporates in seconds leaving dust embedded in the pores of the blasted metal. Based on my recent experiences, I am leaning that way like a three legged donkey leans on a fence.

famous bob said:
you could always go get some stove black for them, it won`t fall off.:eek:ops:
Click to expand...
 
Is it worth it to thin down some ospho with distilled water and blast the ship out of them with that after sandblasting? Could that help etch the metal and remove traces of sand by way of magical chemistry and velocity?

I could blast the ospho mix on there by way of a small pot sand blaster full of the solution, running at 120 psi.


I dont have any other type of prep / etch chemicals around that I can think of.
 
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