dave ellis
Well-Known Member
What's everyone using to prep an aluminum manifold for paint?
Aluminum prep for paint
- Thread starter dave ellis
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I lightly sanded with a 600 grit sandpaper, cleaned with alcohol.
Then the stuff I used that worked in a pinch and in a budget was:
Then I used engine paint on it.
It has held up pretty good for about 3 years so far.
And this is on my friend's old Jeep. (92' Jeep Cherokee with 349,000+ miles)
Then the stuff I used that worked in a pinch and in a budget was:
Then I used engine paint on it.
It has held up pretty good for about 3 years so far.
And this is on my friend's old Jeep. (92' Jeep Cherokee with 349,000+ miles)
Paint companies crack me up with their vague statements. Twice the protection of what?
Correct primer and preparation for aluminum is no different than ferrous metals.
EDIT: the word “correct” was added.
Correct primer and preparation for aluminum is no different than ferrous metals.
EDIT: the word “correct” was added.
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dave ellis
Well-Known Member
Is this paint high heat?
Again I said this was a budget (& quick) way of doing things, you can use certain etch primers as a substitute but even I had various etch primers flake off after awhile, and what I did with that aluminum primer has held up for 3 years so far. These are available at all hardware stores
After you sand the aluminum and then clean with either alcohol or lacquer thinner make sure you start using the primer as soon as you can so the oxide barrier doesn't form again. This is the reason why paints flake off so quickly is because of that.
That was the main problem with some of the aircraft that I worked on in the past, especially in humid climates, some derp Airman (or even Specialists) thought it was ok to simply spot paint a panel with out bringing the part into a controlled climate area. Not only did that humidity affected the paint, that oxide barrier formed quickly because of that as well.
Rustoleum and Duplicolor etch primers suck, do not use.
The other primers that I've used that work would be these but pricey & not widely available: (And they hold up to heat fairly well)
ACID#8 Acid Etch Primer - U-Pol
Spraymax 3680033 SprayMax 2K Epoxy Primer | Summit Racing
As for heat, I wouldn't worry about it too much, that 4.0L in that Jeep likely runs hotter than your car, I know for a fact it runs hotter than my 360.
And also why specific paint prep work used on aircraft is not the same as what you do on cars.
I've used that Spraymax epoxy primer then top coated with paint and then used the Spraymax 2K clear on an aluminum Speedo housing on my old Motorcycle in 2010, still looks good to this day. And that's with 13 years in the sun and several tens of thousands of miles.
*Disclaimer* Be careful! Spraymax products especially their 2K stuff has Isocyanates in it, please use proper rated respirators when spraying these.
After you sand the aluminum and then clean with either alcohol or lacquer thinner make sure you start using the primer as soon as you can so the oxide barrier doesn't form again. This is the reason why paints flake off so quickly is because of that.
That was the main problem with some of the aircraft that I worked on in the past, especially in humid climates, some derp Airman (or even Specialists) thought it was ok to simply spot paint a panel with out bringing the part into a controlled climate area. Not only did that humidity affected the paint, that oxide barrier formed quickly because of that as well.
Rustoleum and Duplicolor etch primers suck, do not use.
The other primers that I've used that work would be these but pricey & not widely available: (And they hold up to heat fairly well)
ACID#8 Acid Etch Primer - U-Pol
Spraymax 3680033 SprayMax 2K Epoxy Primer | Summit Racing
As for heat, I wouldn't worry about it too much, that 4.0L in that Jeep likely runs hotter than your car, I know for a fact it runs hotter than my 360.
And also why specific paint prep work used on aircraft is not the same as what you do on cars.
I've used that Spraymax epoxy primer then top coated with paint and then used the Spraymax 2K clear on an aluminum Speedo housing on my old Motorcycle in 2010, still looks good to this day. And that's with 13 years in the sun and several tens of thousands of miles.
*Disclaimer* Be careful! Spraymax products especially their 2K stuff has Isocyanates in it, please use proper rated respirators when spraying these.
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I have never seen a paint manufacturer suggest using anything finer than #120 grit before primer application. Acid etch under epoxy is not recommended too. If anything, aluminum is more forgiving than ferrous metal. I agree, corrosion after abrasion is the biggest culprit of adhesion problems. That and Ph. 8 hours for iron, 12 for aluminum.
I think etch primer is a poor substitute for proper preparation. Sand it, clean it and use a good direct to metal primer.I never suggested using acid etch under epoxy. (I already tried that as an experiment almost 2 decades ago, yeah you know the story)
What I implied was one or the other.
I agree, but it'll do in a pinch in some cases. Again that Upol #8 for some reason worked decently.
But that Spraymax worked better and is worth the money. (It does suck using that for small projects and then you realize hey I still have quite a bit left. So you desperately try to find something else to spray within 24 hours before that catalyst hardens inside the can. lol)
But that Spraymax worked better and is worth the money. (It does suck using that for small projects and then you realize hey I still have quite a bit left. So you desperately try to find something else to spray within 24 hours before that catalyst hardens inside the can. lol)
dave ellis
Well-Known Member
Appreciate all the help guys, Dave
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