Help with engine paint removal.

[RustiePyles]

I’m at my wits end with the paint on this head. I’ve got 75% of it off but what’s left is clinging with a tenacity I’ve never encountered with paint. I’ve sandblasted, @Jim has sandblasted, I’ve soaked it over and over again in aircraft stripper. I’ve applied xylene. I cannot get what’s left of this paint to budge. Does anyone have suggestions to get this stuff off?

 

[DogBunny]

Not an expert on this, but I Googled medias, and I think the answer is to blast with aluminum oxide blast media.

 

[DogBunny]

Make that silicon carbide blast media.

 

[Jim]

I have an extra Harbor Freight blasting gun if you want to try some Home Depot sand?

 

[RustiePyles]

Make that silicon carbide blast media.

What you see was done with fresh silicon carbide. It removed most of the paint, but it just bounces off whats left.

 

[RustiePyles]

I have an extra Harbor Freight blasting gun if you want to try some Home Depot sand?

We have a blast pot here at work, but I'm afraid that sand that course is going to start removing aluminum. Have you blasted aluminum with play sand?

 

[Jim]

We have a blast pot here at work, but I'm afraid that sand that course is going to start removing aluminum. Have you blasted aluminum with play sand?

That certainly would be a concern.... and no, I haven't.
If you're not in a rush, I should be blasting the Beezer frame later this week. I'll blast an aluminum bit and see how it behaves.

 

[RustiePyles]

That certainly would be a concern.... and no, I haven't.
If you're not in a rush, I should be blasting the Beezer frame later this week. I'll blast an aluminum bit and see how it behaves.

You know me, I don't get in much of a hurry for anything. I'm still a long way off from needing to put that motor in a frame.

 

[Jim]

I'll blast an engine piece then and let you know what happens.

 

[DogBunny]

Grasping at straws here, but maybe heat the part in an oven, and then blast with fresh silicon carbide. I can think of a couple of reasons why this might help. I'm pretty sure you can safely heat those parts to 250 F., maybe higher, research it.

 

[BluzPlayer]

I'm pretty sure you can safely heat those parts to 250 F., maybe higher

They can be powdercoated, so that is 400 degrees.

 

[Jim]

Lycoming engines have a cyl head temp redline of 500°. Same cast aluminum with steel inserts.

 

[JesseeS]

Have you thought about/looked into vapor blasting? Would be an added expense but if it works it may be worth it. It looks like it has potential to get it off

 

[WideAWAKE]

Was the aircraft stripper the new low Voc stuff. If so, you might as well hosed it off with water. That stuff is useless. I’ve also found, unless you can get a scrapper on (the old stuff) with it still wet, it’s pretty useless as a stripper.

I’d let it sit over night in acetone.

 

[RustiePyles]

Grasping at straws here, but maybe heat the part in an oven, and then blast with fresh silicon carbide. I can think of a couple of reasons why this might help. I'm pretty sure you can safely heat those parts to 250 F., maybe higher, research it.

I'm guessing repeated heat cycles at or near 250F is what has caused this stick so tenaciously. But I'm not above trying things at this point. I can do a test spot with a heat gun and see if that helps. If it does I'll toss it in my smoker.

Have you thought about/looked into vapor blasting? Would be an added expense but if it works it may be worth it. It looks like it has potential to get it off

I have not, the cost would be pretty prohibitive. But I may have try that if I can't get anything else to work.

 

[RustiePyles]

Was the aircraft stripper the new low Voc stuff. If so, you might as well hosed it off with water. That stuff is useless. I’ve also found, unless you can get a scrapper on (the old stuff) with it still wet, it’s pretty useless as a stripper.

I’d let it sit over night in acetone.

It was not the low Voc stuff. It was the industrial aircraft epoxy stripper. An acetone bath was kinda what I was thinking. I have several gallons left from cleaning the Honda CJ360 tank. I just need to come up with a metal container to do it in.

 

[GLJ]

Do you have a propane torch? Could be worth a try.

 

[JesseeS]

If you end up getting to a point that you're pulling your hair out I have a spare head on my bench from my runner I'd swap with you (so long as you didnt put financial investment in yours, i.e porting, valve job, etc.). It's dirty for sure, but no paint that I can see. No pressure, but giving you the option of an out

 

[WideAWAKE]

And kinda sucks to say, but you’ll probably just have to keep eliminating what doesn’t work until you find something that does. As I’m sure you already know. And what works for this one, probably won’t work for the next one. The joys!!

I’d also try a pick to scrape it up and open the surface for the acetone to deep in better.

 

[RustiePyles]

Do you have a propane torch? Could be worth a try.

I have propane, mapp, and acetylene. I might give a few swipes with a propane torch and see if that loosens it up.