Amadeus

Amadeus

Well Known Member
What is the source of the copper colored soot clinging to the belly of the plane from the Rotax 912iS exhaust pipe back?

Is there a way to make cleaning this soot off easier? An old aviator at my airport said to spray WD-40 on the entire underside of the aircraft and not wipe it off and the soot would not stick. This is not a viable solution for me but it got me thinking that perhaps there is some sort of wax that could be applied that would make soot removal easier. Has anyone discovered a workable method?
 
Amadeus said:
What is the source of the copper colored soot clinging to the belly of the plane from the Rotax 912iS exhaust pipe back?

Is there a way to make cleaning this soot off easier? An old aviator at my airport said to spray WD-40 on the entire underside of the aircraft and not wipe it off and the soot would not stick. This is not a viable solution for me but it got me thinking that perhaps there is some sort of wax that could be applied that would make soot removal easier. Has anyone discovered a workable method?
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Copper colored like rusty water?
 
IMHO it is likely`a normal mix of crankcase breather mist, possibly engine-driven fuel pump vent mist, and dust/dirt. I use Simple Green Aircraft and Precision Cleaner to wipe this light residue off the belly of the plane.
 
Amadeus said:
Yes, about that shade, but dry and stuck firmly to the belly. Another -12iS was at an airport I stopped into and he had the same substance and did not know the source.
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Jason I’m always watching for better ways to clean the belly but it’s always tough. Rolling around on a creeper, I have been using Simple Green for aircraft, followed by water, and wipe dry with microfiber towel. Then I use a spray ceramic wax and wipe off.
I have a gray soot from exhaust and clean after every third or fourth flight just to keep up.
 
I use Flitz to remove carbon residue (from my "work" aircraft starter-generator exhaust) then seal the pores of the older paint surface with a detailing spray from Oh Oh Oh Reilly's.
 
As Dr_Dave suggested I've has good results using a spray on "show and shine" with other vehicles. It sort of acts like Rainex does for water.
 
I could be wrong, but I believe I started getting a light rust color on the belly once I started using the fuel additive Decalin. I still use it when needed and it seems to work great. I
use Extreme Simple Green.
 
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Jcurry said:
I could be wrong, but I believe I started getting a light rust color on the belly once I started using the fuel additive Decalin. I still use it when needed and it seems to work great. I
use Extreme Simple Green.
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The source of the copper soot is something other than Decalin. I carry a small container of Decalin in case unforeseen headwinds make 100LL a necessity but luckily so far my Rotax has only consumed unleaded fuel. No Decalin has passed through it. Flight planning that incorporates flyunleaded.com has really paid off.

I ordered Simple Green Spray Foam and Simple Green Aircraft & Precision from Aircraft Spruce and it is scheduled to arrive Monday. Can't wait to see if it makes cleanup easier.
 
I don’t get much on the belly but do clean about every 50 hours with 91% rubbing alcohol and a microfiber towel. It cuts through the dirt, doesn’t leave any residue and doesn’t bother the paint.
 
91% rubbing alcohol in a little spray bottle cuts right through the oil and dirt (recommended by my paint shop). Simple Green likely works just as well.. just make sure you get the Aviation version of it, as regular Simple Green eats aluminum.
 
My white belly gets an amber coating of what I assume is some aspect of running about 95% MOGAS. The best thing I have found is Krud Kutter. Lowes carries it and it's cheap (like $4-5 for a 32 oz bottle). I spray it on, and the amber mist literally start dripping off. Literally NO scrubbing. The towel is just to clean up the drips and mess.
 
bigmo said:
I spray it on, and the amber mist literally start dripping off. Literally NO scrubbing. The towel is just to clean up the drips and mess.
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Now THIS is what I like to hear! Last time I did it it was two and a half days of scrubbing and there were traces left at seams and rivet that I just gave up on.

Is Krud Kutter safe for aluminum?

Someone has informed me that the amber/rust/copper coating is from a dye used in mogas. Other than the few times I have picked up some Swift UL94 along a route I have exclusively used 91 octane mogas.
 
Amadeus said:
Now THIS is what I like to hear! Last time I did it it was two and a half days of scrubbing and there were traces left at seams and rivet that I just gave up on.

Is Krud Kutter safe for aluminum?

Someone has informed me that the amber/rust/copper coating is from a dye used in mogas. Other than the few times I have picked up some Swift UL94 along a route I have exclusively used 91 octane mogas.
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Amadeus said:
Is Krud Kutter safe for aluminum?
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They have extensive documentation on it and it makes no mention of being unsafe for any metals. My aircraft is composite - so my experience with it on aluminum is limited to my motorcycles. I have used it dozens of times on raw, painted, and anodized aluminum with no issues. It's produced by Rustoleum, so you can probably call and get an authoritative answer from them.

On my aircraft, when I am done with the Krud Kutter, I wipe the area down really well with Meguiar's detailer. It's super cheap by the gallon (Amazon). Mainly for easy bug removal.

The Krud Kutter is non-toxic and even biodegradable.
 
I use low odor mineral oil. I put that "stuff" on everything. Works well on the build-up directly aft of the exhaust on my -9.
danny
 
The best thing I have found to clean the belly is Dawn Platinum Powerwash Dish Spray. Just spray it on and wipe it off. I hate to admit it but I just cleaned mine off for the first time in 12 years and Dawn cleaned it right off with little effort.
 
What have you guys been doing with your sump fuel? I put it in a ole pickle jar to be green, old habit of not tossing lead onto the dirt.
I would try to use that for something constructive like this.
 
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