An interesting maintenance procedure

The ramblings of our community of aviators.

Moderators: Rick, Lance Murray

Post Reply
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

An interesting maintenance procedure

Post by Rich »

Today I was at our local EAA meeting, planning for a Young Eagles flight next weekend. One of the guys flew in with his 1970 C150 Aerobat. Oil is dripping from the wings and coating most of the airplane including over a very nice paint job. A severe engine oil leak you think? You'd be wrong.

Ready for this?

Apparently there are some signs of corrosion inside the wings. So every few years his mechanic sprays an oil mist all over the inside surfaces of the wings. The excess (and there's a lot) oozes out of the various seams of the wings. Really noticeable streams of oil drips out of the wing roots, running down the fuselage in that area behind the doors.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
Steve
5 Diamonds Member
5 Diamonds Member
Posts: 1953
Joined: Thu Aug 12, 2010 1:23 am
First Name: Steve
Aircraft Type: DA40
Aircraft Registration: N432SC
Airports: 1T7
Has thanked: 81 times
Been thanked: 493 times

Re: An interesting maintenance procedure

Post by Steve »

I’ve heard of this being done, especially for aircraft which don’t have the interior wing structure treated with zinc chromate. Definitely sounds messy. That’s one issue that we don’t have to worry about…
User avatar
Boatguy
5 Diamonds Member
5 Diamonds Member
Posts: 1827
Joined: Mon Jan 22, 2018 4:48 am
First Name: Russ
Aircraft Type: DA62
Aircraft Registration: N962M
Airports: KSTS
Has thanked: 1327 times
Been thanked: 1163 times

Re: An interesting maintenance procedure

Post by Boatguy »

Rich wrote: Sat Jun 19, 2021 8:27 pm Apparently there are some signs of corrosion inside the wings. So every few years his mechanic sprays an oil mist all over the inside surfaces of the wings. The excess (and there's a lot) oozes out of the various seams of the wings. Really noticeable streams of oil drips out of the wing roots, running down the fuselage in that area behind the doors.
And that spray is supposed to slow or stop the corrosion? That sounds like an accident waiting to happen.
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: An interesting maintenance procedure

Post by Rich »

This certainly doesn't appear to be an acceptable method as depicted in AC43 except for the interior of steel tubing, where it is long standing preventative practice.

And ugly it is. :D
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
krellis
4 Diamonds Member
4 Diamonds Member
Posts: 339
Joined: Fri Apr 29, 2011 10:42 am
First Name: Keith
Aircraft Type: OTHER
Aircraft Registration: N853DF
Airports: GA04
Has thanked: 1 time
Been thanked: 63 times

Re: An interesting maintenance procedure

Post by krellis »

User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: An interesting maintenance procedure

Post by Rich »

krellis wrote: Sun Jun 20, 2021 1:05 am Perfectly acceptable and it works.

https://www.corrosionx.com/pages/corros ... pplication
This looks like plain old motor oil and it's literally dripping down the sides of the plane and being sprayed in flight back across the whole aircraft surface from the wings aft. This is weeks after application. Indications are that it's pooling in various locations in the wings and works its way out as the plane is flown and the weather warms so the oil gets less viscous.

We live in a very dusty desert area and this likely guarantees any such dust getting into the wings will cling/build up there pretty much forever.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
krellis
4 Diamonds Member
4 Diamonds Member
Posts: 339
Joined: Fri Apr 29, 2011 10:42 am
First Name: Keith
Aircraft Type: OTHER
Aircraft Registration: N853DF
Airports: GA04
Has thanked: 1 time
Been thanked: 63 times

Re: An interesting maintenance procedure

Post by krellis »

Corrosion X and ACF-50 are both used to mist the inside of wings, empennages, etc. on metal airframes. The products work. Yes, they are messy, but corrosion is worse. Corrosion X Aviation has a slight green tint and a distinctive smell.

You could use Corrosion X on the three screws on the DA40 wings that are prone to corrosion. Maybe not needed in the desert, but might be in many other locales.

I use it on battery posts and a host of other places. It's a great product. I will use it on our RV-7 and RV-10 in a few years.
User avatar
Davestation
4 Diamonds Member
4 Diamonds Member
Posts: 250
Joined: Tue Mar 12, 2019 7:49 pm
First Name: David
Aircraft Type: D-JET
Aircraft Registration: NDJET
Airports: KFTW
Has thanked: 103 times
Been thanked: 100 times

Re: An interesting maintenance procedure

Post by Davestation »

I’ve seen this firsthand, pulling a panel off and a small reservoir of oil is unleashed all over me. The insides generally look like they dunked the whole plane in a pool of the stuff. Sure I suppose it “works” but that can’t be the proper application.
User avatar
Spinner
3 Diamonds Member
3 Diamonds Member
Posts: 89
Joined: Mon Aug 17, 2015 6:55 pm
First Name: Paul
Aircraft Type: DA20-C1
Aircraft Registration: lots
Airports: CYQM CYFC CYYR CYTH
Has thanked: 27 times
Been thanked: 16 times

Re: An interesting maintenance procedure

Post by Spinner »

There are proper spray units for the corrosion proofing but, like myself, we tend to spray lots more than is required. If we are going to do it right get the right equipment to spray it.

I used ACF50 on an aircraft a few times. I spoke with the rep who was selling the stuff about how much my little bottle wand sprayer was using. He shook his head and walked away.
Post Reply