Corrosion-X and Tank Sealant

[FlyingDude]

Hi gang,

Anyone have any experience with Corrosion-X application in areas close to the tanks?  Have you noticed any degradation in the tank sealant due to Corrosion-X? 

Thanks.

[N201MKTurbo]

That's a great question. AFAIK there is only one place where the tank sealant is exposed to the outside world, but the Corrosion-X can seep under lap joints and soften it along that line.

I think the tank resealers would be the only ones who would have the answers. But the ones who use the chemical strippers, will erase the evidence before they could notice the degradation. 

I have a dixie cup of cured CS-3330 in my hangar. If someone will send me a small sample of Corrosion X, I will pour in the cup, cover it with foil and see what happens.

[Shadrach]

2 hours ago, FlyingDude said:

Hi gang,

Anyone have any experience with Corrosion-X application in areas close to the tanks?  Have you noticed any degradation in the tank sealant due to Corrosion-X? 

Thanks.

I use Corrosion X but not annually.  I have noticed no correlation between application and failure.

[FlyingDude]

4 hours ago, Shadrach said:

I use Corrosion X but not annually.  I have noticed no correlation between application and failure.

Did you spray it on the outboard side of the tank outboard rib?  That way anything that finds its way between the sheets would be pulled into the tank by gravity...

@N201MKTurbo I haven't received the bottle from Spruce yet.  But I doubt I could mail you a sample.  

[N201MKTurbo]

8 minutes ago, FlyingDude said:

Did you spray it on the outboard side of the tank outboard rib?  That way anything that finds its way between the sheets would be pulled into the tank by gravity...

@N201MKTurbo I haven't received the bottle from Spruce yet.  But I doubt I could mail you a sample.  

Just package it well and don't tell them what it is. Just say airplane parts...

[A64Pilot]

A whole lot of things were sealed with fuel tank sealer on Army helicopters, like everything attached to the transmission or the gearboxes because they were magnesium and any water wicking in would cause corrosion.

Corrosion-X had no effect, then we used fuel tank sealer on the chemical tank on the hopper on the Ag planes, because it’s darn near impervious to pretty much any chemical but to be fair something that Ag guys spray does degrade it over the years

 

 

[FlyingDude]

On 4/24/2023 at 7:44 PM, A64Pilot said:

something that Ag guys spray does degrade it over the years

Thanks for the info. So far all indications point towards it being innocuous, but yours is the most direct experience.  I also asked Don Maxwell by email - I'll copy his response here if he gets a chance to respond.

I think it resists ethylene and isopropyl and gasoline, but gets softened by methyl based stuff (MEK).  They use toulene as solvent in the sealants and I used acetone while stripping (scraping more likely) my tank, so those soften it too.  Some people had used paint stripper to remove the sealant - though we know that such chemicals are aggressive to aluminum due to their chlorine content, so there's also that.  Though I highly doubt it has chlorine based aggressive stuff in it...  I doubt it contains alcohol-based stuff, as they would be volatile, whereas Corrosion X touts forming a thin film that never goes away.  I wonder if it is similar to Cam Guard that coats your cam?

 

 

 

[A64Pilot]

Ref coatings that don’t go away and coating cams etc.

ANYTHING usually has a lot of totally unsubstantiated claims, there is no truth in advertising.

I know on Apache helicopters that regularly flew over salt water that Corrosion-X substantially reduced corrosion, but I strongly suspect that a good washing removed most if not all of it, the part that got washed anyway. I don’t think it’s a one time treatment. 

I do know that if you plan on painting anytime soon, don’t treat with Corrosion-X, it of course weeps or sweats out of any lap joints and even out of many rivets.

Does it loosen rivets? I’m not saying it does, but can see how it could contribute to “working” rivets.

[mooniac15u]

9 hours ago, FlyingDude said:

Thanks for the info. So far all indications point towards it being innocuous, but yours is the most direct experience.  I also asked Don Maxwell by email - I'll copy his response here if he gets a chance to respond.

I think it resists ethylene and isopropyl and gasoline, but gets softened by methyl based stuff (MEK).  They use toulene as solvent in the sealants and I used acetone while stripping (scraping more likely) my tank, so those soften it too.  Some people had used paint stripper to remove the sealant - though we know that such chemicals are aggressive to aluminum due to their chlorine content, so there's also that.  Though I highly doubt it has chlorine based aggressive stuff in it...  I doubt it contains alcohol-based stuff, as they would be volatile, whereas Corrosion X touts forming a thin film that never goes away.  I wonder if it is similar to Cam Guard that coats your cam?

 

 

 

Ethylene is a gas and isopropyl is a hydrocarbon substructure.  Are you referring to ethylene glycol and isopropyl alcohol?  Methyl is also a hydrocarbon substructure and wouldn't have much affect on something designed to resist fuel or oil.  Acetone and MEK are structurally similar ketones.  That's likely what's impacting their ability to soften the sealant.

[FlyingDude]

57 minutes ago, mooniac15u said:

Are you referring to ethylene glycol and isopropyl alcohol? 

Whatever’s in wine 

Anyway, kidding . I’m not as knowledgeable in chemistry as you are, but I was hoping you have a final conclusion on whether corrosion x would eat into tank sealants…

@A64Pilot Mike Busch really recommends camguard. Along with all the APs I know. I’m not knowledgeable enough to comment on whether it’s a cure-all or snake oil, but I’m sold at least on cam guard…

[mooniac15u]

14 hours ago, FlyingDude said:

Whatever’s in wine 

Anyway, kidding . I’m not as knowledgeable in chemistry as you are, but I was hoping you have a final conclusion on whether corrosion x would eat into tank sealants…

@A64Pilot Mike Busch really recommends camguard. Along with all the APs I know. I’m not knowledgeable enough to comment on whether it’s a cure-all or snake oil, but I’m sold at least on cam guard…

The SDS I found online says Corrosion X is >90% petroleum distillate so it's hydrocarbons like fuel or oil which shouldn't affect sealant.  The rest of it is some proprietary amine in some proprietary percentage.  I wouldn't expect that to have much effect on sealant but it's hard to say for sure.

[A64Pilot]

18 hours ago, FlyingDude said:

Whatever’s in wine 

Anyway, kidding . I’m not as knowledgeable in chemistry as you are, but I was hoping you have a final conclusion on whether corrosion x would eat into tank sealants…

@A64Pilot Mike Busch really recommends camguard. Along with all the APs I know. I’m not knowledgeable enough to comment on whether it’s a cure-all or snake oil, but I’m sold at least on cam guard…

In talking to people who overhaul engines daily, it seems it makes no difference that they can detect, or the ones I’ve talked to anyway.

I don’t think corrosion is a big contributing factor, if it were then there would be a huge difference in cam failure from the desert SW and say Florida, but there isn’t.

I won’t argue whether it is an anti-corrosive or not because I don’t know. Yes I’ve read some articles where they do some ad hock testing, but I don’t have any idea if their testing replicates even remotely what’s going on inside of an engine.

I’ve seen airplanes sit in Florida for over ten years and not have a cam problem when placed back into service. The twin Comanche I saw had two cylinders replaced because of rust, yet over a year later both cams are fine, and I’ve seen flight school airplane that fly pretty much daily eat a cam.

I have theories myself, but they are only theories

I really, really wish it did, Lycoming cam disease worries me more than anything. I feel real sure Camguard doesn’t hurt anything though.

I usually fly twice a week and my oil change interval is 25 hours, I hope that’s enough.

I’m not saying of course that a cam with visible rust on it won’t fail, certainly it will, but I think it takes a long time for that much rust to happen.

My Wife inherited a 1923 Ford Model-T, it has been in her family since 1938, it was restored before WWII, but never run after then, so it sat for 80 years in storage in Alliance Ohio, then her Father got it and he only used it as a Christmas yard decoration for five years or so and it got rained on several times etc.

When I got it I pulled the head and the cylinders and cam etc looked like new, I replaced the valves as a couple were leaking and it was easy and cheap. Runs like a sewing machine

I’ve had farm equipment that sat for years under an open roof for years, only run sporadically with no issues, and have had my Wife’s CTS-V in storage for over five years only running it once a year or so.

So why would Lycoming cams rust if not flown at least every few days? I can’t answer that, cause I’ve abandoned lawnmowers, motorcycles over Winter and when deployed for years and never had any corrosion issues, gummed up carburetors yes, but never rusted cams.

So I suspect that while corrosion could be one possible cause, it causes only a small fraction of the failures, or that’s my belief anyway.

[Pinecone]

I have been wondering the same thing.

Maybe a difference in aviation oil.  But I have torn down car and small engines that have sat for a number of years, and everything inside still is oily.  No bare metal.

But that said, with the cost of overhauls the way they are, I will run CamGuard just in case it saves me some trouble.

If you fly 2 times a week, every week, I don't think you have any worries about corrosion.

[A64Pilot]

Twice a week, nearly every week, last knee replacement I went two weeks before flying, that wasn’t long enough. The two before that maybe a month ea. I guess.

I did have a neighbor with me just in case but didn’t need him, but I was hurting by the time we got back.

But I can’t imagine corrosion in a hangar in even a couple of months, even in Florida. The drill press table and Vise etc aren’t rusting, and it’s common for them to rust.

[ArtVandelay]

I wonder if the difference is whether the engine is store with dirty 50+ hours oil or fresh clean oil?

[FlyingDude]

2 hours ago, A64Pilot said:

The drill press table and Vise etc aren’t rusting,

Maybe it's a quality thing... They vise hasn't rusted but drill press table did after a few months... In the cold Michigan with "unsalted and shark free" lakes...

[A64Pilot]

2 hours ago, ArtVandelay said:

I wonder if the difference is whether the engine is store with dirty 50+ hours oil or fresh clean oil?

I’ve stored vehicles both ways, many times with farm equipment there was no storage intent, just didn’t use it for 6 months or maybe a year later.

‘But clearly clean oil should be better, but even used oil so long as there is TBN left, there isn’t any acid to speak of.

The model T had very black almost tar like sludge in it, but if it were used oil from 1938 I’d expect that.

‘The man who got it in 38, my Wife’s great uncle showed a collection of original Model A’s, I don’t think he had any interest in the T, I assume he got it as some kind of package with an A that he wanted.

 

[A64Pilot]

35 minutes ago, FlyingDude said:

Maybe it's a quality thing... They vise hasn't rusted but drill press table did after a few months... In the cold Michigan with "unsalted and shark free" lakes...

I think it’s humidity, my drill press table in Ga rusted too of course, this one in Fl had rust on it that I cleaned off with a Scott Brite pad and an angle grinder when I installed my mini-split in the hangar, it’s my canary in the coal mine, if it rusts slowly, then keeping humidity below 65% is helping at least with carbon steel corrosion. If it rusted back pretty quickly, then I may just be wasting electricity. So far very little rust in over a year. I have a humidistat that turns on the AC at 65% and off at 60% in Summer, Winter I run a dehumidifier.

But even in the center of Fl corrosion is higher than average, from I believe humidity, I don’t think it’s salt air where I’m at.

I left my tools in the box and closed the T hangar up when we went cruising for three years in South Ga. in particular my Craftsman screwdrivers got an oxide layer on them. The cars were in the same hangar, just parked, my C-85 I pickled.