Tks corrosion question

[rpcc]

Over on beech talk there is a long thread about tks and corrosion - anyone with tks on their Mooney have any issues in this regard? https://www.beechtalk.com/forums/viewtopic.php?f=2&t=104984

[Mark89114]

It is my understanding that the fluid itself isn't corrosive, the problem is that it traps moisture.  Therefore corrosion starts there.  Haven't read that anywhere except on the message boards, so take it for what it is worth.

 

[Guest]

It is an issue on aluminum airframes with TKS installed.

Clarence

[L. Trotter]

Had a long discussion on this very topic with the TKS folks before installing the system on my Acclaim. They are quite certain the TKS fluid and system DO NOT cause corrosion. I guess I would expect nothing else from their perspective. However, the corrosion issue seems to be discussed primarily with in the Bonanza community. The area of corrosion is typically in the same place....the spar right behind the TKS panel. There is a "spar" seam unique to the Bonanza wing that Mooney's don't have . Not certain if it is a metal mis-match interface or trapped moisture with in the seam (favor) caused by the TKS fluid indirectly. I am unaware of Mooney's having this same issue or hinge point issues.  

[johncuyle]

Funny, I mentioned possibly adding TKS to my plane some day while my plane was in the shop and I was told about the corrosion issues with TKS.  IIRC, the mechanic I was talking to had seen in on a Bonanza but didn't believe my Mooney would be immune to it and recommended against (which, it's not really in my finances anyway and it probably makes more sense to simply sell my plane and buy another if I want it but anyway...)

[aviatoreb]

I HAVE had a corrosion issue with my airplane but it was in a location that seems unlikely to be related to tks, which is in the fuel tank area. And I had not been using, or even been aware of, the anti-corrosion misting agents - but I am now!

But - not doing TKS because of worrying about corrosion, is worrying about a chronic problem vs an acute problem.  Sort of like deciding not to get an x-ray to examine your broken arm because you are worried about the possibility of the cancer causing properties of x-rays.

If you find yourself in a situation wanting-needing-wishing for tks, because of an inadvertent (or fiki) ice encounter, I promise you, if you flick that tks on switch, you will not be thinking about corrosion at that moment.

[exM20K]

11 years using TKS extensively for four of those years commuting 50 hours/month NYC-BOS.  No corrosion.

3 years with the Acclaim, previous owner was KDET - based and used it as much as I do.  No corrosion.

 

DMAX did suggest spraying some Corrosion-X in the little slits on the horizontal stab after use.  easy to do, and I do.

-dan

[ilovecornfields]

43 minutes ago, exM20K said:

DMAX did suggest spraying some Corrosion-X in the little slits on the horizontal stab after use.  easy to do, and I do.

 

Any chance you could post a picture of this sometime?

[aviatoreb]

1 hour ago, exM20K said:

11 years using TKS extensively for four of those years commuting 50 hours/month NYC-BOS.  No corrosion.

3 years with the Acclaim, previous owner was KDET - based and used it as much as I do.  No corrosion.

 

DMAX did suggest spraying some Corrosion-X in the little slits on the horizontal stab after use.  easy to do, and I do.

-dan

What little slits are you talking about?

[exM20K]

2/3 of the way back up against the tail.  Pics will prolly be upside down, but maybe Anthony will fix them for me

This is the left side looking forward.  And yes, I did put the screwdriver away

[aviatoreb]

1 minute ago, exM20K said:

2/3 of the way back up against the tail.  Pics will prolly be upside down, but maybe Anthony will fix them for me

This is the left side looking forward.  And yes, I did put the screwdriver away

Thanks.  Why do you feel that spot is more susceptible than elsewhere?

[exM20K]

It allows me to get the nozzle straw down into the tail and spray around, getting the jack screw, the pull-ups, and all the untreated stuff in the tail  

Excess fluid will be pushed backwards in the air on on the ground with the way the long body sits.  I haven’t seen fluid forward.

Edited June 19, 2019 by exM20K

[aviatoreb]

11 minutes ago, exM20K said:

It allows me to get the nozzle straw down into the tail and spray around, getting the jack screw, the pull-ups, and all the untreated stuff in the tail  

Excess fluid will be pushed backwards in the air on on the ground with the way the long body sits.  I haven’t seen fluid forward.

I understand.

And the wings?

[exM20K]

39 minutes ago, aviatoreb said:

I understand.

And the wings?

No handy slot to blast them, unfortunately. 

[FoxMike]

Myn experience with TKS fluid getting into the tailcone is that the fluid washes all the lub off the rod ends and they wear out fast.  I have replaced the  rod ends once in 2000hrs. and I use very little TKS fluid.  The fluid runs down the rudder and blows across all the fittings in the tail.

[j3gq]

Has anyone using TKS also applied ACF-50 for a longer period of time ? Are these two chemical compatible with each other and with bare metal ?  Or is this a case like some antibiotics, X may be good, Y may be fine ... but never use X + Y together ... ? My (wild) guess is that the TKS fluid might just wash your otherwise lasting ACF film down the drain. And this could compromise your anti-corrosion treatment. But I agree with aviatoreb in general, some corrosion long term is better than an icing encounter without TKS.

[exM20K]

24 minutes ago, j3gq said:

Has anyone using TKS also applied ACF-50 for a longer period of time ? Are these two chemical compatible with each other and with bare metal ?  Or is this a case like some antibiotics, X may be good, Y may be fine ... but never use X + Y together ... ? My (wild) guess is that the TKS fluid might just wash your otherwise lasting ACF film down the drain. And this could compromise your anti-corrosion treatment. But I agree with aviatoreb in general, some corrosion long term is better than an icing encounter without TKS.

I did in my 231.  Never a spot of corrosion, and that plane's been flying with TKS for 22 years.

 

Another BT thread suggested that old fluid becomes acidic.  With that in mind, I bought a Ph tester and found mine to be well within spec (6-8, iirc). Ph tester is cheap...

-dan

[GeeBee]

One of the issues with the Bonanza is the use of the use of a carbon steel wire in the leading edge cap piano hinge. When you start trapping moisture with that kind of differential, bad things are going to happen. I believe that on retrofits, they are replacing the wire with a different material now. The Mooney MM however does recommend a fresh water wash down of the airplane when possible after a TKS flight. I usually hose mine down then do a 100 mph dry off (1 circuit around the pattern.)

[hwarnat]

Corrosion at the edges of all TKS panels, wings and elevator. Aftermarket TKS installation 1995 on a 1990 Bravo. An extra 5k during the current annual. Lets hope it will hold for some time. The shop removed the corrosion, and injected some sealing under the edges of the TKS panels. The panels were not removed.

[Fly Boomer]

2 hours ago, hwarnat said:

Corrosion at the edges of all TKS panels, wings and elevator. Aftermarket TKS installation 1995 on a 1990 Bravo. An extra 5k during the current annual. Lets hope it will hold for some time. The shop removed the corrosion, and injected some sealing under the edges of the TKS panels. The panels were not removed.

I would like to know how that happened.  There have been discussions about TKS fluid "causing" corrosion, but I think it has been shown that the fluid itself does not attack aluminum.  What does appear to happen is that the TKS fluid is hygroscopic (?) and attracts water which in turn may cause corrosion.  Is that what happened to this airplane?

EDIT:  I see that, once again, I have posted without reading the topic from the top, and essentially repeated what others have already pointed out.  Apologies to all who made these same points above.  I still would like to hear the explanation for this corrosion on the wing.

[redbaron1982]

My only experience with TKS is of a recent buyer of an airplane that has it. As many of you know, in the first annual inspection intergranular corrosion was found in the left aft stub wing spar bottom cap. I'm not sure if this was due to TKS. Everything seemed quite clean in the airplane, except for that spot that had intergranular corrosion. Maybe it was a another the cause for it.

As an additional point, while Don Maxwell was doing this repair, they found corrosion also in the panel where the TKS tank is sitting.

Something I really will put focus on learning as a new owner of a Mooney with TKS is proper maintenance to avoid corrosion. I will be doing IMC flying so TKS is something that will be used from time to time.

[Fly Boomer]

7 hours ago, redbaron1982 said:

Something I really will put focus on learning as a new owner of a Mooney with TKS is proper maintenance to avoid corrosion. I will be doing IMC flying so TKS is something that will be used from time to time.

If or when you learn techniques to mitigate the effects of TKS fluid -- whatever those may be -- please share with the rest of us.

[redbaron1982]

2 hours ago, Fly Boomer said:

If or when you learn techniques to mitigate the effects of TKS fluid -- whatever those may be -- please share with the rest of us.

Will do!

[ilovecornfields]

On an unrelated TKS question, if it normal for a few spots to not shed ice as well as the rest?

 

[exM20K]

@ilovecornfields not really.  If you get it on early and have the wing leading edge panels good and wet, they should be uniformly clean.  These pictures were of some really bad icing that much more capable planes were complaining about last June.  Some minor accumulation on the panel junctions, and a bunch on the landing light covers. Some minor horns that brok off quickly at the stagnation point, and the inboard panels are not flowing well.  But this was an extreme encounter.

-dan