Fuel stain: Wing Walk Screwhead halo

[bdjohn4]

Hello all, and thank you in advance. 

Setting: ‘69 E-model with Monroy 88gal LR Tanks installed about 9 years ago-ish by Wet-Wingologists. 

I noticed a sort of fuel stain halo around the noted access panel screwhead please see photos. 
 

The associated screw is noted in the boroscope photos. 

Is this indicative of a specific leak location? How would you approach this?

thanks in advance. 

John

 

 

[ArtVandelay]

Id just patch it, over seal the entire access panel and screws.

[EricJ]

This is by far the easiest tank leak problem to fix.   Take an awl or a metal pick and dig the wing walk material off of the top of the screw head, just the head.   This will allow you to remove the screw.   Gently dig any remaining sealant out of the screw hole, then put some Permatex 3 on the screw, per the directions on the bottle, and replace it in the wing.

Get some wing walk material and cover the screw again.

Done. 

As per this old no-longer-public article from Maxwells:

https://web.archive.org/web/20190103195252/http:/donmaxwell.com/fuel-tank-repairs-how-we-fix-them/

[N201MKTurbo]

It is unlikely the leak is coming through the nut plates, and your nut plate looks perfect. The leak is most likely coming from a failure in the sealant at the mating surface of the access panel. Do like @EricJ said above. If you have access to actual tank sealant, I would use it instead of Permatex, but don't buy sealant just to get a tiny dab, Permatex will work.

[bdjohn4]

You guys are the best!  Thank you!

[Pinecone]

Also thanks.   I may have to do this same repair.

 

However, if it turns out the leak is at a rivet, is there an easy way to fix it?

[DonMuncy]

It is almost certainly at a screw, not a rivet.

[A64Pilot]

1 hour ago, Pinecone said:

Also thanks.   I may have to do this same repair.

 

However, if it turns out the leak is at a rivet, is there an easy way to fix it?

Cover the inside of it with B2, depending on where it is determines how easy it is.

Your talking nut plate rivet I assume? I wouldn’t replace the rivet unless it’s really buggered up myself.

Ref sealing a screw with B2, I’ve not done that but bet it would be really difficult to get that screw out later.

[McMooney]

I was told by one of the fuel tank specialist to just ignore it.

[EricJ]

14 minutes ago, McMooney said:

I was told by one of the fuel tank specialist to just ignore it.

The leaks on the top are usually slow, and if the airplane isn't stored full they can be a non-issue if you don't mind leaving the fuel level low enough to not leak, or if you don't mind the small amount of staining.    If it's a panel screw the repair is easy enough that there's not much reason to not do it.

 

[Pinecone]

I have to check.  It is right outside the door.   About the middle of the door.

[LANCECASPER]

10 hours ago, bdjohn4 said:

Hello all, and thank you in advance. 

Setting: ‘69 E-model with Monroy 88gal LR Tanks installed about 9 years ago-ish by Wet-Wingologists. 

I noticed a sort of fuel stain halo around the noted access panel screwhead please see photos. 
 

The associated screw is noted in the boroscope photos. 

Is this indicative of a specific leak location? How would you approach this?

thanks in advance. 

John

 

 

Everything everyone else has said regarding this.

This is something you can do yourself. Here's the Permatex product to use (https://www.aircraftspruce.com/catalog/eppages/permatexprod4.php?clickkey=67242):

I did this "preventive maintenance" on a couple of Mooneys that I owned and used it as an opportunity to replace the wing walk material.

After peeling back the wingwalk and sealing the screw and letting the screw sealant cure for 24 hours . . . I used a heat gun and then Goo Gone and a plastic scraper to get up the old wing walk and adhesive residue. Then I used  Koffler Anti Skid (KSC Super Grip) for the wing walk. It is less expensive and a better product than 3M. 

https://www.kofflersales.com/p/anti-slip-abrasive-tape.asp

I used the custom length option (24" wide x custom length 3' min., 40' max. and 24" width.) I bought 6 feet. When I did it it was less than $50 plus shipping and less if you sign up for their e-mails and they send you a discount code. 

Before taking off the old wing walk I used poster board and traced a template so I could use it to mark and cut the new wing walk material. This stuff sticks amazingly well so it's helpful to have a second person to hang on to the other end it as you are applying it. 

[EricJ]

18 hours ago, Pinecone said:

I have to check.  It is right outside the door.   About the middle of the door.

There's an access panel and a reinforcing stringer for the wing walk right there that both have screws.

[Pinecone]

Thanks

[A64Pilot]

On 1/4/2023 at 5:57 PM, McMooney said:

I was told by one of the fuel tank specialist to just ignore it.

Might just be the best to let sleeping dogs lie

[Pinecone]

OK, was at the plane today, and took the picture below.  It is not one of the inspection plate screws.  You can see that it is about 2 inches from the inspection plate.

[EricJ]

20 minutes ago, Pinecone said:

OK, was at the plane today, and took the picture below.  It is not one of the inspection plate screws.  You can see that it is about 2 inches from the inspection plate.

I'd get a pick and pick the wing walk material off of that.   There are some reinforcing stringers along there that have screws in them, I've fixed them on my airplane before.   It'll be evident whether it is a screw or rivet once you get the material off.

[Pinecone]

OK, that makes sense.  

I did not know there were some screws in there.

[EricJ]

1 hour ago, Pinecone said:

OK, that makes sense.  

I did not know there were some screws in there.

Looking at the IPC I can't tell whether it's a screw or a rivet in that particular spot.    Worth sorting out, as that's not going to get better.    It's fixable either way, just easier if it's a screw.

[LANCECASPER]

Trust me - it's a screw - it's very common, especially on K's and newer.

[Ragsf15e]

1 hour ago, EricJ said:

Looking at the IPC I can't tell whether it's a screw or a rivet in that particular spot.    Worth sorting out, as that's not going to get better.    It's fixable either way, just easier if it's a screw.

I have several darker stains on my wingwalk.  They don’t appear blue and don’t have rings like @Pinecone’s pictures.  I always assumed they were oily stains or something from shoes, etc.  but maybe that’s how fuel stains can appear under the wing walk material?  Just dark blobs.  No blue anywhere…

[PT20J]

1 hour ago, Ragsf15e said:

I have several darker stains on my wingwalk.  They don’t appear blue and don’t have rings like @Pinecone’s pictures.  I always assumed they were oily stains or something from shoes, etc.  but maybe that’s how fuel stains can appear under the wing walk material?  Just dark blobs.  No blue anywhere…

I had a few oil spots on my wing walk. I saw a post where someone suggested using WD-40 to renew the wing walk appearance. I thought that couldn't possibly work--- but, what the heck? I sprayed on a light coat, blotted off excess with a towel and left it overnight. The next morning it was dry, not oily, and the film left behind by the WD-40 made it look new. 

[N201MKTurbo]

15 minutes ago, PT20J said:

I had a few oil spots on my wing walk. I saw a post where someone suggested using WD-40 to renew the wing walk appearance. I thought that couldn't possibly work--- but, what the heck? I sprayed on a light coat, blotted off excess with a towel and left it overnight. The next morning it was dry, not oily, and the film left behind by the WD-40 made it look new. 

You are just going to encourage @Piloto with talk like that.

[EricJ]

2 hours ago, Ragsf15e said:

I have several darker stains on my wingwalk.  They don’t appear blue and don’t have rings like @Pinecone’s pictures.  I always assumed they were oily stains or something from shoes, etc.  but maybe that’s how fuel stains can appear under the wing walk material?  Just dark blobs.  No blue anywhere…

If it's not getting bigger it's unlikely to be a problem, but if it keeps getting bigger it's probably a small leak.

[Ragsf15e]

1 hour ago, PT20J said:

I had a few oil spots on my wing walk. I saw a post where someone suggested using WD-40 to renew the wing walk appearance. I thought that couldn't possibly work--- but, what the heck? I sprayed on a light coat, blotted off excess with a towel and left it overnight. The next morning it was dry, not oily, and the film left behind by the WD-40 made it look new. 

Thanks for the tip!  We’ll see how it dries, but already looks much better.  The more I think about it, the stains appeared after I had an ACF treatment in the wings.  That stuff can weep everywhere.  I wouldn’t be surprised if it ended up there somehow even though it’s on top of the fuel tanks.

BEFORE:

AFTER: