N2652W will have a new home!

[hammdo]

This is how I prepped the area while doing the treatment. Helped keep the Permatex from spreading:

-Don

[LANCECASPER]

I've never used Permatex #3 on rivets, only screws, but since you've cleaned the area so well I'd be tempted to put a light coat on top of those rivets just  to make sure they are sealed up.

[N201MKTurbo]

If the rivets are leaking, it is because the sealant has a flaw allowing fuel to get under that lap joint. You are just putting a Band-Aid on it. 

With all the work you did, you could have saved yourself some time by actually fixing it properly. Removing the panels, replacing the failed sealant and re-sealing the panels. Like the maintenance manual says.

[Shadrach]

I am interested in the outcome of the tank repair.  I have had lousy luck sealing from the outside. I am dubious about a repair that relies on gravity to draw sealant into voids that are currently occupied by concentrated fuel dye.

The only repairs that have ever worked for me involved a draining the fuel, spraying the tanks with soapy water and marking the areas where air was entering the tank for repair. 

What Maxwell is charging is reasonable. However, a lot of the time involved is waiting for sealant to cure. Filet must cure before brush coat which must cure before slosh coat. That's at least three days in my experience.  If I had the credentials, the room and running water at the hangar, I think I could turn a tidy profit at the flat rate being charged, which is as it should be.

[hammdo]

This is leaking from the side Maxwell just completed. No guarantee I was told. I guess I could ask them… I’m pretty sure they didn’t fill the tank.

Total time from final strip to sealing the rivets was 25 minutes.

-Don

[N201MKTurbo]

11 minutes ago, hammdo said:

This is leaking from the side Maxwell just completed. No guarantee I was told. I guess I could ask them…

Totally time from strip to sealing was 25 minutes.

-Don

The no guarantee should apply to the rivets. But there is no excuse for the cover plate to leak. That should be a warranty issue IMHO.

[Shadrach]

7 minutes ago, hammdo said:

This is leaking from the side Maxwell just completed. No guarantee I was told. I guess I could ask them…

Totally time from strip to sealing was 25 minutes.

-Don

Low risk investment for sure.  I hope it works out. 

There is no way to offer a significant warranty on repairs as there are times when an additional seep manifests shortly after the tanks are buttoned up.  That being said, there ought to be some good faith consideration for a seep that shows up days after return to service. 

[hammdo]

Cover plate is good, just the rivets.. seeped right after I filled it up when I got back. The big leak though was fixed - no more dripping in the wheel well..

-Don

[FlyingDude]

I used permatex 1.5 years ago based on a suggestion on MS and deeply regretted it.  Permatex mixed up with fuel, ran off and made a huge mess that took me tons of time to clean.  

You can stuff leaking screws with CS3330.  For internal repairs, just open up the tank and fix the spot.  If you can't locate the tiny leak, smear some CS3204A in the general area.  It is fluid and fills in voids.  Then close up the tank.  It'll cost you $50-60 only.  You'll also have the satisfaction of having used stuff that's listed on the Maintenance Manual.

[Shadrach]

21 minutes ago, FlyingDude said:

 You can stuff leaking screws with CS3330. 

Careful with the wording here. There is a cap like individual seal on each nut plate.  Replacing screws with sealant in the holes will often force sealant out the back side of the nut plate compromising those sealed caps. Best course of action with a leaking screw is to thoroughly clean the screw hole and screw and lightly brush the screw threads with sealant before reinstallation. This way almost all excess sealant squeezes out around the screwhead rather than being pushed past the nut plate cap and into the tank.

[EricJ]

18 minutes ago, FlyingDude said:

I used permatex 1.5 years ago based on a suggestion on MS and deeply regretted it.  Permatex mixed up with fuel, ran off and made a huge mess that took me tons of time to clean.  

Something went very wrong there.    You were using Permatex Aviation Form-A-Gasket #3?   That is made specifically for use around gasoline, water, glycol, etc., etc., and should not have been affected by fuel.   It's often mentioned on Mooneyspace since Don Maxwell posted their article on how they do tank seals and screw repairs, where they indicated that that's what they use.

I've used it to fix leaking screws on the top and the bottom of the tank with very good results.

https://www.permatex.com/wp-content/uploads/tds/80017-.pdf

[FlyingDude]

7 minutes ago, EricJ said:

Something went very wrong there.    You were using Permatex Aviation Form-A-Gasket #3?

Yep.  It's still in the hangar, I can post a pic. (I'm a hoarder on top of CB.)

@Shadrach yes that's the procedure. I didn't want to get into details.  My point is, I strongly suggest and recommend using CS3330 and not Permatex.

[Shadrach]

1 minute ago, FlyingDude said:

Yep.  It's still in the hangar, I can post a pic. (I'm a hoarder on top of CB.)

@Shadrach yes that's the procedure. I didn't want to get into details.  My point is, I strongly suggest and recommend using CS3330 and not Permatex.

Agreed, just don't squeeze it into the tank.  I have seen fuel tank access panels with globs of cured sealant pushed through the nut plate.

[N201MKTurbo]

17 minutes ago, Shadrach said:

Careful with the wording here. There is a cap like individual seal on each nut plate.  Replacing screws with sealant in the holes will often force sealant out the back side of the nut plate compromising those sealed caps. Best course of action with a leaking screw is to thoroughly clean the screw hole and screw and lightly brush the screw threads with sealant before reinstallation. This way almost all excess sealant squeezes out around the screwhead rather than being pushed past the nut plate cap and into the tank.

If a screw is leaking it is because of a sealant failure on the nut plate. I wouldn't put any sealant on the threads, just the head. I would just put a thin coat on the countersink on the wing and a thin coat on a new screw. Use a drill bit to clean the old sealant out of the screw hole before putting the new screw in. The drill bit should be just smaller than the threads. You will twist it with your fingers to dig the old sealant out. then blow the hole clean with compressed air. Don't press down with the drill bit, just twist it. You will know when you have them cleaned out when you hit hard metal at the bottom of the hole. If your fingers get sore, put the drill bit into a tap handle. You have to press down a little, but if you press too hard, you might push the cap off the nut plate. Then you are opening the tank up.

[Shadrach]

2 hours ago, N201MKTurbo said:

If a screw is leaking it is because of a sealant failure on the nut plate. I wouldn't put any sealant on the threads, just the head. I would just put a thin coat on the countersink on the wing and a thin coat on a new screw. Use a drill bit to clean the old sealant out of the screw hole before putting the new screw in. The drill bit should be just smaller than the threads. You will twist it with your fingers to dig the old sealant out. then blow the hole clean with compressed air. Don't press down with the drill bit, just twist it. You will know when you have them cleaned out when you hit hard metal at the bottom of the hole. If your fingers get sore, put the drill bit into a tap handle. You have to press down a little, but if you press too hard, you might push the cap off the nut plate. Then you are opening the tank up.

I seen access plate screws that leak because fuel has found it’s way between the skins of the plate and the wing skin. Same could happen where the nut plate meets the access plate. As you know, fuel has the ability to find any number of ways out of a tank. Sealant failure at the nut plate is not necessarily at the nut plate cap. Indeed all of the compromised caps that I have seen are maintenance induced, either by mishandling the access plate damaging the seal, being ham fisted while scraping the tank or by forcing excess sealant through the nut plate with a screw. Almost any external screw repair is simply buying a little extra time. In my experience they have a less than 50% success rate.The only reason I bother with them is because it’s easy.

 

[hammdo]

I’m trying something different.

I went to a shop that has patched before. Big leak fixed, exiting small seps still there.

Ok, so now I’m trying an approach that the RV folks have used for decades. Worth a shot. The patch is just a stop gap. I’m sure a full reseal is needed at some point - just not now.

I can sure do the internal patch but no A&P around to review so, I’m doing something else.

To me, worth the try. I don’t want to go back, pay an additional flat fee. If the first patch didn’t get it, next one probably won’t either. 
 

This is just a stop gap.. I haven’t found anywhere on MooneySpace where anyone tried this so…I’m going for it….

-Don

[N201MKTurbo]

As far as DMs flat rate is concerned, I think it is a fair price for the whole tank. I mean pulling all six covers. If the repair can be isolated to one cell, like the rivet line on the inner cell, the price is excessive by 2/3s. IMHO.

[Fly Boomer]

13 hours ago, hammdo said:

I took a pic to show how the 'pressure' approach works -- filled in the rivets nicely...

I read your previous posts, and looked at the pictures, but I somehow didn't understand what the "pressure" approach is.  I see that you taped some plastic wrap over the rivets, and they have a whitish look around them, but how was the pressure applied?

[hammdo]

The syringe. The bottom is opened up to cover the rivet. Once filled and placed over the rivet, I used the red palm handle on the plunger and pushed down . With the palm handle, it applies 25 lbs of pressure around the rivet head. The palm handle is the red part in the pic. So, it’s not a gravity fill but pressure applied around the rivet head. I can do a video next time I’m out to the hanger….

RV folks use green loctite 290 to fill those rivet heads. I can imagine the reaction I’d get here if I tried that ;o)

-Don

[Fly Boomer]

1 minute ago, hammdo said:

The syringe. The bottom is opened up to cover the rivet. Once filled and placed over the rivet, I used the red palm handle on the plunger and pushed down . With the palm handle, it applies 25 lbs of pressure around the rivet head. The palm handle is the red part in the pic. So, it’s not a gravity fill but pressure applied around the rivet head. I can do a video next time I’m out to the hanger….

-Don

Ah I see.  No video necessary for my benefit.  I saw the syringe and saw the red palm handle, but it just didn't click.  Thanks for the explanation.

[hammdo]

Np! I figure if it works for the RV guys (some use a good sealer but others use loctite) it’s worth a go. Many have had great success doing this approach..,

-Don

[FlyingDude]

8 minutes ago, hammdo said:

The syringe. The bottom is opened up to cover the rivet. Once filled and placed over the rivet, I used the red palm handle on the plunger and pushed down . With the palm handle, it applies 25 lbs of pressure around the rivet head. The palm handle is the red part in the pic. So, it’s not a gravity fill but pressure applied around the rivet head. I can do a video next time I’m out to the hanger….

RV folks use green loctite 290 to fill those rivet heads. I can imagine the reaction I’d get here if I tried that ;o)

-Don

I'm interested in seeing that.  One doesn't have to express an immediate reaction to a procedure (either by adopting it or fighting it).  I see no harm in looking at other people's perspectives and experiences.  To the contrary, it might be interesting.  So, please post a link.  Thank you.

[Fly Boomer]

2 hours ago, hammdo said:

Np! I figure if it works for the RV guys (some use a good sealer but others use loctite) it’s worth a go. Many have had great success doing this approach..,

-Don

Wonder if a technique like this could be used on smoking rivets?

[hammdo]

RV folks use this for those also. Most use seal-all thinned down since it’s clear or the green loctite.

-Don

[47U]

4 hours ago, Fly Boomer said:

Wonder if a technique like this could be used on smoking rivets?

To keep the smoke in? 

(Sorry… I couldn’t resist.)

Seriously, sealing the rivet won’t keep the two assemblies the rivet is fastening together from movement against each other, or the rivet, whichever is the case causing the smoke.  The rivet should be drilled out and reshot.