Fuel Stain removal

[Shadrach]

Hi Folks,

I have a couple of fuel tank access panel screws that are weeping. I know that trying to tighten them will make it worse.  I am planning to reseal the screws with Permatex#3. What is the best way to remove the fuel stains? The areas are not large, but the dye is sticky and concentrated. Avgas does not seem to work great (and I dislike working with it as a solvent).

[MinneMooney]

I have used a bit of polishing or rubbing compound on a rag.

[INA201]

Not sure if this will work but I used a McGuire’s clay bar all over my plane following the directions and it removed the light staining in the paint really well. Polish and compound as mentioned above will probably do it too.  I have no experience with fuel stains but worth a shot and if nothing else you can use it in other places. 

[steingar]

Yeah, it'll take polish.  The dye works it's way into the paint, to remove it you've got to take off a bit of paint.  I had fuel stains on the wheel pants of my Cherokee (Cherokee sumps are notorious for leaking) and they never ever came off until I polished.

[Shadrach]

30 minutes ago, steingar said:

Yeah, it'll take polish.  The dye works it's way into the paint, to remove it you've got to take off a bit of paint.  I had fuel stains on the wheel pants of my Cherokee (Cherokee sumps are notorious for leaking) and they never ever came off until I polished.

I don't think min will ever come out totally.  I have to be super careful with any polishing agent. The original paint on the 60s era Mooneys is so thin that you can polish right through it with little effort. The paint on the underside of fuselage is so thin you can see the yellowish primer through it and that area has never been polished or sun baked.

[MinneMooney]

Well, a polished aluminum Mooney would look awesome!

[Guest]

Careful use of Acetone with remove fuel dye.  In your case extra careful use f you paint is very thin.

Clarence

[EricJ]

I'd try mineral spirits and then acetone if that didn't work.    One of those should make easy work of it.

 

[PT20J]

Didn't @Cody Stallings mention some magic sealant he uses for fuel tank screws a while back?

Skip

[Cody Stallings]

2 hours ago, PT20J said:

Didn't @Cody Stallings mention some magic sealant he uses for fuel tank screws a while back?

Skip

Yes Sir!!

3M sells it. It’s EC-776 an it is a must for all Mooney owners.

Its a Bit pricey, but worth it

[PT20J]

5 minutes ago, Cody Stallings said:

Yes Sir!!

3M sells it. It’s EC-776 an it is a must for all Mooney owners.

Its a Bit pricey, but worth it

How do you apply it? Do you take the leaking screw out and coat the screw with it, or do you paint it on top of the screw? Does it work well in the wing walk (always problematic) area?

[Andy95W]

Skip, there's another thread about this same subject.  Permatex #3 works extremely well, and is what Don Maxwell recommends.  It has worked well even on my wing walk area.  It's not rocket science, it's just smearing on some goopy shit.  Pull the screw, put a big dab on the threads and base of the screw, reinstall.  One tube will probably reseal a thousand screws.

[FloridaMan]

Use avgas. The dye dissolves in it. 

[Shadrach]

29 minutes ago, FloridaMan said:

Use avgas. The dye dissolves in it. 

It does not work well at this stage. I've neglected it for too long. Stain is a sticky mess. Avgas evaporates quickly and is not very effective. The rag just sticks to the dye and deposits fibers in it.

[jaylw314]

18 minutes ago, Shadrach said:

It does not work well at this stage. I've neglected it for too long. Stain is a sticky mess. Avgas evaporates quickly and is not very effective. The rag just sticks to the dye and deposits fibers in it.

Have you tried mineral spirits or lacquer thinner?  both evaporate slower than avgas and are relatively slow at eating away paint.

[Shadrach]

12 minutes ago, jaylw314 said:

Have you tried mineral spirits or lacquer thinner?  both evaporate slower than avgas and are relatively slow at eating away paint.

I have,  That's what I use to clean the belly.  They don't seem to harm my original paint at all.  I think I will devise a way to soak the stain for a few minute.  I may use a plastic scraper.  It's a small weep. It's not enough to run or drip or really even spread,  so it stays in a concentrated area.  The more it concentrates...the more it concentrates.

[FloridaMan]

Paging @cujet to the white courtesy phone. 

[MinneMooney]

Once the blue dye has had a chance to penetrate into the coating, you will never be able to remove it with solvent unless you actually dissolve the coating. The best way to control how much coating you want to remove is to use rubbing compound. You can rub a bit, clean and inspect the area and repeat until all of the stain is gone or you notice the paint getting thin. 

[Steve W]

The best solution is what a previous owner of my plane did and just paint the bottom half blue. And now I realize why.

Edited June 19, 2019 by Steve W

[Browncbr1]

MEK works, but it will also dry  the paint out if you use tons of it so it looks oxidized.  It’s ok if you put some on a rag and rub the stained area.  Reapplying wax removes the oxidized paint look.  

[Shadrach]

8 minutes ago, Browncbr1 said:

MEK works, but it will also dry  the paint out if you use tons of it so it looks oxidized.  It’s ok if you put some on a rag and rub the stained area.  Reapplying wax removes the oxidized paint look.  

MEK will strip the original lacquer right down to bare aluminum. So in a way it will indeed work for me, but a bit too agreesive. 

Years ago an unknowing mechanic almost wiped my pinstripes off completely. I didn’t really fault him for the initial mistake, but he kept at it on the other side.  When I found that he’d timed the right mag to about 100 degrees ATDC,  I realized I had an idiot on my hands. Multiple idiots.

[Shadrach]

8 hours ago, MinneMooney said:

Once the blue dye has had a chance to penetrate into the coating, you will never be able to remove it with solvent unless you actually dissolve the coating. The best way to control how much coating you want to remove is to use rubbing compound. You can rub a bit, clean and inspect the area and repeat until all of the stain is gone or you notice the paint getting thin. 

Agreed, this will be with me until the plane is painted. I just want to get rid of the gooey, sticky mess so I can seal the screw and move on.

[PT20J]

You didn't say if the stains are on the top or bottom of the wing, but from your description it sounds like the bottom. In that case, it might be easiest to use some acetone to remove the sticky stuff and then polishing compound to remove the stained paint. If the paint ends up too thin or down to the primer, you can take the tail access panel to an auto paint shop and get a color match in a spray can and touch it up. It won't blend perfectly but underneath it won't be noticeable. Even if it's on the top of the wing, you will have to look really hard with the light just right to notice the repair if you use a little polishing compound to blend the edges of the paint. That's what I've been doing with some blemishes in my paint and no one but me notices them.

Skip

[Shadrach]

17 minutes ago, PT20J said:

You didn't say if the stains are on the top or bottom of the wing, but from your description it sounds like the bottom. In that case, it might be easiest to use some acetone to remove the sticky stuff and then polishing compound to remove the stained paint. If the paint ends up too thin or down to the primer, you can take the tail access panel to an auto paint shop and get a color match in a spray can and touch it up. It won't blend perfectly but underneath it won't be noticeable. Even if it's on the top of the wing, you will have to look really hard with the light just right to notice the repair if you use a little polishing compound to blend the edges of the paint. That's what I've been doing with some blemishes in my paint and no one but me notices them.

Skip

It’s on the bottom as you’ve surmised. We’re on the same page as to how I’m going to proceed. You would not believe how thin the paint is on the bottom of my bird. No way the painter made more than one pass in some areas. You can see through the pigment right to the primer. I don’t know why so austere. The finish is super smooth (devoid of orange peal) but very thin. perhaps they were trying to keep the weight down. I’ve talked to two paint shops and neither want to strip the old paint. Both said they’d be challenged to get anything to adhere as good or better than the original paint. I don’t know enough about it to know if that just means they have better margins without the strip.