Fuel Tank Sealant Removal

[philipneeper]

Hello fellow mooney owners and operators,

   Sorry I havent been on in a while, Im deployed and having mooney withdrawals. Im looking into re-doing my tanks when I get home. Whats the best way to remove the old sealant? I have read paint stripper, brush on and wipe off and also PolyGone™310-AG Gel. I have read mixed reviews about the polygone. What have you heard or done?

 

Thanks- Philip

 

[DrBill]

Save your effort for a more satisfying job on the airplane.  Get it done ONCE, RIGHT and Professionally.  I elected to go bladders when I compared prices and longevity.  I actually gained a couple of gallons with the new style caps(pics in my gallery).  I expect my bladders to last 20 years.  I don't hear that from any re-seal job. The guy in the hangar next to mine has now re-sealed his Grumman 3 times in 5 years.

Good luck.

 

Bill

[Piloto]

I have a 1982 M20J with the original tanks and never needed a reseal. If the bladders only last 20 years the wet tanks in miine lasted over 30 years. 

 

For the reseal you would be better off taking it to an experienced shop. If you still want to do it yourself the easiest way to remove the sealant is by using aluminum scrapers and MEK. Just cut several pieces of 0.050" aluminum sheet in different width and sharpen them to become a scraper tool. Insert the scraper between the sealant and the surface to lift the sealant. By keeping the sealant wet with MEK on a rag it will soften the sealant making it easier to remove it.

 

José

[philipneeper]

I dont want to take my mooney somewhere and have it done. I have used MEK before when i did a patch job a year ago, but now i wanna do a full reseal. I have read on those two techniques, didnt know if anyone tried them.

[Hank]

I've also been told that pieces of formica edge trim work well and won't scratch the aluminum tank surface.

 

Have plenty of time, lots of elbow grease, much patience and small flexible arms to reach all of the tanks through the few access holes.

 

Be careful when applying new sealant to not mess up the fuel intake openings, fuel sending units, drain holes and the through-holes in the ribs connecting the bays . . .

[KSMooniac]

Don't forget rope so you can hang yourself about halfway through the job.  

 

I vote for Weep-No-More!  If it were me, I'd arrange for Paul to do it while you're deployed and that way you can enjoy the plane when you get back instead of wrestling with it for several weeks huffing MEK and cussing up a storm.

[carusoam]

I think he was supposed to seal, then paint. He might not make it to the halfway point...

Remember to use good ventilation when working with the solvents.

Best regards,

-a-

[1964-M20E]

Yes good ventilation otherwise you will not need a Mooney to fly you will be sky high. :-))

[DrBill]

I've read somewhere what the solvent that the pros use.  They pump it in and have a sprayer in the tank and it drains out the sump drain, filtered and them pumped back in.  They let it go 24 hrs a day for a few days and it gets 90 percent out.

Good luck.

BILL

[John Pleisse]

Hey Phil,

 

I have watched you work real hard on that plane and we all like your photos. Remember, most tank sealers hire women for stripping (tank sealant) because their hands are small and most young A&P's wear athletic shoes to work, so when asked to work on tanks, they can RUN. The entire reseal job is predicated on only one thing, a perfect strip job. Good luck. You're a hard worker and a brave guy. Hope it goes well.

[mcpilot]

Hey guys..

 

I was speaking to a AP at my home base and the subject of leaking Mooney tanks came up.  He has worked on M20s for many years and said that the real problem is not the sealer but the rivets becoming loose.  I don't remember exactly the procedure, but I seem to remember that he  pressurizes  the tank and lets liquid (soap suds?) come out and rebucks those rivets until there is no more signs of leaks.  I think he then puts a sealer in each tank under pressure to finish the job.  He swears that this is 100% effective..

 

Mike

[philipneeper]

I've read somewhere what the solvent that the pros use.  They pump it in and have a sprayer in the tank and it drains out the sump drain, filtered and them pumped back in.  They let it go 24 hrs a day for a few days and it gets 90 percent out.

Good luck.

BILL

Any idea the name of solvent?

[philipneeper]

Hey Phil,

 

I have watched you work real hard on that plane and we all like your photos. Remember, most tank sealers hire women for stripping (tank sealant) because their hands are small and most young A&P's wear athletic shoes to work, so when asked to work on tanks, they can RUN. The entire reseal job is predicated on only one thing, a perfect strip job. Good luck. You're a hard worker and a brave guy. Hope it goes well.

Thank you. Its alot of work.

[Cruiser]

You will do very well by contacting Jason Doscher JED-AIRE Aviation, LLC and talking to him about his support for your locally done tank stripping and reseal. 

http://jed-aireaviation.com/index.html

[Lood]

I've just gone through this exercise. I've tried many solvents and even had my own version mixed at the laboratory of a chemical company. In the end, we scraped most of the sealant off by hand, using perspex scrapers of different sizes and it took three weeks to completely clean one tank.

The best solvent that I used was Turco. It is approved for use on certified airplanes, but believe me, this stuff is extremely potent and no pleasure to work with. The MEK only really worked well, right at the end when there wasn't much sealant left.

Good luck to you and rest assured that you are indeed going to expand your vocabulary during this project.

[philipneeper]

Hmmm.... so the paint stripper wont be much better i presume???

[1964-M20E]

Any idea the name of solvent?

Before I got my current Mooney with bladders I was contemplating a tank reseal in the next couple of years as I could see some leaks beginning. I was going to make up a sprayer using a metal gear pump and I was going to use the liquid Poly gone and let it circulate for a few days. You will need a metal sealed and metal gear pump for the sprayer so the chemicals do not attack the pump parts or the seals. I guess you could try a cheap bilge pump with some poly gone first to see if it will hold up for 4 or 5 days after all you only need it once.

[Hank]

www.weepnomore.com. (I think; that IS their name in Minnesota)

www.wetwingologists.com (Edison did my tanks in Florida)

www.donmaxwell.com (uses Weep-no-more process in Texas)

This is the best way to reseal your tanks.

[DAVIDWH]

Hank,

 

Down time?

 

Approx. cost per side?

[Hank]

I left the plane for about a month; he had three other Mooneys there when I dropped her off, and another one when I picked her up just before Thanksgiving. He does give a discount for MAPA members. Your R will cost more, my tanks are only 52 gallons.

[orionflt]

The polygone from RPM tech is one of the better products for removing sealant, that being said expect to spend days per side just cleaning out the tanks. also NEVER use an aluminum scraper, use a plastic or similar scraper, I recommend getting some plexi glass (old window) and make your own. all it needs is an edge just use a file, and remember to keep the edge dressed. I have resealed a number of tanks and the prep work is the worst part, make sure you air the tank out for a couple of days before you start to stick your head into it, and use a pneumatic vacuum for cleaning up debris. when you are ready to seal the tanks start from underneath sealing the top of the tanks first then finish up the power portion. when you buy your sealant, buy the quart cans and only mix as much as you can apply with in 30 min (even though it may have a 2 hr working life after 30 min you will want a little break) once the sealant sets up, apply PRC-1005 top coat to help protect the sealant. biggest thing with the whole project is don't get in a rush, take your time.

 

Brian

[Hondo]

An Introduction to Tank Sealant  http://www.vansairforce.net/articles/tank_sealant.pdf

Note Advanced Chemistry and Technology was acquired by MMM.

 

With Flame master sealants, tanks are typically sealed with CS3204B-2 and topped with a protective coat, CS3600.

CS3330B-2 is used with access panels, to make them easier to remove.

 

What is the recommended procedure for fixing a leak from an access panel screw?

[Shadrach]

RE: Polygone stripper:

 

It does not work easily...

 

It does not work fast...

 

It does not even really work well...

 

But, it does work!

[rbridges]

RE: Polygone stripper:

 

It does not work easily...

 

It does not work fast...

 

It does not even really work well...

 

But, it does work!

 

you ought to be part of their marketing team.  

[N201MKTurbo]

An Introduction to Tank Sealant  http://www.vansairforce.net/articles/tank_sealant.pdf

 

What is the recommended procedure for fixing a leak from an access panel screw?

Remove the screw. Get a new screw. Use a #30 drill bit to clean out the existing sealant from the bottom of the screw hole. Just spin the bit between your thumb and forefinger do not use a air or electric drill motor. Use a flashlight to look into the hole you should see fairly clean plastic in the bottom of the hole. Get as much old sealant from the threads as you can. You can run a fresh screw into the hole a couple of times to clean the threads. Clean all the sealant from the countersink. You can use the bit from a micro adjustable countersink in your fingers to clean up the countersink. Mix up some sealant and thin it with MEK until it is brushable. Use an acid brush to paint the countersink of the plane and the countersink and threads of the screw with sealant. Screw it in. Wait a day and then clean the extruded sealant with your fingernail.

When removing the screw try not to push down too hard. You could break the sealant bond between the panel and the wing.