Fuel tank sealant removal machine

[isaacpr7]

I am doing research on the process for sealant removal from the fuel tanks and it looks like everyone agrees that it is a huge PIA. This made me dig deeper on to what possible solutions the big companies such as "Weep no more" and others are doing to make their lives easier at such a task. It seems that they use home built system, in which no pictures are displayed, that cycles fluid through the tank and back to its source for many hours until all of the sealant is dissolved. This is by no means something I will be doing right now because I will be deployed soon and have no time for such a task; however, I do love tinkering around and building things from scratch whenever I get a chance. That being said I came up with recirculation system that is placed inside the tank and can do what I described. I have most of the parts assembled but still waiting on some nozzles from China that I need to incorporate. Once tested out I will let you guys know how it went. Does anyone have any ideas that I can use that I have not thought off yet? Maybe someone out there made one already and would like to share some pics and ideas

[MooneyPTG]

I like pneumatic pumps because you can control flow and they can handle caustic chemicals. We use them on our coating machines in the printing industry. FYI. Good luck and let me know how it's going

[HRM]

I am doing research on the process for sealant removal from the fuel tanks and it looks li, e everyone agrees that it is a huge PIA. This made me dig deeper on to what possible solutions the big companies such as "Weep no more" and others are doing to make their lives easier at such a task. It seems that they use home built system, in which no pictures are displayed, that cycles fluid through the tank and back to its source for many hours until all of the sealant is dissolved.

 

I believe Bruce Jaeger invented the first machine (used by weep no more) to do this and I don't think it is a big secret or anything. I doubt they are just freely handing out the plans for it. Apparently one of the challenges was to keep gobs of loosened sealant from clogging the pump and they did this with a screened sump system if memory serves. Anyway, I don't believe there is any rocket science involved, just a super messy, tedious task made slightly easier with a specially designed solvent sprayer. After seeing the seminar put on by Paul Beck (Bruce's protégé) at the October Mooney Summit, I concluded that sealant removal was only half the job and letting him do it is well worth the price he charges.

 

Done right it will last a long time, done wrong, with even a small mistake, and the tragic nightmare begins.

[Danb]

Isaac thank you for your service....semper fi

[isaacpr7]

Isaac thank you for your service....semper fi

Dan, it is my honor to serve this wonderful country

[isaacpr7]

I believe Bruce Jaeger invented the first machine (used by weep no more) to do this and I don't think it is a big secret or anything. I doubt they are just freely handing out the plans for it. Apparently one of the challenges was to keep gobs of loosened sealant from clogging the pump and they did this with a screened sump system if memory serves. Anyway, I don't believe there is any rocket science involved, just a super messy, tedious task made slightly easier with a specially designed solvent sprayer. After seeing the seminar put on by Paul Beck (Bruce's protégé) at the October Mooney Summit, I concluded that sealant removal was only half the job and letting him do it is well worth the price he charges.

Done right it will last a long time, done wrong, with even a small mistake, and the tragic nightmare begins.

I already though about the clogging issue, which is why I plan to add a screen on the return side and I also plan to use full cone spiral nozzles that have larger openings to prevent clogging. I'm sure there's a lot more than removing sealant to the task; nevertheless, I love to build things and tinker around I am also currently building an Artic Air Cooler for about 75 bucks for a friend. If you guys want pics just let me know.

[isaacpr7]

I like pneumatic pumps because you can control flow and they can handle caustic chemicals. We use them on our coating machines in the printing industry. FYI. Good luck and let me know how it's going

That's a genius idea

I didn't even know of the existence of such pump for fluid. I will definitely look into this. That would definitely fix my concern for which electric pump pressure would work for my setup.

Do you have a good one in mind that would sell for about 100 bucks or so?

[isaacpr7]

This is what I have so far for my prototype. It has no holes drilled or nozzles installed at this time. I put it toghether with quick disconnects so that I can assemble and disassemble inside the tank.

[N201MKTurbo]

I saw the system at Willmar when I had my plane done. It was nothing special. It had a stainless steel sump with screens around the pump. I don't recall what kind of pump it was, but I don't think it was a pneumatic pump. It used lawn sprinkler heads to spray the solvent.

 

It would be best to build a system that screwed to the bottom cover plate holes so the solvent doesn't get on the paint too much, it will strip your paint. After most of the sealant is off the stripper will start to seep through the seams and strip your paint off. After Willmar did my tanks I had to strip and repaint my landing gear and there were big areas under the wing with no paint. I wasn't expecting that. I understand that Paul Beck is doing a better job now that he is running the business.

[isaacpr7]

I saw the system at Willmar when I had my plane done. It was nothing special. It had a stainless steel sump with screens around the pump. I don't recall what kind of pump it was, but I don't think it was a pneumatic pump. It used lawn sprinkler heads to spray the solvent.

It would be best to build a system that screwed to the bottom cover plate holes so the solvent doesn't get on the paint too much, it will strip your paint. After most of the sealant is off the stripper will start to seep through the seams and strip your paint off. After Willmar did my tanks I had to strip and repaint my landing gear and there were big areas under the wing with no paint. I wasn't expecting that. I understand that Paul Beck is doing a better job now that he is running the business.

Do you remember if the sprinkler heads were made of plastic? If the were, then maybe I can get away with a bilge pump that I can place inside the sump. As far as the paint issue goes i will try to figure out if I can mask in such way that the outer skin is protected. Any suggestions?

[carusoam]

Take some time to think about the safety issues... (If there are any regarding the solvent you use)

Flammability.

Breathing.

Skin contact.

Use appropriate precautions. Safety advice for a guy going on a military tour?

Expect that pumping the solvent doesn't need a fine spray or mist or much pressure. Slopping, soaking and sloshing the stuff around should work pretty well.

Blowing up a closed up hangar would be bad...

I don't know anything about the solvents for dissolving tank coating.

Best regards,

-a-

[mooniac15u]

Anthony makes a really good point about safety.  Liquids flowing through non-conductive (plastic) tubes can lead to a build-up of static electricity.  If your solvent is flammable this could cause a very dangerous situation inside your fuel tank.  You should probably make sure every part of your system, including your reservoir, is grounded to the airframe and grounded externally.

[MooneyPTG]

That's a genius idea

I didn't even know of the existence of such pump for fluid. I will definitely look into this. That would definitely fix my concern for which electric pump pressure would work for my setup.

Do you have a good one in mind that would sell for about 100 bucks or so?

That's a genius idea

I didn't even know of the existence of such pump for fluid. I will definitely look into this. That would definitely fix my concern for which electric pump pressure would work for my setup.

Do you have a good one in mind that would sell for about 100 bucks or so?

I will look at what we use...I think Aro by infers all rand. It is a great recirculating pump, slow or fast

[MooneyPTG]

I will look at what we use...I think Aro by ingersall rand sp? It is a great recirculating pump, slow or fast

[sleepingsquirrel]

Dichloromethane  Methylene Chloride Paint Stripper

 

I got the idea that this is the solvent for cured sealant. Any other ideas.

 

MSDS for polygone:

 

http://www.aircraftspruce.com/catalog/pdf/09-03491msds.pdf

 

 

 

[isaacpr7]

Take some time to think about the safety issues... (If there are any regarding the solvent you use)

Flammability.

Breathing.

Skin contact.

Use appropriate precautions. Safety advice for a guy going on a military tour?

Expect that pumping the solvent doesn't need a fine spray or mist or much pressure. Slopping, soaking and sloshing the stuff around should work pretty well.

Blowing up a closed up hangar would be bad...

I don't know anything about the solvents for dissolving tank coating.

Best regards,

-a-

I considered some of those things you listed when I searched for the appropriate product. From what I gathered, as long as I don't swallow I don't swallow or bathe in the product I should be safe. Also, it has a flash point of >160 degrees. I will still take any precautions such as grounding and completely de-fueling the aircraft.

[isaacpr7]

Anthony makes a really good point about safety. Liquids flowing through non-conductive (plastic) tubes can lead to a build-up of static electricity. If your solvent is flammable this could cause a very dangerous situation inside your fuel tank. You should probably make sure every part of your system, including your reservoir, is grounded to the airframe and grounded externally.

The prototype is made of CPVC but once I get everything fitted a few times I am planning to do all the final cuts out of metal tubing. It's just cheaper that way while I have to adjust my cuts

You make a good point on grounding everything. I will make sure it is done correctly; )

[N201MKTurbo]

I believe the sprinkler heads were plastic, I would use brass, it isn't that much more. I would use some kind of inline filter after the pump to keep from clogging the sprinklers.

[Piloto]

Issac,  Do you know the size of the market for your machine? Mooneys are the only planes that I know were the sealant was applied after structural assembly. Non Mooney planes with integral tanks that I have seen have the sealant applied before structural assembly in between the riveted parts (ribs/skin). Once the sealant is applied to the mating parts they are riveted together. This reduces significantly the possibility of leaks and reinforce the bonding force between the parts. It also eliminates moisture trapping thus corrosion. To remove the sealant would require massive structural disassembly. The Mooney TN tanks and new Ovations are assembled this way. If there is a leak you just brush in the new sealant at the leak point in the tank. A B777 holds 1,000 times (50,000+ gals) the fuel capacity of a Mooney. Can you imagine if the B777 were sealed like the old Mooneys!!! 

 

José

[isaacpr7]

Issac, Do you know the size of the market for your machine? Mooneys are the only planes that I know were the sealant was applied after structural assembly. Non Mooney planes with integral tanks that I have seen have the sealant applied before structural assembly in between the riveted parts (ribs/skin). Once the sealant is applied to the mating parts they are riveted together. This reduces significantly the possibility of leaks and reinforce the bonding force between the parts. It also eliminates moisture trapping thus corrosion. To remove the sealant would require massive structural disassembly. The Mooney TN tanks and new Ovations are assembled this way. If there is a leak you just brush in the new sealant at the leak point in the tank. A B777 holds 1,000 times (50,000+ gals) the fuel capacity of a Mooney. Can you imagine if the B777 were sealed like the old Mooneys!!!

José

José,

I'm not sure about the market for this machine but I'm not looking for profit on this. I'm just making it for personal use and to help out some friends along the way. When it comes to charging people for using some of my abilities I really suck at it because I end up doing everything for free. Maybe when I retire in a few years I will have no choice but to make a profit on some things but for now I would rather build good friendships along the way I'm posted the pics because I would like to collect ideas from the great wealth of knowledge in this forum and test out the product so that I can help anyone else out if they are interested in doing the same. After all, what I love about owning a Mooney the most is having you fellow mooniacs so willing to help each other out. Not only because most of us form a part of the cheap bastard club, but many of us don't have deep pockets like most non owners believe, just because you own a small aircraft Heck, some sports cars are way more expensive to own than some amazing mooneys.

[isaacpr7]

I believe the sprinkler heads were plastic, I would use brass, it isn't that much more. I would use some kind of inline filter after the pump to keep from clogging the sprinklers.

That's a great idea too. I will incorporate that into the final product

[isaacpr7]

Started to work on the tank. What a PIA to get the leaks to stop. I'm sure trying to hone my welding skills.

[Yetti]

poly tank at Tractor Supply

[mooneyflyfast]

Have you talked to the people who sell "Polygone" they may be able to give you some good ideas.

Good luck with your project!

[isaacpr7]

Have you talked to the people who sell "Polygone" they may be able to give you some good ideas.

Good luck with your project!

I had not thought about that to be honest. I might give them a call.