Plastic Fuel Tank Repair

[metricmonkeywrench]

Over the weekend i pulled out the mini-tiller to do some landscaping cleanup. its one of the little weedwacker 4 stroke motor models and is great for small work and doesnt beat you up like the weedwacker convertible ones.

A couple of years ago it developed a leak along the seam of the white plastic halves that slowly dripped some fuel. I used some generic epoxy and it worked for a while, but this year the epoxy separated from the tank and the seam leak turned into a real life hole making it unusable. I did try the soldering iron melting which only served to make the hole a bit bigger.

Has anyone come up with some sort of fuel resistant flexible patch for these type tanks? Of course being a bunch of years old the tank is no longer available from the OEM or aftermarket.

My thought at the moment if some sort of glue will not work is to try some rattlecan Bedliner or worst case find some kind of secondhand small fuel tank of a weed whacker or something and figure out a new mounting setup.

[Winger Ed.]

The best I've found is JB weld.

But getting the surface clean enough for it to get a good 'bite' on it is a problem.
I'd try cleaning with the harshest solvent you can get your hands on, maybe acetone.
Then scuff sand the area around the place you want it to stick.

[jonp]

https://www.amazon.com/Plastic-Welding-Repair-Kit-Sandpaper/dp/B092MB176Z/ref=mp_s_a_1_11?keywords=plastic+welder&qid=1690826126&sr=8-11

[TD1886]

Over the weekend i pulled out the mini-tiller to do some landscaping cleanup. its one of the little weedwacker 4 stroke motor models and is great got small work and doesnt beat you up like the weedwacker convertible ones.

A couple of years ago it developed a leak along the seam of the white plastic halves that slowly dripped some fuel. I used some generic epoxy and it worked for a while, but this year the epoxy separated from the tank and the seam leak turned into a real life hole making it unusable. I did try the soldering iron melting which only served to make the hole a bit bigger.

Has anyone come up with some sort of fuel resistant flexible patch for these type tanks? Of course being a bunch of years old the tank is no longer available from the OEM or aftermarket.

My thought at the moment if some sort of glue will not work is to try some rattlecan Bedliner or worst case find some kind of secondhand small fuel tank of a weed whacker or something and figure out a new mounting setup.

I've repaired stuff like that by soldering, but I used donor plastic of the same time as the "solder". Worked very well.

[HWooldridge]

Not sure how big the hole is, but I have also created a sandwich effect by using two fender washers and gasket material captured on either side of the leak, then bolted together. It works well under the right conditions.

[popper]

https://www.wikihow.com/Repair-Polypropylene
Really hard stuff to fix

[TD1886]

https://www.wikihow.com/Repair-Polypropylene
Really hard stuff to fix

Did you see the part in there if it could be welded? It said yes if you use a Polyproplene welding rod. Just like I mention in a previous post about welding with the same material.

[foesgth]

Did you see the part in there if it could be welded? It said yes if you use a Polyproplene welding rod. Just like I mention in a previous post about welding with the same material.

If you have a heat gun with a narrow tip it works better than a soldering iron. You need to concentrate the heat along the crack area. At that point it is just like gas welding steel. You make a weld puddle and feed in the rod.

[Finster101]

I have done it using an electric soldering iron and strips of a cut up milk jug.

[TD1886]

I have done it using an electric soldering iron and strips of a cut up milk jug.

I done it on my ATV which I think is ABS plastic and I used ABS plastic strips for the welding.

[Shawlerbrook]

Had a mishap years ago with the plastic tank on my Stihl weedwhacker. Cleaned the area with a degrease solvent and roughed it up a bit with sandpaper. Then applied some JB Weld epoxy. Still working perfectly.

[BLAHUT]

I just give it to a friend, he does plastic welding .

[Gewehr-Guy]

I have used a product called Seal All. Reminds me of contact cement. I have used it to seal gas leaks, Will usually hold the season.

[TD1886]

There's a gas tank sealant for vehicles called Red Dog. Work really good.

[Finster101]

I'm also curious as to how much a replacement tank cost. Might not be worth the effort.

[ih772]

A lot of plastic gas tanks are made from HDPE. Use a heat gun and some HDPE strips cut from a five gallon bucket to repair the seam.

[jimlj]

I have fixed holes in a plastic tank with JB weld and a piece of window screen.
Clean the area and rough it up with sand paper. Apply the epoxy to the tank and bed the screen in the epoxy. The screen reinforces the epoxy preventing future cracks,

[metricmonkeywrench]

I'm also curious as to how much a replacement tank cost. Might not be worth the effort.

I looked with the first leak. Everywhere I know to look either list them as no longer available, I cant even find them on fleabay.

the engine still runs great which is why I don't want to give this up too easily.

The hard epoxies I used just flaked off the flexible plastic. I store this outside so it sees all 4 seasons.

Didn't think of a milk jug and I also have a plastic soap drum and an old gas can that may also be some good donor material.

[challenger_i]

Over the weekend i pulled out the mini-tiller to do some landscaping cleanup. its one of the little weedwacker 4 stroke motor models and is great for small work and doesnt beat you up like the weedwacker convertible ones.

A couple of years ago it developed a leak along the seam of the white plastic halves that slowly dripped some fuel. I used some generic epoxy and it worked for a while, but this year the epoxy separated from the tank and the seam leak turned into a real life hole making it unusable. I did try the soldering iron melting which only served to make the hole a bit bigger.

Has anyone come up with some sort of fuel resistant flexible patch for these type tanks? Of course being a bunch of years old the tank is no longer available from the OEM or aftermarket.

My thought at the moment if some sort of glue will not work is to try some rattlecan Bedliner or worst case find some kind of secondhand small fuel tank of a weed whacker or something and figure out a new mounting setup.

Mil-S-8802 ProSeal. Is an aviation sealant for fuel tanks. New material will cost a chunk, but you can find "out of date" 8802 on FleaBay for cheap.
As you are working with a poly tank, you want to clean the surfaces thoroughly with alcohol (Everclear is actually cheaper than denatured alcohol from the pharmacy), then roughen the area you wish to apply the sealant.

Check this: ebay #142478239976

[TD1886]

Mil-S-8802 ProSeal. Is an aviation sealant for fuel tanks. New material will cost a chunk, but you can find "out of date" 8802 on FleaBay for cheap.
As you are working with a poly tank, you want to clean the surfaces thoroughly with alcohol (Everclear is actually cheaper than denatured alcohol from the pharmacy), then roughen the area you wish to apply the sealant.

Check this: ebay #142478239976

One can buy Red Dog sealant ar O'Reillys and it's not expensive.

[JonB_in_Glencoe]

SNIP>>>

Has anyone come up with some sort of fuel resistant flexible patch for these type tanks? Of course being a bunch of years old the tank is no longer available from the OEM or aftermarket.


Super glue and baking soda. No Joke.

I have a Stihl chain saw that had a crack in fuel tank. I tried all kinds of things and nothing worked permanently with the high revving vibrations and fuel proof. 2 years ago, I did the Super Glue and baking soda on the crack...still leak free.


https://www.youtube.com/watch?v=QFrfRxnpdBQ

[Cabinfever35]

A+ what JonB said I fixed a fuel tank on an generator no leaks it works.

[Alstep]

A few years ago, my neighbor had a leaking plastic overflow tank on his John Deere tractor. Needed it fixed fast as his crop harvest was at stake. I took a 4" floppy disk grinder to clean up the leaky area down to bare plastic. Then really roughed up the area with a coarse rasp. Covered the area with a generous coat of JB Weld. Thought it would be a temporary fix, but 2 years later it's still holding up. He said a replacement tank would have cost a couple hundred $$$.

[TD1886]

Super glue and baking soda. No Joke.

I have a Stihl chain saw that had a crack in fuel tank. I tried all kinds of things and nothing worked permanently with the high revving vibrations and fuel proof. 2 years ago, I did the Super Glue and baking soda on the crack...still leak free.


https://www.youtube.com/watch?v=QFrfRxnpdBQ

That is simply amazing Jon.

[Shopdog]

OK,gonna try the super glue/baking soda method on wifeypoo's Subaru,Linda Blair edition,windshield washer reservoir. $60 for a new one,but worth trying a fix first. Thanks for the headsup.

[Lloyd Smale]

Super glue and baking soda. No Joke.

I have a Stihl chain saw that had a crack in fuel tank. I tried all kinds of things and nothing worked permanently with the high revving vibrations and fuel proof. 2 years ago, I did the Super Glue and baking soda on the crack...still leak free.


https://www.youtube.com/watch?v=QFrfRxnpdBQ

old dog got a new trick today! thanks!

[Jsm180]

I've used West Systems G/Flex epoxy on RV waste tanks, works well.

https://www.amazon.com/gp/product/B002IZFPQE/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1&psc=1

[dverna]

Super glue and baking soda. No Joke.

I have a Stihl chain saw that had a crack in fuel tank. I tried all kinds of things and nothing worked permanently with the high revving vibrations and fuel proof. 2 years ago, I did the Super Glue and baking soda on the crack...still leak free.


https://www.youtube.com/watch?v=QFrfRxnpdBQ

Amazing!!

Thanks for sharing that.

[MaryB]

Super glue and baking soda. No Joke.

I have a Stihl chain saw that had a crack in fuel tank. I tried all kinds of things and nothing worked permanently with the high revving vibrations and fuel proof. 2 years ago, I did the Super Glue and baking soda on the crack...still leak free.


https://www.youtube.com/watch?v=QFrfRxnpdBQ

The old model airplane gap fill technique!

[imashooter2]

Scuff up the area, pile baking soda on it (make a dam with tape if you have to) pour generous amounts of super glue on the baking soda. The result is better than the plastic it replaces.

Edit, I see it has already been mentioned. Good stuff baking soda and super glue.

[BJung]

Amazon and HF sells plastic welders starting at around $26 or so. They look like soldering irons and some come with screen mesh to melt into the plastic along with plastic rods. One reviewer said that he repaired his plastic gas container with it.

[fecmech]

I would also recommend ProSeal but that super glue baking soda sounds pretty neat.