# Stihl FS-76 Gas tank leaking



## Undy (May 24, 2015)

I've got a crack in the gas tank on my FS-76 trimmer. It's old, and I'm having trouble finding a replacement. The tank is a translucent plastic. I've read other threads here about plastic welding, JB weld, and other epoxy types, dating back a few years. 

I've had poor luck before trying to weld a tank from some Italian scooter, so I'm somewhat reluctant to go practicing on this thing.

Has any "best solution" been found?


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## lone wolf (May 24, 2015)

Undy said:


> I've got a crack in the gas tank on my FS-76 trimmer. It's old, and I'm having trouble finding a replacement. The tank is a translucent plastic. I've read other threads here about plastic welding, JB weld, and other epoxy types, dating back a few years.
> 
> I've had poor luck before trying to weld a tank from some Italian scooter, so I'm somewhat reluctant to go practicing on this thing.
> 
> Has any "best solution" been found?


JB might work try it. You need to clean the area real good first.


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## sawfun (May 24, 2015)

MarineTex works very well and sets up fast.


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## Undy (May 24, 2015)

Thanks guys. I'll see what I can do.


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## JB Weld (May 24, 2015)

Do you have any pictures of the crack? 

As per my username, I am a big fan of JBW, and I have used JB weld kwik on a cracked carb bowl (on a generator). I patched it on the inside and it worked great and lasted a long time. For a gas tank on a trimmer though, I think plastic welding would be the way to go. The tank is probably made from HDPE, so you can use a milk jug cut into 1/8" strips for your rods. I think the trick to a permanent weld in a scenario like this is to first tack the crack closed and then melt a small piece of screen (that has a good overlap on the crack) into the plastic. Then use your milk jug rods to cover the entire area with the screen. It will take time, but it will give you a permanent repair. I have done this very same procedure to weld a gas tank on a briggs splitter engine. It saved me $50 and it has lasted for years of regular use. Harbor Freight Tools has an inexpensive plastic welding kit that I used on many projects before it finally died. It has a nice wide head on the welding iron.


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## Undy (May 24, 2015)

JBW, 
It is HDPE. Says so on the tank. Perhaps I better experiment on some other plastic and see if I can get good.


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## JB Weld (May 24, 2015)

I have repaired plenty of thin stuff with a regular ol soldering iron. That wide head on the HFT welding iron is nice though. Since the tank is thin, just remember to go easy. A good thing to practice on would be a milk jug or any other bottle made from hdpe (very common). Cut a slice in it and patch it. It is definitely a DIY project. Any metal window screen will work just fine.


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## backhoelover (Jun 5, 2015)

super glue and baking soda


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## Undy (Jun 5, 2015)

Baking soda?? FWIW, I got it fixed w/ a soldering iron and screen. But I'm really curious how the baking soda method works. Details?
Thanks.


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## backhoelover (Jun 5, 2015)

gets hard as f**K, try it. a 60 year tech through me


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## backhoelover (Jun 5, 2015)

fwiw ?


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## Undy (Jun 6, 2015)

FWIW - For what it's worth... It's one of the very few texting abbreviations that I use. 

I just meant that I'd gotten it fixed, but I was still curious about your suggestion about super glue and baking soda. I guess I've got some experimenting to do!

Thanks.


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## JB Weld (Jun 8, 2015)

Glad you were able to Weld it. That screen makes a huge difference in a plastic Weld.


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