Repairing a cracked plastic gas tank?

[beastmaster]

A friend of mine gave me a ms200 sthil. That is the good news. The bad news is it looks like it was run over by a truck. I'm not complaining though.
He said it rode down with a big limb about 60ft to the ground. Any way I've been checking e-bay for the parts I need to replace.
The gas tank has a two inch or so crack in it that runs from the inside (facing the cylinder)and around the side and leaks pretty good. Other then that its alright. Is there a reliable method to repair a cracked plastic tank? I was thinking of maybe beveling the crack out and using JB weld? There has'nt been a lot of sthil 200t part on e-bay and no gas tanks and i can just imagine what a new one would cost.$$$$, so my options are slim. The top handle is broke also but I put a few wire ties around it and that seems to be working so far. any tips or suggestions would be appreciated. Thanks, Beastmaster.

 

[briantutt]

A friend of mine gave me a ms200 sthil. That is the good news. The bad news is it looks like it was run over by a truck. I'm not complaining though.
He said it rode down with a big limb about 60ft to the ground. Any way I've been checking e-bay for the parts I need to replace.
The gas tank has a two inch or so crack in it that runs from the inside (facing the cylinder)and around the side and leaks pretty good. Other then that its alright. Is there a reliable method to repair a cracked plastic tank? I was thinking of maybe beveling the crack out and using JB weld? There has'nt been a lot of sthil 200t part on e-bay and no gas tanks and i can just imagine what a new one would cost.$$$$, so my options are slim. The top handle is broke also but I put a few wire ties around it and that seems to be working so far. any tips or suggestions would be appreciated. Thanks, Beastmaster.

I used the wide flat head on my soldering gun and melted the crack in my tank back together after it got crushed by a Bobcat (Husqvarna 362XP).

 

[1steve]

Hey BM can you post a picture of the tank?

 

[MCW]

I have a couple of mates with plastic welders and one of them fixed a split tank on my Dolmar 7900 with a nylon filler rod from memory. I'd take it to a plastic welder mate and get it done properly if at all possible. Won't cost much and will be as strong as new or even stronger.
Good luck with the 200T, great little saws when running right

 

[Rookie1]

I just fixed one for tree cutter I know. I used PC7,which is like JB Weld. Vee out crack and make sure its clean and no gas or oil on it. I even used a piece of screen on the outside to help strengthen repair.

 

[AUSSIE1]

I used a plastic epoxy by Dyna-Grip I think it was to patch up a very bad 365 tank. Worked spot on. Make sure you clean the split well with carb cleaner. I had to keep costs down to warrant putting this saw back in wood otherwise plastic welding would have been the preferred option. It hasn't given any grief since the repair early in the year.

 

[Roanoker494]

I believe Advance auto sells a product for repairing plastic tanks on cars. Should do just as well on a plastic saw tank.

 

[pioneerguy600]

If you want to repair the tank yourself and do it cheaply then the soldering iron as mentioned in one of the previous posts does a good enough job of melding the crack back together, then take a piece of metal flyscreen and inbed it into the plastic covering the crack, it will inbed by just heating it with the soldering iron tip and pushing it down into the plastic, smooth any plastic that raises up through the screen with the tip and when completed it should be strong and leakproof. Sometimes I will add a thin layer of JB weld over the whole repaired area , let it harden and then sand it smooth.

Pioneerguy600

 

[imagineero]

There seems to be widely varying opinions and results on this one. I read a lot of posts about fixing cracked tanks before attempting a fix on my 192t fuel tank. The consensus seemed to be that it depended on the type of plastic, but welding was preferred to glues. Haven't seen any pics of solder repairs.

My 192t had cracked around the flippy cap. There was no way to repair it that would leave the flip cap usable so I cut the threaded portion off an 019 screw cap fuel tank I had spare and glued it to the 192 so I ended up with a screw cap. I used a fuel proof automotive grade plastic weld glue ($$) which was rated for high strength. I drained the tank completely, washed it out 3 times, first with turps, then degreaser, then preparation solvent. I dried it with compressed air, then preheated it. Prep is critical to success if you are going to glue. I keyed the surface lightly with some 80 grit sandpaper then glued. After letting the glue dry 3 days I rekeyed the glue and put an extra fillet on the inside and out then let it dry another 3 days. It took me a week all up and cost me about $25.

The end result looked really strong. I used it for probably about 200 hours of work before it broke. I have to admit it was probably my fault. The screw cap was really old and the washer in it was hopeless and needed replacing but i never had time to pick one up, so I tightened the cap super tight with a pair of vice grips every time which put way more stress on it than it would normally receive. I eventually snapped it off and then broke down and got a used 192t case of another AS'er for cheap.

Shaun

 

[JayB]

On a Husky I tried JB Weld, worked a day, then leaked. Tried an epoxy made for plastic, worked a couple days before leaking. Plastic welded with a soldering iron like others have mentioned, then covered that with JB Weld to give it a little more strength and it's been going for over a year now. I think the flexibility and vibration is what made the first two tries fail. Good luck!

 

[briantutt]

There seems to be widely varying opinions and results on this one. I read a lot of posts about fixing cracked tanks before attempting a fix on my 192t fuel tank. The consensus seemed to be that it depended on the type of plastic, but welding was preferred to glues. Haven't seen any pics of solder repairs.

My 192t had cracked around the flippy cap. There was no way to repair it that would leave the flip cap usable so I cut the threaded portion off an 019 screw cap fuel tank I had spare and glued it to the 192 so I ended up with a screw cap. I used a fuel proof automotive grade plastic weld glue ($$) which was rated for high strength. I drained the tank completely, washed it out 3 times, first with turps, then degreaser, then preparation solvent. I dried it with compressed air, then preheated it. Prep is critical to success if you are going to glue. I keyed the surface lightly with some 80 grit sandpaper then glued. After letting the glue dry 3 days I rekeyed the glue and put an extra fillet on the inside and out then let it dry another 3 days. It took me a week all up and cost me about $25.

The end result looked really strong. I used it for probably about 200 hours of work before it broke. I have to admit it was probably my fault. The screw cap was really old and the washer in it was hopeless and needed replacing but i never had time to pick one up, so I tightened the cap super tight with a pair of vice grips every time which put way more stress on it than it would normally receive. I eventually snapped it off and then broke down and got a used 192t case of another AS'er for cheap.

Shaun

Finally the term "flippy cap" comes up in a thread. What is it? I would like to see a pic.

 

[pioneerguy600]

Finally the term "flippy cap" comes up in a thread. What is it? I would like to see a pic.

All the newer Stihls with the MS designation have flippy caps. LOL

Pioneerguy600

 

[briantutt]

All the newer Stihls with the MS designation have flippy caps. LOL

Pioneerguy600

All I know is "flippy caps suck" ...maybe it's a good thing I don't know what it is...

 

[pioneerguy600]

All I know is "flippy caps suck" ...maybe it's a good thing I don't know what it is...

Naw, flippy caps are great, I have used them from the get go and have not had a problem with even one of them. I won`t post what I think of users that cannot use a simple device as a flippy cap. LOL

Pioneerguy600

 

[briantutt]

Naw, flippy caps are great, I have used them from the get go and have not had a problem with even one of them. I won`t post what I think of users that cannot use a simple device as a flippy cap. LOL

Pioneerguy600

I am so simple I don't even know what they are :yoyo:

 

[pioneerguy600]

I am so simple I don't even know what they are :yoyo:

Just check out the gas and oil caps on any of the newer Stihl MS series of saws. I must have picts of my saws with those caps somewhere.

Pioneerguy600

 

[Dan_IN_MN]

Finally the term "flippy cap" comes up in a thread. What is it? I would like to see a pic.

Here's your answer:

<object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/q4hIVaXlaw4?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/q4hIVaXlaw4?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object>

 

[briantutt]

I think a flippy cap just passed me in a truck box :blush:

 

[briantutt]

Here's your answer:

<object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/q4hIVaXlaw4?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/q4hIVaXlaw4?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object>

That clip almost killed me...now I understand...

 

[alderman]

First time I've seen a flippy in action. I think I'll pass.