Leaking fuel tank, what sealant is best for plastic tanks.

[Scott McArdle]

I have a cheap chainsaw here... It's my mothers and it was leaking fuel only when holding it in the normal cutting position... I pulled the whole thing down to see if I could get the tank apart to no avail... What would be the best sealant to use on something like this being plastic.
Thanks in advance.
Regards Scott MC

 

[HarleyT]

What the hell is that?

What bootleg brand?

 

[HarleyT]

Sorry,
I apologize..

This site is "inclusive"...

 

[Van462]

If its ABS you could take a razor knife and shave some extra material from under the handle. Place the shavings in a glass jar overnight with a bit of acetone. If it dissolves into a thick slurry it may work as glue. If it does dissolve the scraps you may be able to apply acetone to the sea, let capillary action draw it in and give it some time to melt the plastics then clamp it up.
Also have seen some use a soldering iron to melt the seam.

 

[Huskvarna hotellgäst]

Looks like a Zenoah G5000 copy. If so, new tank! 20 bucks on eBay.
Example only. Not a recommendation. https://www.ebay.com.au/itm/FUEL-TA...306577?hash=item23b548dcd1:g:ZLIAAOSwV51cWQ4G

 

[Ketchup]

I have used SealAll successfully on a few tanks, but have had leaks come back on others. A friend turned me on to welding plastic tanks with a soldering iron. It helps to have some long shavings or rods of the same plastic to add volume. It’s ugly, but it works.

 

[SteveSr]

Another option if it a seam that is leaking is to clean the plastic completely with non-chlorinated brake cleaner or similar and then use a wicking viscosity of super glue. Super glue is highly resistant to both gasoline and ethanol.

BTW, there should be some markings molded into the tank for recycling purposes that tell you what the material the tank is made from.

 

[buzz sawyer]

There is an epoxy kit available specifically for plastics. I have used it before with success but not on a chainsaw tank. Might be worth a try. Advance Auto carries it.

 

[Huskybill]

Devcon plastic weld ?

I welded a plastic gas tank that was cracked with a sodering iron. I went right on top of the crack and sealed it.

 

[SEAM]

If welding is not an option, I use Aron Alpha Pro for seams and Aron Alpha Pro + tissue paper for cracks. The tissue paper acts like fiber material... Aron Alpha is very popular over here

 

[Huskybill]

I just ordered more devcon plastic weld for repairing cracked top covers.

https://www.amazon.com/Devcon-22045-Plastic-Welder-Dev-Tube/dp/B003NUGL9S

 

[BigbubdaddyGus]

The only thing I found that works is welding it back together with a soldering iron and the nice thing is you can check it to see if you fixed it before putting it back together and once fixed it's permanent. Works best.

 

[Toyboy]

I've also done what Gus has done with a soldering iron. I do shave some slivers of the plastic to use as weld material. Once it melts get the heat off it. I'll use pressure decay of 10#psi to test if it's completely solid before I put fuel in it.

 

[vizette]

There are various tank sealers, like redkote, kreem, por-15 that you might be able to swish around where the leak is. I doubt these would stick to a plastic tank very well overall, but you might be able to get it to fill the leaky spot.

I'm with the prior responses - plastic weld it with a soldering iron. Side note: lots of ventilation if you do. Don't want to be breathing that in.
Might want to practice a bit before doing the tank though, just to get a feel for it. Make sure you get into the plastic a good bit and don't just skim the surface, or it won't hold. If you run out of filler, or don't want to shave strips off as filler, I've seen plenty of postings about people using string trimmer line or milk jugs as plastic filler. I've always just worked with what's there (disclaimer: never done a tank)

 

[buttercup]

Another option if it a seam that is leaking is to clean the plastic completely with non-chlorinated brake cleaner or similar and then use a wicking viscosity of super glue. Super glue is highly resistant to both gasoline and ethanol.

BTW, there should be some markings molded into the tank for recycling purposes that tell you what the material the tank is made from.

Super glue (CA, Cyanoacrylate) is definitely the most aggressive glue towards any plastics, it can glue stuff nothing else can. You can get it in any viscosity from super thin penetrating (like acetone), to thicker glue like substances.
It has a tendency to smear out if you try to dry away excessive and make it "not so pretty";
if you get it on to a plastic surface unintentionally it etches in to the surface immediately, so you can carefully remove excess but you cant remove it completely clean like you can with for example epoxy or sealant.
It may become brittle if the crack/seam has a too big void, also it may make a bleached white shade around the seam because of its etching acidic gas as it cures.

 

[James Parler]

There are various tank sealers, like redkote, kreem, por-15 that you might be able to swish around where the leak is. I doubt these would stick to a plastic tank very well overall, but you might be able to get it to fill the leaky spot.

I'm with the prior responses - plastic weld it with a soldering iron. Side note: lots of ventilation if you do. Don't want to be breathing that in.
Might want to practice a bit before doing the tank though, just to get a feel for it. Make sure you get into the plastic a good bit and don't just skim the surface, or it won't hold. If you run out of filler, or don't want to shave strips off as filler, I've seen plenty of postings about people using string trimmer line or milk jugs as plastic filler. I've always just worked with what's there (disclaimer: never done a tank)

For filler material I have used zip ties. That repair was done last summer on my Super 2 and is holding. The tank is stuffed into the case pretty tight and pressure and vibration are not it's friend.

 

[dmb2613]

just plain old pvc glue use the cleaner too, I cant believe no one had commented on this

 

[BigbubdaddyGus]

I never tried PVC cement for pipes. I may try that when welding is not feesable.
Never thought of that. Thanks for the idea.

 

[vizette]

just plain old pvc glue use the cleaner too, I cant believe no one had commented on this

That holds up over time? I would expect that with the "abuse" and vibration that is inherent in a chainsaws life, a plastic tank seamed with any type of adhesive/glue would re-crack. Yeah, I know it can bond PVC/ABS stronger than the original material, but those are lapped (and mildly compressed together), not butted.

 

[dmb2613]

I have fixed a few that way no problems as of yet. not much pressure with a tank, 100 lbs. on an irrigation system and every time the pump comes on the pipe jerks.