Anyone used TAP Poly-Weld to repair fuel tanks?

[ManjiSann]

My 390 fuel tank has a hairline crack in a joint where the front handle attaches. The epoxy I tried to use worked well for a day or so, seems to have bonded good but I think the stress and vibrations fractured it  :( :(



I was wondering if anyone on the forum has tried the TAP Poly-Weld adhesive? It says it works on HDPE and their video shows a person standing on a joint bonded with the stuff... so if you can believe their marketing it's strong stuff and the label says it's flexible so in my mind it shouldn't crack/fracture. 


Brandon 

[btulloh]

No experience with that, but it sounds good.  And it's for HDPE, so there's hope.

There are a lot of high tech repair things around now.  Some of the UV cured stuff should be pretty good too.  I keep seeing ads for Bondic.  Supposed to be really good.  According to the manufacturer. anyway  ;).

Hopefully there'll be some first-hand feedback.  

[ManjiSann]

Supposed to be really good.  According to the manufacturer. anyway  ;).

Wish we could always trust the manufacturers to be 100% honest and objective.

I think it's $15 for the small tube of the stuff which I think will be plenty for what I need to do. I may get a small section of fiberglass to help reinforce the area as well. If no one on the forum has tried the stuff I'll likely do it just so I can report back. It'd be really nice to have a reliable fix for fuel tanks as it's a real bummer when you have to replace one at $150 a pop. 

I emailed the manufacturer to see what they suggested as one of the steps is to flame treat the plastic but they specifically say not to flame treat fuel containers... seems like an obvious safety concern there. However if the flame treat is crucial to the bonding process then there's a problem. We will see what they say.

Brandon 

[lxskllr]

Maybe you could fill the fuel tank with water, leaving enough room to keep the crack dry. Remove any lines to the carb first, and plug any holes.

[Allar]

Get a soldering iron and melt it. 

[btulloh]

This looks interesting. Couldn't finish watching cause my refrigerator just died and I'm dealing with phone now. Panic!
https://www.youtube.com/watch?v=62kTNwtPmE8

[ManjiSann]

Get a soldering iron and melt it.

I have a woodburner and I may try that but my concern is that because the crack is in an area that gets a lot of force I don't have confidence the "weld" will hold. 
Brandon 

[ManjiSann]

Maybe you could fill the fuel tank with water, leaving enough room to keep the crack dry. Remove any lines to the carb first, and plug any holes.

That thought occured to me. Makes me wish I had a mig welder then I could flood the tank with the shielding gas to displace the oxygen *sigh* I miss my mig welder.  When I do the repair I will have the fuel tank off completely so I have full and easy access to all areas.


I've welded motorcycle gas tanks without mishap by rinsing them out with hot soapy water several times, letting them sit in the sun a bit then another rinse or two. Sweated bullets the whole time I was doing it but no problems. That being said, I still don't enjoy it and flame treating the chainsaw fuel tank isn't my idea of fun but I'm sure it could be done safely. 


At the moment the leak appears to be behaving itself so I am going to not worry about it other than keeping an eye on it to ensure it doesn't get worse. When the snow really starts to fly I'll probably take the saw apart and give it a good clean up and inspection so I can hopefully be ready for spring. I hate doing emergency repairs.


Brandon 

[ManjiSann]

This looks interesting. Couldn't finish watching cause my refrigerator just died and I'm dealing with phone now. Panic!
https://www.youtube.com/watch?v=62kTNwtPmE8

oh man!!! I hope it's a simple/cheap fix on the refrigerator!!

I'll check the video out. 

The thing I've noticed with a lot of repairs is the holes are in a flat area or somewhere that isn't a mounting point or one that gets a lot of force on it. I was all set to use JB Weld but the concern I have with that is the plastic flexes ever so slightly and JB Weld really doesn't so I expect over time the JB Weld would crack and fail. 


Brandon 

[petefrom bearswamp]

Cut a hole in the tank of my echo cs600p several years ago, dont ask how it happened.
JB weld has held since.

[ManjiSann]

Cut a hole in the tank of my echo cs600p several years ago, dont ask how it happened.
JB weld has held since.

One more vote for the JB Weld  ;D
Brandon 

[Allar]

Get a soldering iron and melt it.

I have a woodburner and I may try that but my concern is that because the crack is in an area that gets a lot of force I don't have confidence the "weld" will hold.
Brandon

Well i think melting the  plastic is going to be the strongest option. You could also melt in some steel wire as reinforcement.
We used to fix car bumpers like that. But if you decide to go with jb weld,i would still melt it first and then cover it with jb.

[Southside]

I agree with using something to reinforce the weld.  Years back the breather box on my truck cracked, it was really just cosmetic, and the dealership said they could fix it for nothing using a plastic welding tool they had.  I watched him do it and it was sort of OK, but it didn't hold for long.  He did not use anything to reinforce the weld which looking back on it was probably the reason it didn't hold.  

[ManjiSann]

Allar and Southside, 

I may still try this PolyWeld stuff but I'm on the fence. 

I'm also thinking I'll do as both of you are suggesting. I may melt the crack back together, imbed some mesh in it then cover the whole thing with JB weld. I really wonder why no gussets were incorporated in the design or at least a larger radius on the corner. 

I'm sorta dragging my feet waiting for the snow to start flying then I'll know I'm not likely to be cutting down trees. Once that happens I'll take the saw apart, give it a good clean, repair a bunch of stuff and put her back together. 

Brandon 

[Allar]

While watching videos on youtube i stumbled onto this:
That's exactly how i'v been welding plastic and seems like it does work on chainsaws aswell.

https://www.youtube.com/watch?v=Se6TkuzzY0E