plastic welding

[ned coed]

has anyone out there had any experience with plastic welding on a chainsaw. i,ve got a fracture in the chain oil reservoir on an other wise perfect huskey. anybody had any of this type of repair done before and what was the out come?.
regards, Ned.

 

[Lakeside53]

has anyone out there had any experience with plastic welding on a chainsaw. i,ve got a fracture in the chain oil reservoir on an other wise perfect huskey. anybody had any of this type of repair done before and what was the out come?.
regards, Ned.

I use a professional hot air welder... like you'd use for car bumper repair. Much tricker than you'd think, but after a lot of practice, the results are fine if you are careful. First you need to match the type of plastic, so look carefully on your housing for a mark like "PA66-GF" etc... This example basically means Nylon with Glass Fiber, so you'd use a Nylon rod.

I many cases it's easier and just as good to use a marine epoxy to seal the hole or crack, but you must degrease it completely and rough up the surface or it will fail.

 

[sawn_penn]

has anyone out there had any experience with plastic welding on a chainsaw. i,ve got a fracture in the chain oil reservoir on an other wise perfect huskey. anybody had any of this type of repair done before and what was the out come?.
regards, Ned.

It could be easier and cheaper to buy a new oil tank...

Otherwise I'd go with an epoxy (Araldite?) As the previous post indicated, degrease and rough up the edges well before applying the epoxy. Leave the epoxy to cure properly (days not hours!)

I wouldn't do this with a fuel tank. If the oil tank fails again, who cares? If some part of the epoxy very slowly disolves and goes out with the chain oil, who cares? I can't say the same for the fuel tank....

 

[TimberPig]

It could be easier and cheaper to buy a new oil tank...

Since the oil tank is part of the cases of the saw, I think fixing it is probably a more economical option here. Unless a person can get used parts that are serviceable, saws with plastic cases aren't likely to be valuable enough to warrant the cost of a new set of cases, plus the time and effort (or labour costs if paying someone to do it) to repair them. Plastic welding or epoxy makes for a much more economical, less time consuming repair.

 

[klickitatsacket]

I do it here on a daily basis. I do not like the hot air welder. It sits in the cupboard most of the time. I prefer a wood burner and I just cut a piece off the identical plastic I am welding from a crap tank or cover. I have welded well over 50 peices with great success in this manner. We even guarentee our tanks never to leak.

 

[deerlakejens]

A few more details please!

Dean, could you give a few more details in how you are doing this? It sounds like you have hit on a good technique.

Thanks

 

[Andy1234]

In the past I have used an electric soldering iron (110 volt, radio shack cheapie) to seal cracked radiator end caps that were plastic.
Cleaning the material involved some strong soap and hot water, I would think even more so on an oil or gas tank.
I did not use any filler rod unless the cracks had a large gap. I obtained filler rod from strips that I cut out of scrap end caps. Otherwise, I just melted the plastic along the crack and it fused back together again.
By the way, if you do this, DON'T BREATHE THE FUMES! :angry2:
FWIW,
Andy

 

[big1079]

befor you try a welder try this. It worked for me. Plastic fusion. it is a 2 part fast set epoxy I got at home depot.

 

[klickitatsacket]

here is a series of pictures of welding a tank.
3/8" hole simulating a chain strike
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2548.jpg
preheat tank and soften the edges of the hole
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2547.jpg
melt the rod and tank at the same time
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2546.jpg
using the soldering iron scrape material to the softened edges of the hole filling it in.
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2545.jpg
filled hole
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2544.jpg
using a blade scrape the ragged edes
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2543.jpg
use a rasp to knock down the high spots
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2542.jpg
sand
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2541.jpg
finnished product
http://i5.photobucket.com/albums/y186/klickitat/plasticwelding_2540.jpg
If done right this will never leak unless you strike it with a chain again. I have repaired many a tank that the JB Weld or other epoxies have worked loose or the fuel finally starts to work its way through. Remember to use the identical plastic that you are welding. I use snips to cut strips off of an old tank or cover to make sure I have it matched.

 

[stihltech]

plastic

Where do you get the filler?

 

[TimberPig]

Remember to use the identical plastic that you are welding. I use snips to cut strips off of an old tank or cover to make sure I have it matched.

It's in his last line

 

[West Texas]

Dean those were superb photos and an excellent explanation. Thanks for sharing your secret. Tom

 

[stihltech]

rod

Missed it, I did not realize he made a rod out of the old material.

 

[046]

thanks dean, very useful info to have.

was just getting ready to purchase a plastic welding tool

will pull out wood burner instead on next job. nice tip about using identical plastic

 

[deerlakejens]

Great info, thanks as always.

Really appreciate your sharing the technique and taking the time to photograph the process! Thanks again, I'm going to try it tomorrow!

 

[bigealta]

Old thread but info still very relevant. Thanks