Let's talk plastics

[cash192t]

Okay, talking plastics...the 192t I have has a cracked center section I just discovered. I have it cleaned up and roughed up. I was going to use the old jb weld plastic epoxy. Does anyone have a better idea? seeing how you have to disassemble the saw to get to it I would rather not do it more than once. Also, heat maybe a factor as it is close to where the muffler goes. thanks

 

[Paul Fithian]

Epoxy doesn't play well with heat. Got a picture of what you are trying to repair?

 

[davidwyby]

How about sanding out dirty scratches and bringing shine back?

 

[nenicu]

Super glue and baking soda worked for me on Stihl plastics

 

[nenicu]

Oil pump side on a ms 230

 

[Paul Fithian]

You can polish nylon with a series of finer sand paper and polishing compound like you would for aluminum or painted surface.

If you really want to make it pop, clear coat it.

 

[legdelimber]

Back in the 1970's early 80's, We used to sandpaper/buff out those hazy plastic gauge lenses on motorcycles.
There was some brand of clear liquid floor wax (danged if I recall the brand now) that did a really nice job of finishing things up.
The wax job usually lasted through the summer and then time to do it again.
I do the same thing to those #%&## plastic headlights on my truck nowdays.

 

[Paul Fithian]

Ran a small experiment with two globs of PL Premium. Both cured for a week in air, then one was immersed in a 40:1 gasoline;oil mix for a week.



Cutaway shows they look the same inside after gasoline exposure:


Both globs felt the same, so this little test shows that a gas/oil mix has no affect on PL Premium.

For something like a fuel tank split at the seam, clean and degrease throughougly, open up the split a bit with a thin cutter, and fill with PL Premium. Clamp together and let sit for a few days before testing.

 

[NateSaw]

You can polish nylon with a series of finer sand paper and polishing compound like you would for aluminum or painted surface.

If you really want to make it pop, clear coat it.

I couldn't find a before picture. But these polished up nice... But, the older plastic is different...
This 461 filter cover was pretty scratched up. I was able to grind the scratches off, but it wouldn't polish past 800 grit. So I can only assume there's a difference in fiber content. I did these saws before finding this awesome thread.

 

[MustangMike]

Ran a small experiment with two globs of PL Premium. Both cured for a week in air, then one was immersed in a 40:1 gasoline;oil mix for a week.
View attachment 397111


Cutaway shows they look the same inside after gasoline exposure:
View attachment 397112

Both globs felt the same, so this little test shows that a gas/oil mix has no affect on PL Premium.

For something like a fuel tank split at the seam, clean and degrease throughougly, open up the split a bit with a thin cutter, and fill with PL Premium. Clamp together and let sit for a few days before testing.

Good info! I would also recommend putting a mesh screen over the seam. I have had wood open up after being glued with PL Premium. Not often, but it has happened.

 

[NateSaw]

You can polish nylon with a series of finer sand paper and polishing compound like you would for aluminum or painted surface.

If you really want to make it pop, clear coat it.

View attachment 397115
I couldn't find a before picture. But these polished up nice... But, the older plastic is different...View attachment 397116
... Because this 461 filter cover I used on this 440 was rough, so I sanded the scratches out. But after say 800 grit, it wouldn't take higher. I'm sure it had a different fiber content. And maybe the newer saws use different plastic too. Didn't think to check the numbers as I hadn't found this cool thread yet.

 

[beaglebriar]

Super glue & baking soda is holding up well on this tank. Been a few weeks of on and off use.. zero leakage.

 

[Woodwackr]

Old thread…but, which pL premium? I find several different ones.

 

[Paul Fithian]

This one:

https://www.lowes.com/pd/LOCTITE-PL-Premium-3x-Brown-Polyurethane-Interior-Exterior-Construction-Adhesive-Actual-Net-Contents-28-fl-oz/3228498

Clean surfaces and clamp securely. Let cure for 24 hours before removing clamps.

 

[MustangMike]

Also, lightly sand smooth surfaces and dampen nonporous surfaces.

If you need additional strength, I have sometimes drilled a bit to let the PL Premium make "posts". Even more effective when you can drill through a surface and let it make an anchor on the opposite side (like when I put #s on my plastic mailbox).

The clamping is important because it expands a little when drying. If it needs to look neat, you can trim the excess after with a razor knife. If I can't clamp it, I usually tape it in place.

I always keep it around, it is my favorite glue, and I use it on wood, plastic and metal. (I use the original 3X strength) in caulking tubes.

Have not tried the newer, stronger stuff ... no need.

 

[lehman live edge slab]

I was researching some and found out most zip ties are made of the nylon 6/6 so if I buy the ones close in color and use a plastic welder they would work well for an ms 250 oil tank ect? Can you use nylon 6/6 on a nylon 6 part or not? Or would dried out string trimmer line be a more appropriate filler?

 

[lehman live edge slab]

Well I used just a basic soldering iron style plastic welder and a few zip ties to patch that leak on a ms 250 tank seam. Not real pretty when done but not one drip so the owner was happy with the 30$ repair vs hour labor and used tank to switch it.

 

[Woodwackr]

Well I used just a basic soldering iron style plastic welder and a few zip ties to patch that leak on a ms 250 tank seam. Not real pretty when done but not one drip so the owner was happy with the 30$ repair vs hour labor and used tank to switch it.

I have a few misc trashed tanks that I cut up to use as plastic filler

 

[lehman live edge slab]

I have a few misc trashed tanks that I cut up to use as plastic filler

Figured I’d try zip ties since the plastic matched even though it’s not reinforced like the tank was just a leak on old weld seam.

 

[Paul Fithian]

Yes, nylon 6 is compatible with 6/6. There are many alloys of these materials commercial sold.

You are correct that most cable ties are made from nylon, both types.

Nylon welds very well, our cars and chainsaws depend on it.