Good Sealer for Crack in Plastic?

[Ben]

I have this ATV herbicide sprayer that has sprung a leak in the tank. Refer to the photo below. It's right on the convex corner where the black support is resting on plywood. I found the leak a couple of days ago, and all I had around was some silicone sealer, so  I tried that. It held well yesterday, but this morning I walked into the shop and had a puddle of herbicide on the floor.

I'm wondering if the silicone couldn't handle the herbicide? It's a diluted mix of 2-4-D. Does anyone have any suggestions for a plastic patch material that is chemical resistant and will also form well and hold on a convex surface like that?

[K Frame]

Well, sounds funny, but FlexSeal is supposed to be pretty chemically resistant. A quick google search seems to bear that up.

You might want to try either the flex paste or flex tape, both of which also get good marks.

[Ben]

Well, sounds funny, but FlexSeal is supposed to be pretty chemically resistant. A quick google search seems to bear that up.

You might want to try either the flex paste or flex tape, both of which also get good marks.

I actually thought of that, but was thinking "last resort" only because I read that once it's on, that's it and there's no easy way to scrape it off to use something else. This stupid tank costs nearly $400, so I wanted to see if there are other options first. If not, I will in fact end up using the Flex Seal.

[bedlamite]

Drill a hole at each end of the crack so it doesn't grow when you heat it, then use these:

https://www.amazon.com/Poly-Welder-Polyethylene-Welding-Strips/dp/B00VMGO1IS

[Kingcreek]

I used JB weld “plastic” a few years ago in the same application on a backpack sprayer and it’s still holding. I roughed the surface before applying and I was able to get my arm inside also so I gobbed both sides. Right on the bottom corner same as your pic.

[charby]

Depending on the pesticide, you may have a repaired leak that will continue to leak.

You can buy poly tanks pretty reasonable if you search online.

[Ben]

Okay, while I'm at it, how about fixing something like this? This is a photo of the cover to my wheel line motor. Likely these tears happened when the former owner let the wind catch the cover when he was opening it. This is another stupid thing that costs like $250 to replace a plastic cover. I'd like to just do a field expedient repair here. The cover only comes off during maintenance, so it's only lifted (it tilts open, it doesn't come completely off) maybe once or twice a month. For running the wheel line, there's an access hatch to the pull cord for the motor, so I can leave the cover in place when using the wheel line.

I wonder if those welding strips Bedlamite posted might do the trick here?

[bedlamite]

I wonder if those welding strips Bedlamite posted might do the trick here?

Depends on the type of plastic, you have to match it. That looks like it might be ABS, I'm not sure.

[dogmush]

For the second one I would just get a couple pieces of galvanized strut and some angle braces of the correct size and through bolt them.  One piece of metal inside and one outside.

[Kingcreek]

For the second one I would just get a couple pieces of galvanized strut and some angle braces of the correct size and through bolt them.  One piece of metal inside and one outside.

^ 👍

[Ben]

For the second one I would just get a couple pieces of galvanized strut and some angle braces of the correct size and through bolt them.  One piece of metal inside and one outside.

That's a really good idea. If I had half a brain, I would have thought of that myself. 

I have exactly the correct stock sitting in the shop.

[RoadKingLarry]

det cord Duct tape.

[Kingcreek]

If it broke there, it was only because it wasn’t properly backboned with some galvanized stock to begin with!

You can still goop the cracks with some epoxy if you want to. I know people laugh about JB Weld anything but they have different flavors that really hold up well if used in the proper application. I know there is a model T block with a cracked cylinder out there somewhere that was JBW’ed and still running. Lower compression than modern stuff of course.

[Ben]

If it broke there, it was only because it wasn’t properly backboned with some galvanized stock to begin with!

You can still goop the cracks with some epoxy if you want to. I know people laugh about JB Weld anything but they have different flavors that really hold up well if used in the proper application. I know there is a model T block with a cracked cylinder out there somewhere that was JBW’ed and still running. Lower compression than modern stuff of course.

That's actually a good idea too. I'll look at doing that before I secure the metal stock.

[charby]

For the second one I would just get a couple pieces of galvanized strut and some angle braces of the correct size and through bolt them.  One piece of metal inside and one outside.

Yep, sheet metal on both sides, bolt/rivet.

[grampster]

I put some of that Flex Seal Glue on a plastic inflatable kiddie pool that had about a 3 inch slash in it.  Worked great.  I also have some cracks in my concrete stoop and a cement patio that I squeezed that Flex Seal glue into with my finger and smoothed it out then painted the stoop and patio with tinted oil base concrete sealer.  I'll see what that looks like in the spring.