How To: Repair Cracked Washer Fluid Bottle

[Spittybug]

I tried using up the last bit of POR15 I had in an open can. I TSP'd and marine cleaned first, but with that odd shape all I could really do was swish it around. I poured a little paint in and oriented the bottle so that it would collect at the crack. This morning I filled it up with water and no drips! However, the paint immediately un-stuck from the walls of the container and I pulled it out in a sheet. Tested again and it still doesn't leak, so I'm thinking that enough got into the crack via capillary action and has done the job.

It's not like it's a mission critical fluid and if it leaks again I'm no worse off than I was yesterday, so I'm going to re install and keep my fingers crossed.

[DMCMW Dave]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

[Dangermouse]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

But the guy on TV said that Flex Seal will stick to anything, or my money back

I wouldn't have believed it more if Billy Mays had said it himself.

But wait, there's more:

Actually thinking about it, the flex-seal wouldn't have to stick to the bottle for very long. As long as you completely covered the bottle, you would be creating an impervious outer skin. Any water that got into the gap between the bottle and the Flex Seal (assuming that it didn't stick) would drain back into the bottle when the water level dropped below the level of the crack.

[Mark D]

If laying a patch over the top isn't sealing well enough there are a couple alternatives you could try...

-Use sand paper to rough up and form a slight V groove along the ridge of the crack. You can also use dremel or a very sharp exacto knife if you are careful.
-Cut very thin narrow strips of plastic to use as a "welding rod."
-Use your soldering iron to melt to heat up the bottle along the V groove while slowly feeding in your filler material.

OR

Lay a patch over the top of the crack as I described in the first post. (no need to get a complete seal using the heat gun)
Use your soldering iron to flatten out the edges of the patch and melt them into the surrounding plastic. As long as you seal the edges of the patch the crack below does not need to be completely sealed.



It took me a few tries to get my repair to seal completely...didn't use a soldering iron but remember having to press down in a few spots with a blunt object while using the heat gun to work the two layers of material together. This was back in 2009 and it's been holding strong since then.

Oh, and another trick. If your bottle starts to sag inward from the repeated heating attemps just blow into the bottle (gently!) to push it back out until it cools off again. It's also a good way to allow you to push a little harder as you try and press the patch material down into the bottle.

[Spittybug]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

Dave, I could have sworn that it was HDPE....PP is usually softer. But if indeed it is PP, that would certainly explain the difficulty in getting a HDPE patch to really adhere! PP and PE don't usually play well together once extruded and formed.....

[Spittybug]

Damn it! Put it back in the car since it looked like the combination of the POR15 in the crack and the plastic welding was holding. NOT.

Now in the market for a WW fluid tank.

[Mark D]

Damn, sorry to hear you're still strugging with the leak issue. There's gotta be a way to melt that thing back together. If the material is PP and not HDPE then dig through your recycling bin to find something with a #5 recycling code on it instead of using the milk jug plastic. (HDPE is #2)

[Dangermouse]

Now in the market for a WW fluid tank.

World of Warcraft? World War? Wascally Wabbit?

[DMCMW Dave]

Damn, sorry to hear you're still strugging with the leak issue. There's gotta be a way to melt that thing back together. If the material is PP and not HDPE then dig through your recycling bin to find something with a #5 recycling code on it instead of using the milk jug plastic. (HDPE is #2)

I could be wrong, but it is some sort of plastic that always feels greasy. I just assumed PP.

[stevedmc]

You could just sand it and then wrap it like crazy with fiberglass.