Plastic Repair

[Wingnut]

Yesterday was a good day all around ... not only did I toast the pressure washer, but I also got stopped halfway through spraying cleanser on the house first. I have a sprayer unit from Black & Decker that has a 3 gal plastic tank (on a rolling frame) and a Versa battery unit to pressurize it.
Anyway, halfway through ... just as I'd dumped another gallon of cleaner in the tank and was repressuring, I noticed that I'd sprung a leak. Don't know it it was stress or a manufacturing defect, but there's a crack on the bottom. Since I've had it 2 years (although only used it several hours at most) it's long out of warranty and I'd always rather fix than replace.
Anyone tried "plastic welding" yet? If so, is it strong enough to withstand pressure? Is there a better way to attempt a repair? (I was thinking maybe epoxy from inside?)
Hope I don't have too many more days like that .... $400 pressure washer and $100 sprayer becoming toast in one afternoon ....

 

[Ozarker]

I have never tried to mend a place where there is pressure but I use that two part glue called Plastic Welder from Devcon and it is fantastic stuff. I have used it to repair my grandsons toys and if he breaks it a second time, it is never where I used that Plastic Welder.

When I repair someplace that will have stress, I cut a small splint out of an aluminum drink can and embed that in the repair.

 

[Gary_in_Indiana]

Have you considered some type of bladder/liner for it?

 

[chim]

The AgriFab 15 gallon tow-behind sprayer developed a leak after I stressed the plastic by jacknifing it behind the tractor last year. The tank has what appear to be nuts embedded in the plastic to accept mounting screws that go through the tube frame. I was doing a little "chemical mowing" and managed to kill a 2" wide by several hundred foot strip of grass before noticing the leak. Oops.

The fix was smearing gobs of Goop - real name - on the inside of the tank. Fortunately the tank has a big screw-on cap near the center that allows reaching the whole inside if necessary.

This stuff is seen in hardware stores, supply houses and the 'Marts. I've seen different versions of Household Goop, Plumber's Goop, etc. I think I used Plumber's Goop. I reassembled the tank and frame, and used it a couple of times on its own wheels. This Spring I had the guys in one of our fab shops whip up a small 3PH platform to strap it onto. This is a much better setup since it doesn't trail on wheels - handy for backing in places and maneuvering.............chim

 

[Bird]

Wingnut, I have no experience with plastic welding; haven't even seen it done, but when my brother was running the tool truck, he sold a plastic welding machine of some kind to a body shop and told me the guy that bought it could do miraculous things with it. You might try calling body shops in your area to see if have such equipment.

 

[Wingnut]

Thanks guys,

Gary, not sure about a bladder ... but I'll try that if nothing else works ... that's one idea I hadn't considered.

Ozarker and Chim, my first thought had been some sort of patching material ... first I thought of epoxy but I remember using goop one time ... the problem will be getting it down there ... kind of hated the "pour it down to the bottom and twist the container to spread" method that would be required since the opening isn't large enough for my hand (and arm).

Bird, that welding was what I was thinking about ... just wondering whether our "brain trust" had tried it on stressed or pressurized tanks yet. Back when I was Alberta, the Grain News weekly that I subscribed to had a series of articles by a guy who did all kinds of plastic welding .... Harbour Freight even sells a cheap kit now for about $35. I just didn't want to try something that would make it worse instead of better.

I guess try # 1 will be whatever Goop promises it's chemically resistant.

 

[Ozarker]

You couldn't pour that Plastic Welder stuff in and spread it by twisting the tank around. It isn't fluid enough. You would have to remove the tank and repair from the outside.

 

[Kodiak]

You might try the rubberizes roof coating paint that they sell for motor home and travel trailer roofs. Sno Seal is one brand that comes to mind.

 

[Chuck52]

Does the tank have a screw top? I wonder if it might be a standard container. Nalgene makes various sized plastic carboys. They sell mainly to labs and lab supply companies. Might not be too expensive to simply replace the tank.

Chuck

 

[centex]

I have used an old wood burning pen as well as soldering irons and scrap plastic to weld plastic in the past with good results. I have used things like Bic ball point pens as filler but for a clear plastic tank I would try to find something similar to use a filler. I am not sure this type of plastic will take the heat without burning though. It is always best to practice on similar scrap material - maybe an old piece of tupperware.