I have a Toro "Recycler" lawnmower with a 5HP engine. The gas tank is plastic and bolted to the top of the engine. It has a leak in what appears to be the seam. New tank is $50. I don't want to spend that much because the mower is pretty old and I also don't know the history on it. After I cleaned out the carb and put on a new air filter it seems to run and cut well.
Is there an inexpensive way to fix this tank??
thanks chuck
Can't be too old, probably only 8-12 years. There are kits that use hot air guns to weld plastic with little filler rods. If that doesn't work, ask around local shops and mower boards online. Someone might have some old tanks sitting around.
GTO(John)
Unfortunately HDPE plastic is almost impossible to glue. Professionally it is done similar to tig welding but with a hot air gun. They carefully control the temperature and use a filler rod of HDPE. The welds are not as strong as the base materiel so they must be reinforced. That is how it is done on new plastic but it would probably not work on old plastic.
Perhaps you could mount a gas container on the push handle and run a tube to the carb?
Pete.
I was watching a boat fix-it program yesterday. They had some new stuff called cyanopoxy. It sounds like a marriage of super glue and epoxy. You might want to check and see if you can find any of that. Be sure to clean the surface. Hell, I'd drain it, leave it in the sun for a few days, wash it with acetone, let it dry another hour, then do the old JB Weld trick. I fixed some cracks on a stainless steel top of my pool filter with it, and it's still holding. It is good stuff if you can get it to a clean surface.
Steve
I have a heat gun used for surface mount electronics. So it will get hot enough to melt solder. I could heat the seam up and hope the plastic runs together? What are the odds this will work? What kind of scrap can I use as filler material?
chuck
The stuff is "SEAL-ALL", cheap, works great!!!
The newest issue of Home Shop Machinist (May/June 2004) has an article on a hot-air based welding setup for plastic. I don't know how it will work with that specific plastic, but the core of the toolkit is a $30 tool from Harbor Freight. Add in some effort on your part, and if I only ever thought I'd fix this one thing with the tool, I might just buy the part new.
Pete
Chuck,
I had the professional model of the plastic welder and it is a PITA to use. If you want to fix the mower you might be able to glop silicone glue on the tank and then use gauze to reinforce the silicone. The idea here is to mold the rubber around the tank to form a secondary seal, not to glue the HDPE back together.
Plan "B" would be to fab a new tank from metal and just replace your tank.
I wouldn't futz with trying to weld the tank even if I had the pro model welder.
Where do I start looking? Auto part places like Auto-zone? Hardware store?
chuck
I found this:
chuck
Unfortunately it doesn't work well on new plastic tanks. Other than that it's the best thing since sliced bread.
Wayne Cook Shamrock, TX
How about old plastic gas tanks? :) Like 10 years old. chuck
I keep a tube in my tackle box on fishing trips in the bush. I've used it on plastic tanks with excellent results. I've seen my repairs a year later still holding and that stuff gets more abuse than average. However, you might be right about NEW plastic. Maybe the right repair would be to "hot-knife" it.
Why wouldn't a fiberglass patch work? No one has mentioned that yet. Gary Brady Austin, TX
Because it won't stick to the plastic of the tank. Go ahead, try it if you want to.
However, my peferred solution would be to replicate the setup of some older mowers, and hang a tank (preferably metal) off the handlebars, with a hose to feed the carburetor. You can use a larger capacity tank than generally fits on the engine, and you don't need to keep or exactly replicate the old tank shape.
Professionally
Don't bother to use silicone, gasoline turns it into a sticky glop. Even silicone gasket cement is not recommended for use in carburetors.
Pete.
HDPE does not run when hot. When welding it is more of a push the mush together. Doing that and making it gas tight is a real trick.
Pete.
If it's old and weathered enough to start fading then you've got a chance. It may not last forever like it does on steel but it will stick to the rough surface some.
Wayne Cook Shamrock, TX
I've got a old cheap Radio Shack 15/30 watt iron which never really heated well enough for soldering especially in the 15 watt mode. I took the tip and flattened it with a hammer till it was shaped like a spatula and that's what I use on these tanks. It works ok but you will need some more material to put in there and the repair never seems as strong as the original.
Wayne Cook Shamrock, TX
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