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gas tank

gillenb's Avatar

Join Date: May 2009
Posts: 21

08-20-09, 06:04 PM   #1  
gas tank

I have a mtd ridding mower it has a plastic gas tank it has a whole in it about the size of nickel do you know any way to patch it ive tried jb weld it didnt hold. gas likes to soften
up a lot of things

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31YTech's Avatar

Join Date: Feb 2008
Posts: 1,263

08-20-09, 06:17 PM   #2  
I've had zero luck trying to repair plastic fuel tanks, Is it worth the risk (fire) to do so ?

I suggest going to your local repair shops and see if they have a used one if a new one is out of your price range.

Good Luck

larryccf's Avatar

Join Date: Jun 2009
Posts: 45

08-21-09, 05:46 AM   #3  
what 31YTech said

but another suggestion - egay always has mower parts for sale

if you're willing to adapt a different tank, there's a honda 3813 lawn tractor tank on the bay right now - and they never sell - they're built from pretty thick plastic, and the 4 or 5 i've seen on egay didn't sell - seller started this auction at $0.99 - they sit flat, about 10 X 10", maybe 5 -6" tall, 1.98 gal capacity, with a built in fuel guage, and pretty heavy plastic. Feed nipple is on bottom side of the tank for gravity feed

99 cents is a hard price to beat if it'll serve

woodsman23's Avatar

Join Date: Aug 2009
Posts: 9

08-21-09, 05:12 PM   #4  
Try buying a small fiberglass/resin kit, roughin up the plastic with some sandpaper and mix resin with hardener, double or triple the fiberglss sheet over the hole and apply use lots of resin this has worked for me many times.

hopkinsr2's Avatar

Join Date: Feb 2005
Posts: 1,561

08-21-09, 05:55 PM   #5  
What is a new one worth??? I'm thinking the old one wouldn't be worth the material or effort to chance a repair... What happened to the old tank to get a hole that size in it ??? Is the plastic getting brittle??? Roger

31YTech's Avatar

Join Date: Feb 2008
Posts: 1,263

08-21-09, 07:20 PM   #6  
Posted By: hopkinsr2 What is a new one worth???

If it's the one under the hood with the cut-out for the steering shaft their in the $50/$60 range without tax and shipping......

cheese's Avatar
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Join Date: Jul 2001
Posts: 16,570

08-21-09, 07:41 PM   #7  
Fiberglass resin doesn't stick to plastic too well. Not for use with contact with gas either.

"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

geogrubb's Avatar

Join Date: Jun 2006
Posts: 2,333

08-21-09, 08:49 PM   #8  
It all depends where the hole is, it can be welded using a pencil type soldering iron, or it on a flat surface you can use a bolt and bell washers, however, usually you will spend more time and money trying to fix it than buying a new one. Have a good one. Geo

larryccf's Avatar

Join Date: Jun 2009
Posts: 45

08-23-09, 08:21 AM   #9  
Posted By: cheese Fiberglass resin doesn't stick to plastic too well. Not for use with contact with gas either.
actually, depending on the polymer, it will - i work with fiberglass and epoxies - if you rough the polymer with a wirebrush, or rough sand paper, the resin will get a better bite to the surface and clean the polymer surfaces with a strong degreaser that will evaporate completely, like MEK. A lot of folks confuse, in use, laminating epoxies with structural adhesive epoxies - laminating epoxies have all their strength in "sheer" load - example of sheer load, put your hands like in prayer, then trying to slide them in opposite direction is sheer load. But laminating epoxies are usually low in peel strength (most i've seen were in 12 - 15 lbs per sq inch) which means they'll peel away if the substrate flexes, as the epoxy/fiberglass will resist flexing with the polymer. For repairing an existing polymer tank, a structural epoxy is best, but need to make sure it will tolerate fuels, especially fuels that contain MTBE, ethanol, alcohol and all the other additives the EPA is requiring be added to fuel.

Best proof, all the underground gas tanks at gas stations - fiberglass is laid up or wetted with epoxies. But the issue is, getting the proper epoxy. I wanted to build a fuel tank and did a little research - got the correct epoxy in from Dow Chem - and found i'd need two other additives to mix in. The damn chems were literally an explosion waiting to happen if not combined with the epoxy resin in correct fashion & order - and if combined directly to each other, would explode. I built the tank and disposed of the remaining epoxy & chems quickly. -

most epoxies though, you're right, they're subject to chemical corrosion from fuels, especially fuels with alcohol - they'll soften

in long run, i wouldn't waste the effort trying to fix with epoxy

most polymers can also be welded with a soldering iron, but as 31Ytech reported, results will be spotty at best, unless you have a lot of practice. And you do need to be able to clamp from both sides of the area being welded.

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