Community Forums

cubano222 · 03-13-2013, 04:06 PM

On my 1979 Dodge Concord, the gas tank on the drivers side is some kind of plastic. I have been told it's polyurethane or polyethelyne material. I have had a crack in it for several years & have tried JB weld plus 4 other different gas tank repair kits but it still leaks gas. If it's below 1/4 full it doesn't leak because the crack is above that level but I would like to fix it. Nothing seems to stick to this type of plastic. I talked to a guy with epoxygator company & he said I would need to buy from them a product called polypoxy which you mix together & will bond to the tank. It is $25 for 2-4 ounce tubes.
I cannot locate any plastic welders in or around the Nashville area. I have contacted several RV repair places & they have not been any help.
Any suggestions?
Thanks,
Jerry

cwit · 03-13-2013, 04:25 PM

For 25.00$ I would go for it.

TQ60 · 03-13-2013, 07:43 PM

Replace it...

Too risky if it fails on the road with full tank.

May be able to put one of many different sizes.

Remove, drain, rinse and take it to some wrecking yards to see if any of them may have something that would work.

DeOrellana · 03-14-2013, 02:12 AM

Gas tanks are usually made of either polyethylene (PE) or polypropylene (PP). PE is usually clear and PP is usually black. Most body shops can weld plastic these days, or they have someone they use. The question is if they are willing to work on a gas tank. Rinse it out well for them. A correctly welded plastic tank is about as strong as the original.

If you can't find somebody to weld it, I would replace it. Trying to patch it on the outside with various fillers is a temporary fix at best. Not much sticks to PE or PP.

cubano222 · 03-14-2013, 07:56 AM

It's a pretty large tank. I am trying my best not to have to remove it. I wanted a plastic welder to come to the house or I drive the RV to their place to have it welded with the tank on the RV. I found out polypoxy is a 2 part putty & the guy tells me it will stick to polyethylene or polypropylene. For $25 it may be worth a try. It just drips a little gas right now & we usually stay within 50 miles of the house so if it starts leaking again, I will have no other choice but to remove the tank & have it welded. Will keep updating on what happens.

cubano222 · 03-14-2013, 08:01 AM

Update. The guy just emailed me & said nothing will stick to polyethylene but this product will definetly stick to polypropylene. My tank is black so I'm assuming it's polypropylene.

cubano222 · 03-15-2013, 08:02 AM

I think maybe it's best for me to buy a plastic welding kit from Harbor Freight for $15 & try to seal the crack be welding it myself.

Dave78Chief · 03-15-2013, 01:33 PM

Many radiator shops can do the plastic weld repair as long as the tank is out of the vehicle. They have to flush and clean it out to prevent gas fumes from causing an explosion (even you would have to do that). Because of the lite weight solder head on the iron, the harbor Freight kit is basically one shot deal (bends and breaks off). All you need it a 80 watt Weller soldering iron with a 1/4 chisel tip. For water tanks, just purchase a roll of polyethylene ice dispenser tubing supply hose. I believe Harbor freight does sell a plastic solder kit that contains polypropylene rods for say $15.

Dave

Itldo · 04-20-2013, 08:54 AM

I am just guessing here, but the plastic welding system is like a soldering iron, if I understand the system, and has no open flame. If there is no gas leaking out of the crack in the tank when being welded, and no vapors, wouldn't it be pretty safe to attempt the weld?

cubano222 · 04-22-2013, 08:30 AM

Yea, the plastic welding kit is like a soldering iron with a triangle flat tip. Pretty easy to use. I actually melted some of the sorrounding plastic around the crack to fill in then used the PP rods to beef up the area. So far has worked well. I have used this Harbor freight kit several times now, on 4 wheeler fenders & such & still works great.

desertranger · 04-22-2013, 09:50 AM

Quote:

Originally Posted by Itldo

I am just guessing here, but the plastic welding system is like a soldering iron, if I understand the system, and has no open flame. If there is no gas leaking out of the crack in the tank when being welded, and no vapors, wouldn't it be pretty safe to attempt the weld?

Gas tank repairs are not permanent, especially plastic tanks. They always fail. Replace the tank.