Looking For Suggestions, Gluing Cracked Plastic Fuel Tank

[halfdome, Danny]

This past June while returning home from vacation I had my fuel pump replaced in my 99 Blazer and now I smell gasoline. My local mechanic removed the tank today and found a small crack in a non removable vapor recovery fitting that's some kind of white plastic. Since it's on the top of the tank I'm hoping it could be glued and save me from buying a new gas tank at $550 plus installation. Has anyone had any experience using any gasoline proof/resistant glue on plastic? I found a couple on the shelf at Schucks and one online called Sealall. Danny

[asianflava]

I thought I had it bad because I had to pay $475 for a new gas tank. It was a polyethelene tank and this is what I tried.

Gas tank repair putty, probably works for metal tanks but popped off after some flexing.
Epoxy with cloth, started to delaminate after the gas hit it. I roughed up the poly but the epoxy had a hard time sticking to it.
Heat activated glue used to fix cracks in polyethelene kayaks. Had some terpidation about putting a flame so close to the tank but it was my last resort. I emptied out the tank and let it sit in the sun for a week. I blew compressed air in a few times during that week and right before I cured the glue. It lasted a week but it started leaking again.

I bit the bullet and bought a new tank form a dealership in Phoenix. No one would ship used tanks andI couldn't find an aftermarket one. Shipping on a 20gal tank wasn't as bad as I thought, plus I didn't have to pay sales tax. A few months ago my naighbor asked me what I did to fix the tank because his truck had the same problem. before I traded in my truck, we swapped tanks. His was cracked in the same exact spot as mine.

See if you can find an aftermarket replacement, that may be a cheaper option.

Good luck.

[doug hodder]

Danny...I just did a search on plastic fuel tank repair...found all sorts of answers...some had good luck with an RV shop doing a plastic weld on them, most people said that they were fixed for a while but then started leaking again...General consensus was to get a new tank. I checked...POR 15 has nothing for plastic tanks. Have you tried a local junk yard, but you might just be buying someone elses problem. Doug

[Lesbest]

The ONLY epoxy, glue, or 2 part chemical bonding agent that I've found to seal fuel tanks of plastic can't be bought at a store. It was mail order only out of the south and right now I can't remember the name or address. I will check tomorrow--I think I still have the literature in my tool box at the shop. You have to keep the activator in the freezer after opening and it will seal anything that you can clean. Alu. radiators, cracked blocks and heads, gas tanks, plastic or metal. A/C lines,are not a problem. When it dries it looks like porcelin and is hard. But the parts have to be absolutly clean before you apply the mix. The activator is a clear liquid and the rest is a powder. The powder stores ok, the activator not so long. It was $35.00 for a small kit. Enough for what you want.
I'll check tomorrow.

Les

[Miriam C.]

Now why is this looking like a manufacturers defect? Maybe someone needs to file some complaints to see if they can get if fixed free.

[halfdome, Danny]

Thanks for the responses. The only after market OEM tank available for my 4 door is from http://www.partsamerica.com/ for $155.60 with shipping and would take 2 weeks to ship to me, maybe longer who knows. The new tank doesn't have the cracked part included so I'd have to find one. I'd need to have the mechanic reinstall the tank so it could sit at home waiting. I'm hoping there would be a way to save the tank. There is a same year & model being parted out in the Seattle area but like Doug said might just be buying someone else's problem. The cracked part is replaceable the year prior and 3 years after my year model so Murphy strikes again. Les if you could find that glue I'd really appreciate it. I had the fuel pump replaced in my pick up truck this year too. It's just a fuelish year for me. Danny

[halfdome, Danny]

Now why is this looking like a manufacturers defect? Maybe someone needs to file some complaints to see if they can get if fixed free.

Miriam, this isn't a defect just a defective mechanic in Coos Bay Oregon. He broke the tank strap using an impact wrench without soaking the part, had to weld a new thread on it. I wonder why I don't trust mechanics. Danny

[jeepr]

OK, since it is on top of the tank. I know this sounds odd, but regular auto body filler like Bondo works really well on gas tanks. I have never tried it on a plastic tank and it may not hold, but who knows. I had a new metal gas tank for a Jeep with a factory installed pin-hole. Because of time constraints, I was forced to use what I had. I Bondoed (is that a word?) it with the intentions of replacing it later, but never did. Since you don't have to worry about how it looks, slather it on thick, maybe it will hold.

[depatty]

Depending on the kind of plastic I have had the best luck on long term repairs with plastic welding or melting. If it is a thermo setting plastic most times a soldering iron or gun can melt the crack back together to effect a permanent repair. Have fixed several car batteries that had taken a blow or gotten into the fan blades and then used them till they died a natural death.

A quick test of applying a soldering iron to the piece and seeing if it melts or powders should let you know if it can be repaired this way. If it powders or just doesn't melt then it can't be repaired in this manner.

If it melts use the point to make a series of dots along the seam of the crack and just past the ends, which should keep the crack from running any more. Then using the edge of the tip to wipe the sides into the pits and smooth it over. Let it cool and check for any places you missed. I use magnifiers for this to see any small spots I may have missed.

Good luck!

[halfdome, Danny]

Depending on the kind of plastic I have had the best luck on long term repairs with plastic welding or melting. If it is a thermo setting plastic most times a soldering iron or gun can melt the crack back together to effect a permanent repair. Have fixed several car batteries that had taken a blow or gotten into the fan blades and then used them till they died a natural death.

A quick test of applying a soldering iron to the piece and seeing if it melts or powders should let you know if it can be repaired this way. If it powders or just doesn't melt then it can't be repaired in this manner.

If it melts use the point to make a series of dots along the seam of the crack and just past the ends, which should keep the crack from running any more. Then using the edge of the tip to wipe the sides into the pits and smooth it over. Let it cool and check for any places you missed. I use magnifiers for this to see any small spots I may have missed.

Good luck!

Sounds like a way to fix it but I'm worried since it's a 3/4 tank (13 gal.) of gas. I guess I could have it reinstalled and run it down to empty then drain any left overs before using a heat source. Danny

[bobhenry]

http://ippnet.com/EN/main/solutions/1551.html

Probably polyethelene or poly propalene both show as difficult to glue good luck.

[Miriam C.]

Depending on the kind of plastic I have had the best luck on long term repairs with plastic welding or melting. If it is a thermo setting plastic most times a soldering iron or gun can melt the crack back together to effect a permanent repair. Have fixed several car batteries that had taken a blow or gotten into the fan blades and then used them till they died a natural death.

A quick test of applying a soldering iron to the piece and seeing if it melts or powders should let you know if it can be repaired this way. If it powders or just doesn't melt then it can't be repaired in this manner.

If it melts use the point to make a series of dots along the seam of the crack and just past the ends, which should keep the crack from running any more. Then using the edge of the tip to wipe the sides into the pits and smooth it over. Let it cool and check for any places you missed. I use magnifiers for this to see any small spots I may have missed.

Good luck!

Sounds like a way to fix it but I'm worried since it's a 3/4 tank (13 gal.) of gas. I guess I could have it reinstalled and run it down to empty then drain any left overs before using a heat source. Danny

I saw someone melt lead for an old tank one time. The rule then was to put water in the tank before applying a heated source. Might still be the safe way now.

[depatty]

Sounds like a way to fix it but I'm worried since it's a 3/4 tank (13 gal.) of gas. I guess I could have it reinstalled and run it down to empty then drain any left overs before using a heat source. Danny

Takes a spark or open flame and sufficient concentration of fuel vapors to ignite. But I do understand your concern. If you have fuel in the tank you can use the in-tank (I'm assuming) pump to remove most of it however an empty tank is more likely to blow than one that is full. Welding or soldering one with a torch can be fun even after purging with water and blowing out with air. They tend to make an interesting whoosh at times. Not that "I" have ever had that happen.

If I were doing the repair, I'd leave the fuel in the tank, block all openings into or out of the tank and use a soldering pencil (straight plug in and it's on 30 to 45 watt no trigger to spark type unit) and do the job at a cool or cold time of day (or night) when the vapors are lowest. And I'd also do the job outside where any vapor that is present/escaping can't build up.

Just my $0.02 worth...

[SkipperSue]

Since it's on the top of the tank I would use JB Weld, excelent stuff!

http://en.wikipedia.org/wiki/J-B_Weld



(Note JB Weld package in my avatar)

[halfdome, Danny]

I know JB Weld is an excellent product, used it before, was looking at it yesterday. Got to go look in some of the auto parts stores again, today. The mechanic doesn't have any experience in gluing plastic gas tank fittings so it's up to me to figure it out or pay $550 for a dealer tank. Thanks Danny