85 liter plastic gas tank repair/replacement

[NickP]

Earlier this week I posted in the sale section hoping to buy an 85L plastic gas tank to replace my cracked, leaky tank. Not much showed up other than a few other cracked tanks. I was also buoyed after reading some suggestions that my tank may be repairable which, along with my mechanic (Wayne Baker) we started exploring. I thought I'd share my findings so far.

The first option is some sort of external adhesive such as an epoxy compound, JB Weld, or something similar. The cracks in my tank are on the seams where the recess for the fuel lines are.

The second option is to determine if it's possible to "plastic weld" the the tank to repair the cracks. I don't know much about plastic welding other than it's pretty similar to regular metal welding in principal but I don't know if the type of plastic used on these tanks is suitable for this type of repair. On the surface it sounds good though.

Third, and Wayne's preferred option is to send my tank to Fuel Safe and have them fashion a bladder for the tank. Wayne believes this will result in the safest tank if it's possible to make this work. A must for me is that the tank retains it's original look, at least when viewed from the trunk. Assuming they will need a port for the bladder, I'm fine with them cutting a hole in the tank as long as it not in view. We will take pictures of the tank and send them to Fuel Safe next week for their assessment.

Meanwhile, I have a very nice rally tank available to me that I may use in the interim. It holds about 18 gallons and has the filler located on the driver side on top of the tank. It's a pretty cool gas tank and would be pretty easy to install.

We'll see...it will be interesting to see which of these potential solutions is the best for getting my tank back where it belongs. There's also the possibility that none of these work but I'm hoping something will. Of course, any input is welcomed.


Nick

[super9064]

I would try to weld it first. There is a lot of plastic welding technology out there. I did a quick Google search and quite a bit turned up. The problem with a bladder is that first, you will kill the value of your tank, second, have you priced a custom bladder? have you read their replacement recommendations? They have a rather limited lifespan.

http://www.plasticweldingandtools.com/

Good luck with your project.

[NickP]

Thanks Raj and Rob

Finding an experienced expert who can assess the situation and bond/plastic weld is by far my first choice. The reason Wayne isn't too keen on it is for the exact reason Raj states; unless done properly the cracks will still be there and flex/contract over time. Also, the plastic tank hangs very low and is quite exposed, even with the skid plate which flexes when hit and makes contact with the underside of the tank. Wayne thinks the chances are very good that the tank will re-crack pretty easily. Good idea to reach out to the marine industry. San Diego has several boat repair places and I know a few guys who have nice boats who can probably suggest some sources.

The bladder idea might be too expensive vs finding another un-cracked tank down the road when it's all said and done. I agree that the value of the tank is gone, but if my tank is unrepairable then what the heck, who cares at that point.

I'm hoping the plastic weld solution is possible. Fingers crossed; and if anyone out there knows of someone with this experience, please let me know. I think there are lots of 40 year old tanks out there that could be saved!

Nick

[steve shea]

Nick, plastic welding has been done for years with a great deal of success. I have been in the ski industry all my adult life and first started using welders for base repair 30 yrs ago. As a matter of fact skis flex MUCH more than a gas tank would and are used in temperature extremes from well above freezing to well below zero all the while running in direct contact with an extremely abrasive surface, snow. The welding unit is a small bench top size and requires the use of compressed air and a significant amount of heat. The heat and air are controlled separately. The heat and air are mixed and blown out of a hand held nozzle. Also on the nozzle is a second short tubular fitting that the welding rod goes through. The second tube acts as feed guide for the rod to be applied to the damaged area. Cracks are easy! We typically weld holes/cracks up to 3/8" wide. The issue would be to determine the exact make up of the tank material, find the suitable welding rod and it should work. You could conceivably make rod from another tank that is not salvagable. You would not need much. This truly a weld. As long as both the rod and the crack are heated properly it should not crack again. My experience with this technology is only skis. But skis go through an awful lot more than a gas tank plus the material is thinner! I answered your thread the other day and got lucky but I was fully prepared to weld it myself. I'm familiar with only one aspect of this technology basically the same for thirty years. I'm sure with some searching you can find other industries using this form of repair. If you were here I'd give it a go! Good luck SS

[69Sman]

I had Scott Hendry repair 2 of mine, still good

[NickP]

Thanks guys, I connected with Scott last week and am sending him photos of my tank on Monday. He has repaired these tanks by having them plastic welded with success. It's good to know that there are several repaired tanks out there.

[Mr9146]

Thanks guys, I connected with Scott last week and am sending him photos of my tank on Monday. He has repaired these tanks by having them plastic welded with success. It's good to know that there are several repaired tanks out there.

Sooooo, my Scott Hendry recommendation on the first thread wasn't good enough for you?

[NickP]

Dude- I asked Wayne Baker to call Scott as soon as I got your recommendation. I called him after Wayne gave him the details on the tank. You must still be in a pumpkin pie haze. Your words are like gospel.

[mike curnow]

Who is Scott Hendry?

I had Scott Hendry repair 2 of mine, still good

[NickP]

He is the owner of Scott's Independent Porsche Repair located in Anaheim, Ca.

http://www.scottsind.com/index.htm