Another leaking tank topic...

[Spiral]

Hey There Steamer Owners,
When I acquired my '98 Steamer earlier this year, The previous owner showed me where he had repaired
2 leaking captive nuts on the right side of the tank. The captive nuts were not spinning but fuel was seeping
out anyway. His solution was to just fill the nuts and surrounding area with some type of epoxy.
Both repair sites started seeping again. Today I removed all the epoxy from the previous repair and
sanded the area around the nuts down to the plastic. I cleaned out the captive nuts and can install the shroud
screws all the way in tight. I am not sure exactly where the fuel is seeping from. It must be from around the
outside of the captive nuts as I believe they are not open ended based on pics I've seen here.
I would like to use the screws when finished with the repair as they were both out when I got the bike.
If fuel is seeping from around the nuts, Then I don't believe more epoxy from the outside is going to
penetrate around the nut sufficiently to stop the leak. Is coating the inside tank the best course of action?
Or should I try to epoxy around the outside of the nut with a screw in place? 

[ssevy]

I really feel your pain! At the present time I am waiting for my tank to come back from an auto body shop which originally plastic welded the tank inserts for me. The plastic rod they used to do the welding repair apparently was not the correct one and it only held for 3000 miles. They have new rod coming in based upon the plastic vendor's recommendation, and I'm hoping they get the repair done soon. If you want to wait I can report back on the success of that repair. The other option is JB Weld. Original JB Weld is supposed to be fuel proof and some have had success with it, but it failed for me. Calling JB Weld directly, they suggested Plastic Bonder for our tanks, not to be confused with Plastic Welder.
As for lining the tank, I have used Caswell tank repair kits and they work very well for metal. I called Caswell and they highly recommended using them on the inside of plastic tanks such as ours as well. If you were to do this it should seal all the leaks and prevent gasoline from coming in contact with the plastic. unfortunately, I cannot personally vouch for using this on a plastic tank, but according to the manufacturer it should be fine.
Good luck! This is a very frustrating problem to have.

[Spiral]

What a Pain indeed...
I think first maybe put some fuel back in the tank and pinpoint exactly where it is seeping from.
Might get lucky and be able to epoxy around the nuts.

[Jon H.]

I did a repair about 2 years ago using JB Weld. The repaired area, at one of the battery box captive nuts, is leaking again. I had built a mold inside the tank and created a 1.5' block of JB weld around the captive nut site. The entire block is now crumbling.  I believe plastic welding is the way to go.
Ssevy, did your shop tell you what type of plastic the tank is made of?  I think I remember that it is Nylon??? 
Spiral, yes the captive nuts are closed.  They have just a little bubble of plastic around them on the inside of the tank, and no amount of patching on the outside will last for long. BTDT
I have just purchased a used tank off Ebay,...just in case.

[London_Phil]

Sorry to hear your having tank trouble. Seems to be an increasing problem.
Please note that the way the insert is molded into the tank, leaves very little material to play with when problems occur.
Although this is for the fuel tap, all the tank inserts are similar, so be very careful when dealing with the inserts around the tank.
On my tank, I was lucky enough to be able to remove all fasteners, and I replaced them with Allen caps, so I was never in a position to risk rotating the insert.
Good luck

[ssevy]

The body shop told me that the new rod they used was nylon. The tank had to be heated and kept at a certain temperature for this rod to work. At this point, I cannot say that it is successful or not, as I put a Caswell kit in the tank last week, and have had it propped with the exhaust from my dehumidifier blowing into it for 4 days.
I plan on installing it later today, and then putting some fuel back in it. Unfortunately, the last tank weld job using polyethylene rod held up for about 3000 miles, so unless this rod fails immediately, I can't really tell you if this is a permanent fix or not.
You can also pressure test the tank gently with compressed air, spraying some soapy water on the spot you hear the hissing, and this will reveal the leak visually for you. Basically, just like looking for a hole in an inner tube. Once discovered, you have two choices I think:

1- Get some of the plastic bonder from JB Weld and epoxy the nutserts back into place. Then buy a Caswell kit and seal the entire tank. You want to mix the entire contents of both cans for a tank this large.

2- Find a body shop that will plastic weld the nutserts back into place using nylon rod. Then install the Caswell kit inside.

In either case, you want to install a full Caswell kit and not just try and cover the nutsert areas, as fuel could potentially infiltrate the seam between the Caswell epoxy and the tank surface inside, and then fail. I read on a Moto Guzzi forum where this happened to someone with a plastic tank and the Caswell kit. According to Caswell themselves, they have sold many kits to dirt bike riders who have plastic tanks with no complaints, and their tanks are subject to a lot more banging around than are ours. Also, I went to the dollar store and bought a large plastic bowl and a rubber spatula with which to mix my Caswell, and once it hardened I was still able to flex the bowl a bit with no cracking or separation.

You'll need Dawn dishsoap to wash out and flush the tank to prep it. I used hot water to wash it good with the Dawn, and then set the tank out on my lawn with a garden hose in it and all of the openings unplugged to rinse. Then you better let it dry for a day or so. I used my dehumidifier for that step as well.

Good luck. I'll post up my results in my other thread once I have anything to report.

[Sin_Tiger]

Good points Ssevy. The suspense is killing me