[Roeland]

Hi,

I'm planning to re-weld the broken bracket on my petrol tank over the weekend. I'm just very concerned about the petrol fumes. What would be the best method to eliminated the fumes before I start welding. About 35 years ago I used to place an empty tank on the driveway and lit it with a match - a big flame and bang it was all cleaned out - it worked but I don't feel that adventurous anymore and would like to employ a safer method.

[High On Octane]

Drain the gas out and completely and let it air dry for a few hours out in direct sunlight.  Some guys will fill the tank with water, but if you don't have a good air compressor, it will take a couple of days for it to dry out on its own.  I always just drain the gas and let it dry for a while.  Before I start welding I will take a BBQ lighter and try to light the fumes, if nothing happens, your fine.  If the fumes do ignite, there will be a slight "poof" and the flame will only burn for a second or two.  If it does ignite, you won't have any issues with it igniting again after that unless there is still liquid fuel in the tank.

Scottie J

[gashousegorilla]

 If your tank is lined, you will have to chemically strip the liner from the inside of the tank. Or it will burn, or at least burn out the area where you are welding. After welding you will have to re-line the tank. If you don't strip out the liner and just weld, corrosion will concentrate at the bare metal inside the tank, from the missing liner. What I do is to flush the tank out with soapy water about 5 times.... Dawn dish detergent works nice. Plug the holes and shake it up good. Dry it out with a stream of compressed air... a blow gun off your compressor taped open and stuck in the filler hole for a while. Then let it sit for a day or two , to air out.  You can try the blow it up technique, if your brave !   If you don't get killed..... You will likly rupture the rest of the seems on the tank.     Could also just get a new tank....

[Roeland]

If your tank is lined, you will have to chemically strip the liner from the inside of the tank. Or it will burn, or at least burn out the area where you are welding. After welding you will have to re-line the tank. If you don't strip out the liner and just weld, corrosion will concentrate at the bare metal inside the tank, from the missing liner. What I do is to flush the tank out with soapy water about 5 times.... Dawn dish detergent works nice. Plug the holes and shake it up good. Dry it out with a stream of compressed air... a blow gun off your compressor taped open and stuck in the filler hole for a while. Then let it sit for a day or two , to air out.  You can try the blow it up technique, if your brave !   If you don't get killed..... You will likly rupture the rest of the seems on the tank.     Could also just get a new tank....

The tank is not leaking and it looks the bracket has been broken off slighly below the seem. I obviously have to inpect that after I remove the tank. Would it still be required to strip the liner? Perhaps I can try to keep the tank as cool as possible (ice water)? If not what type of liner is recommended? I cannot recal any form of liner used 30+ years ago. Thanks

[gashousegorilla]

 Look inside the filler Roland. My 09 has some form of liner inside. If yours has it, It will be very hard to keep that heat away from the inside of the tank. If you use Ice water, you will likely wind up with a cold weld, with not enough penetration and it will crack again.  I like RedKote tank liner....

[Roeland]

Thank you - I will look into it.

[High On Octane]

I have never had a tank blow up on me, I've never even had anything ignite actually.  The soapy water works well, but not everyone has an air compressor.

[Roeland]

I have never had a tank blow up on me, I've never even had anything ignite actually.  The soapy water works well, but not everyone has an air compressor.

I used to use this method and once the tank is off I will decide which way to go. Thanks

[Roeland]

Perhaps I don't weld the bracket back? One bracket at the rear of the tank may suffice? I don't like the idea of the head steady bracket being bolted with the tank - I suspect this may be the reason these brackets break in the first place....

[gashousegorilla]

I don't like the idea of the head steady bracket being bolted with the tank - I suspect this may be the reason these brackets break in the first place....

 I agree !!  It's STUPID spot to mount the tank to...sharing the same mount location , with all the vibration front the head steady.  Rubber mounted front and back, at a separate location from the head steady. That is how I mounted my tank.

[ace.cafe]

This has been a common problem for years, going back to the Iron Barrel design.
I don't know the exact details of the UCE mount there, but I know it is similar. What breaks the tabs on the iron Barrel models is the squeezing of the tabs by the bolt and nut arrangement, and this flexing breaks the tabs from metal fatigue over time.
We have found that if we put washers on the bolt in the right places to allow the tabs to come straight down from the tank, and not be squeezed or flexed in either direction when you tighten the bolt, that typically solves the problem. It is a little more time consuming when you have to remove/re-fit the tank, but it almost always stops the tabs from breaking.

These tab locations vary, perhaps due to hand welding these things on the tank during manufacture. I have noticed that when I changed tanks, I had slightly different tab locations and spacing, and had to change the arrangement of spacers/washers that I used on the bolt.

[Ducati Scotty]

A pic of the break would help a lot.  One or more members have tried re-welding a tank only to create more leaks, weld those, more leaks, etc.  If you show us the break you may get better advice on how exactly to fix it.

And yes, several members have reported breaks in the tank.  RE now uses a rolling spot weld on the new tanks.  Also, the new tanks are notably wider at the mounts.  More than just a washer or two would take up.  If you get a new one don't just torque it down.  Build/buy  some spacers first.

Scott

[mattsz]

Also, the new tanks are notably wider at the mounts.  More than just a washer or two would take up.  If you get a new one don't just torque it down.  Build/buy  some spacers first.

FYI - my new tank had a wider front flange, but the rear mounts seemed to be the same.  But don't take my word for it, check!  As the man said, the tank you save may be your own...

[barenekd]

I fill the tank with water, then pass the torch over it. You want as little gas area that's reasonable, about an 1" or so from full so when the poof comes, it won't be big enough to split the tank open. I do this until there are no more poofs, lowering the water level a bit each time until it's empty. Worked for me for 40 years or so!
Bare

[Ducati Scotty]

And if the tank is already leaking from the bottom, well then it's one seemless, continuous process!