Forum

[Chris Tindal]

My petrol tank sprang a leak over the weekend. The paint started bubbling at the rear where the lower braket bolts to the frame. Turns out there is a weap from the rear seam and when I drained it lots of small rust pieces came out from the inside. Is it worth repairing and if so how is it best done?


Thanks for your help


 


 

[Alan R]

Hello again Chris ----------- isn't the price of a "second grade" tank or one from E-bay or from one of the Classic bike shows cheap enough rather than specialist repairs ?? You know how on a car bodywork when you find some rust and try to rub it down the rust patch underneath is actually bigger than you first saw ?? The inside of your tank is going to be something like that as well. The seams are quite deep so to be showing like that means it's well established inside I should say. When working on British Railways as a Diesel Technician, we used a kit known as "Liquid metal" for repairing stone hits on the underslung fuel tanks. With over 500 gallons of Diesel fuel inside, draining was not an option. I don't know the commercial name--maybe someone here will ?? I've done a few weld/Braze motorcycle tank repairs in the past but  it has to be drained, vented, water-filled and allowed to be de-gassed first. My advice ? Buy another one, check it out whilst it's still empty and have it lined with the latest Ethanol proof stuff. At least you know where you are then.  

[Chris Tindal]

Thanks Alan. I would like to repair it eventually as its nearly 60 years old and replacements are unavailable. I have a repro one that I had made but the knee pad screw holes are in the wrong place and it looks naff. Is brazing an option?

[Mark M]

Chris, brazing will work (an old school motorcycle mechanic fixed several pinholes in exactly this location on my 53 Meteor tank) but because water tends to collect at the bottom of tanks, especially in this area, I think you should strip the paint off a larger section and examine it closely. It doesn't help that the rear fixing lug is prone to being over stressed if incorrectly fitted over the head steady. Brazing is best because it's slightly flexible, degassing shouldn't be too difficult as previously suggested.


REgards, Mark 

[Chris Tindal]

Thanks Mark, next project comming up.

[grunda 12]

leaking petrol tank throw it in the skip get a new one or enter yourself in the human candle race

[Chris Tindal]

Thanks Paul

[Alan R]

Hi Chris ------- my Bank account sprang a leak at the week-end,------------- I bought our hosts 32mm Mk1 Concentric kit-------- ouch, that hurt. As our late friend Jimmy Saville used to say " 'Ows about that then, guys & gals ?  err--err---errr---err (you know the noise I mean)

[Dennis C]

Hi Chris


Brazing is a good way to repair a seam leak and will be permanant if done correctly I have repaired three leaking tanks over the past ten years.


Drain all the petrol, wash it out well with water and leave in a warm dry place with the cap off for about a week, after this the residue of the petrol fumes will have gone and brazing will be safe, after brazing use a good cleaner and tank liner and it will be fine for another fifty years or more.

[Peter]

Agree with Dennic C, though i would do the fine gravel shaking then copious rinsing to derust first. this will help to purge the tank, look up POR 15, everybody raves about it.