Tank Hole

[Foxfix]

I have a very small (microscopic) hole on the side of a petrol tank about 40mm up from the bottom crimp.
Its created a very small bubble in the paint about 8mm round over the last 4 weeks.
After cutting the bubble out of the paint , I can see a very small spot/stain on the surface of the metal about 1mm round. The steel all around it is good shiny steel.
Its not letting enough petrol out to cause a drip, just evaporating away.

My thoughts are to fully empty the tank and clean the small area back to good steel and apply a small amount of Petrol Tank Seal and monitor it for a few weeks before repainting.
I don't want to bother with internal fluid type tank linings.

Question?
Has anyone had a similar problem and if so which Tank Seal Product did you use as there seems to be a few including a JB Weld one which I have found to make decent other products.

Thanks

[r3sc]

I think you have a somewhat larger problem than you anticipate as in my experience it’s highly unlikely that there will only be one hole and I suggest that there will be other areas of corrosion inside the tank that will be close on breaking through in time.

I’m not suggesting a liner as I really don’t like liners but that’s your call but if it was me I would be on the lookout for a good replacement tank and paint it, especially as you already need to paint your existing.

[Foxfix]

Thanks R3sc

I agree with you there, but I have now removed the paint on a larger area around the hole and the steel is not showing any other signs of other holes or damage, so I intend to lightly centre punch the hole back and fill with a petrol resistant filler and watch it for a month or so before paint...........but as you say, keep looking for a good replacement tank

[Z1streetfighter71]

If it were my tank before i took anymore paintwork through sanding ( i presume thats how you are taking down the paint) i would take a philips screwdriver and in one inch increments on both the sides around the base and the actual base too, stab the metal work with firm but not hard force and feel for any softness in the steel. If you are lucky and its only localized to one area have the tank media blasted with walnut media to a clean finish. That way you can surmise the damage. If the damage is small a good braze welder can repair the hole and a liner applied inside.
edit. I did exactly all of the above in a Gpz750 tank years ago as they are prone to it and it lasted years after.

[warren3200gt]

Empty and vent the tank then braze the hole. It'll never leak there again.
If you use a pin point flame to braze it then it'll not affect the remainder of the paint and it'd just need localised paint.

[Z1streetfighter71]

Empty and vent the tank then braze the hole. It'll never leak there again.
If you use a pin point flame to braze it then it'll not affect the remainder of the paint and it'd just need localised paint.

What if there are a bunch of holes that are a few microns away from coming through? Seems like a bunch of work that may have to be done again 3 months later. When i did the same to my Gpz there were 4 holes where i thought there was one. Not saying the screwdriver method is the best but it proves or reassures there isnt a bigger problem unseen. There is the magnet method too.. Use a small magnet on where you know is good metal, build up a baseline to the resistance you feel taking it on and off, then do the same to suspect areas of the tank, less resistance the thinner of corroded the metal.

[warren3200gt]

Empty and vent the tank then braze the hole. It'll never leak there again.
If you use a pin point flame to braze it then it'll not affect the remainder of the paint and it'd just need localised paint.

What if there are a bunch of holes that are a few microns away from coming through? Seems like a bunch of work that may have to be done again 3 months later. When i did the same to my Gpz there were 4 holes where i thought there was one. Not saying the screwdriver method is the best but it proves or reassures there isnt a bigger problem unseen. There is the magnet method too.. Use a small magnet on where you know is good metal, build up a baseline to the resistance you feel taking it on and off, then do the same to suspect areas of the tank, less resistance the thinner of corroded the metal.

Thats the reason to braze it so you can flood the surface area, bit like tinning it with braze.

[Z1streetfighter71]

Empty and vent the tank then braze the hole. It'll never leak there again.
If you use a pin point flame to braze it then it'll not affect the remainder of the paint and it'd just need localised paint.

What if there are a bunch of holes that are a few microns away from coming through? Seems like a bunch of work that may have to be done again 3 months later. When i did the same to my Gpz there were 4 holes where i thought there was one. Not saying the screwdriver method is the best but it proves or reassures there isnt a bigger problem unseen. There is the magnet method too.. Use a small magnet on where you know is good metal, build up a baseline to the resistance you feel taking it on and off, then do the same to suspect areas of the tank, less resistance the thinner of corroded the metal.

Thats the reason to braze it so you can flood the surface area, bit like tinning it with braze.

I hear you on the Braze welding, It was partly my bread and butter for 7 years but as all welding the cleaner the surface the better. I used work in an industrial Paintshop. We had a acid vapor degreaser, i was about 5 meters tall. could strip the paint off a tank to bare steel in 3 minutes. God i miss having access to that thing.

[Skid Mark]

If there is a hole in the tank, that is 100% section loss to the steel, the surrounding area will not be unaffected. There are numerous pin holes about to break through and likely at least one wider area with reduced section. Clean and Braze or solder are the second best options but don't skimp on the area, if you do, you will have it all over again in a few months. A liner is not optimal, but if done right will future proof it for some time, best route is a good tank. Just remember, when cleaning back for either brazing or lining you are likely going to introduce more holes, I cleaned a tank with DEOX, the area around the original leak was like a tea bag.