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Classic Cars @ AZT Update

Classic Cars @ AZT - what became of the ailing tank?


June 2021


Dear classic car friends,

In April we reported here about the leaks and fuel loss on our BMW E21. The matter has been repaired and we will tell you more about the story: 


The removed tank was marked with extensive rusting. In the edge areas, where the upper and lower tank halves are welded together, clear corrosion was visible between the sheet metal layers.


In our last report we already mentioned that a new spare part was not available. We therefore decided to have the tank professionally repaired.

We have needed to sandblaste the tank in order to determine the complete extent of the damage. This blasting process is gentle on the rust but the steel sheet of the tank remains unchanged. Before sandblasting, however, the glued-on insulation mats had to be removed, as the blasting material would have bounced off them to no avail.

After sandblasting the tank was in a good condition. What you see in this photo is bare, undamaged sheet metal.



However, the corroded suspensions of the tank on the front side in the direction of travel were only rudimentary:


Welding the plate would be risky as the original weld seam could become leaky due to the additional heat input.

We therefore decided to make new sheet metal mountings and fix them in place using modern adhesive technology.



After the adhesive had cured, the tank could be taken to the paint shop and painted:



Primed and sanded. The sealing of the two tank halves against penetrating moisture, as well as the sealed repair area, are shown here:



The result is convincing. The work was worth it.


You can see that even a rather unnoticed component, such as the fuel tank, can play a major role in the preservation of an old vehicle, and that its restoration requires a certain amount of effort in any case. However, the result usually compensates for all the previous efforts.

Actually the tank is now too good to hide under the car. You won't see much of it anymore, but the assurance of no more leaks is also worth a lot.



More on the topic:

Article about the purchase of the BMW 318, year of construction 1975

Article about fuel loss at BMW 318 - A little petrol story