Making a 1950 David Brown Tractor Fuel Tank From Scratch

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Hi folks. I’ve been commissioned to make a David Brown 1950 Tractor fuel tank from scratch. It’s a nice project, with a few quirks, so maybe of interest to others.

I played around with a few techniques - particularly shrinking - as I wanted to see which method would work best/fastest for the given situation. Of particular interest was an old school method of torch shrinking I hadn’t done in a while. Time to fire up the oxy-acetylene 👍

Hope you like the project as it slowly evolves.

Here’s the knackered, rusted out tank. DB only made 330 of These, so very scarce!

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First step was to make card templates. I decided to make the top half from three pieces and weld the three together in the center of the double radius. Easy access for smoothing and planishing.

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I cut the blank with an additional 1/2” border to allow for the flange and excess to then cut away.

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For the first shrinking method, I used my Pullmax with homemade shrinking dies. The result was very fast and got me to about 80% of where the shrink needed to be.

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After shrinking on the Pullmax, the end panel was blended to smoother the transition from the shrunk radius to the low crown shape of the end of the tank.

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The first side plate came out well. Happy with the fit and finish, although I did employ another shrinking technique just on the edge: my kick shrinker.

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For the main part of the tank, I folded the two 90 degree flanges and then hand bent the panel over the tank. I then employed some heat shrinking to create the double curvature.

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The curvature of the tank was then smoothed out, some more heat shrinking was applied until the desired shape was formed. A final planish brought the panel to readied state for tack welding the two parts together.

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Once the two parts were tack welded, some planishing and cleaning ensued to help make the final weld as clean as possible.

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I then tig-welded the joint to reduce heat damage. I added additional filler metal to enable enough material for the weld zone to be filed, smoothed and planished. I wanted an invisible joint from the outside. Penetration was super important.