Anyone ever made a tank? I am starting to plan my lorry mods and the provision of a bigger tank is on the list. I was going to get some from old trucks but now think I may be able to make some.
Your welding needs to be perfect, if not better. I've been trying to weld a container for hot oil and the pesky stuff gets out of welds that look sound.
A very slight fuel leak may not be noticed, especially petrol, as it may evaporate as fast as it leaks.
TBH If I was making a fuel tank I'd cut & bend the steel and get it TIG welded by a professional.
Most production fuel tanks seem to be resistance seam welded (or plastic mouldings these days). I reckon a tank could be MIG welded. I've made coolant header tanks before and they've been pressure proof, so not impossible.
Continuous seam welding with MIG should work. The bits between the end of one weld and the start of the next might be problematic, but they could be ground down and welded again. Trick has to be to develop a method of testing the tank for leaks before putting any fuel in.
Not a problem if you are a reasonable welder, if you are worried about being totally fuel proof get some tank sealer from Frosts. Also stops the inside of the tank from going rusty. Don
If you can weld properly its not a problem. Just pay attention to stop and starts.
I test using compressed air. WITH A REGULATOR, at a lowish pressure. Whatever cap you fit on it, make an adaptor for an airline coupling. Fill it with air and a bit of boubles on any suspect areas.
Hull integral Boat tanks are tested to 5psi, with leak detector sprayed on the seams. Higher pressures can warp the plates or cause a nasty explosion if you get really carried away!
You can always use dye penetrant testing before the tank is sealed, but pressure testing is cheaper and easier.
Dye pen will be extremely difficult on welds (i take it you have the dye and developer kit?), if you've used it you'll know what I mean. I'd go for pressure testing with the ole soapy water round the seems.
Dye pen is for spotting hair line cracks on flat panels or structual members. Even machine tooling marks will show up once you put devloper on the area.