I'm wanting to engine turn my ally petrol tank rather than just polish it - anyone have any tips, hints or tricks for doing this yourself?? I want that "Spirit of St Louis" look.
I found an ultra cheap how to on another forum. Basically take an old valve, spray adhesive a round piece of ScotchBrite to it and put it in your drill press. Tada-an engine turning bit.
Search "Kevin Lee" he did a tech article on how exactly he did his firewall. Was very informative. Found it: http://www.jalopyjournal.com/forum/showthread.php?t=107830
sounds easy, but give it a try on some practice convex surfaces.....not nearly as easy as it looks. if your going to do that tank....spend a lot of time practicing before you go at it.
I used an abrasive stick sold by Eastwood. It's very difficult to get the swirls evenly spaced and consistent in texture even when doing a flat piece with the stick (or whatever you are using to cut) in a milling machine. The problem is that the abrasive end wears and clogs as it cuts, so you have to watch closely and know when to apply more or less pressure as you go.If you want to do that tank, you may be able to come up with a way to align the end of the cutting piece/stick so it's perpendicular to the surface on the flat ends, so the swirls will be even. But I'd be stumped to know how you'd free-hand over the convex surfaces. Probably would have been better to engine turn the sheet before welding....
to do a surface thats not flat i think it would be best to use a wire cup brush for in a drill you can get a small size get as soft as you can find for aluminum then put a worm clamp around the strands to hold it into as tight of a diameter as you want you can then put this in a drill press and set up something to hold your parts to work back and forth just eye up the spacing judging by the center of each previous row or column it should work out pretty well for you good luck Zach
It would be tough for a gas tank, but I know a large, round, flat faced erasor in a drill press works perfect on instrument panels. -Dean
On the spirit of St Louis they used a drill and wire brush. Thats probably about the only way you'll get it done on that tank now that its done. I'm guessing that the tank is aluminum you'll probably want to experiment on a different s**** piece and don't lean on it too hard.
use the eastwood "sticks"they sell,but and i stress this,after each "turn" spray a light coat of penetrating oil or wd 40,this prevents "clogging" and will give a even pattern throughout. practice first,the key is to apply the same pressure each time.
To do a straight line on a curved surface,lay down a piece of 1/8th or 1/4" masking tape.If you are using a wire brush(a bit abrasive on aluminum)in a drill,lay the outside edge of the brush down so it is just touching the tape.Do one and the orient ths brush so it is halfway into the first circle and just touching the tape.Repeat until one line is completed.Clean the surface and then lay down another piece of tape so that the edge goes through the center of the circles just done. The hardest part to me would be keeping the drill vertical to the surface and centered.You don't have to use a lot of pressure to do it thankfully so "wander" shouldn't be a factor.
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