Vintage Tech | New Life For An Old Tank
01. As you can see, this tank suffers from a very common ailment. Dents, grinds, and file marks left behind from the ’60s and ’70s when it just wasn’t cool to have all those stock badges and decorative trim. Back then, the hipster had to have a “smooth” bike. Out went the decorations and candy canes and in came the bondo and smooth chopped necks. To cure this problem and get the tank back in prime shape, you could re-introduce new bondo. But wait, what about putting new badges on and turning this 1941 tank into its former stock glory? You can’t just leave all those screwdriver dents and pry marks! Well, why not just pull all of the dents with a slide hammer? Hmmm, sounds like lots of highs and lows. What about water and a freezer? It’ll probably turn it into the shape of a football. So what the heck do you do?
01. As you can see, this tank suffers from a very common ailment. Dents, grinds, and file marks left behind from the ’60s and ’70s when it just wasn’t cool to have all those stock badges and decorative trim. Back then, the hipster had to have a “smooth” bike. Out went the decorations and candy canes and in came the bondo and smooth chopped necks. To cure this problem and get the tank back in prime shape, you could re-introduce new bondo. But wait, what about putting new badges on and turning this 1941 tank into its former stock glory? You can’t just leave all those screwdriver dents and pry marks! Well, why not just pull all of the dents with a slide hammer? Hmmm, sounds like lots of highs and lows. What about water and a freezer? It’ll probably turn it into the shape of a football. So what the heck do you do?
02. The answer is as simple and straightforward as Forrest Gump. Just get a box of chocolate. When you are done eating, grind the backside welds down on a 45-degree angle, and separate the tank halves just like the factory had them made. You will notice both halves were made on tooling and there is a lip pressed on the inside tank portion for shape and weld penetration on the inside pattern. It’s a good idea to tighten and leave the through tank petcock before you pull your old tank apart. If you pull the petcock your work can take the alignment out and your petcock will no longer seal, resulting in leaks.
03. Next, you want to do a quick run through on the English Wheel—a very simple and crude device that forces the metal between two dies to manipulate the metal. You can put concave, convex, or compound curves into metal with this simple wheeling device. You can also make metal perfectly flat with it. Understand that you are stretching the metal while you roll and it is becoming thinner and thinner the more you roll. It will also become denser. With this in mind, when you have a factory drawn (a manufacturing process of pulling steel over a die) piece, you want to make sure not to alter its dimensions. So go easy on the time in the wheel. The idea is to bring it back to original, not to a whole new shape!
04. This is what it looks like straight out of the English Wheel. The only things that are not removed are the grind marks and an old repair in the center of the tank where a tack was pulled through the metal. You won’t be able to remove grind marks in metal unless you stretch and thin the metal beyond the depth of the grind mark—this will severely alter the shape of the tank. In this picture you may also notice that there are several small dings towards the rear of the tank where the English Wheel could not reach.
05. Next, you’ll want to make sure your tank is still holding its shape, so it’s best to fit the inside panel back in and check for discrepancies. In this case, the work was done perfectly and the shape of the tank has not been altered. Also notice that tank’s mounting tabs were not removed. This is important, as it would create more work and potential problems.
06. Next, finish the small dings out with a hammer and dolly of your choice. It really doesn’t matter what you pick. A guy with experience in metal work can use anything to knock with. It’s more or less a feeling rather that having tools with fancy names. When you are hitting, you can feel and push your dolly (on the backside of the metal) around with your hammer. In this fashion, you can correct creases, dents, etc. with any shape dolly. Here a 3-pound sledgehammer and metal wheel were used, pretty high-tech, huh? The metal will look marred when you are done but this will come out with an abrasive disc, sand paper, or high-build primer. Notice that the dings at the rear of the tank are gone.
07. Finally, weld the inside panel back on making sure to weld on the inside edge of the tank half and not the top. Factory welds were placed on the inside edge and the top was smooth. Try to simulate the “ropey” look of the factory weld, as you will be leaving it as is and will not be dressing the weld.
08. Once you have checked for leaks and confirmed you are done with the repairs, you can add on the factory tank strips and any other items that were hacked off many years ago.
09. At the end of the day, you should have a decent and very straight factory tank to send to your painter. Tell him with a proud smile on your face to leave the bondo can in the corner this time!
For all of you who get excited when you see vintage iron, understand that it probably didn’t look that pretty when the owner took on the project. Most vintage enthusiasts have to complete some form of restoration to their old steed before he/she will allow it to hit the pavement. Here we will lightly examine what it takes to put some new life into an old gas tank that has been beaten and abused after many years of trustworthy service.
Now you may have heard old wives tales about filling tanks up with water and freezing them to remove dents or the like, but there is a correct way to accomplish this task and there is no better way than to pull the tank apart and cure the actual problem. Experience proves that you will spend about as much time, or possibly save time, by doing it the correct way the first go-round. HB
**Source:
U.S. Choppers**
949-394-8609 | uschopper.com
