MGS Custom Motorcycle Gas Tank Build-Off for Ernie's Chopper

I am at a point in the build to start working on the sheetmetal. You may recall from the December 2005 issue that I sent a tank carved out of a foam block to MGS Custom Bikes in Lancaster, California. In case you missed that issue, a large block of foam was shipped to my house from MGS, and I was able to cut it to the shape I wanted for my bike. I also marked all the points to mount it to the frame, including the filler cap and petcock. When I called the shop, the crew said they were ready to show me how the second half of the MGS Liquid Steel Program works. Fortunately, I was able to bring my frame along to show how well the finished tank looks on my frame. Things were moving fast and I decided to make a few small changes to the shape of the actual tank during the fabrication process.

The first thing Mike Stafford,...        read full caption The first thing Mike Stafford, owner of MGS, needed to do was make sure that the tank was the right size for this frame. When I was shaping the foam, I cut a little too much off the bottom (OK, I dropped it and messed up the shape on one side). Mike measured the backbone with the foam in place to see how much I was off.	Next, Mike measured the w...        read full caption Next, Mike measured the width.	When Mike was satisfied with...        read full caption When Mike was satisfied with the overall dimensions, he pulled out the construction paper and started to cut out his first piece of the tank, the top.
He then double-checked it...        read full caption He then double-checked it to see if its shape would fit the bike.	Next, Mike traced the pattern...        read full caption Next, Mike traced the pattern on to a sheet of 16-gauge flat-stock sheet steel.	With a plasma cutter, Mike...        read full caption With a plasma cutter, Mike had the top pan cut in about 15 seconds.
After Mike deburred all the...        read full caption After Mike deburred all the edges, he started to roll the outside edges using an old Pullman. As shown here, he wanted to get the top piece to stretch out.	Next, he moved over to the...        read full caption Next, he moved over to the air hammer to speed up the process of shaping the top piece of the tank.	The planishing hammer will...        read full caption The planishing hammer will smooth out the deep hammer marks. Mike wanted to make sure that the metal was taking the correct shape.
Mike finished it off using...        read full caption Mike finished it off using the English wheel. After about 30 minutes, the top was just as smooth as when he started with the flat stock.	The top piece was then placed...        read full caption The top piece was then placed on the backbone. To hold it in place, Mike tacked a small piece of round stock to the frame and then set the tank where he envisioned it would sit to get the next measurement.	Mike taped a piece of construction...        read full caption Mike taped a piece of construction paper to the side and marked the shape of the side panels that I wanted. He then headed back to the flat stock and quickly cut out two pieces with the plasma cuter.
Both of the side pieces were...        read full caption Both of the side pieces were shaped with the planishing hammer just like the top piece.	With a few small tack welds...        read full caption With a few small tack welds to hold the sides in place, we were able to see how the tank was shaping up.	The shape of the tunnel for...        read full caption The shape of the tunnel for the tank was the next aspect of the tank to build. Mike took a piece of pipe and had it welded in place on the welding table with a small gap to fit the flat stock. He then slid a piece of flat stock under the pipe and bent it around the pipe with a little help from a rubber mallet.
The tunnel was placed inside...        read full caption The tunnel was placed inside the tank shell. Mike then marked along the tank's side to show how much of the tunnel needed to be removed.	Next, the fill cap was installed....        read full caption Next, the fill cap was installed. I got a Crime Scene Choppers new flip-up filler cap. It has a weld-in bung and a rubber seal, as well as eight small screws that hold the flip cap to the bung. Mike marked where the cap would go, then he cut out a hole in the top of the tank to weld it in place.	After sanding the edges of...        read full caption After sanding the edges of the hole where the bung was to go, Mike tacked the bung in place so he could check to see that the cap was in the dead center. He then welded it to the tank.
We moved on to mounting the...        read full caption We moved on to mounting the tank to the frame. MGS makes and offers mounting brackets and bosses. They also offer hidden crossovers, tank mounts, bar tabs, and threaded bosses for petcocks.	After the lower side pieces...        read full caption After the lower side pieces were tack welded in place, Mike cut out where the mounting brackets would go.	He then welded it in place...        read full caption He then welded it in place to look something like what's shown here.
Next, the bracket was welded...        read full caption Next, the bracket was welded to the frame. The tank was placed on the backbone with a small piece of round stock under the tank to keep it off the frame. Mike then welded the tab to the frame where the tank would mount. One tab would hold the rear of the tank, but the rear section of the tank was too small to fit two mounts across the bottom.	After pulling the tank from...        read full caption After pulling the tank from the frame, Mike marked where he would french in the side panels.	After marking where the side...        read full caption After marking where the side panels were going to be frenched, Mike cut along the top line with a small Radiack die grinder.
To make sure that the tank...        read full caption To make sure that the tank would be symmetrical, the same pattern was traced from one side to the other and from top to bottom.	Next, Little Mike cut out...        read full caption Next, Little Mike cut out a small piece of metal to use as the fill piece along the inset for the tank shape. He then tacked it in place.	As Big Mike was taking a few...        read full caption As Big Mike was taking a few phone calls, Little Mike cut down all the extra metal along the top so it could be welded.
When Mike got off the phone,...        read full caption When Mike got off the phone, he jumped right back into the final welding. He worked on one side for a few welds, then moved to the other allowing the tank to cool as he switched sides to prevent the tank from warping.	After the tank had time to...        read full caption After the tank had time to cool, Mike sanded down all the welds. He then took the tank over to get presser tested.	With no leaks to be found,...        read full caption With no leaks to be found, Mike placed the tank back on the bike.
Just before we loaded up my...        read full caption Just before we loaded up my roller, Mike was using my rear tire to show off his new line of spun 12-gauge steel fenders. I have an 18x5.5-inch rear wheel with a 180mm tire, and it was the right size to show how it sat on the bike. I will say that it followed the wheel perfect so I took it. I hope Mike didn't mind. Although, I need to trim it back a bit, so I'll show how I did it in the next issue.	Here is a one-off custom tank...        read full caption Here is a one-off custom tank from MGS. Mike did say this was the first bobber-style tank he has made-well, one of the smallest anyway.