Learning to French sheet metal - for a motorcycle?

Hey guys,

Long time lurker who grew up reading Hot Rod, thought I'd come here for advice as most of what I'd like to do on my project seems to fit under basic old-school customization.

I have an early 2000's suzuki with a thin-gauge metal gas tank, that I wanted to french a set of gauges into. ***uming frenching is the right term here, what I'd like to do is create a recessed 'bucket' for the gauges to sit in on top of the tank, which would clean up my handlebar/front end significantly.

I have the option of running a skinny aftermarket digital gauges, but well, I've spent a lot of time looking at the original gauge set and want to maintain some of what I've enjoyed about this bike over the years I've had it, and there's a few diagnostic tests I can only run with OEM gauges.

As for my equipment and experience, I just bought a TIG brazing setup (seems to be the least risky method to get leak-proof welds without distorting my thin-gauge steel) and am currently learning to make a somewhat consistent weld. It looks like I may be able to grind and re-weld areas with pinholes, so I don't think I need to have a perfect bead, and can 'hack' my way to something that looks good once its been sanded and painted. I also have paint/body tools and a decent 3-d printer.

Here's a rough sketch of my idea: https://i.imgur.com/be5LOhC.png

My gas tank looks like this - top: https://i.imgur.com/JD1NMvj.jpeg
Side: https://i.imgur.com/8IdDBkI.jpeg

My gauges look like this - Top: https://i.imgur.com/Mi0dQUP.jpeg
Side: https://imgur.com/cb1bf372-229b-45b3-9877-d5e8693de5fe


I'll need to print a new case for the gauges that should create a smaller profile and make it overall about 2-inches tall, from a current 3.5 inch height, so I won't need quite as much room as it seems from the OEM gauge picture.

My thought originally was to cut a vertical section out of the gas tank that matches the 2-d profile of my gauges, then create a 'tub' underneath as the floor to hold the gauges, leaving room for the signal cable to come up through the tank, meeting the gauge on the back panel.

From my limited fab experience, this seems like the best/only idea, but before I start chopping things up, I wanted to ask the folks here if I was biting off more than I can chew here. In theory this seems like a matter of aligning metal with tack welds until I'm happy with the shape, then grinding and re-welding until waterproof, then a thin bit of filler, primer, and paint.

I want to make this look OEM - am I crazy? Is this just a matter of careful work, or is there something here that looks way more difficult than I'm expecting?

My biggest anticipation is that I can't effectively and accurately bend small curves, let alone 3-d curves that would look good around the edge of the gauges. Originally I thought I could get this looking right with bondo/careful blocking, but am I way above my pay grade here as an amateur?

Any advice or criticism appreciated.

 

Welcome to the HAMB.
Gas tanks have been modified and can be done.
A common one was to cut out the sides and swap side to side to create coves.
If it's a matter of doubting your skills, I'd suggest getting a cheap slightly damaged replacement and trying it. As @anthony myrick says, it's just metal. Follow basic safety instructions, search for metal shaping tutorials and go for it.

 

Can’t see the pics
Most guys here probably don’t use apps like that

you can post em here.

don’t over think this. A while back on another site a guy asked who could 3d metal stamp a fender flare based off their template . That’s expensive. My answer was to used the template to create a surface pattern to English wheel/hammer out the flare. That was too simple.
use the gauges to make the French bucket/recess.
Welding in a tank has concerns. Fumes. Plus leaks.
Ive used compressed air at low psi and let it sit in the tank for hours before welding. An old school way was to plumb car exhaust in it till the fumes were gone.
Low psi air and a mist of soap and water can detect leaks. Ive seem compressed air and submersion of the tank used.

Used the taillight to create this French bucket