The gas tank that I plan on using on my Speedster project has loose baffles. Should I use it as is or try to repair it? Can you weld a tank together after cutting it open??
The baffles are to control the sloshing when you drive
Most gas tanks are soldered, not welded
So yes it "can" be done, but to avoid blowing your head off requires special care and skill IF the tank is used
Hal, I have done a couple. I cut an opening in the top with tin snips(non sparking) after drilling a start point. I then blast the inside to get it clean and re solder the baffles with a large copper iron, I cut a closure from a piece of galvanized sheet at least 1/2" larger than the opening. I tin the surfaces of both pieces with tinning butter and solder this cover in place again using the large iron. You could most likely use a torch but would probably burn off the zinc coating and it will give you a sore throat breathing the fumes unless well ventilated. The copper iron works really well and the solder flows well onto the galvanized metal. I usually solder up any pin holes and resolder the sediment bung and cap while at it. I use a good epoxy sealer then on the inside and am good to go. Sound like a lot of work but you would be surprised what you can salvage by taking your time. The outside can be cleaned with vinegar and steel wool on the rusty spots and touched up with cold zinc paint or any other finish you desire. Tinning butter can usually be found at your local radiator shop or just use a good flux and pre tin with the solder. Good luck. KGB
I'd just buy another gas tank. Bob's has them.
So much for trying to be helpful. KGB
Anyone have a need for a rusted through on the bottom of an oval tank and has a baffle rattling around insider ?
If they are just loose not floating free i would seal the inside on the tank with kwik poly search it online i use it in tanks and wood wheels and other wood parts
Keith, I'll give it a try...nothing to lose and I want to use the parts that I have on hand. (Called cheap skate) I have more time than money for this job.
Bob, the baffles flop from end to end when you flip the tank. It's only 10 gallons, why are they needed?
I'd check with a radiator shop that's been in biz a long time, we have one here in Santa Monica that goes back to the 30's old time family owned and work on all old stuff. and gas tanks. Check in with Griffey
George, I've got one of those right around the corner from my shop. The owner's name is Hal and I have lunch with him often. He has an old race car that needs to be pushed to start and I guess it's worth big bucks.
Hal, if he's an old timey kind of guy I'd ask. I shot a note over to Griff your needs.
Of course, the warning first. Even a gasoline tank that has not had liquid gasoline in it for a few decades does have the potential to explode if welded on with any kind of torch or arc. Even if you cannot smell the gasoline. There are several methods to make the job "safer". Blowing oxygen-starved air (car exhaust?) through is one I have not tried and personally do not really trust.
What I have done a few times. First, remember that the flat sides of the baffle go on the top and bottom of the fuel tank. The baffle goes at about a third of the way in from both ends. It goes under the pressed ribs if the tank is late enough to have them (usually, these are the ones that have loose baffles because the baffle was originally held in only by the pressed rib). Wherever you are placing the baffle, drill four holes, about 3/8 inch, two each side, between the 4 o'clock and the 2 o'clock positions on one side of the tank and the 8 o'clock and 10 o'clock position on the other side. Make sure they are close to straight around the tank.
The tricky part, putting the baffle back. If you have more than one to fix? Start with the one farthest from the filler hole. Flip the tank so the loose baffle is near the filler hole. Put steel wires (coat-hanger size or slightly larger) through the drilled holes making an "X" inside (bend ends over to hold them in place). Flip the tank over to drop the baffle onto the wires. You may have to rotate the baffle to put the flat sides where they need to be (top and bottom). A bent steel rod can be used to tap the baffle into place. This all can take several tries, and can be quite frustrating.
More tricky stuff. Once the baffle is wedged into place, hopefully it will stay in place long enough. Carefully, gently, remove the steel wires. Have the (vent hole plugged) gasoline cap and pipe plug, torch, and braze rod at the ready. Plug the fuel drain hole with the pipe plug.
The four holes? I used electrical tape wrapped around about four times to block the holes, one at a time (we used to buy electrical tape by the case at work). Duct tape could probably be made to work. With the filler hole at the top, SLOWLY and GENTLY (so as to not knock the baffle loose) fill the tank with water. The tape covered holes will leak a little bit, a little bit is okay, but you NEED that water.
Gently (same reason), roll the tank to one side bringing one of the holes to the very top (with a slight lean to put most of the air in the end you are working on). Remove (cut) the tape from that topmost hole only (the reason for a slight angle with the tape around the tank over one hole at a time). You need about a half inch of air in the top to expose the hole and the baffle, BUT NO MORE THAN THAT HALF INCH! Using a small tip on the torch, heat the baffle first (working through that little hole is tricky). Braze from the baffle to fill the hole. Once that hole is thoroughly filled (and the baffle attached), rotate the tank to place another hole at the top, cut the tape, and again braze through the hole, baffle first, fill the hole. Rotate, repeat. Rotate, repeat.
BE CAREFUL!!!! This is not something that should be tried by someone without a fair amount of torch brazing sheet metal.
A couple things that make this tricky. As the small amount of air inside the tank gets hot, it expands, and will blow back at you and may spit water at you (remember, no more than a half inch at the baffle). You may get a little flame blown back at you also, it may be stray acetylene, or it could be gasoline vapor boiled out of the metal surface if you believe in that (it is what I was taught). Also, the water will draw the heat out of your effort to braze, that is why you do need a little air space. But too much air space can allow residual gasoline and/or stray acetylene to accumulate and go kablooey. The larger the air space, the bigger the kaboom. No kaboom is good when you are staring at it a foot away. BE SAFE! BE CAREFUL!
But that is how I have fixed a few baffles in gasoline tanks.
By the way. I have welded on gasoline tank sheet metal a few times? And, for whatever it is worth? Metal that had no odor of gasoline at all before welding, had that unmistakable stench of stale gasoline after I got it hot. That alone is enough to scare me a little bit. So, again, Be careful welding, or brazing, or even soldering, gasoline tanks. They don't need much in them besides air, heat, and a spark, to go bang rather spectacularly.
Keith and Wayne, I printed your instructions and will do it, one way or the other.! Wayne in Grass Valley, drop by sometime. I'm not always at the shop so give me a call 916.359,5032. My T shop is located in a corner of Hal's Auto Care, run by my son Mike. I'm there sometimes (916.485,9215)