Soldering

[gumby302ho]

 Just a general question. Do you think I could solder a very small area on the side and bottom seem of my fuel tank with just a regular plug in soldering iron aka the wood burning type from those old wood burning sets some of us got when we were kids. Not sure if it would be enough heat to run the solder. My other option is cold weld. I did do a caswell job on the tank but I guess I did not swish enough to that area like I thought. I called caswell about a 2nd dose as it were and they said yes but can be tricky and would need to slosh acetone in the tank for whatever amount of time bla bla. I dont think its a good idea to try it again. F!@#$% pinholes.

[red]

Just a general question. Do you think I could solder a very small area on the side and bottom seem of my fuel tank with just a regular plug in soldering iron aka the wood burning type from those old wood burning sets some of us got when we were kids. Not sure if it would be enough heat to run the solder. My other option is cold weld. I did do a caswell job on the tank but I guess I did not swish enough to that area like I thought. I called caswell about a 2nd dose as it were and they said yes but can be tricky and would need to slosh acetone in the tank for whatever amount of time bla bla. I dont think its a good idea to try it again. F!@#$% pinholes.

Gumby,

You would need a soldering iron about the thickness of a broomstick, to put enough heat on the work.  No telling what all that heat would do to the sealant that you already have in there.  I would do exactly as the maker recommends, and then add a second coat of sealant inside.  When it comes to pinholes, you have just too many to try a single fix on each one.

Soldering irons are sold by wattage.  Little ones are usually 45 Watts, and you would need maybe 150~200 watts or higher.  It might be expected that fixing one area with solder will degrade nearby repairs, so it could become a losing game with solder.

[krusty]

To repair pin holes you're wasting time using a soldering iron, insufficient heat transfer to work surface. I have used a method called lead wiping. I've attached a vid showing the method. I use plumbers' stick solder which has a high lead content. A tip is to tap the pinhole with a ball pein hammer so as the hole is lower than the surrounding surface. Anyway there are probably other vids but this is the first one that came up when I searched.
https://www.youtube.com/watch?v=_udbIMNk17U

[atoyot]

Most old school radiator shops should have old copper soldering irons that are quite thick, and they should be able to solder your tank. Irons are heated up with LPG/compressed air torches to a point where they will run solder and retain enough heat to solder areas such as fuel tanks.

[Motofun]

I still have a blow torch that runs on white gas (lead-free high test from AMOCO).  there's a tray that sits over the torch in which you rest a soldering iron the size of a sausage.  Used for leading in cast iron sewer pipes.  I can't imagine trying to fix a gas tank with this contraption.

[T Legg]

I've soldered up many things using very carefully applied heat directly from a small propane torch for low temp solders but the surface must be well sanded down to clean metal and fluxed. You can't overheat the flux either. This couldn't be done without burning the tank sealing epoxy on the otherside. It would have to have been done before. I don't think soldering is an option for this tank without completely removing the epoxy first and I doubt that is possible.
    Years ago  I bought  one of my CB 750k1 Honda's. The original hm300 four into four exhaust pipes have a small hole on the under side of each pipe at the lowest point to allow any accumulated water to drain out . At some point before I bought it one of them became plugged causing water to sit and badly rust the bottom of the pipe. One used replacement pipe would cost more than I payed for the entire bike so used silver solder to braze over the damaged area and it is still holding up. It isn't pretty but unless your under five inches tall you can't see it without a mirror.


         
                 

[johnod]

Just a general question. Do you think I could solder a very small area on the side and bottom seem of my fuel tank with just a regular plug in soldering iron aka the wood burning type from those old wood burning sets some of us got when we were kids. Not sure if it would be enough heat to run the solder. My other option is cold weld. I did do a caswell job on the tank but I guess I did not swish enough to that area like I thought. I called caswell about a 2nd dose as it were and they said yes but can be tricky and would need to slosh acetone in the tank for whatever amount of time bla bla. I dont think its a good idea to try it again. F!@#$% pinholes.

I've soldered gas tanks using a propane torch.
Not difficult.
Obviously you want no gas fumes in the tank.