Soldering a Steel Tank - solder type and input needed

It was good to read this...I thought that I was the only one who hated Oatey solder. I have used Kester for years and have always had good results. All this lead-free solder is just so much crap...

 

Thanks man! It's a Crafty B cap. He made a matching sender cap for it as well.

And yep... Gonna' drill out the nut-serts/riv-nuts.

 

Was just at ACE Hardware for some other things and decided to see what they had in the solder area. They carry the Nokorode so I got some. They carried a bunch of 60/40 tin/lead solder, but it was all flux based. Going to have to find another source.

For curiosity sake, they had "silver bearing solid wire" solder. Was pricey, but I grabbed a small roll of it. What would I expect if I used something like this??

 

Believe me, there is nothing wrong with 60/40 or 70/30 "electrical" solder and resin flux. That is the only solder I use, copper, steel, electrical, plumbing. You name it, I've probably soldered it with that stuff. Relatively low melting temperature, no corrosion (ever) and flows well.

Anyway, why solder? If the purpose is to generate a seal and the surfaces are clean, how about LockTite? It will flow a little into the joint, lasts forever and nothing that is available on the consumer market will melt or soften it. Lately, I've been using it as a pipe sealer, great stuff!

Just a thought.

Bill

 

It's soldered... Post pics in a bit. And YES, I drilled out the rivet nuts. Was pretty tricky with resetting them after tinning the surfaces. Had to use clamps, and heat each area up as I went and set the riv-nuts while keeping it hot so I wouldn't get a gap between the two surfaces after the solder starts flowing. Also had to make sure to keep the surrounding areas cool because of the other soldered joints on the tank.

The whole point of this was to be consistent with how the rest of the tank is constructed. The easiest thing would have been to TIG weld it. But then it would look different than the rest of the tank. Just paying attention to the details.

Stand by for some pics!

 

So here's what I did...

Hit both surfaces to be fluxed and tinned with 120 grit. Next I softened up a little of the Nokorode flux and applied with an acid brush. Tinned both surfaces with the silver solder and wiped any remaining flux out. Aligned the two surfaces using the un-set rivet nuts as guides. Used two small C-clamps to pull it down tight. Warmed the surface back up until I could tighten the clams down more. Then went around to each rivet nut and set them one at a time while keeping the solder warm enough to flow while setting. Once the rivet nuts were set and I was sure the screws would go in straight, I went back and finished the perimeter of the flange until the "bead" looked as consistent as I could get it without undoing my work and/or getting too much heat in it. I had to be real careful not to get the tank too hot because I would start softening up other soldered joints. I popped a baffle at the top by the flange because I didn't keep it cool enough at one spot, but no harm no foul. It won't effect anything overall. The baffle is trapped by the bead in the skin during assembly.

So here's what I have... Not the prettiest thing, and doesn't look anything like a TIG weld, but then neither does the rest of the tank. It definitely appears to be sealed and will get POR15 liner in the tank as well. Fuel should never even see the back side of this seam. Still need to make the cap gasket, but you get the idea.

 

Ok this is great I am learning a few things here!! But WHAT is tinning and is this tank soldering like swaeting copper pipe? And Scotter whered ya get that sweet flip-top cap?

 

Yep! Pretty much like sweating a plumbing fitting for your water heater.

I'm sure someone can describe the reason for tinning better, but essentially it's the act of flowing some solder on to the surfaces to be joined before you join them while wiping away any extra flux hanging around that might cause some issues later. When you put the two surfaces together and apply the heat again, the solder will flow and fill the nooks and crannies assuring a good seal.

Did I describe that correctly guys??

The cap is from Kirk at Crafty B. Great little cap!

 

Too much solder in that seam. You should barely see a line of solder between the parts. And please, DO NOT use a tank sealer! You WILL regret it.

 

I added solder around the exterior for aesthetics. Is that bad? Was going to take it down a bit when doing final prep before paint.

I've used POR15 tank sealers on cycle tanks and never had any issues. They work great when properly installed. AND the new formulation resists all these new ridiculous fuels you get from the pump. Never heard of any issues with the POR15 stuff or the red stuff (whatever it's called). The seam for the exterior is on the bottom of the tank. Was thinking this would be a good way of being proactive for all the bumping around this tank will see. Is it really that bad of an idea?

 

I'm too late now, but you were worried about the riv nuts getting looser after replacement...I was goint to suggest that while you had the fire lit, tin them and be sure holes were tinned, then after they were expanded into place a hit with some heat would totally seal and extra-lock them.

Sealers worry me...there have been several generations of them since they hit the olde car market, and several generations of epidemic failure as new gas formulations arrive.
What's gonna be in the tank 5 years down the road??
Wait...you are restricting the thing to a totally traditional Hemifeed of Nitromethane spiked with Hydrazine, now I remember, so no worries! I was thinking gasoline, but that's just for Chevies.

 

HAHA! Good point... Thought I was being pro-active. Maybe I'll just try it without and move on.

And I'm ahead of ya' on tinning the rivet nuts! I indeed went ahead and tinned them up. Should have got some decent solder around each one.

I value everyone's input... Maybe I'll rethink the tank sealer then.

 

Heat the solder and wipe with a wet cloth, less solder will look cleaner.

 

Yep! Agreed! I did that once already. You should have seen it before! HAHA!

 

Now fire up the barbecue and tin the whole inside! It'll take the bastards YEARS to develop gasoline that will dissolve THAT!!

 

The tank already appears to be galvanized. Good to go from that standpoint! More concerned about the seams than anything.

The tank started out life as one of these:

http://www.thehotrodcompany.com/shopnow/show_dept.asp?dept_id=78

Maybe it would be worth asking the HAMB population who own these tanks if they've experienced any issues.

 

Put in a couple of gallons of thinner or something, should be able to find leaks too small for gas, and hang it up at different angles. It would be pretty easy to plug the vent, also, and give it a couple of pounds of air pressure with a bicycle pump hooked to a fitting. The thinner will leave you no cleanup issues if work is needed.

 

Excellent thought, Bruce! I'll give it a try! Thanks!

For curiosity sake, I started a thread trying to get the attention of those who own these tanks.

 

Model T's are somehow immune to fire...they drive around drizzling everything and just chug on eternally.

 

Your close on the description of tinning. After applying solder, the excess solder is wiped off the parts while still hot (of course) so you end up with a thin film of solder. The idea is to have a surface that will readily accept solder. Nothing accepts solder better than solder.

Bill

 

What stops the gas from leaking past the riv nuts ?

 

Silver Solder or Acid Core.... and Deff Tin both before doing it cause you will get a leak if ya dont.

 

They are expanded into place rather like pop rivets, plus these are now soldered. As with pop rivets there are also special ones out there for use with flammable liquids.

 

They expand filling the hole, but as Bruce mentions, they are also tinned/soldered during the process. Originally it would have got sealer on top of all that, but will probably not end up adding a sealer to the tank. Nothing says I can't actually finger some sealer in around the bottom side of the seam lip from the inside. The hole is big enough to get a smear in and we keep a supply of aircraft sealer for fuel tanks on hand.

 

That tank should not need any sealer. They are tested before they ship. Now, having said that - you have done a lot of mannipulation to the tank so it may be a good idea to test again. These tanks are built exactly like Henry made them in 1927, so much so that Ford Motor Company used them in their "Model T" re-creations for the 100 year anniversary.

 

Thanks man! I was hoping you would see this...

Going to give it a test and run without the sealer!