silver solder?

halfevil333 · Mar 31, 2012

Ok I just used silver solder to braze in my petcock bung, so, my question is:
HOW MANY OF YOU WHO'VE BUILT A TANK BEFORE THINK THIS A MISTAKE?
... I would rather find out now, before I tack weld it together.
I used a 1/4" brass female so that I could more easily use the copper fuel line....
Will try to post pictures tomorrow, no webbernet in the garage,....

culvercityclassic · Mar 31, 2012

It's all good. I have used it often in the past with NO issues.

bairdco · Mar 31, 2012

me too. i use silver solder on all my copper tanks, and i've done sheet metal repairs with it as well.

halfevil333 · Mar 31, 2012

So, you don't thumb the heat of the welded will loosen it?
I know enough to go in quick bursts, but that's just 'cause I am using 22g. On the sides and top...
16g. On bottom, and so I figure the thicker metal should diffusion the heat some... But this is my first tank, and I really don't want to botch it....can't afford to right now...$$

halfevil333 · Mar 31, 2012

...sorry auto correct...
I thumb you get it though..

halfevil333 · Mar 31, 2012

Oh, and BTW, I managed to get HOT flux in an open wound......OUCH!
NOW I REMEMBER WHY I'VE ALWAYS HATED MAKING MY OWN TATTOO NEEDLES, this or rubbing it in my eyes would ALWAYS happen to me.
Yup, one thing I'm GLAD they make by machine nower days@

dragray · Mar 31, 2012

as long as you cleaned everythign really good, and used flux with the solder, it'll be fine.
I put 2 fuel outlets in a tank with silver solder (not petcocks, copper tubing).
I also used silver solder to seal up holes, seams and gaps in a tank that I made.
Pressure test it with compressed air and water to check for leaks after you're done.

thegnu · Mar 31, 2012

when you pressure test with compressed air ..DO NOT EXCEDE ABOUT 3 TO 5 PSI I almost exploded a tank I built that way

dragray · Mar 31, 2012

good point gnu....but the tank i did was made of heavy gauge steel and was welded together.
the only parts on mine that were silver soldered were small holes and gaps.
but it is a good idea to keep the air pressure low because you could blow out the soldered areas if the pressure is too high.
I did mine with about 7 psi of pressure.

halfevil333 · Mar 31, 2012

Ok, thanx guys! I've had the materials cut and shaped for about 3days now, hesitant to do any more till I got word from my forum brotherhood...
Even a piece of sheet metal is out of my price range at the moment.
Hopefully I can sell my current bike to fund my new projects, but its hard to get anyone who hasn't been through this themselves to understand why I won't let her go for $4-500.....
Heck, I've got more than that in parts alone, nevermind time and effort.

2door · Mar 31, 2012

It always concerns me when I hear people refer to "silver solder" because I've heard it called that when the material was in fact just lead based alloy meant for plumbing. Yes, I know soft solder is usually silver in color but that doesn't make it silver solder. I'm assuming the OP knows the difference between real 'silver solder' which is an allow that requires far more heat than the soft solder meant for copper pipe/fittings, is much stronger and needs a little skill to get a good joint made.

Silver solder will cost several times as much as soft solder. It requires its own special flux and needs much more heat.

I added this because there might be a member/reader who isn't aware of the difference.

Example: My neighbor brought me the tail light assemble from his truck and asked if I could "silver solder" a broken contact in it. It was all plastic except for the metal lamp contacts.

Tom

thegnu · Mar 31, 2012

I weld my tanks with 18 gauge steel now , but my first one used mixed gauges when I hit it with air the top swelled up an scared the crap outta me , but put a nice easy curve on it that ended up as a bonus . never had a prob with silver solder holding my crossovers on an fillin pinholes .

Gary

halfevil333 · Mar 31, 2012

I'm using "silver bearing solder" which I've used to build many things, just not something I planned to weld AFTERWARDS...

Fugi93 · Mar 31, 2012

Right. They need to use something similar to this if they have fairly tight fiitting joints. It is low temp. Larger gaps would require the high heat silver solder.

http://www.harrisproductsgroup.com/en/Products/Alloys/Soldering/Lead-Free-Solders/Stay-Brite-8.aspx

Ibedayank · Mar 31, 2012

real Silver solder is not ment to bridge gaps but to be used in a lugged frame where fitup is really tight with almost no gaps. It does not make real good butt joints

halfevil333 · Mar 31, 2012

Yes, I used the staybright, bit am now confused...is the silver beariing/ staybright different from "real" silver solder? ...It's always held with GREAT reliability before...again, my question was really about the ability to weld after...and not have it rattling around in a finished tank.

Ibedayank · Mar 31, 2012

you do not weld on soldered brazed or silver soldered stuff
the heat from welding will melt/weaken it

plus the braze/s.s. or solder will make a very poor weld it contaimanets the weld

GearNut · Mar 31, 2012

He is not welding on the silver solder. He soldered a fuel fitting to the sheet metal using silver bearing solder and now plans on welding up the perimeter of said sheet metal to fabricate a fuel tank. He is concerned about the heat generated by welding which will travel through the sheet metal and may or may not be hot enough to mess up the silver solder job.

Ibedayank · Mar 31, 2012

GearNut said:
He is not welding on the silver solder. He soldered a fuel fitting to the sheet metal using silver bearing solder and now plans on welding up the perimeter of said sheet metal to fabricate a fuel tank. He is concerned about the heat generated by welding which will travel through the sheet metal and may or may not be hot enough to mess up the silver solder job.

A rag soaked in cold water and wrapped around the fitting is the cure for this problem. But you have to remember that lots more people read this forum and not post at all. That is why we all should try and give as accurate information as we can. Joining metal is not to be taken lightly if done wrong the results can be costly on wallet and body parts.

After welding/brazing/silver soldering I would seal the tank with a sealer made to seal gastanks and use one that is not effected by Ethanol fuels.
It will prevent the tank from rusting and seal any pinhole leaks it may have.

halfevil333 · Apr 1, 2012

Aaaah so, most wise!
Don't really know why I didn't think of the rag, OR THE WHOLE BOTTLE OF "HEAT SHIELD" I HAVE....

And although I've recently discovered a product called "ethanol shield" which claims to negate, or at least lessen the effects of ethanol.... I do NOT believe in, nor trust tank liners! And also don't believe ANY of them can actually withstand the eth'
Too many friends have had very messy, and quite expensive lessons learned dealing with them, I'd much rather spend more time pressure testing and brazing pinholes than deal with that crud!
The eth' shield DOES HELP save a paint job which may have been applied a bit too hastily, however.

silver solder?

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