welding with 45% silver

[The Breeze]

I have to brase some stainless food tubes with 45% silver as a repair. what would be the best silver type and size? can't use much heat 1/64 stainless tubes .this is a repair or i would just tig it but it would be really time consuming to completly take it apart and clean it for welding, plus it is a large peice that the ends have come loose on thanks inadvance.


ps it is put together with silver from the factory tryed to find out from them they say it is a trade secret

[burninbriar]

I'm sure its silver soldered, not welded (not to nitpick terminology). Harris makes a 45 percent silver solder rod, check with Airgas.

[The Breeze]

what size torch and type flux is the main thing i need to know is there better flux than the old stand by i allready have the ribbon 0.50 solder 1/2 in wide because it will be a overlap job

[Tailshaft56]

For siver soldering you will need a tight fit up. Ther does need to be a few thou clearance so the solder can wick into the joint. Punch marks work well to allow for this. You will also need the proper flux. If you have never hard soldered before it would be wise to practice on some scrap first. Once you get the hang of it the process seems almost magical. I seem to do best with an air acetelyne torch than with O/A.

Good luck

[jbspeed]

welding with 45% silver

I am glad you asked this question for I have the need of this info also. Thanks

[turboglenn]

After seeing this thread i went to the garage to try and solder some SS together with the 45% and didn't have any luck what so ever. I could get it to almost lay down but then if I applied anymore heat the stay-silv rod would just ball back up to it's self. The only way i could get it to fuse to the parent metals was to concentrate heat around the edges of where teh 45 would ball up and wait for the SS to get hot enough to combine with the "ball of solder/brazing rod" (it's the radnor/harris Stay-silv 45 w/ flux.

Any idea what i'm doing wrong or am I trying something different than what's being talked about?

[spotsineyes]

It sounds like you are getting it hot too fast and burning the flux off. Try re-applying the flux, thinning it a little more. Then heat it more gradually and over a broader area with a soft flame, constantly testing with the solder to just get the temperature to the solder's melting point.

[spotsineyes]

I just reread your last post, you're using solder with the flux on it? Try some silver solder flux applied to the base metal instead.