Need help silver soldering in Brisbane

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xlev

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Hi guys

I recently bought an element guard for my 2.4kw heating element http://www.5stardistilling.net/element-guard/ and I tried to solder it yesterday. I got a 15% silver solder and flux. I heated up the metal using the propane blow torch and tried soldering it to the pot. The metal was glowing red but the solder didn't just flow, it was a pain to put the solder on. Anway I soldered it the first time, and when it cooled down it basically came right off, then I tried again, and same story. Btw the pot and the guard are both stainless steel.

Is there anyone in Brisbane who could give me a hand in soldering it? Not even sure if I can still use the same pot or element guard after I tried to solder twice?

ANy help would be really appreciated!

Thanks

Alex
 
give them a clean with Citric Acid, watch some youtube videos and have another go
Propane might not even be hot enough for brazing, you're better off with MAP Pro gas
 
sp0rk said:
give them a clean with Citric Acid, watch some youtube videos and have another go
Propane might not even be hot enough for brazing, you're better off with MAP Pro gas
Hi thanks for the tip, however I don't have the MAP Pro torch, and I don't really have the funds to buy one. Is it possibe to do it with propane?

Also if anyone has a MAP Pro torch and is willing to help me out, it would be greatly appreciated!
 
Soldering requires what is know as intergranular penetration. To achieve this the base metal has to get hot enough to allow the molten solder to actually penetrate the surface and get in among the granules that make up the base metal, when the whole thing cools there is a layer of the base metal that is a mixture (not an alloy) of both the base metal and solder, then a layer of solder, then another layer of mixed metal joining the other part.
Short answer is you didn't get the base metal hot enough to allow the solder to penetrate the surface.
The problem with Silver Soldering Stainless is that its easy to get a oxide layer that neither the solder or the flux can lift.

Clean the metal, ideally lightly sand or grind the surface.
Coat with a thin layer of flux before heating, this prevents the formation of an impenetrable layer
Heat the whole job evenly until the flux forms a fluid glassy film covering the area you want to solder
Heat until the solder flows, don't heat the solder directly, the tip of the solder should met on contact with the joint
The solder will flow toward the hottest zone so move the heat around to cause the solder to flow where you want it.

To silver solder stainless effectively you usually need an Oxy/Fuel torch (Oxy/LPG or Oxy Acetylene)
Mark
 
I'm not sure if that's the right flux mate? That is the same flux we use at work for copper and brass. Pretty sure you need black flux? for stainless to stainless.
 
xlev said:
Hi thanks for the tip, however I don't have the MAP Pro torch, and I don't really have the funds to buy one. Is it possibe to do it with propane?

Also if anyone has a MAP Pro torch and is willing to help me out, it would be greatly appreciated!
What torch are you using?
When I was building my heat exchanger, I used my 3 ring burner to boost the heat up speed, otherwise it was taking forever and using up all my MAP gas
This is the torch I use, for a budget torch it's surprisingly good, it's dealt with soldering SS ferules to 2.5" copper without breaking a sweat
It took a while to get up to heat for bigger stuff (soldering 7 x .5" tubes into a plate took a while) but it did it
http://www.ebay.com.au/itm/Mapp-Gas-Torch-Turbo-Heat-Single-Brazing-Welding-LPG-Map-Plumbing-Refrigeration-/111598034780?pt=LH_DefaultDomain_15&hash=item19fbc2df5c
 
Curly79 said:
I'm not sure if that's the right flux mate? That is the same flux we use at work for copper and brass. Pretty sure you need black flux? for stainless to stainless.
It should work fine, it's suited to stainless
 
What about the 15%silver solder rod. Should it be a brazing rod instead ?
 
This video by BrewHardware in the US shows and discusses how to silver solder a fitting to a pot.



Note the importance of roughing up the contact surfaces with emery paper and then cleaning the same surfaces thoroughly with a solvent. After cleaning do not touch the contact surfaces. Also very important to pre-heat the surrounding area of the pot to stop it becoming a heat sink and dragging the heat out of the area you want to solder. He also advises against MAP gas as it can get the work pieces too hot.

Also note the use of a strongly acidic liquid flux rather than a paste, and the importance of not breathing the toxic fumes - use a suitable mask and work in the open air, and also wear hand and eye protection.

PS. make sure your solder is lead free.
 
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Curly79 said:
What about the 15%silver solder rod. Should it be a brazing rod instead ?
It's hard solder, same thing as braze just a different name
 
Feldon said:
This video by BrewHardware in the US shows and discusses how to silver solder a fitting to a pot.



Note the importance of roughing up the contact surfaces with emery paper and then cleaning the same surfaces thoroughly with a solvent. After cleaning do not touch the contact surfaces. Also very important to pre-heat the surrounding area of the pot to stop it becoming a heat sink and dragging the heat out of the area you want to solder. He also advises against MAP gas as it can get the work pieces too hot.

Also note the use of a strongly acidic liquid flux rather than a paste, and the importance of not breathing the toxic fumes - use a suitable mask and work in the open air, and also wear hand and eye protection.

PS. make sure your solder is lead free.
Bobby is doing silver bearing soft soldering there
That's why he says not to use MAP
xlev is trying to Hard solder, you need the extra heat
 
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And Bobby makes the point that what he's doing is perfectly adequate, and easier to do.
 
Feldon said:
And Bobby makes the point that what he's doing is perfectly adequate, and easier to do.
That is very true, but I guess since xlev has already paid out the rear for 15% silver solder, if he can borrow a MAP torch he might as well use it
 
Thanks guys for the comments. I don't think I can do soft solder any more at this point, as the silver solder is already on the welding spud since I tried to solder already, but it just detached clean off the brewing pot.

I'm happy to pay for the MAP gas if anyone can lend me at least a nozzle, or if I can give a few beers to anyone who is willing to help!

CHeers

Alex
 
xlev said:
Thanks guys for the comments. I don't think I can do soft solder any more at this point, as the silver solder is already on the welding spud since I tried to solder already, but it just detached clean off the brewing pot.

I'm happy to pay for the MAP gas if anyone can lend me at least a nozzle, or if I can give a few beers to anyone who is willing to help!

CHeers

Alex
Just out of curiosity, did you get the welding spuds locally or from brewhardware?
 
sp0rk said:
Just out of curiosity, did you get the welding spuds locally or from brewhardware?
I got the spud that came with the 5star distilling element guard (link above)
 
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