Soldering Stainless steel

[twst1up]

why is silver solder preferred over regular plumbing solder as noted in the OP?

 

[Bobby_M]

Regular plumbing solder (lead free stuff) is mostly tin with some antimony. Harris stay brite, for example, replaces the antimony with silver and the benefit is a stronger joint that is less sensitive to heating/cooling cycle stress.

 

[Docbruw]

What has been the best/cheapest method for making holes for 1/2 NPT couplers and 1.5" TC?
I plan to use a 7/8 hole saw for the coupler but can't find a good size for the TC.

Parts for the keg tools:
1/2" coupler> McMaster 45605K725 & 4335T65
1.5 TC> McMaster 45605K711 & 4335T64

If it helps I got my reducer coupling here:
http://www.amazon.com/gp/product/B003RWTYPA/?tag=skimlinks_replacement-20

It was less expensive and if you are a prime member free 2 day shipping.

I also used a 1" PVC coupling instead of the SS version. It was less and $1 and worked great to dimple 7+ holes in my keggles.

Also make sure to get a grade 8 nut and bolt.

 

[renthispace]

I am going to attempt to create a dimple to solder a 90° elbow to the side of my pot. My question is, how much smaller should I make the hole compared to the elbow to make a solid shoulder?

And for you smart people, I will be grinding the lip on the elbow off so that the bend will be flat against the pot, as in the soldering will be done as close to the bend as possible.

I will be using this to create the dimple http://www.mcmaster.com/#45605k111/=or1oaf. If I remember correctly, the outside diameter of the elbow is 1.011". So to create a decent shoulder for that sized hole, my drilled hole needs to be smaller. The question is how much. 1/8", 1/4"?

 

[Bobby_M]

Most elbows have a raised ring at the edges but reduce in size towards the bend. I don't know how flush you'll really be able to get it. The butt weld 1/2" side will just fit into 13/16 so that would be your minimum place to start with the hole size.

 

[humann_brewing]

I am looking to do this as a fix for a weldless fitting I made and made the hole a tad too large and I can't quite get a good seal with standard rubber seals that go around a 1/2" NPT nipple which goes through the hole and then 2 locknuts smashing them against the keg wall.

This is on the side of the keg, so it is rounded so I think welding spuds are out right? What are my other options?

 

[Bobby_M]

How big is the hole? The large OD flat gasket might be the ticket if you're using an oring now.

 

[wbarber69]

Yay I made it to the end. Now to start soldering. I noticed at least 1 of you are using kobalt sockets to make your dimpling tool. What sockets are recommended for 1/2" full coupler. And if possible what sockets should work for a 1" half coupler?

 

[cyberbackpacker]

I gave my keg tool a few turns too many and oversized the hole for a 1/4" coupling.

I want to pull a dimple for two 1/4" npt couplers to install Bobbym sight glasses... What size hole do I need to drill?

 

[RDatsun]

Ruby fluid is also a good flux fairly cheap also , muriatic acid will work . As much as some of you pay for flux and silver solder . Prob have it tig welded .

 

[bigtex52]

Has anyone noticed any difference in difficulty in soldering the various alloys of stainless? (18/8 vs 316, etc.)

 

[Bobby_M]

Has anyone noticed any difference in difficulty in soldering the various alloys of stainless? (18/8 vs 316, etc.)

Not at all.

 

[bigtex52]

Thank, Bobby.

 

[Docbruw]

Ruby fluid is also a good flux fairly cheap also , muriatic acid will work . As much as some of you pay for flux and silver solder . Prob have it tig welded .

I paid $12 for my .5 oz stay bright flux and silver solder combo pack and I've dimpled and soldered 9 couplings between the kettle and HLT. I have more than enough solder and flux left to do the elements in both. I'm still on the same 14oz propane tank for my torch also. The dimple tool I used was <$20.

How much does tig welding cost? I've never looked into it.

 

[lorglath]

Quick questions... I have been trying to solder my stainless pots but I am having an issue with the pot splitting. I have been using a punch, now at 7/8" and using a dimpler to grow it to 1" but it has been causing the pipe to split rather than just grow. After the pot split, sometimes in a few areas I still tried to solder everything... the hole soldered well, but where there are splits, the solder drips out rather than filling the holes... so I have two questions...

How do i fill the gaps where the solder initially bled through? I can likely re flux it, then just let the solder bead drip through it by melting it above the hole and hoping it stop, drys and sticks to the openings... other than that I am at a loss... use a soldering iron?

How can I grow the holes such that it doesn't split?! Should I warm the pot up before I try to use the expander? should I use a drill so there is a constant force? Should I get an even larger punch, say 15/16"?

 

[humann_brewing]

How big is the hole? The large OD flat gasket might be the ticket if you're using an oring now.

I currently have a 1/2" ID NPT threaded nipple going through right now and there is too much space around the edges that the rubber gasket that is used, slips inside the hole, albeit a tight fit, but not water tight

 

[Bobby_M]

Quick questions... I have been trying to solder my stainless pots but I am having an issue with the pot splitting. I have been using a punch, now at 7/8" and using a dimpler to grow it to 1" but it has been causing the pipe to split rather than just grow. After the pot split, sometimes in a few areas I still tried to solder everything... the hole soldered well, but where there are splits, the solder drips out rather than filling the holes... so I have two questions...

How do i fill the gaps where the solder initially bled through? I can likely re flux it, then just let the solder bead drip through it by melting it above the hole and hoping it stop, drys and sticks to the openings... other than that I am at a loss... use a soldering iron?

How can I grow the holes such that it doesn't split?! Should I warm the pot up before I try to use the expander? should I use a drill so there is a constant force? Should I get an even larger punch, say 15/16"?

Wow, that's unfortunate. Honestly, if you can't pull a 7/8 hole to 1", I don't think this method is viable for you. If you use a 15/16" hole and pull it to 1", that's only 1/32" contact patch. I suspect there may be too large of a gap between your mandrel and die for the thin-ness of your pot. What's the ID of your pulling die?

 

[lorglath]

This is the puller I am using.

When I put it through the hole made from the die, it makes it about a 1/2" through before meeting resistance, I do notice it doesn't want to pull straight through, which is telling me there is more stress on once side vs. another.

Any suggestions on how I can fill the holes left from these cracks? would pictures help?

 

[Bobby_M]

Are you using regular Harris stay brite or stay brite #8? The higher silver content of #8 will fill larger gaps. One trick is to get everything nice a clean again, flux, then cold solder over the hole. This isn't really ideal, but it will seal the holes just fine... Warm up the area where the hole is by applying direct flame right to it, remove the flame and see if you can get some solder to melt but just barely. Keep heating, trying, heating trying.... as soon as it kinda melts but sticks... apply the flame and feed solder in and remove the flame immediately. You're not trying to get the whole thing to reflow, just applying enough heat to the solder to use it as "putty".

I see what you're using as the puller... I'd call that part the mandrel... which is the object that forms the inside of the flare. The "die" side of the pulling tool could also be called the "receiver". I know it's confusing because you also make the hole with a punch and die... If you're using the pipe reducer as your mandrel, what are you using as the cup shaped die on the other side of the pot wall?

 

[Docbruw]

That's the exact mandrel I used on all my dimples and it worked great on all my kegs. I used this as my die/receiver side.

 

[lorglath]

The kettles I got were either this, or extremely similar.

This is the solder I used

This is the Flux I am using.



The die is a 1" ID threaded coupler I got from Menards.

I also have some pics... I will try that cold solder technique... and have a few questions on another hole... but I will first add pics for the holes in question.

Here is one of the problem childs...

Bottom with the tear...

View from the inside... uncleaned yet

Here is my next issue... the first hole I did was FANTASTIC! except after the solder had reflowed... I moved the pot too quickly causing the solder to run all over... I add more solder and reheated it, but I didn't add more flux.. I believe I caused a bad joint... Can I fix this by adding more flux around the spot and then just reflowing it one more time?

Outside - looks pretty

inside (out of focus, sorry) - you can see it is a rounder bead rather than laying flat

 

[Docbruw]

How big of a hole did you start with? I started with a 7/8" hole and it worked perfect.

What kind of heat source are you using? I didn't get that much discoloration of the stainless or burning of the flux around the joint.

 

[lorglath]

I started with a 7/8" hole, but the greenlee punch for some odd ass reason leaves a little cut out on the edge, not a perfect circle :-/ I am a bit disappointed with the performance, all my other greenlee punches are great.. not sure what's wrong with this one...

Also, I think the metal in the pot is simply too thin or brittle to work properly...

I have been doing the cold soldering to fix the joints and they are looking great... just gotta keep going slow I guess.

 

[wilserbrewer]

Might a slightly larger receiving die not create such a sharp bend at the dimple and be less prone to cracking?

Some of the other dimples posted here seem more gradual and not as abrupt. As if the outer part against the pot is slightly larger diameter,

 

[lorglath]

Might a slightly larger receiving die not create such a sharp bend at the dimple and be less prone to cracking?

Some of the other dimples posted here seem more gradual and not as abrupt. As if the outer part against the pot is slightly larger diameter,

Worth a shot!

 

[phasevariable]

Also, I think the metal in the pot is simply too thin or brittle to work properly...

From your description, you have had several problem pulls. Are the tears always nearest to the bottom of the kettle?

If so, could the proximity of the hole to the bottom of the kettle play a part? I imagine that the area closest to the the bend receives more stress during the forming process and may have left the metal more susceptible to tearing.

Just my two cents.

Sorry to hear you are having problems.

Good Luck.

 

[bigtex52]

Stainless steel has a tendency to work harden when sawing, drilling, filing, etc. Are you punching your 7/8" hole or drilling before drawing? I have had better luck drawing a dimple after drilling rather than punching. There are stresses induced when punching that don't seem to be when drilled with a step drill at a rapid rate.

 

[lorglath]

How big of a hole did you start with? I started with a 7/8" hole and it worked perfect.

What kind of heat source are you using? I didn't get that much discoloration of the stainless or burning of the flux around the joint.

I am new to this and was using way too much flux. I have watched some videos now and have been using much less, and heating the kettle more before applying heat to the coupler, which is resulting in much less discoloration. Also, in the pictures I hadn't cleaned the joints yet.

From your description, you have had several problem pulls. Are the tears always nearest to the bottom of the kettle?

If so, could the proximity of the hole to the bottom of the kettle play a part? I imagine that the area closest to the the bend receives more stress during the forming process and may have left the metal more susceptible to tearing.

Just my two cents.

Sorry to hear you are having problems.

Good Luck.

Nope, even when I do my 'water input' holes for the top of the kettle it splits. Tried with the larger coupler, and it still happened... but at the same time I was having another issue with my pulling bolt and nut... so I'm trying again once replaced tonight.

Stainless steel has a tendency to work harden when sawing, drilling, filing, etc. Are you punching your 7/8" hole or drilling before drawing? I have had better luck drawing a dimple after drilling rather than punching. There are stresses induced when punching that don't seem to be when drilled with a step drill at a rapid rate.

I drill a small pilot hole, then punch to 7/8. I tried using my step bit, but my step bit has worn down in several areas and it's very hard to grow the hole past those areas... again, when I was new to making the holes I didn't realize high pressure low speed was needed... pretty sure I cooked the damn thing (even using cutting oil).

 

[OMJ]

Lorglath

I have the same pots and in order to avoid tearing I started with a 15/16 hole. Makes for a smaller dimple but its plenty for soldering.

 

[bucfanmike]

Thanks for all that contributed. I added 4 full couplings between my HLT and MT this week. Showed them off to brew club friends when I brought my stuff out for our club teach a friend homebrew day. Everyone was very impressed.