allclene, were you using the liquid flux or paste? Some of what you described matched the results BobbyM found when he tried the paste flux. Despite what the label says, the paste flux will not work.
Soldering Stainless steel
- Thread starter BargainFittings
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wyzazz
Well-Known Member
I am getting ready to do this soon and was thinking about MAP vs propane. Just guessing but could it be possible that MAP being hotter could cause the solder to melt too fast on one side of the coupler, while the other side not in contact with the flame does not get to temp fast enough. With propane it takes longer to get to temp and therefore has more time for the heat to even out through the coupler and the kettle wall.
allclene
Beer, What a beautiful thing
I used the liquid flux in the home depot kit mentioned in this thread.
I will drop the dime and buy the other flux and try a test sweating again.
I looked at all the pictures on this thread and I have to tell you, they don't
look like they show any wetting up onto the stainless. One picture looked
good though but most didn't.
If you have a picture of the solder wetted to the stainless, show it for me
please.
I will drop the dime and buy the other flux and try a test sweating again.
I looked at all the pictures on this thread and I have to tell you, they don't
look like they show any wetting up onto the stainless. One picture looked
good though but most didn't.
If you have a picture of the solder wetted to the stainless, show it for me
please.
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don't use map, use the blue bottle.
once that flux etches the stainless you will get a nice flow and wetting of the solder, works great.
good luck.
wyzazz
Well-Known Member
I used Mapp but that was because it's what I had on hand. I kept the heat at the end of the coupler (the end furthest away from the keg) because I figured it would heat the thinner stainless by convection. I had a puddle of flux on the inside of my dimple and a ring of solder inside of that. Once I could see the solder wick through my dimple on the outside I removed the heat and let everything cool for 5 mintues or so.
I also roughed everything up pretty well with emery cloth before pulling the couplers through, I think that is a key part of this process.
wyzazz
Well-Known Member
I'll attempt to get a picture of one of my fittings soldered to the kettle, but I don't know that my camera will give a decent picture up that close. If I can get a decent pic I'll post it up for you.
starman
Well-Known Member
Even if every person in the thread has a terrible cold joint, the result more often than not is a workable non leaking kettle.
I machined my half coupling down on a bench grinder to fit right inside the divot. This gives more surface area for bonding if you're having problems.
I machined my half coupling down on a bench grinder to fit right inside the divot. This gives more surface area for bonding if you're having problems.
Attachments
Starman,
whooo... like it. how long did that take you to grind down?
whooo... like it. how long did that take you to grind down?
Huaco
Well-Known Member
What is wrong with this? SOLID joint and ZERO leaking. I could not be happier with this joint because I could do it myself and didn't need a highly skilled TIG welder do the job for me.
Your image does not show as the link requires us to log into your site to see it.What is wrong with this? SOLID joint and ZERO leaking. I could not be happier with this joint because I could do it myself and didn't need a highly skilled TIG welder do the job for me.
Oh well.
Huaco
Well-Known Member
starman
Well-Known Member
rekoob said:
Once I figured out my psuedo lathe, it wasn't that bad. Maybe 20 - 30 mins of actual grinding/cooling. I put a 1/4" - 1/2" bushing on the spindle of an old grinder and threaded the coupler on that. It was crude but allowed me to spin it down evenly.
It fits pretty flush. Here's a before solder pic dry fit. My previous post the half coupler is on the right.
Awesome job!
allclene said:
You have at least 100 people on HBT with successful and robust solder jobs and everyone is crazy because YOU had trouble doing it? Confused.
allclene
Beer, What a beautiful thing
Bobby_M said:
I didnt have trouble doing it. I just could not get a good mechanical bond. Show me a joint you did that you took apart and proved there was wetting on the stainless and I'll eat my words. I want to see solder adheared to the stainless.
slakwhere
Well-Known Member
nobody is using this method for the mechanical bond. that's why you pull the dimple and then pull the coupler through the dimple. the press fit is the mechanical bond. they're using it for liquid tight seal.
allclene said:
I'm confused also. I have picked up my kegs by the fittings that I soldered in (empty obviously). I had zero fear of the bond that I got from the solder breaking. If you need a picture of that, I'd be happy to take one. I'm not sure what you're doing wrong, but I can assure you that plenty of people are getting great bonds using this method. Unless you're using different flux, solder, not cleaning your surfaces enough, or just flat out overheating it, you should be getting good solder bonding also.
It works, and works well. I have soldered electronics for most of my life and I can tell you for sure you will get wetting through the complete joint if you are using the right flux and cleaning your joint prior to. Many of us have had our couplers in place and being used for a very long time without any issues at all. Like Krazydave I pick my kegs up by the coupler/valve all the time, heck even screwing down my valve when I put it in the coupler, with a lot of force to get it in position I wanted, the joint held without issue. Use the right flux and you will be happy with your results.
Good luck.
Good luck.
I had not really thought about this before but do you guys usually fit your valves to the coupler, "dry-fit" it to mark the top or whatever, so when you solder it in place and eventually attach the valve, the handle is on top? I had not thought that far ahead but Rekoob's quote above made me think of it.
I just stuck all my couplers in and then tweeked on the valve/sight glass/dip tubes/etc... to get it in place. I put in 9 or 10 couplers and didn't worry about it, every item I attached I lined up where I wanted it, inside and out without any leaks or anything breaking loose.
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wilserbrewer
BIAB Expert Tailor
OK...here is what Palmer, an "expert" in the field of metals has to say...
SOLDERING
Stainless steel can also be soldered or brazed to itself or to brass or copper, with good results. taken from the link below...http://morebeer.com/brewingtechniques/library/backissues/issue2.6/palmer.html
from wikipedia...
Palmer is from Midland, Michigan and attended Michigan Technological University. He graduated with a degree in Metallurgical Engineering in 1987.[2] John worked in the space program at a failure analysis lab in Irvine, California, and he has helped design, build, and inspect hardware that is currently flying on the International Space Station.http://en.wikipedia.org/wiki/John_J._Palmer
i'd imagine one common expression he never hears at work, "we're not building rockets here", well, yes in fact they are
SOLDERING
Stainless steel can also be soldered or brazed to itself or to brass or copper, with good results. taken from the link below...http://morebeer.com/brewingtechniques/library/backissues/issue2.6/palmer.html
from wikipedia...
Palmer is from Midland, Michigan and attended Michigan Technological University. He graduated with a degree in Metallurgical Engineering in 1987.[2] John worked in the space program at a failure analysis lab in Irvine, California, and he has helped design, build, and inspect hardware that is currently flying on the International Space Station.http://en.wikipedia.org/wiki/John_J._Palmer
i'd imagine one common expression he never hears at work, "we're not building rockets here", well, yes in fact they are
wilserbrewer
BIAB Expert Tailor
Nice Vid Bobby,
Specifications for the Stay Brite 8 list the tensile strength at 14,000 psi, and the shear strength at 10,600 psi, so with your 1/3 square inch soldered washers, you were good up to about 10,600/3 or 3,600 lbs, or more than a ton and a half. (Toyota Camry w/ 400lbs in the trunk)
http://watchmaking.weebly.com/uploads/1/1/7/9/1179986/staybright_solder_spec_sheet.pdf
Specifications for the Stay Brite 8 list the tensile strength at 14,000 psi, and the shear strength at 10,600 psi, so with your 1/3 square inch soldered washers, you were good up to about 10,600/3 or 3,600 lbs, or more than a ton and a half. (Toyota Camry w/ 400lbs in the trunk)
http://watchmaking.weebly.com/uploads/1/1/7/9/1179986/staybright_solder_spec_sheet.pdf
Surface area is important of course and that's why we go through the trouble of flaring holes, turning down flats on couplings, or whatever. That's why I really like the welding spuds for one-sided ports. Even a face-soldered locknut is better than a edge-fillet joint on a half coupling.
One of the most frustrating parts of doing this is the fine line between getting the materials hot enough but NOT burning the flux off. I start by heating as far from the joint as possible and then when the solder starts flowing, I'll move the heat directly to the joint area. Don't be afraid to squirt some flux on again if you burn the original stuff.
Scuff/sand the surfaces, wipe residue off with solvent, flux if the surface will be hidden, heat, solder.
Scuff/sand the surfaces, wipe residue off with solvent, flux if the surface will be hidden, heat, solder.
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