HELP NEEDED SS ferrule to copper pipe

[StillerBoy]

Most of the time you try to connect copper to stainless with regular plumbing solder and it will flow onto the copper and just sit on the stainless or ball up on the surface and fall off, a bit like playing with mercury. At least that's my experience with it, having the right flux makes a massive difference but usually the more aggressive acid fluxes that really bite into stainless are reserved for brazing processes or if you use regular rosin-type fluxes you don't stand a chance.

Next time try Superior 71 paste which can be used on both ss and copper.. in my book it's the best, easy to use, and cleans up with just some hand soap.. it solder's ss to copper very easy.. the major problem with most people trying to solder using way to much heat, and they don't clean the surfaces properly.. using acetone and a propane low pencil flame with do the trick every time..

You have done a nice job on brazing you setup, I rely like you having taken the time to clean it up.. but brazing is a total different process than solder..

Mars

[acfixer69]

It's just easier when trying to connect stainless to copper or making parts from stainless. If it's copper to copper then it is defiantly worth just using regular soft solder. Most of the time you try to connect copper to stainless with regular plumbing solder and it will flow onto the copper and just sit on the stainless or ball up on the surface and fall off, a bit like playing with mercury. At least that's my experience with it, having the right flux makes a massive difference but usually the more aggressive acid fluxes that really bite into stainless are reserved for brazing processes or if you use regular rosin-type fluxes you don't stand a chance.
My Boka has a load of 3/8 BSP fittings on which I silver brazed, every joint is either tig welded or brazed as I fancied doing an "over built" still. I have one of the large Irwin 12" vice-grip adjustable and I can really swing on the brazed unions to get things to the right angle so they look right without fear of them snapping off, the brazed joints also stay shiny silver and don't turn that murky gray and get a dirty coating on them when used.

This is what the Silver Flo 55 looks like. All the material is 2mm stainless which is brazed, ground to shape and then polished. The joints are barely visible, strong enough to swing on with a large wrench and polish up nicely too thanks to the silver content.

You are over simplifying this. As Otis said braising is very different then soldering. If not needed and not in the OPs wheel house why throw it in. If OP was in a builders world he wouldn't have started this thread. Most HD guy's don't have the equipment to back purge with inert gas to prevent oxidation on the inside of the tube.
If you want to give us brazing lesson post a thread. I retired from doing this shit every day 6 yrs ago. I haven't heard of new techniques.

[paddy1000111]

I only added it because judging by the thread the OP has been trying and trying to solder it together with little success. I only suggested silver brazing with JM55 because they do small amounts of the stuff on ebay for cheap and it can be easier because there isn't as much of a "golden zone" between the melting point of the solder and the burning temp of the flux. I would say silver brazing with a low temp alloy is in the wheelhouse of the OP. I am not talking about Silicon Bronze, I am talking about something that can be used with a blow torch.

The UK doesn't have easy access to the heavy duty acid fluxes required, I have tried to buy it before and ended up down the silver braze road. I have just looked for Superior 71 paste and unless I want to import it from the US at 3 times the cost of the product it's a no go. I am sure there is a heavy duty acid flux in the UK somewhere but between people marketing regular plumbing flux as silver solder flux and Health and Safety issues with selling acid to the public (I assume) buying the correct flux in the UK is tough and if you do find something it's hard to use as the OP found out. He also wouldn't need to back purge because its an open tube.

So far the OP has been suggested different types of solder, different fluxes and probably spent about 4 times more than he would have done by just buying a small pack for about £5 and silver brazing the whole thing. He also wouldn't need to back purge because its an open tube. I was only suggesting something that I know will work and something I found easier. Minimal allowance is given in this forum for the difficulty of sourcing the correct product in the UK. Acid is a bit of a sore topic at the moment.

If anyone can recommend a soldering paste flux that is heavy duty enough to cut properly into stainless and is readily available in the UK and reasonably priced (Some in the UK are £55 for a 500g tub) then I am all ears

[Swedish Pride]

https://www.ebay.ie/itm/142916217124" onclick="window.open(this.href);return false;" rel="nofollow

not UK, but ships from the states.
Works a treat. I know there is one in UK too I just forget the name of it as I don't live in UK and bought this one and didn't have to look further.
Plain old Lead free solder is all you need.

This is not paste, is liquid, works great

[bronctoad]

+1 SP that's the stuff
not a huge amount of heat, put the flux on twice (more after it sizzles)
a little more heat and the solder flows and wetts both metals beautifully feed until the joint
is just full, then don't touch it till its cooled wha-lla or how ever its spelt

bronctoad

[paddy1000111]

Maybe I will give it a go. I do wonder if the solder I tried before was wrong though. It was Fry Powerflo lead free 99c grade. Sadly the data sheet doesn't say what's in it!

*Edit* Scratch that, it's around 95% tin, 5% copper so not having any silver is probably part of the issue. I guess not all plumbing solders are created equal.

[Swedish Pride]

https://www.ie.screwfix.com/fernox-sold ... -free.html" onclick="window.open(this.href);return false;" rel="nofollow this is what i got.
https://www.amazon.co.uk/Frys-Metals-Le ... B0001P07KW" onclick="window.open(this.href);return false;" rel="nofollow < if thats the one you got it should be fine.

rough up the SS and copper good with sandpaper/ file or what ever floats your boat, clean the dirt off it, add flux, mate the ss and copper, heat the copper only, when the flux is sizzling you're almost good to go, feed some solder in there and flame off.

[paddy1000111]

Well I thought I would give an update for the OP. I bought some Topnik TS-80 flux as it says on the datasheet it is for soldering Stainless steel including acidproof and I think that is your sticking point. I had the same results as the OP. I make a living from soldering copper pipe in peoples houses so to say the least, I know how to solder. I also have small electrical workshop where I do PCB repairs and SMD rework so I am pretty used to soldering various grades of components and cleaning and repairing corroded and damaged parts.

I started off using my rework station using the hot air gun set to 280'c as the solder that I got (silver bearing solder, 96s type designed for stainless steel) has a melting point of 225'c. I sanded the part with 240 grit paper then cleaned it with tissue and IPA until the wipe came off clean. I applied the flux and started heating the test pipe, as I was going I was applying more and more flux until it was practically dripping off the bottom. As it got hot it bubbled and smoked like hell. As I was going I was constantly removing the heat and wiping the solder across the surface to find the melting point but the flux slowly turned brown/caramel and then a little more heat and the solder was melting, it balled up and fell off so I applied even more flux and again, balled up and just rolled off. The closest I got was the solder melting and "sticking" to the surface but it didn't flow and didn't wet correctly so I upped it to the Mapp torch thinking I was taking too long to get to the temp.

I got out the mapp torch and set it to a super low flame, the same flame I use for soldering copper and have NEVER had an issue with soldering. I slowly warmed the pipe so it was warm and applied some flux then continued heating with a soft flame. As I was slowly heating the pipe I was adding more and more flux which was dripping off the pipe. I then continuously wiped the surface with the solder waiting for it to wet. Again it never did. The flux turned to an amber colour again and slowly turned black, this whole time I was removing the flame and touching the solder to the surface waiting for it to wet. It just got to the point where it would ball up on the surface and drip off. Again I could get it to stick to the surface and look like it was wetting but I tried it and it broke strait off with a screwdriver when it cooled so obviously didn't bond.

I tried it with copper, the same flux with the same solder and although it wasn't nice to use it wetted fine and didn't turn black so it's defiantly an issue with stainless.

Here's some pics just to give you an idea of what I am working with. The pipe looks like it has just been overheated and the flux burnt but I was trying the solder on the surface all the way from cold-hot so if I got it to the right temp then I would have found that before it turned black.

He's the flame setting on the torch-



The pipe after sanding and IPA cleaning-



The pipe after soldering, all ready for the trash-

[Expat]

In my experience there are two different types of black in soldering stainless. If the black is within liquid solder then it's normal and it means that the flux has etched the surface. If the black is on the stainless surface and won't wipe off, it's burnt and sanding is required.

For interest I did three 3" stainless ferrules this past weekend. Total time was around and 45 minutes including clean up.

Edit: Rough finished joint picture

[paddy1000111]

See, that is a properly wetted and soldered joint! Is that with the Harris stay clean flux?

[Expat]

Yes, Harry Stay-Clean liquid flux and off the shelf Oatey Safe Flo #29023 solder (the red label).

I enjoy working with the liquid flux, on copper you don't even have to heat it before you can see the surface change; it's quite agresive and easy to clean.

Also for reference, stainless to stainless for 2" to 3" cap reducer.

[BigYin]

Any UK based members able to recommend suitable flux and solder that are readily available here please?

[Swedish Pride]

I believe bakers liquid flux is what you are after.

But you have a tig, play with that?

[BigYin]

I'm more comfortable with soldering than the TIG at the moment!

[Manc]

https://www.cupalloys.co.uk/soft-solder ... /index.asp

I've recently bought this on a recommendation I've not used yet hopefully soon it's not cheap but comes from a trusted source.

Lee

[Swedish Pride]

well there you are, you do have stay clean in UK, I'd go for that if I were you Yin.

[BigYin]

So, I've ordered the flux - https://www.cromwell.co.uk/shop/welding ... RY8756014E

and some brazing rods (that also come with a little flux) - https://hvacstore.co.uk/johnson-matthey ... d-5g-flux/

I'll let you know how I get on with them!

[Expat]

So, I've ordered the flux - https://www.cromwell.co.uk/shop/welding ... RY8756014E

and some brazing rods (that also come with a little flux) - https://hvacstore.co.uk/johnson-matthey ... d-5g-flux/

I'll let you know how I get on with them!

A couple of items.

First. Not sure if you're considering two different techniques, but Brazing is different than soldering; the two processes don't use the same materials. You will need silver soft solder, melts at a MUCH lower temperature, brazing rods wont work in a soft solder process.

Second. Just as a word of caution; liquid fluxes are very strong acid, so make sure you are taking all appropriate precautions. e.g. eye protection, cover skin and anything else you'd prefer not to have a chemical burn on. Also, ensure you're working in a very well ventilated location (read: Outside) as the fumes from the process are bad news for your lungs.

[Yummyrum]

So you realise that when you are brazing you need to have the metal glowing red hot ( around 650°C ) as apposed to soft soldering ( around 300°C )
You will need an oxy torch or at minimum a Mapp gas torch . I tried brazing a ferrule onto a 1m length of 2” and it took nearly a bottle of gas to get it hot enough . The copper pipe just kept pulling the heat out of the area .... it was a pain in the arse . I now soft solder to large items like that .

The only times I braze bigger items with a Mapp torch I use a propane gas burner under it to pre-heat and then use the Mapp to bring the brazing area up to red hot .

If you only have a Butane torch forget brazing . It wont even have enough heat to braze a penny .

[hypnopooper]

I use Muggy Weld SSF-6 56% solder to braze stainless ferrules to copper sleeves. It's a bit expensive, but, works nicely. For Copper to copper, I use Harris SB831 & SCFPF4 Stay-Brite #8 Silver Bearing Solder with Flux. My torch, is the Bernzomatic TS800 High intensity trigger torch. I can do everything I need to do with only propane. Her's a couple pics of a 4" SS sight glass to 4" Cu coupler I brazed with the Muggy Weld SSF-6 Solder.

[BigYin]

thanks folks I plan to use a MAPP torch, which ought to do the job - and I'm patient enough with it

[jef]

reviving an old thread, but this is the discussion that kept coming up when I was looking for info. Like the OP, I am UK based, the oft recommended Harris products are available, but at silly prices.

Happy to report that I've just used A8 flux from soldersandfluxes.co.uk, currently about £18/20 for 125/250ml delivered, you could save upon postage and halve the cost if you can collect from Monmouthshire, just over the Severn bridge.

It is a Zinc Chloride & Hydrochloric acid flux, which seems to be very similar to the description of Harris.
I have used this with standard plumbing solder & 4% silver to tin 2" ferrules. Neither solder was fluxed.

This was after a good number of unsuccessful attempts using a variety of other flux alternatives.
I had no joy with;

• Phosphoric acid - tried at 85%, 12, 20, 40-ish%
• Making Zinc Chloride with 10% HCl & cap zinc (zinc carbon batteries), at time of writing in the UK you now need a home office license to purchase HCL >10% and Phosphoric >30%
• Easyflo flux powder (for brazing)
• variations of the above with standard plumbing solder flux, or with a wetting agent

both the acids just dried up and left a residue before the solder would melt. The flux powder was lying around so with a go, but 250ºC is I assume too cold for it to be active, the working range is something like 550-700ºC, in any case it didn't help.

I lightly sanded the ferrules with 320 grit, wiped with a rag. With a MAPP torch on a very gentle setting and a couple of applications of the A8 flux it tinned a treat, brushed around with wire wool. Hope this info is useful to someone else

[Reefer1]

I built my own column, i tried several attempts at soldering ss 2" furrules to copper, gave up in the end and sucked up the cost of getting copper ones.
I tried several different acid fluxes, solders.
+1 jason, regarding getting the harris flux etc here in uk.
I am pretty competant at soldering copper.
Jason, do's the screwfix Bernzomatic flux+paste work ok,
Iv'e been looking for a solution for a while to join Ss to copper.
I couldn't get anything to stick to SS at all and agreed tinning is the way to go.

[Swedish Pride]

Nice one, I'm down to ¼ bottle, this will be handy whyi run out

[NormandieStill]

I built my own column, i tried several attempts at soldering ss 2" furrules to copper, gave up in the end and sucked up the cost of getting copper ones.
I tried several different acid fluxes, solders.
+1 jason, regarding getting the harris flux etc here in uk.
I am pretty competant at soldering copper.
Jason, do's the screwfix Bernzomatic flux+paste work ok,
Iv'e been looking for a solution for a while to join Ss to copper.
I couldn't get anything to stick to SS at all and agreed tinning is the way to go.

I use Griffin S-39 which is made in Belgium and commonly available in France. I'm sure you can get it in the UK. I have no affordable way of doing TIG so my ferrules are silver soldered (3% Ag) to my 30l keg using this stuff.

If you don't want it to go everywhere, lightly heating the surface first and painting it on with a heat resistant brush works well. Using this I've done multiple stainless-to-stainless joints with a standard propane plumbers torch.

[Yummyrum]

Bernzomatic flux paste is best applied to the rubbish bin .
Zinc chloride HCl flux is the go.

+1 on using a heat resistant brush to apply . Genuine Hog bristle are the best . Beware the plastic look-a-likes

[Reefer1]

Righto guys comments duly noted,
Muchas grasiarse.