StillSmart

Re: What do I need to solder copper and SS?

2013-04-08T23:17:23+00:00

Copper to ss is quite easy with soft solder and propane aidanmac, just takes time to get the ss up to temp, slow and steady. We use aqua safe soft slider and bakers fluid flux in aus, don't know what the eqivelant would be over there?.

Statistics: Posted by googe — Mon Apr 08, 2013 11:17 pm

Re: What do I need to solder copper and SS?

2013-04-08T15:17:19+00:00

lol yes but I have only just logged on again after being caught up in bills and work for a long time. Even though he may have finished or abandoned or, like myself, stalled his project; the question and answer still stand for other people reading the thread for information. Also answering helped me get the info back in the front of my mind. I get most of my information from reading the posts of others who have gone before me and like to try and help a little to pass the information on.

So far I have brazed copper to stainless with borax flux and silver solder. I used a brazing hearth which uses propane and forced air. Different silver solders have different melting points. Some will work with propane alone I believe. I plan to try and use soft lead free tin based solder with a soldering gun and zinc chloride flux next. The beer people reckon it works. Time will tell if I can do it. I'll let you know either way.

Having said that i think Chubby was actually wanting to solder stainless to stainless as he mentioned a stainless bowl and a presumably stainless stockpot lid. If the lid was ally then the answer would be no. You would need an ac tig or that technoweld stuff to have any chance at all with that. Still be dubious and would never want ally anywhere in a build myself. Horrible toxic stuff.

Statistics: Posted by ant — Mon Apr 08, 2013 3:17 pm

Re: What do I need to solder copper and SS?

2013-04-08T00:11:38+00:00

I'm assuming, Ant, that you do realise Chubby78 posed the question on Jan 16 last! but I admire your dedication in the face of passed time

That said, it has been my experience that SS to Copper requires Silver Soldering skills and heat above what propane or butane alone can deliver. m

AM

Statistics: Posted by Almanac — Mon Apr 08, 2013 12:11 am

Re: What do I need to solder copper and SS?

2013-04-07T22:38:25+00:00

Depends on your soldering skills but in theory, yes you can. You don't want silver solder for soldering though, it is for higher temp brazing. I know the name seems misleading. Soldering is done with low temp lead free solder.Brazing uses a borax based flux and soldering uses a zinc chloride flux.

Statistics: Posted by ant — Sun Apr 07, 2013 10:38 pm

Re: What do I need to solder copper and SS?

2013-01-16T11:16:11+00:00

hi all

iv got some silver solder rods and flux on the way
i was just wondering if i could sodler a stainless steel bowl to a stockpot lid

or is the only way to do it is weld it ?

Statistics: Posted by chubby_78 — Wed Jan 16, 2013 11:16 am

Re: What do I need to solder copper and SS?

2012-12-18T13:42:53+00:00

Glad to be of service John.

YHB I have been in one of my stops but hope to be in one of my starts again soon. Not so much the flux for the low temp soldering; it was easy enough to do. I filtered it in the end to remove traces of manganese etc I had carelessly allowed to remain on the zinc. Just a coffee filter into an old lime juice bottle. darkish green glass I thought would be good for shelf life.

Just my day job and life taking up time and lack of motivational energy. Want to get hold of an old style Weller soldering gun to do the low temp solder with. The homebrew beer people report good success with this combined with the proprietary american brand of the flux I looked up and copied. Not so much new as new to me and home-made for a reasonable saving.

Statistics: Posted by ant — Tue Dec 18, 2012 1:42 pm

Re: What do I need to solder copper and SS?

2012-12-02T09:19:41+00:00

For the Burco lid I'm going with a 54mm brass tank connector, the 64mm hole saw arrived yesterday so will attempt the cut sometime today.

It's still relevant info for me ant, so thanks for posting as another project I'm thinking of, (a non synthetic amazing still,) involves soldering 2 x 15mm copper pipes into a 1.5mm stainless steel plate.

Statistics: Posted by John51 — Sun Dec 02, 2012 9:19 am

Re: What do I need to solder copper and SS?

2012-12-01T15:02:31+00:00

Ant,

Nice to hear from you again, I missed your posts.

Are you still working on your still or have you been side-tracked developing this new flux?

Statistics: Posted by YHB — Sat Dec 01, 2012 3:02 pm

Re: What do I need to solder copper and SS?

2012-12-01T14:57:35+00:00

Took exactly twice as much zinc as I calculated so some early morning math error in there somewhere. Also the volume did not increase due to the removal of the displaced hydrogen as bubbles of gas. Otherwise I seem to have flux. Need to get an old soldering gun now as easier to use than the flame for this low temp flux.

Statistics: Posted by ant — Sat Dec 01, 2012 2:57 pm

Re: What do I need to solder copper and SS?

2012-10-05T14:29:50+00:00

15.5g of zinc in a six pack of cheap unused aaa batteries. 186mm of HCl should total out at around 200ml of flux. I read some flux is up to 20% HCl as well as zinc chloride. My 4% ish might not cut it. I will try and see. Could always add another 300ml ish of acid to bring the strength up. Give me an even half litre of flux off a six pack of triple A. Not too bad if it works.

Needless to say zinc chloride solution and acid are both nasty stuff so together should be viewed as hazardous to the careless. Watch you don't get a Darwin award.

Statistics: Posted by ant — Fri Oct 05, 2012 2:29 pm

Re: What do I need to solder copper and SS?

2012-10-05T01:11:44+00:00

OK curiosity got the better of me and if I am right it should take 12ml of 33% conc HCl to dissolve 1g of zinc with a slight acid excess; around 4% ish. Gives me a baseline to work with.

Statistics: Posted by ant — Fri Oct 05, 2012 1:11 am

Re: What do I need to solder copper and SS?

2012-10-05T00:35:18+00:00

Well I should research before I post. The powder is a mix of carbon, manganese dioxide and ammonium chloride. Zinc chloride is produced in the reaction when the cell discharges. This eats the zinc away as it is formed from the zinc. It is the white goop that comes out of old leaky cells. So I will probably package the powder and carbon rods up in case I find a use for them and dissolve the zinc metal in hydrochloric which I already have. I will report on the weight of the zinc, the amount of acid I use and the amount of flux I end up with from one six pack of triple A's. I could do the whole atomic weight and molar quantity thing to calculate the result from the weight of the zinc but I am lazy so feel free to do that for me as I will probably just play with it and see.

Discharged cells would give a lower yield as the efficiency of recovering the formed zinc chloride from the other goop and then converting the remaining zinc with hydrochloric will be less than just converting all the zinc directly to begin with. Of course if you have enough free used cells any zinc you recover from them is going to mount up and be better than buying new unused cells in most cases. But you will then be dealing with toxic zinc chloride paste so be careful.

Statistics: Posted by ant — Fri Oct 05, 2012 12:35 am

Re: What do I need to solder copper and SS?

2012-10-04T23:57:11+00:00

Easy mistake to make when the original topic title mentions solder.

I just bought some smartprice zinc chloride batteries from asda. They were in the bargain sale for 10p a pack of six instead of 90p so I got them even though they were only aaa. Because they are the cheapies they don't have the protective steel case over the zinc which makes them easier to take apart than a better brand. I disassembled a pack of six tonight and got a quantity of black powder and zinc metal for my trouble. I will weigh them soon and report the quantities. I would probably use larger batteries if I were collecting used ones for free or if they were on sale too.

I will research to see if the black powder can be used directly to make flux for soft soldering stainless and I know the zinc metal can be dissolved in Hydrochloric acid to make flux.I bought 20 packs as I use that size anyway and for a couple of quid thought it a reasonable punt for some cheap flux.

If it works and you try this yourself be extremely careful about the black powder. Zinc chloride is a very toxic salt. wash your hands and tools when you have finished. Work over a piece of paper. Keep track of the powder. Don't eat drink or smoke whilst working. Wear latex or nitrile gloves while working. The zinc is a soft metal easily cut. A rare situation where the cheapies are actually better for purpose than the better quality examples.

Statistics: Posted by ant — Thu Oct 04, 2012 11:57 pm

Re: What do I need to solder copper and SS?

2012-10-04T11:52:24+00:00

whoops, I thought it was soft solder you were talkng about

Statistics: Posted by stubbydrainer — Thu Oct 04, 2012 11:52 am

Re: What do I need to solder copper and SS?

2012-10-03T11:07:28+00:00

zinc chloride is for low temp soldering with lead free solder 200 something deg C Borax is for high temp brazing/hard solder/silver solder 400-600 something deg C which would burn the zinc flux up.

Statistics: Posted by ant — Wed Oct 03, 2012 11:07 am