Solder? Silver Solder? Soft Solder?

Shaun · Post by **Shaun** » Mon Jul 03, 2006 3:32 pm

Hi,

Yes I am a newbie, I have almost completed the valved reflux still and I have a question? I have read the details on solder / soldering in your manual but I am still unclear on parts of it.

1) In Australia all plumbers braise copper pipe with what we know as "silver solder", the only percentage avalible is 2% 5% 7%. Is this suitable for the jointing of copper in the still?

2) The soft solder you talk about is harder to use and often does not take properly and seems to contain alot of other metals, and I am not sure about using it.

3) I am a plumber and maybe should know the answer but I am sure that it does not contain cadinum (read packet) and it is suitable for hot and cold water, gas pipes etc.

I would love some feed back as I have almost finished my still and want to know if I have to start again!!

Arnie_sla · Post by **Arnie_sla** » Mon Jul 03, 2006 10:21 pm

Hi Shaun, The Plumbers Solder is not "Silver Solder " at all. Real Silver Solder comes in very thin lengths of about a foot long and is used for soldering jewellery, rings etc. It is hard, not soft and takes much more heat to melt. It's not even silver in colour, its more of a dirty tan colour. Plumbers solder is just a form of soft solder. It is soft and easy to bend and melts at a fairly low temp. The next bit says basically the same but is an extract from the web site shown below text.

“If silver alloy is used, brazing can be referred to as 'silver brazing'. Colloquially, the inaccurate terms "silver soldering" or "hard soldering" are used, to distinguish from the process of low temperature soldering that is done with solder having a melting point below 450 °C (800 °F). Silver brazing is similar to soldering but higher temperatures are used and the filler metal has a significantly different composition and higher melting point than solder. Likewise, silver brazing often requires the prior machining of parts to be joined to very close tolerances prior to joining them, to establish a joint gap distance of a few mils (thousandths of an inch) for proper capillary action during joining of parts, whereas soldering does not require gap distances that are anywhere near this small for successful joining of parts. Silver brazing works especially well for joining tubular thick-walled steel pipes, provided the proper machining is done prior to joining the steel parts.”

http://en.wikipedia.org/wiki/Brazing" onclick="window.open(this.href);return false;" rel="nofollow

Shaun · Post by **Shaun** » Mon Jul 03, 2006 10:47 pm

So basiclly does this mean the "plumbers solder" in a thin (3mm) stick that I have used is ok?

I have no idea what base metals etc are in it, they just told me it is 5% silver solder.

The stick does look brown and the exterior of the weld is quite visiable.

Kiint · Post by **Kiint** » Mon Jul 03, 2006 10:52 pm

I dont have the brand/model of the solder to use, but if you ask your local gas welding supplier (BOC, CIG, etc) then ask for 45% Food Grade Silver Solder and they shouldnt look at you stupid. I think its 245 Silver Brazing Alloy. Make sure it doesnt have Lead, Antimony or Cadmium etc. It should be just 45% Silver and 55% Tin.

Make sure you get the right flux as well, and if you dont have an Oxy kit, a MAPP burner is ideal.

*edit*

http://www.matthey.com.au/JMA_eService/ ... lloys.html" onclick="window.open(this.href);return false;" rel="nofollow has a few details.

hornedrhodent · Post by **hornedrhodent** » Tue Jul 04, 2006 4:44 am

I use 2% silver 98%copper and oxy acetylene flame - no flux required for copper.

The only reason to use soft solder I can see is that you dont have oxy acetylene or MAPP to melt hard solder.

Shaun · Post by **Shaun** » Tue Jul 04, 2006 3:07 pm

Thanks......

Does everyone agree 2% solder is ok.....You just need a oxy torch to weld it, no flux too.

Great .....I don't need to start again!!

Shaun · Post by **Shaun** » Tue Jul 04, 2006 4:33 pm

Sorry to be so repedetive but I have go the make up of the 5% solder I have used can anyone determine exactly if the ingredients are safe?

Ingredients

Silver - 7440-22-4 < 15%

Tin - 7440-31-5 < 10%

Antimony - 7440-36-0 <10> 60%

Phosphorous - 7440-14-0 < 10%

Kiint · Post by **Kiint** » Tue Jul 04, 2006 9:37 pm

This is the stuff I will be using to assemble my still.

BOC ProSilver 56t

MSDS (Materials Safety Data Sheet)
https://pgw100.portal.gases.boc.com/boc ... /GB003.pdf" onclick="window.open(this.href);return false;" rel="nofollow

Part Numbers
https://pgw100.portal.gases.boc.com/boc ... er_56t.asp" onclick="window.open(this.href);return false;" rel="nofollow

The only downside according to the MSDS is that some rods (56t doesnt) may contain lithium in small amounts, but then again Lithium is also used in pshycotic medications so I doubt its too harmful in the amounts in the MSDS if leeched by alcohol vapours.

Kiint · Post by **Kiint** » Sat Jul 08, 2006 10:37 pm

Actually, a little more research shows the Comweld 965 silver solder is suitable for making stills.

96.5% Tin
3.5% Silver

Lead, cadmium, and zinc free.

Could be alot cheaper than higher percentage silver solders brazing alloys.

stoker · Post by **stoker** » Sun Jul 09, 2006 1:23 am

I use a simular one

see also http://homedistiller.org/forum/viewtopi ... highlight=

Kiint · Post by **Kiint** » Wed Jul 12, 2006 9:28 pm

(repost from a different thread mistakenly posted there from a search)

Damn I hate this ...

All the stuff I want to use is too damn expensive. They will only sell me 250g or 500g packs which start going into the $100 - $200 range of prices, I only need 2 damn sticks not a whole pack.

Stuff it.

I have settled on some Phos-Copper silver brazing alloy.

It contains
Silver - 15%
Phosphor - 6%
Copper - Balance

From what I can determine, the phosphor itself isnt poisonous, its supposedly used as a flux for the copper and is removed when the final product is washed. It melts at 700degC and is meant to be mechanically stronger than the softer solders. The phosphor only becomes poisonous when it reacts with additives in the chemical industries forming highly poisonous compounds ... supposedly (from the manufacturer) the phosphor doesnt react to form these compounds when used in a silver brazing alloy and is therefore safe. I just dont know.

All I know is that there is no lead or cadmium, phosphor in its natural forms (well, not pure, thats white phosphorous which is lethal) isnt poisonous or anything, its only when combined with other more poisonous elements etc it becomes dangerous (organo phosphates etc).

At $4 per stick (the only stuff that is cadmium/lead free) it is cheap enough and available enough to use. Otherwise I have to buy a 250g bag of the Comweld 965 which is dangerously soft for my tastes and at $120au I will only use one or two sticks and its wasted.

hornedrhodent · Post by **hornedrhodent** » Sat Jul 15, 2006 4:52 am

If you're going ' silver brazing' - oxy-acet or mapp gas - why go past 2% silver - no flux - $1.50 Au a stick - no worries mate.

rkidtech · Post by **rkidtech** » Mon Aug 14, 2006 6:02 am

Try this link Shaun,
I wrote it a while back
http://homedistiller.org/forum/viewtopi ... highlight=
hope it helps
Geoff
(A one handed ex-plumber)