Page 1 of 1

Soldering 2" copper with propane

Posted: Wed Dec 03, 2008 9:34 am
by Kenny8906
Hello, I'am curious if a LP torch is sufficient enough to solder my 2" copper column, or do I need to get a MAPP torch. I've solder 1/2 & 3/4 copper serval times but wasn't sure if the LP would put out enough heat for the 2". BTW I am new to the forum, although been lurking around for a couple months soaking in all the reading. I thank everyone for their input.

Re: Soldering 2" copper with propane

Posted: Wed Dec 03, 2008 9:45 am
by eternalfrost
propne works but is quite slow. you would be better off with mapp

a can of mapp gas is like 5 bucks and will fit onto the same torch as the propane torches. you only need the cheapo bernz-o-matic type

Re: Soldering 2" copper with propane

Posted: Wed Dec 03, 2008 9:55 am
by HookLine
Propane and MAPP use different torch heads. You can get a head that will do both.

Re: Soldering 2" copper with propane

Posted: Wed Dec 03, 2008 12:46 pm
by eternalfrost
HookLine wrote:Propane and MAPP use different torch heads. You can get a head that will do both.
they come with different heads when you buy the package at the store. the mapp ones seem to always come with the self-starting trigger type.
i bought a simple propane blowtorch and when it ran out just got a mapp canister. it works fine with the propane head. it might not be optimal but works just fine.
MH746313.jpg
MH746313.jpg (7.67 KiB) Viewed 17986 times
ul100.jpg
ul100.jpg (17.35 KiB) Viewed 17975 times

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 1:57 am
by CoopsOz
I have the exact same torches as above (although I have the proper MAPP head) and honestly, I have found the MAPP gets to damn hot and it burns my flux, which then requires quenching and cleaning. I prefer to just use the propane for soldering and leave the MAPP torch for when I get around to learning how to braze.

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 2:24 am
by ZAXBYC
I used Propane to do my 2" column, becuase it is copper it conducts heat away very well! :roll:

Took about 5 minutes to get the thing up to a decent temperature that solder would flow easily.

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 4:57 am
by bourbonbob
I have both but I much prefer oxy/acet, handles anthing you throw at it

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 5:14 am
by billy_bob_95
Soldered some 3 inch copper with propane. Does take a while to get it hot enough but it can be done. Just take your time. Once it's hot it's hot and doesn't take a whole lot of heat to mantain a working temp.

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 12:13 pm
by Dutchmancreek
I use a Presto-Lite torch....air/acetylene. Four different sizes of tips for most work. A tank exchange costs about $22US. It's hot enough for silver soldering (hard) and light brazing.

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 5:00 pm
by snuffy
When I'm using propane, I put a couple of bricks up like a corner wall to trap the heat. A small draft can rob a lot of heat when you're doing heavy copper. I also put a dab of flux with a bit of solder on it on top of the joint. That way you can see when it gets to the right temp.

Silver soldering some fittings, I use thin (3/32") acid core silver solder. one turn around the pipe, cut off with wire cutters, flux the joint with water soluble flux. No wasted solder.

Re: Soldering 2" copper with propane

Posted: Fri Dec 05, 2008 10:14 pm
by HookLine
Good tips, Snuffy.

Re: Soldering 2" copper with propane

Posted: Fri Jan 30, 2009 7:52 pm
by farmerdfw
I am a plumber and i think it is worth just getting a map gas torch head the auto start head at the parts house is 50 usd well worth the cost

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 4:13 pm
by RJB510
Yeah, I'm only doing 1/2" copper atm for a mini pot still, and i cant even get that hot enough to make the silver solder flow with LPG/Propane.

What sort of flux are you meant to use? Can you just use ordinary flux? or does silver solder require a special flux for it? Joining Brass to copper.

Cheers

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 4:39 pm
by myles
RJB510 wrote:Yeah, I'm only doing 1/2" copper atm for a mini pot still, and i cant even get that hot enough to make the silver solder flow with LPG/Propane.

What sort of flux are you meant to use? Can you just use ordinary flux? or does silver solder require a special flux for it? Joining Brass to copper.

Cheers
Just to be sure because I made this mistake - what type of silver solder are you using? I started off in this game using 56% HARD silver solder. Damn good stuff and rock solid joints but it melts at 600 odd degrees. I then found out most folk were using 4% ish SOFT silver solder that melts at only 200 or so degrees.

Both work fine but I needed MAP for the hard solder. In fact I built a 3 foot tapered lyne arm from 2" pipe and had to build a small forge to get it pre-heated to the point where the MAP would get it hot enough. Thick copper can soak up a huge amount of heat.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 4:49 pm
by RJB510
I'm only using 2.5% of silver solder, has some other compound in it. I have sticks of 3% and that doesn't work either. If my theory is correct, i should heat the copper so its hot, then touch the solder to it, and it should melt and run around the join. Mine isn't getting hot enough for the solder to melt without direct flame on it from the torch, and then it is beading, not flowing like it should. This points out to me that i'm not getting it hot enough (and i just spent 5mins trying then) and the flux is wrong.

Working casual in hardware, i should know this, but never really done it myself, just sell it to plummers! can you use normal zinc Chloride flux? or should it be proper silver solder flux?

This is becoming more expensive than its worth.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 5:27 pm
by myles
Get proper flux. NEVER heat the solder. Beading is 99% of the time a flux problem. Clean the surfaces properly use the right flux and heat the joint. Get it right and its dead easy. When it starts to flow it is simple. Stainless is a bit more tricky but copper is no problem. Keep at it and soon you will be putting us all to shame. :)

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 6:18 pm
by RJB510
I just called my mate who is a plummer, he told me some basics, when he does it, he uses normal silver solder flux, nothing heaps special unless he's doing something really big. But he said that the metal needs to be cherry red for it to flow properly. So just heat it till its cherry and it will be fine but keep it at that temp. I did that and i managed to tin one end on 1/2" pipe, but it wouldn't get hot enough if i was heating the middle. When i put direct heat on the part, it wont get hot enough, only at the end. He said best gas for home use is the Mapp, so i might have to get that. My joints are just not getting hot enough to make it work.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 6:40 pm
by HookLine
The copper only needs to be cherry red for hard brazes, temp around 700 C.

Soft solder only needs temps around 200-220 C. Much hotter than that and the flux will oxidise and become useless.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:20 pm
by RJB510
Well then something is wrong, because my solder isn't even melting unless the metal is cherry red. Maybe i have brazing rods and they were just labeled wrong and i am trying to braze the metal together?
I'm not using soft solder such as 50/50 like is used on normal plumming connections. This is the actual silver solder rod.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:28 pm
by Ugly
That rod is brazing rod, likely nickel silver and takes big heat to use well. You;d be better off with soft solder i think for most of the copper work.

When you use a pure argentium or sterling wire braze on copper, you don't need flux at all. I know some guys don't use flux for lower ratio silver brazing as well, but I'm not that good, I at least crack out the borax with softer stuff. Flux is required for stainless connections of any kind.

A propane torch on 2" requires a really long heat up time > two inches or so away from the joint to be soldered. Be patient, let the heat move without oxidizing the flux. If you burn the flux, it's useless. Clean it off and start over. A small oxy/mapp gas kit (the little disposable cylinders) can make the job a real dream (super easy). I use oxy/acet or oxy/propane for everything - brazing and soft soldering. I have a mapp torch for 1/2" to 1" plumbing and even then I hate waiting for the inch parts to heat up.

Two torches can help a lot with heavier copper same as dual headed professional torches.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:33 pm
by RJB510
Well that'd explain my frustration, I managed to get it on 1/4" pipe, but nothing bigger because thats all i could get to heat up so it was red hot.

So i got silver solder rods that are brazing rods, because i know every other "silver Solder" as in normal copper connections usually has lead of some sort in it. It didn't look silver when it went on. So now at least i have a handful of brazing rods.

Now i need to find normal Solder with no lead. I have flux for that.

Cheers

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:37 pm
by Ugly
normal solder these days has no lead, it's usually 2 per cent silver, the rest mostly tin and a little copper and sometimes phosphorous, nothing dangerous as long as it's for domestic water systems.... and it melts easy :)

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:43 pm
by eternalfrost
i cant say i know shit bout soldering, but i just use the 'lead free' stuff thats at pretty much any hardware store. practically any solder sold in a plumbing section these days will be lead free and advertise it proudly. I doubt any company would risk putting lead into a 'food' product now-a-days

then just scrub the joints with some steel wool etc. put a touch of flux on them and heat it up. the key for me is to not heat the joint directly, but place the seam itself just out of the reach of the flame. this way the flux dosent burn up, just let the heat transfer through the metal itself rather then directly from the flame.

once its hot enough, just touch the solder to the seam and it will suck up into all the cracks by surface tension. for 2" you kind of have to do 2 or 3 sides separately if you are just using a bernz-o-matic but it still works the same, just takes longer.

if you boil the flux or get weird crud on the seam you just have to start over simple as that.

Re: Soldering 2" copper with propane

Posted: Mon Mar 23, 2009 7:52 pm
by RJB510
Yeah, i find it very ironic that i work in hardware, know how to solder normal copper joints to tell other people what to do. Yet... I find that most of our coils of solder still contain a bit of lead (I think), and I was using brazing rods that were advertised as silver solder to avoid that...

Don't I feel smart now :oops: .
Maybe i should just hook up the gas welding gear and blast it all and braze all joints together in the bastid :twisted: .

Thanks for the help tho fella's!