soldering with propane?

[Cosmic Muffin]

gday blokes
i was just wondering if you can solder copper with a bernzomatic propane torch, because im sure you can but when i tried it i cant get it to work. could i be doing it wrong? or am i wasting propane?
and also does MAPP work for soldering copper?

cheers guys

[Lentamentalisk]

OK, well you can't solder it, because that is what you do for circuits. When joining pipe with "solder", it is called sweating. You need to have the flux paste, to help the solder flow into the connection. Propane will be more than enough. Just make sure you heat up the fitting a fair amount before applying the solder.

[Cosmic Muffin]

oh ok well soldering, sweating you get what i mean
cos when i do it all i get is the copper turning red then black, and the solder wont melt on contact (which is apparently what it is meant to do).


http://www.hardwarestore.com/media/prod ... ont200.jpg

thats what i have

and also im using 2% silver solder for type L copper is that the right sort?
i looked at a how to on the net net and the guy rekons thats the right stuff, just want to check though.

[Lentamentalisk]

Are you using flux? With out flux, you will have a very hard time getting it to work.
The only other thing I can think about is that you may not be holding the pipe in the right part of the flame. When you look at the flame, there are two different shades of blue, one that ends pretty close to the head of the torch, and the other that continues on from there. Right at the intersection is the hottest point, so you want the pipe right there.
It may take a long time for the pipe to be hot enough. If I remember correctly, the flux started to smoke a little when it got hot enough.

[Cosmic Muffin]

yer i thort you only had to use flux when sweating copper to brass
so i havent been using flux.
but i have been using the feather flame (chemistry lessons finally pay off)
ill give it a go and report back. cheers for all your help mate.

[Cosmic Muffin]

this is what it turns out like.
i got it melted at least. the flux sure did help.

<a href="http://tinypic.com" target="_blank"><img src="http://i39.tinypic.com/eddeb.jpg" border="0" alt="Image and video hosting by TinyPic"></a>



<a href="http://tinypic.com" target="_blank"><img src="http://i44.tinypic.com/34hcke9.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

the solder is just forming around the edge, its not going into the gap man its so frustrating

EDIT: sorry for the double post

[microman171]

Oh dear... IIRC, You need to apply flux, then heat until the copper changes to a deep copper colour. Then you apply the solder slowly to the fitting. It should wick its way around as you move the solder around the joint.

Looks to me like you used too much...

Also, make sure you have CLEAN fittings, you need nice shiny copper .

The feather flame is the outer one right? I never learnt that one


Let us know how you get on...

[VH_man]

I had this problem as well.

Make sure you have the correct solder. There is High-temp solder used for attaching those huge cast-iron drainage pipes that melts at a far higher temperature than the normal stuff.

go into the hardware store and ask them. I garuntee you they will say something like "shit dude! you actually even got that to melt!"

And for gods sake, Get new fittings..........

[FishBoy]

I've done it before. It worked fine, I didn't have any of the above problems. I just got one of the small solder kits from home depot with a roll of solder and some flux.

[JDP12]

wow... I am going to agree with VH here that you have some heavier duty solder, and also, your fittings are filthy it looks like. That isn't going to help solder bond either

[pizlo]

Yes it is completely necessary to sand both parts until they are a very shiny copper color, and apply a lot of flux paste to both parts. Also make sure your pipes are dry on the inside and that you use the right solder.

[psycix]

There are a few good instructional videos on youtube.
Example:
http://www.youtube.com/watch?v=CH5Uy8Uf1xs


It looks like you are melting the solder with your torch and are just blobbing it on. That is not the way to do it.
You heat up the pipe, and the hot pipes will just melt and suck the solder in there. (capillary effect) Dont blob!

[john bunsenburner]

Arg those solders are scary...What is the melting temp of our solder? I got some 750°C and it still works for Cu...But the oters are wright about all they said.

[psycix]

750?!
That is HIGH.
Somewhere between 2 and 3 hundred °C is normal I believe.

[john bunsenburner]

Well soldering is up to 300 while brazing is everything above that, in german it is called soft soldering(weich löten) and hard soldering(hart löten) and what i am using is silver and a heep of other exotic metals in a little reallyexpensive rod...but hey it works, the pipe has to be fairly thick thogh or it will oxidise and fall apart.

p.s. brazing ussually uses silver filler metal while soldering uses lead or tin as main fillers, everything contains wierd extic metals too which make the price increse, i like using fishing weights to solder when i dont feel like spending lots or when something doesnt have to look clean or be strong.