# Soldering copper pipe problems melting solder



## DJALEXIS (20/6/17)

I have watched countless videos and read a lot on soldering before buying stuff and trying myself.
I got the blue canister blow torch from bunnings, the plumbing flux in the same section as the blow torch and the 2% silver soldering sticks from the plumbing section. 

I do exactly as i'm instructed and no matter what i do the solder WILL NOT MELT at all. 

i have to put the flame right onto the solder stick to get the solder stick to liquify the tiniest bit and the second im not right on with the blue flame -- it hardens. 

so i went to reece plumbing and showed him all my stuff and he said it should work. i tried the 5% silver solder stick from them hoping for more luck. watched more videos and read more blogs. did exactly as told. same result. i'm cooking the hell out of these pipes and the solder just wont melt. sooo...
should i return the blow torch and tell them it doesn't work? the blue can is labeled for soldering and brazing and everything i bought is for soldering copper pipe as far as i know. i clean those pipes so they look like new.... but they are old pipes and quite thick. but that doesnt explain why the blow torch needs to be right on the solder stick to melt it. sounds like the torch isnt producing the temperatures it claims and therefore ... a bad torch? any help, ideas, thoughts on getting the solder to melt?
thank you!


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## Ducatiboy stu (20/6/17)

MAP gas

You need a hot flame for hard solder

If you have over heated the copper its prob no good


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## labels (20/6/17)

Get away from 2% silver solder. You need oxy acetylene for that. At Bunnings you can buy lead free soft soldering sticks in the plumbing section. They are silver colour, about as thick as your little finger and around 300mm long. You then need soldering flux and Bakers soldering fluid is as good as any.
Clean your copper with fine emery, paint the joint with flux before assembling, heat the joint evenly and apply solder, It should instantly flow around and into the join. Easy peasy.


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## MHB (20/6/17)

There are lots of possible answers, to some extent its going to depend on a few factors like the size of the torch and the pipe.
Just an ordinary propane flame will struggle on anything other than small pipe, Turbo torches are the best bet.
Can you post some pictures of the torch, flame, flux and pipe, with some clues as to scale.
Mark


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## AJS2154 (20/6/17)

Yep, what labels said.


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## Lionman (20/6/17)

You have propane, you want this bottle

https://www.bunnings.com.au/tradeflame-tf-ultra-gas-performance-gas-mapp-replacement_p5910238

The straight propane should work but it will take longer and you will have to be more precise. With the MAPP equivalent you will get more heat so its quicker and easier. 

Get the copper really hot and the apply the solder while continuing to heat the copper (ie right in the hot spot of the flame).


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## Hermies (20/6/17)

I use MAP gas from Bunnings and lead free solder and have no problems soldering the copper pipe . My routine is clean all the pieces I am going to solder with sandpaper so that everything is clean, dip the pieces I am going to solder in flux or if using paste brush it on . Using the gas canister I evenly heat up the copper focusing in on the tip of the blue flame, this is the hottest part, this takes only maybe 20 seconds or so, touch the solder onto the pipe to see if it is hot enough , if it is the solder will run around the join and then let it cool down by itself . Using a flux paste or liquid flux is important to get a good join . I use the plumbing Bernzomatic solid wire solder which comes in a reel like PTFE tape . This solder is lead free .


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## Ducatiboy stu (20/6/17)

^^^^
Clean everything, have the right flux, right torch, heat the work NOT the solder. 

Solder should run easly and sweat in to the joint. Dont use heaps of solder. Less is sometimes best


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## MHB (20/6/17)

Be a really good idea to learn the difference between hard and soft solder.


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## Stouter (20/6/17)

At a guess from your description, there's not enough heat from your torch, especially if you're using one of the little blue ones, or you're trying to weld anything over 1/2", or if you've got any water in the line. The 5% will flow easier with the right torch. While it might look like you're cooking the hell out of it you should be ok.
If you're welding copper to copper you shouldn't need flux paste, only if you're going copper to brass.


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## Stouter (20/6/17)

MHB said:


> Be a really good idea to learn the difference between hard and soft solder.


Soft solder has lead content, hard/silver solder has silver content. Those big thick sticks are used for welding gutters, sheet metal, etc, and are used along with acid flux as a surface prep.


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## Maheel (20/6/17)

go the soft lead free "aquasafe" or go a hotter gas.

If you joins are not structural go the soft solder.

If your trying to solder copper to SS it can be tricky with soft solder but doable.
Heat differences in the metal cause problems, the flux etc and how big an area you need to heat etc.


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## Maheel (20/6/17)

https://www.bunnings.com.au/consolidated-alloys-500g-aquasafe-solder_p5060362

this is easy to use, LPG will melt it with a torch 

if you only need a small amount let me know and i will mail you some.

i think they do a 50 / 100 gram stick of the aquasafe in some stores 
make sure it is the right stick in the right box at bunnings......


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## MHB (20/6/17)

You can get Silver Solder in both hard and soft, the soft version is usually 2-3% silver and 97-8% Tin, still lead free and makes a lead free replacement for the old 50/50, 60/40 Lead/Tin that been around for about 1000 years.

Hard solder is much better for dissimilar metals and Stainless Steel but requires a lot hotter flame, or best of all a fuel/oxy flame, its a lot stronger and way better for some jobs.

If you are doing Copper to Copper or Copper to a brass fitting, the soft solder will work.
Mark


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## Ducatiboy stu (20/6/17)

Stainless to brass...now thats fun


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## Maheel (20/6/17)

Ducatiboy stu said:


> Stainless to brass...now thats fun



TIG it if you can.... looks the shiz when done right 

if you want to get very tricky you can plate the SS with copper and then it solders like brass to brass. Electrodes / anodes and copper in solution to plate the SS = fun chemistry at home


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## Ducatiboy stu (20/6/17)

I soldered a brass nipple into a 20l Big W pot....

Had to use a particular cigweld flux.

Was a right bitch, but it never moved or leaked


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## Lyrebird_Cycles (20/6/17)

Stainless to brass is actually fairly easy with the right material: I use Harris 56% silver or Cycle Designs System 45, both work well but are sold by the troy ounce due to the cost.


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