Solder copper

I have had a lot of trouble is soldering some designs on copper even
though I cleaned it very well and I’m I don’t understand what I’m
doing wrong any suggestions?

Clean extremely well and solder very hot

Many times I have students not able to solder copper. I usually find
they are not using enough heat and the piece oxidizes too much right
away. Not knowing what kind of heat you are using it’s hard for me
to say for sure but I have often seen this problem fixed with hot,
fast, heat of a nice hot torch. Hope this helps :slight_smile: joy kruse

I have had a lot of trouble is soldering some designs on copper
even though I cleaned it very well and I'm I don't understand what
I'm doing wrong any suggestions? 

the easiest and quickest way for you to get the answers you need is
to,

  1. go to a welding supply store,

  2. Taking your work with you,

  3. ask what torch size you need to give the right heat imput ?

  4. what is the right flux you need ?

5.what gas or gases you need. ?

  1. With the solder you plan to use. Is this soft? aka lead based? or
    do you mean hard? aka silver brazing alloy?

  2. Half an hour will give you all the info you need on what your not
    doing right.

  3. Then buy the right tools for the work.

Ted

I have had a lot of trouble is soldering some designs on copper
even though I cleaned it very well and I'm I don't understand what
I'm doing wrong any suggestions? 

Please tell us more.

Two guesses:

  1. Uneven heating and taking too long to solder and then the metal
    becomes oxidized and won’t go are two very common reasons for
    soldering failures.

  2. You say “soldering some designs on” copper, leading me to guess
    that you’re soldering small decorative bits on a larger bit. In this
    case, people often overheat the small bits while underheating the
    larger bit, see #1.

If that’s the issue, put it on a tripod with a screen and heat the
larger piece from below first, before popping up to the top with the
flame.

Elaine
CreativeTextureTools.com

Mary- I’d love to help but…

We need a little more info on what exactly you are trying to solder
in copper. Would you be so kind as to send photos or a more detailed
description of what you are trying to do. What kind of torch fuel,
tips, solder, and flux you are using? -Jo

Hello Mary,

We need more What metal are the designs and how large
is the copper piece? What kind of solder are you using? What is the
torch?

FYI, copper really sucks heat and demands hotter temps than silver
for soldering.

Judy in Kansas who has harvested enough beans to start canning.

Hi Mary,

Since you didn’t mention what metal the designs are in it is a
little hard to offer any advice but here goes. I often make earrings
that are copper discs or squares for a field with a silver or brass
bit of flash that is soldered to the field. Some fluxes will work
well with one metal andnot the other so what I typically do with
silver is to flux the silver with Battern’s and “Tin” the silver
with solder first.

I then clean and polish the copper and then clean it again. I may
wipe it down with alcohol being careful not to touch the field and
get finger oils on the metal. I will then use boric acid and alcohol
flux on the copper and set the flash on the field. Heat it from
below so the copper comes up toheat and draws the solder to the
copper.

I will always tin dissimilar metals when I know that there is an
incompatibility with fluxes. I am sure other folks have different
approaches that are less complicated but this works pretty well for
me.

Good luck.
Don Meixner

Mary, Copper is difficult to solder simply because it oxidizes so
rapidly. Cleaning it is good but oxidation will return immediately as
you apply the torch. And, copper requires excess heat to affect
solder to flow. You must use a high temperature flux such as Stay-
Silv or something similar. Check it out on-line. This stuff looks
ugly…it is black and messy but it keeps copper clean right up to
around 1900 deg or so!

Cheers from Don in South Florida.

Just use Prips flux, get it hot fast, and heat from below if you are
sweat soldering the design on. Use a neutral flame, but on the bushy
side (a little less O2). My high school students do it every day.

Linda
In Beautiful BC