heat coloring (was Temper colors) on Copper

[Maillemaker]

What is the temperature range for oxide colors on copper?

[Pat Roy]

I don't have a temperature range, but I use a propane torch to reach the colors I like for a given piece. It takes a little experimenting and practice, but it's not hard to do.

[Thomas Dean]

I will use a regular cutting torch or brazing tip, whichever is on the torch at the time. As Pat said it will take a little experimenting/practice but you should get desired result fairly quick. I will have a long blue flame and hold the piece about 10-12" from the flame, too close and it gets too hot too quick and you are past the pretty color stage. Also remember that the colors will deepen (get darker) far a while after you have taken away the flame so you might want to heat and wait, heat and wait until you get what you are looking for. AND remember this, if you spray ANY type of finish or wipe ANY type of wax on the colored copper you WILL loose the pretty red and purple hues, but the resulting color is pretty also, just not like it was before the fininsh was applied. I have a few roses in my gallery, check the colors on them, they do not have any type of finish on the copper just from the torch. http://www.iforgeiron.com/gallery/member/249-thomas-dean/ (Hope the link works!)

[Pat Roy]

I also use a butane micro torch which has a smaller flame for more control. One thing about copper is that it conducts heat much better than steel, so it is difficult to keep the colors where you want. Practice on some scraps before attacking a finished piece. As a last resort you can drop a piece in the pickling solution ( I use vinegar) to clean off the oxides and start over.

As Thomas reports, a coating of clear lacquer or wax will steal some of the color from your piece, but sometimes it is necessary if it will be handled. Oh well, nothing is forever. Have fun with it.

[bigfootnampa]

I like a smaller flame.  I usually use a propane torch adjusted to a low flame and I quench when I get the colors I want.  Sometimes I will do several heats for complex colors.  A direct wash of the flame will usually burn the colors away... but some color usually returns then as it cools.  Practice is needed to gain skill at the process!  I have spent many happy hours practicing this myself!  Have FUN!

[Frosty]

I'm blaming the great white . . . birch for not remembering the thread or subject but this has been ongoing for a bit recently. I got some really cool colors by treating copper like a Raku pottery glaze. Heat it and subject it to various smokey reducing atmospheres. Drop it into coarse saw dust, crumpled paper, straw, lawn clippings, forest litter, etc. then I started playing with different patination chemical dampened smoke generators and got a terrific candy orange color from ammonia dampened sawdust. Unfortunately, before you ask I have NOT been able to reproduce the color with any kind of regularity, at all.

 

I have seen nice oranges in raku glazes and it may be reproducable on copper, I just don't know.

 

Frosty The Lucky.

[BIGGUNDOCTOR]

The oxides are not that permanent, so you definitely need a clearcoat. I pulled some parts out of the inert atmosphere heat treat oven after a batch annealing, and there was a small air leak somewhere since the parts looked like they were from Mardi Gras -purple, green, and gold.  The reds wipe off with a rag.

[Black Frog]

After playing with the steel and copper lampshade, I wanted to get a better handle on how the flamed copper colors develop, and how they control it.

 

I'm still learning lots on each attempt, but getting it more dialed into what I'd like to see.

This copper leaf turned out my best.  Colors were fantastic, hard to capture the iridescent spectrum on a picture.

I'm learning fast that I need smaller torch...

The second pic shows the colors with a flash.

 

 

[Jim Coke]

Greetings Frog,

 

Hot always travels to cold...  Controlling the movement is a challenge..  Try preheating the whole object to say about 200 and try again..  Think hot to cold and resist the temptation that the torch is a color pen..   Oh and keep a good supply of steel wool on hand ...  A clean start is always a factor..

 

Forge on and make beautiful things

Jim

[Black Frog]

 Controlling the movement is a challenge..  Try preheating the whole object to say about 200 and try again..  Think hot to cold and resist the temptation that the torch is a color pen..  

 

I've been looking at a few "copper painter artists" out there doing intricate patterns and color designs by flame, and most everything I've seen is done with copper sheetmetal. 
I have to imagine that is much more consistent and controlable for the heat patterns than is a thicker (and irregular) piece like this leaf.

 

I'm finding the flame type can play into this a lot as well.

Nice thing is that doing this is almost like a chalkboard, you can erase it and try it again.  :)

 

Once I get one I really like, what is the best way to preserve the vibrancy of the colors on the copper?

...I found out these copper colors do NOT like Ren Wax! ;)

[Jim Coke]

Greetings Frog,
 
The trick is WISP ..  A very light spray of clear enamel ..  Walk away and let it set....  Once again  WISP....  Let it set...   Then the wax... It sets up a flexable  surface and last a long time...  If you put too much enamel on at a time the vehicle or material that allows the spray will melt away your color..
 
Good luck
Forge on and make beautiful things
Jim

[Black Frog]

Thanks for the tip! 

[BIGGUNDOCTOR]

Try using the oven to see what colors happen at what temp. I batch anneal parts at work, and if we have a seal going that let's oxygen in we get vivid rainbows of colors. With the oven you can control the temps easier. Start at 300, and bump it up 50 degrees at a time.

[beth]

that leaf is stunning! i love it exactly as it is :) i also love when you CANT control something too much, there is such an added element to that, and once you know the control, you can never recapture the glorious lack of it :) love it  - its Beautiful!

[Black Frog]

Thanks Beth!

I'm finding that if you have a reducing flame (or oxidizing), that throws another factor in the mix... watching the colors dance across the surface of the copper when tinkering with this is so cool to see.

[beth]

i bet it is, and i must try - i love the fact that those colors are on a three dimensional bulk rather than sheet which you do commonly see - it makes it far more appealing - and makes the forge marks look gorgeous. im going to try some :) havnt forged much copper, but ive bits lying about. im not very good at understanding/remembering the oxidising reducing talk, just information i cant seem to retain.. maybe you could tell me again so i can try to remember.. thankyou! that is just so pretty on the hammer marks....

[Black Frog]

Those were fullering marks made with a large radius fullering tool I made.

Copper forges at lower temps than steel, if you're not careful in watching your temps, you'll melt/burn it easily.

.....you learn that mistake fast.  ;)  Dull red is plenty. 

Copper will work harden too after a while. Quench in water to soften it back up.

 

Reducing flame is a fuel-rich flame.  Oxidizing flame is an oxygen-rich flame.

I played with all sorts of torch settings.  I only have a couple of torch tips, I will be getting a few more smaller than what I have, and try that too.

Learning lots as I tinker with this.

 

I also played with, as you noted, angling my torch flame to "skip across" the tops of the fullering marks from a few different side angles.

That is what produced the colors in the leaf pictured.   

The top ridges of the leaf got a bit more heat at just the right time and the other colors crept down into the valleys.

 

....I had about 10 attempts on these copper leaves at getting some idea of what I was doing before this one came out perfect.

Exactly what I was trying for- deepest color low and central with the spectrum of colors creeping out from there.

I probably couldn't do it again if I tried.  :)

[Frosty]

Heat colors can be really stunning and you've gotten some dandies.

 

There are other tricks, one I think I've mentioned here before. Putting heat colors on copper especially is very much the same process as raku pottery glazes. The oxide depth alters the defraction and makes different colors. I had some serious fun and cool colors by heating the copper to fast oxidizing temp and then playing it in and around different smoke makers like saw dust, leaves and sticks or moose poop. The smoke deoxidizes the copper and can make for some vivid colors in interesting combinations.

 

Another technique I toyed with briefly was using a hot iron instead of a torch or fire. The copper will draw heat out of a hot iron surprisingly quickly. I really liked the effects I got fro a piece of 1/2" rd. I put a rounded point on. It retained enough thermal mass to  work for a while but the point allowed some fine marks. Don't get it too hot though or it'll gall or even melt the copper.

 

Keeping the colors intact for any length of time isn't something I've had much luck with so I'm paying attention.

 

Frosty The Lucky.

[Black Frog]

I've switched to a smaller torch, this time using propane/oxy.

Reducing type of flame, and redid a bunch of leaves after wire brushing them.

This time it seemed easier to do, and getting a better handle on how it works.

I read somewhere that some copper artist had good luck using Krylon Workable Fixatif to keep copper colors intact.

I've tried it tonight on these leaves.  This pic is right before I sprayed them lightly. 

I'll take another pic with the same lighting tomorrow.

[seldom (dick renker)]

black frog,

these are awesome

seldom

[bigfootnampa]

IME propane air works pretty well.  A very small flame is helpful on jewelry sized pieces.  I like to have a plain water quench handy to freeze the colors when I get good looking ones... it is frustrating to watch retained heat run them off the surface! Surfaces that are more satin or matte than shiny seem to hold the colors better.  To get more even colored pieces, I would tend to use larger flames washed over the surfaces quickly.  Yours look quite lovely!  Keep going!

[Sasha Crow]

These are stunning!

I know it's been a few years since this thread was moving but I have just begun flame painting copper and am desperate to find a sealant that doesn't mute the colors. Wondering if the Krylon fixative worked for you? Hoping for some good news. 
 

[bigfootnampa]

You will remain desperate.  The colors are delicate oxides and their iridescence is a great feature that makes them so attractive.  IME ANY type of finish detracts from the beauty.  Some finishes more so than others... but EVERY finish degrades the delicate beauty of the oxides!  

[Al Stephens]

Thank You for reviving this post Sasha. I recently obtained a beautiful wall hanging scenery piece done all with flame, by Dan Hedblom in Minnesota. I admire it every time I pass it. This is another thing thing on the "I want to try some day list"  Al

[Sasha Crow]

I just found this - on a page of an artisan who does flame painting on copper for a living  (is it ok to give external links here? The artisan's name is Philip Cook and the article is titled" "Painting Gorgeous Colors onto Copper Using Only An Open Flame" They have a web site and there's a link to it at the bottom of the article)

"Once the background colors, shapes, and details are made to the artist satisfaction, the final piece is dipped into a lacquer bath of acrylic urethane that preserves the one of a kind colorful design." 

Thanks for the response, bigfootnampa! 

Onward........