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View Full Version : Need help !! about polishing soldered brass/copper jewelry.



jmorbid
4th Oct 2016, 11:38 PM
I am currently working on a small piece of brooch (brass/copper), I have spent quite a long time soldering the pieces together and it has a lot of colorful "burnt" marks... I am not sure what I can do to remove the "burnt" marks and what should I use to polish it.


Thank you! :B

12bolts
4th Oct 2016, 11:55 PM
Some pics would be good.
But brass and copper polish up very easily. Citric/acetic acid will remove most oxidation and some flux from the surface. Heating the acid to 80-100 C will improve the effect considerably. Fine steel wool and scotch brite pads do a good job to polish. You cant beat buffing with rag wheels and compound for the final lustre

Cheers Phil

jmorbid
5th Oct 2016, 12:24 AM
Thanks for the reply ! ( http://i.imgur.com/aYMaIjI.jpg )
this link is a picture of the jewellery (a brooch) that I've made, I have soldered both copper and brass together to create this funny looking beetle.
I have all kinds of sanding papers for jewellery making but I have no access to acid.. can soaking the jewellery in vinegar remove the "burnt" mark?

Thanks again!!

sacc51
5th Oct 2016, 11:33 AM
Being a small item, I wouldn't be using a bench grinder for that job, lots of bits sticking out a wheel can grab and either bend or fling the brooch against the wall/floor/ceiling/your head. A dremel type tool with buffing wheels and rouge is the way to go and should polish that up nicely. If you like you can make your own buffing wheels using a hole punch and some cotton cloth, you will go through a few. Any of the rouges will do the job; although, I'd stay away from green until the final buff, Bunnings stock jewelers rouge. Neither brass nor copper will hold their polished appearance for long so after polishing you'll need to coat the brooch with something. Removing the scale can be done a number of ways, just be careful if using abrasives to be gentle and not score the brooch's surface, very difficult to polish out score marks on such a small item. No idea which acids to use, never use them.

Oldneweng
5th Oct 2016, 12:50 PM
Thanks for the reply ! ( http://i.imgur.com/aYMaIjI.jpg )
this link is a picture of the jewellery (a brooch) that I've made, I have soldered both copper and brass together to create this funny looking beetle.
I have all kinds of sanding papers for jewellery making but I have no access to acid.. can soaking the jewellery in vinegar remove the "burnt" mark?

Thanks again!!

Vinegar contains about 4% acetic acid. Coke probably has a higher percentage of citric (?) acid, but I am only guessing here. It is used to clean coins much to the disgust of real coin collectors.

Dean

Ropetangler
6th Oct 2016, 09:03 PM
Citric acid is available from your supermarket from the spice and baking powder section. It may also be labeled as food acid. Tartaric acid from the same section of the supermarket may also work, and both citric and tartaric acids are good for cleaning the calcium carbonate deposits from kettles as well, just add a couple of table spoons of acid powder to a full kettle of water, bring to the boil, and leave for 1/2 hour or so and the job will normally be done. Just rinse well before using for your tea or coffee.

Oldneweng
7th Oct 2016, 11:04 AM
Don't lick your fingers if using tartaric acid :rolleyes:. The taste is something else again. :C:D

Dean

sacc51
7th Oct 2016, 11:21 AM
Would molasses work?

Oldneweng
7th Oct 2016, 12:18 PM
Would molasses work?

What? Licking your fingers? :D Ask a cow.

Sorry. Couldn't resist.

Dean

lightwood
7th Oct 2016, 01:12 PM
What kind of solder and flux did you use?
Was there instructions on the flux for removal?
Peter

Peter McBride Goldsmith Jeweller (http://www.petermcbride.com)

lightwood
7th Oct 2016, 03:40 PM
Might be of some use to explain what is happening to the copper and brass, and how to avoid the problem.
A critical lesson to learn in jewellery making is to look more than a few steps to ahead to the things that will cause problems. Especially those involved with polishing. A little prevention is a whole lot better than a try at a cure .
I've done this for more than forty years, and I'd have a real challenge to get a decent polish onto the brooch you've made.
My usual metals are gold, platinum & silver, but I occasionally work in non-precious metals.
Here are some pics and some notes on some brass and copper I just ran through a quick trial. It shows how to save a hell of a lot of work.

Cheers,
Peter

First I took a 10 x 20mm rectangle of copper, and square of 60/40 brass, heated up to just on melting temps, cooled in air.
What happens to the pure copper is similar to what happens to the copper alloyed in the brass, it reacts with oxygen, and some of the zinc is burned off and the copper is left at the surface and oxidizes.
http://www.petermcbride.com/temp/images/heat36.jpg

Then I placed it in a pretty innocuous pickling solution, alum in hot water, in a saucepan for 10 min just under boiling.

http://www.petermcbride.com/temp/images/heat37.jpg

scrubbed both with one of those wire toothbrush things from bunnings...it needs to be physically removed. File, emery paper polish etc. A more aggressive acid pickle solution will eat more away, but some folk are worried about acids.
Next to the two pieces is another piece of brass I cut from the same strip, polished up a bit.
http://www.petermcbride.com/temp/images/heat39.jpg

After a painted coating with a generous layer of Boracic acid powder suspended in metho painted on, I burned the metho off leaving a coat of powdery flux (only on one side). I heated it up to red hot, the "flux" went glassy and coated the brass, and the back was oxidized just like the earlier two pieces (copper & brass) above.

http://www.petermcbride.com/temp/images/heat41.jpghttp://www.petermcbride.com/temp/images/heat42.jpg

the back....
http://www.petermcbride.com/temp/images/heat43.jpg

Into the hot alum again for 10 min. I rubbed the piece of brass with a mixture of Bi-Carb Soda and water with my finger and thumb. The coated surface is great, the un-coated side is stained red like before.

http://www.petermcbride.com/temp/images/heat44.jpghttp://www.petermcbride.com/temp/images/heat45.jpg

Anorak Bob
8th Oct 2016, 11:13 AM
Might be of some use to explain what is happening to the copper and brass, and how to avoid the problem.............

Hello Peter,

Thank you for the wonderfully documented response. :2tsup:

Bob.

beck-t
8th Oct 2016, 11:50 AM
I second that anorak-bob! Peter thank you for running through this process, I work with a lot of brass and also struggle to get a good clean after soldering. I've not heard of mixing the borax with metho, will give this a go. My main issue is the difficulty with removing any excess solder, I find I have to remove a lot of metal in order to get rid of the shadowy silver solder marks.. And no I don't flood it with solder I'm talking about only a little excess. I guess this is one of the issues of silver solder on yellow metal? Are there other solders one could try?

lightwood
8th Oct 2016, 12:34 PM
I second that anorak-bob! Peter thank you for running through this process, I work with a lot of brass and also struggle to get a good clean after soldering. I've not heard of mixing the borax with metho, will give this a go. My main issue is the difficulty with removing any excess solder, I find I have to remove a lot of metal in order to get rid of the shadowy silver solder marks.. And no I don't flood it with solder I'm talking about only a little excess. I guess this is one of the issues of silver solder on yellow metal? Are there other solders one could try?
Hi Beck,
What solder and flux are you using?
A picture of a problem joint will help me suggest removal strategies. My bench is covered in tools to remove metal in many different applications.

A little more info about the metho mix.
Not borax in the metho, boracic / boric acid powder is what to use.
There is another very helpful step in the process. That is, I buy the boracic acid powder and find the particle size is a fraction large, so use one of these cheap coffee grinders (http://www.kmart.com.au/product/stainless-steel-coffee-grinder-with-variable-grind/562305) to belt it into a very fine dust.
Then in a jam jar, three or four table spoons to about 1/4 - 1/3 cup of metho.
The larger particles tend to group together, but the fine dust gives a far better coverage after the metho is burned off.

Soldering without excess solder flowing where you don't want is an art. :U
Just remember, if you put too little on, you can usually, STOP... pickle it again, and reflux and put a little more solder in.
What does happen when the solder is held for too long molten, or the flux has been cooked is, it stops flowing and the temptation is very strong to feed more in. Resist that. Go back a step and clean the joint and use a little solder.
Experience will give you more certainty about how much solder to use. I still try and think every time I solder, "I must use less solder than I reckon the joint needs"!!
Remember also, heat will drag the solder towards the hottest place. It is a balancing act to get right. So watch carefully as you solder and avoid the overheating, and holding the solder for too long molten.

Good luck,
Peter

Just noticed, its your first post!
Welcome!

beck-t
8th Oct 2016, 09:31 PM
Peter thank you so much for this fantastic response :D I need to rifle through my things to find an appropriate piece and then photograph. Will send a proper response tomorrow!

beck-t
10th Oct 2016, 09:08 PM
Hi Peter,

I haven't been able to get one decent photo of the silver shadowing on a piece yet, would help if my camera phone had a macro function! I will continue to try.

In terms of my soldering setup - I use a borax cone with water. I grind it to a reasonable consistency, still quite runny but almost opaque, nowhere near a paste like consistency. I paint it on to the area around the joint, heat it slowly until the flux stops bubbling and begins to settle down on the surface. I then add my solder. Heat until it flows, although sometimes once it becomes glassy it seems to form a layer between the solder and the joint and refuses to flow. I use medium or hard wire solder from Koodak:no: I don't want to say to much about that place... you never know who's reading... other than that I go there because it's the only place I know of that still carries a reasonable amount of stock, unlike the store I use to frequent one floor up from them in the Century Building, Swanston Street. I once enquired about what exactly was in the solder Koodak were selling but they didn't have any idea. I did a fusing/granulation workshop and the teacher (R.B.) was using 'Au flux'. He said he also used it for work with silver and base metals, I've been meaning to buy a bottle. What are your thoughts on that? I've never gone near Tenacity, that seems like pretty nasty stuff.

Your metho/boracic acid combination sounds great,it makes a lot of sense that the metho would spread the particles far more evenly. Is there any issues with applying a naked flame to metho? Also, let's say my ventilation set-up is currently pretty primitive (an open window). Can the boracic acid powder be acquired easily?

"I must use less solder than I reckon the joint needs" is great advice, also avoiding overheating, applying heat evenly, knowing when to stop. There's just something about having a torch in your hand :B there's always a temptation to hold it on that little bit longer than what it requires. I guess ultimately it's a matter of good advice - you have given me more in that one post that anyone has ever taught me at uni!!- and practice, practice and more practice. What's the figure - 10,000 hours to become proficient at a craft... While I'm trying my hardest I've got a fair while 'til I get there!

Many thanks for your time, advice and warm welcome :)
Beck

lightwood
12th Oct 2016, 01:34 PM
Hi Peter,

I haven't been able to get one decent photo of the silver shadowing on a piece yet, would help if my camera phone had a macro function! I will continue to try.

In terms of my soldering setup - I use a borax cone with water. I grind it to a reasonable consistency, still quite runny but almost opaque, nowhere near a paste like consistency. I paint it on to the area around the joint, heat it slowly until the flux stops bubbling and begins to settle down on the surface. I then add my solder. Heat until it flows, although sometimes once it becomes glassy it seems to form a layer between the solder and the joint and refuses to flow. I use medium or hard wire solder from Koodak:no: I don't want to say to much about that place... you never know who's reading... other than that I go there because it's the only place I know of that still carries a reasonable amount of stock, unlike the store I use to frequent one floor up from them in the Century Building, Swanston Street. I once enquired about what exactly was in the solder Koodak were selling but they didn't have any idea. I did a fusing/granulation workshop and the teacher (R.B.) was using 'Au flux'. He said he also used it for work with silver and base metals, I've been meaning to buy a bottle. What are your thoughts on that? I've never gone near Tenacity, that seems like pretty nasty stuff.
.....
Beck

Beck,
plenty of observations that seem pretty close to mine about our jewellery supply chain. :C

These folk look like the go to place for boracic acid!
Boric acid (http://www.boricacid.net.au/)

Try this procedure on a couple of pieces of brass or silver.

Polish them up to about 1200 W&D, then on to a heating wire mat, paint your boric/boracic acid on a couple of times burning it off after each layer.
Gently warm the work, then use the AU Flux to sizzle into the joint. (never liked borax cones)
With AU flux I can watch the solder flow, if I get a failure with that, I go to Tenacity flux. It gives a more reliable flow...BUT you can't actually see the metal flowing. So you need to be sure you haven't loaded up the joint.

Heat the work from the area with the largest mass to the smaller piece, watch the flux glass off, then apply the medium silver solder moving the heat towards the solder wire (but not all over it) quickly in, then out again as you feed a little in.
If you are using pallions of solder, you can use a brush to place them, or a fluxed steel poker to pick them up and place them. But I'd get it warm first before putting solder on.
Solder will run to the hotter place, so you can drag it along a joint using the torch.
I did this with my mouth blown torch and took a video of it on the phone.
Ill try and upload it for you to see.
Then into the acid pickle for a short time.
Warning!!!! too long with brass in acid is a problem with lifting out the zinc, leaving a nice red copper layer to be removed afterwards. ( look up colouring gold... leach out the alloys and leave a nice pure gold surface to be brushed or burnished...nice finish....a coulple of local jewellers like/do that process. It imitates the very early granular look as well. It also is how to prep sterling silver for enameling, there you need to leach out the copper with acid since it reacts with some of the oxides in the enamel.)

As an aside, jewellery making is complete with the handling of many things like poisons, flames, acid and sharp tools.
We don't need to a poke crocodiles with a stick, and surf with sharks to make jewellery....but we need to be able to understand how to not poison, burn or cut ourselves.

On this piece I soldered here, I deliberately pushed the silver onto the brass to make a stain. If you place the solder wire into the joint carefully you will not get this. Then I used a home made 600 grit W&D emery disk, make these by sticking packing tape onto the back of the W&D then cutting into squares and cutting round with scissors, then I followed with a fiberglass brush under running water.

Cheers,
Peter
http://www.petermcbride.com/temp/images/heat97.jpghttp://www.petermcbride.com/temp/images/heat100.jpghttp://www.petermcbride.com/temp/images/heat105.jpghttp://www.petermcbride.com/temp/images/heat106.jpghttp://www.petermcbride.com/temp/images/heat107.jpghttp://www.petermcbride.com/temp/images/heat108.jpghttp://www.petermcbride.com/temp/images/heat110.jpg

Anorak Bob
12th Oct 2016, 03:46 PM
Hello Peter,

I can't thank you enough for taking the time to describe the processes and techniques you use. Beck isn't the only one who will benefit from your expertise. It has been thirty years since I have experienced the satisfaction of watching solder flow where it was meant to flow.:)

BT

lightwood
12th Oct 2016, 05:30 PM
Hello Peter,

I can't thank you enough for taking the time to describe the processes and techniques you use. Beck isn't the only one who will benefit from your expertise. It has been thirty years since I have experienced the satisfaction of watching solder flow where it was meant to flow.:)

BT
Bob,
Thanks for that.
I made a video, and did a solder joint using my mouth blown torch, with medium silver solder on brass. (I'll try and embed a video in the next post .... )
After about 10 minutes in the pickle, I took a couple of pics, then gave it a polish with a short bristle brush and white DIALUX compound. That took off the white stain really quickly.
The boracic/boric acid really does a good job of preserving the polish.
I still remember the first time I was shown that trick, over 40 years ago. I know where I was, and who showed me. The bloke I worked for was a goose and had no idea, and it was a real nice fellow who worked for my employer's brother in the workshop next door.
Here are some more pictures.
Peter

http://www.petermcbride.com/temp/images/heat110a.jpg
http://www.petermcbride.com/temp/images/heat111.jpg
http://www.petermcbride.com/temp/images/heat112.jpg
http://www.petermcbride.com/temp/images/heat113.jpg
http://www.petermcbride.com/temp/images/heat114.jpg

lightwood
12th Oct 2016, 05:40 PM
Looks like this might work ... first video I've put up here.
Please excuse the rubbish music in the back ground, the iPod decided I needed some jangling instead of calming tunes.
There are some steel ball bearings in the boracic acid bottle, a shake gets them to mix up the settled powder into the metho.
Having control over the torch with both hands on the work using the mouth is a bonus. Another old tool that has been consigned to the "too hard to master category", and rejected by those who think they know better.
I get questions from all over the world from folk wanting to buy them.

Peter


https://youtu.be/1Sf77HYVinA

Anorak Bob
12th Oct 2016, 07:42 PM
Fantastic!!! :2tsup:

RayG
12th Oct 2016, 08:31 PM
Not that it needs to be said, but I'll say it anyway. Beautiful work! :2tsup: Nice to see someone with that 10,000 hours under the belt. :)

Ray

Michael G
13th Oct 2016, 06:48 AM
Having control over the torch with both hands on the work using the mouth is a bonus. Another old tool that has been consigned to the "too hard to master category"

So is the mouth control of the torch feeding (exhaled) air directly to the flame or does tube control a diaphragm valve or similar to vary oxygen flow?
Interesting

Michael

lightwood
13th Oct 2016, 03:10 PM
So is the mouth control of the torch feeding (exhaled) air directly to the flame

Michael
Michael,
You had it right first time. They are a very basic torch.
In the past they were just a tube with a gas flame at the end, and a blowpipe in the mouth.
A spirit lamp or candle will make a usable flame for a blowpipe.
The one I use has a nozzle with gas supply controlled with a tap, and the air blown through a small pipe in the center.
More pictures...

http://www.petermcbride.com/jewellery_tools/pmcb%20picturea.JPG

From a book, around 1950s

http://www.petermcbride.com/temp/images/blow_pipe01.jpghttp://www.petermcbride.com/temp/images/blow_pipe03.jpg

Some of the mouth blown torches and blowpipes I have.

http://www.petermcbride.com/temp/images/blow_pipe04.jpghttp://www.petermcbride.com/temp/images/blow_pipe05.jpg

This torch below was used during the 1950s in a Melbourne jewellery workshop when gas strikes were common.
Bottom of this page (http://www.petermcbride.com/temp/hurwitz_tools/)

http://www.petermcbride.com/temp/images/blow_torch.jpg

Cleokitty
20th Oct 2016, 05:28 PM
I'm looking forward to reading this whole thread having just skimmed it because of time constraints. One way of cleaning copper that I've heard about but never tried is to use tomato sauce (ketchup, catsup). You've probably got some in the pantry or the fridge!

beck-t
3rd Dec 2016, 12:51 AM
Peter I've just become aware of the fact that the reply I posted a couple of days after your series of posts never actually ended up online. I think it had something to do with the fact that I was replying via my phone. So many fantastic points that you have raised and the photos and video really help to paint a picture. The mouth torch is so great, the only other person I've known who uses one is a friend who was over from Germany on exchange. I had no idea of the extent to which it frees you up. I wonder how difficult it would be to get my hands on one? You appear to have quite a substantial collection, love the pictures from the old book also. I'm going to continue this post tomorrow, until then.. Beck :)

China
3rd Dec 2016, 02:13 PM
beck- t this mob used to sell them they may even make one for you it has been many years since I dealt with them



Bulgin Gas Equipment Pty Ltdy
Unit 6/ 64 Oak Rd Kirrawee, NSW 2232


Phone:
(02) 9545 639

beck-t
4th Dec 2016, 02:28 PM
Peter,
Your point about only leaving it in the pickle for a limited time - 10 minutes - is something I've not heard before/lecturers have neglected to tell us. It sounds like limiting the time as well as polishing with the DIALUX compound is the way to remove the pink tinge as well as the silver ghosting effect. The binding wire 'devil' featured in one of the images from the '50s book looks cool. I imagine the air circulation it would provide would probably be far superior to most of the 'honeycomb' blocks I have used up until now. I solder almost everything on a horizontal surface - usually a soldering block. Holding the piece in the air and having control over it with two hands is such a different approach, allowing more freedom of movement and preventing heat from being drawn away by the surface of the soldering block.

I have printed out your notes and instructions which are now up in front of my soldering bay at the studio and have sent screen shots to a couple of friends/fellow jewellers as it's more comprehensive than anything anyone else has ever provided us with by a million miles!

Many, many thanks,
Beck

beck-t
4th Dec 2016, 02:33 PM
Hi China,
Interesting, I will give them a call and see if it is something they still offer... unfortunately having one made for me would probably be a little out of my budget for now. I've been keeping my eyes peeled on ebay and gumtree but no luck so far :))
Regards,
Beck