Metal Artist Forum

ok, first problem. im working mostly in silver at the moment and almost every single piece i finish comes out with really bad firestain. just to clarify, by firestain i mean a copper oxide deposit under the surface that comes out after polishing looking like a bruise in the metal, and which is not affected by pickling.
I dont know why! i know it's meant to be caused mostly by overheating ( i think?) but i never used to get it so much i dont think, and i was being so careful on my last piece that the solder didnt even flow propperly and i still got firestain. can it be caused by heating too slowly?
some people recomend coating the whole peice with flux but i havnt found it made any difference. i thought i might try using something like Argo-Tect. has anyone used this, or knows if it's any good?

Also, does anyone know anything about solder inhibitors? I've learned what little i know in a very slapdash manner without much help, and i havnt come accross the idea before but i was reading a metal techniques book from 1968 which said you could use a paste of rouge, yellow ochre or some other things to prevent solder flowing to certain places, or to stop it oozing out of a join if reheated. I havnt been able to find any info on this anywhere, appart from one mention of using Tipp-Ex for the the purpose. again, id be really grateful if anyone could give me advice on this.

basicly im just having trouble with soldering and any general or specific advice would be great. at the moment ive ended up using mostly the pre fluxed solder paste that comes in a syringe because once it's in it seems impossile to re-melt, but this isnt always a good thing and i find it really expensive and nasty to to use. I'd ask for advice again but i think you get the picture. this is just a general cry for help.

thanks

Scarlett

Scarlett, i haven't worked with silver alot but I have read that coating with flux will stop firescale which it seems like thats what your getting. A place that you might call that supplies silver and flux and all sorts of cool stuff is http://www.allcraftonline.com they are very knoledgable and I'm sure would have an answer and maybe product that would help. They sell a ton more stuff than they have online. So if I was you, I'd call and talk to someone and request a catalogue. They sell tons of goodies

Well any soldering on silver other than the new agentinium (spelling) silver will have some fire scale. they have something new they are selling stateside that is supposed to prevent the fire scale. I don't know if it works and will find the copy in the mag ad for name web site ect.
Yes yellow oche mixed with water and painted on is a solder stop, migration preventer. The flux I use is battens flux a sort of lime green color flux that is liquid.The borax and alcohol mix is an old school flux The fire scale mix they taught us in class is boric acid mixed to the point you can't mix any more in alcohol. Each time you use it you have to mix it up real good, as it falls out of suspension vary fast since it is a super saturated liquid mix. You paint or dip the item so it is covered with the liquid and the you burn off the alcohol so the white powder is dry and will not steam when you are soldering, moving the solder chip or paps around ect.
Same with the solder flux, we were taught to burn or dry the flux with a flame as not to move the solder or parts around from the water or alky steaming off.

Something that is used is the typing correction fluid in the small bottles I have been told that color doesn't matter and some people use the different colors for different temps of solders.
It seems if you ask a question you will get as many answers as people you ask. I stick to what works for me.
You should look up the book called Complete Metalsmith by Tim Mcreight they are any number of editions from student to pro the student has the least and the pro has the most info.
Or a local or school library should have a copy of Oppi Untracht Jewelry Concepts and technology the most complete collected knowledge of metalworking in 840 pages. Look for a used copy as new it Is over $100.00 US. it covers everything.
Finally check this sites archives out and join the email listJewelry knowledge datta base
They have this question about once a month

Ok he is the stuff. I have not tried it yet. As i 'm happy with the regular methods I use. It has been in most of the magazines on this side of the pond.
Here is their blurb;
Firescoff™ is a revolutionary heat activated ceramic spray coating. Firescoff™ combines a scale preventer, a high performance non-fluorinated flux (for both hard and soft solder) and the convenience of easy removal in warm water, all-in-one.

Leading Jewelers and Jewelry Manufacturers have switched from using boric acid, paste flux, and pickle solution to Firescoff™ because Firescoff™ is faster, offers more protection for gemstones, and features a no-acid warm water cleanup. Other benefits include:

* Integrated non-fluorinated flux for consistent soft and hard solder welding.
* Perform multiple soldering operations without waiting.
* Enjoy strong, non-brittle, void-free welds.
* Greater control when reticulating with silver or gold.
* Superior performance over boric acid & Batterns flux or paste flux.
* Provides stray heat protection for gemstones.
* Prevents scaling of metal alloys including gold, stainless steel, copper, and silver.
* Warm water cleanup - less than 2 minutes in an ultrasonic cleaner.
* Remove dangerous pickling acids from the workbench.
* Alcohol-free - no dangerous flash, no frustrating burn residue.
* No smell, no outgassing.
* Significant improvement in safety over traditional methods.
* Available in 1oz, 4.25oz, and bulk sizes.
* 20% discount available for Jewelry Schools and attending students.

here is the companies web site
The one drawback is the price as 1-oz 30ml is S9.85 a bottle US
They do take Euro's and ship around the world according to the site.

one other item you will come across, on the orchid/ganoksin site and other places is the use of a US powdered hand soap 20 mule team which is a borax product. I don't know if it works or not some people swear by it. I would think that it is not 100% pure borax. But has the usual soap additives mixed in the processing of the borax to make it work as a soap. the cost of the borax cones or from chemical house isn't that much more than the soap. This is just my opinion.

Scarlettt Wrote:ok, first problem. im working mostly in silver at the moment and almost every single piece i finish comes out with really bad firestain.

basicly im just having trouble with soldering and any general or specific advice would be great.
Scarlett

Hi Scarlett....
hope this helps....it's a hand out that I give to all my jewelry students regarding soldering.
The short answer...boric acid powder and denatured alcohol will take care of your firescale, and if your to slow in the soldering process you can burn up the properties of the fluxes. Ideally you want to be able to "get in and get out" in as little time as possible. The longer you play the flame over the soldered joint after it flows......the more porosity you'll get.....as it burns out some of the alloys.

Soldering

The basics of soldering- Clean, fit, flux, flame, pickle

CLEAN- Solder won't flow on a dirty or greasy surface. Use a degreasing detergent cleaner and an abrasive pad, or an abrasive such as pumice powder, to remove dirt or grease from the metal being soldered. You can also use an ultrasonic cleaner or a steam cleaner to prep the article before soldering.

FIT- Parts, findings and joints must fit tightly together. Large gaps in joints and poorly matched junctures between parts create a poor solder joint which could result in pitting of the solder or in a weak joint that could break. Occasionally , solder simply will not fill a poor-fitting area.

FLUX- Flux prepares the metal surface to receive the fluid solder. When applying flux, make sure it is in contact with the solder at all times and that it touches both metal parts being joined. Some self-pickling fluxes also help dissolve oxides. Keeping the joint oxide-free is important for creating the ideal soldering surface. "Batterns" is a great self pickling flux, available through any jewelry supplier.

FLAME- Use either a neutral flame ( equal part oxygen and gas) or a reducing flame (more gas than oxygen). The metal adjacent to the joint must reach the necessary temperature before solder will flow. First concentrate the heat on the surrounding surface, then on the joint to be soldered. Remember, solder flows to the hottest part of the surface and toward the flame. TIP ....you CONTROL the flow of the solder with the heat.
REMEMBER......use flux to start with and then if you have to come back again with the flame, to rework the area, you must clean and re flux the area before applying the heat. Failing to use the pickle pot or keeping the metal clean is the MAIN cause of failure...when soldering. Solder will not flow over dirty metal. IF your ever having problems getting the solder to FLOW.......9 times out of 10 ....the metal isn't clean. Drop it back in the pickle pot......clean it. Re flux and start over.

PICKLE- After soldering, use a mild acid pickle to clean nonferrous metals. This removes oxides and other soldering residues prior to finishing. When storing solders, keep them free from dirt and grease. Sheet solders may be cleaned to remove dirt or residue. "SPAREX # 2" , is a dry acid compound, available through most jewelry suppliers, and is specially made for pickling, cleaning and removing surface oxidation, scale and encrustation from nonferrous and precious metals such as silver, gold and copper. This dry compound is added to water and the solution is kept in a "pickle pot" which keeps the solution warmed to speed up the pickling process. Commercial "pickle pots" are available..but a small crock pot works fine. TIP......when retrieving a piece of jewelry from the pickle solution......you must use either a copper or non metallic tong to reach into the solution. If you use a pair of tongs or tweezers that are made of steel....they will CONTAMINATE your pickle solution. And ruin it for future use.

SURFACE FIRE SCALE

FIRE SCALE OR OXIDATION- When heated, some metals unite with certain chemicals in the air- usually sulphur- and forms an oxide - or fire scale. While this is useful in antiqueing, most of the time it is bothersome and is to be avoided.
The practice of ALWAYS using flux will reduce this fire scale- so, always use flux. Everytime- before using fire/heat on the metals.......use flux, as it is much easier to apply the flux than it is to remove the fire scale. TIP.. the oxides/fire scale that forms on the metal.....is HARDER than the metal itself. Which means that it's harder to remove.......than if you were removing some of the metal.

Besides fluxing the area that you'll be soldering, it is advisable to coat the entire article with an "anti fire scale" coating. This protects the area not being soldered, but still being heated.......from creating oxides.There are commercially available solutions, but you can make your own by mixing Boric Acid and denatured alcohol.
Boric Acid Powder is available at any good pharmacy. Once you have the boric acid powder in a solution of denatured alcohol, all you do is submerge the article in the solution. Then you set it on your soldering block or station. By igniting the alcohol.......it burns off leaving a coating of the boric acid all over the article that you plan to solder. This coating protects the areas not being soldered, but still being heated. By protecting the whole article...it makes the clean up much quicker and easier.

Thanks for all your replies.
there seems to be some confusion between firescale and firestain, i dont know if it's just a british language thing. my problem is not firescale,the normal oxide deposit which you get on the surface of most metals when heated and which can be removed from silver by pickling, which is what i do. firestain seems to be under the surface and it is not removed by pickling and i think the only way to get rid of it once youve got it is by grinding down the metal.

this is just cos i want to make clear what i'm talking about as not everyone uses the same words and most of what i know i learned from a fairly eccentric drunkard.

I'm coming to the conclusion that alot of this is because im heating too slowly. ive recently set up my own workshop and the torch i have came with a pretty small tip, it's only since then that ive had so much problem with firestain. i think il get a bigger tip and see what happens. im pretty warey of buying anything im not totaly sure i need cos i have no money, and there's so much i need.
I actually rather like the old borax cone and dish method of flux. ive started using Auflux, which i think is the same lime green liquid flux you mentioned? it's fine but i like to be able to mix to whatever consistancy i want.

By the way, the book i was talking about is Oppi Untracht's Metal Techniques for Craftsmen. i do want to get myself some more jewellery technique books but again money is something of an issue.
anyway thanks alot
Scarlett

Bill probably explain it better than I but the boric acid and denatured alcohol is the fire/scale/stain preventer or slows down or cuts down the amount.

Quote:Hi Scarlett....
hope this helps....it's a hand out that I give to all my jewelry students regarding soldering.
The short answer...boric acid powder and denatured alcohol will take care of your firescale, and if your to slow in the soldering process you can burn up the properties of the fluxes. Ideally you want to be able to "get in and get out" in as little time as possible. The longer you play the flame over the soldered joint after it flows......the more porosity you'll get.....as it burns out some of the alloys.

from Bill's post.

Scarlettt Wrote:Thanks for all your replies.
there seems to be some confusion between firescale and firestain, i dont know if it's just a british language thing. my problem is not firescale,the normal oxide deposit which you get on the surface of most metals when heated and which can be removed from silver by pickling, which is what i do. firestain seems to be under the surface and it is not removed by pickling and i think the only way to get rid of it once youve got it is by grinding down the metal.
anyway thanks alot
Scarlett

No confusion, I believe that they are one and the same. Oxides form on the surface of the unprotected, heated metal because of it's reaction with the atmosphere. It can't form under the surface.
And when soldering I suggest that you make sure that your using a "reducing flame" and not an "oxidizing flame". A larger reducing flame is MUCH better than a small, hotter oxidizing flame. And if it "seems" as though it's taking a long time to solder a piece....then the flame isn't adequate, or large enuf for the piece being soldered. Like I mentioned.......the longer the soldering process takes the more likely you are to burn off the Protective Properties of the flux, and even the boric acid coating that is protecting the surface from firescale/firestain. Your "gut feeling" is probably correct, that it's taking to long. And your probably correct in thinking it's related to the small torch tip that you have. I'd suggest that you need to get a larger tip for your torch. It won't be a waste of money because without it you will be limited to only soldering small items.

PTsideshow Wrote:Bill probably explain it better than I but the boric acid and denatured alcohol is the fire/scale/stain preventer or slows down or cuts down the amount.

[lol]it's an exhibition.....not a competion. They'll be no wagering. We did kinda duplicate the info........but more is better right?