EUTECTIC SOLDERING This is an email question we received on April 4, 2004:
I am curious about your "eutectic" solder. I found it mentioned several t imes on your web site but with no real explanaition. Is it solder used to simulate granualtion and filligree fusing?
Thanks for the email. Eutectic solder is a solder that contains only silver and copper. There are no other added metal elements. It is the ideal melting point for both metals, which happens to be at a lower temperature then either metal by themselves. Since it only contains those two metals it can be used to make a solder join on a piece that you wish to use vitreous enamel. You can be enamel over the seam(s) since it a pure form of solder with no other additives to cause the enamel to bubble. It is used for fine silver, copper, or sterling silver. In the powder form it is used with a paste flux, with a paste it is used just as it comes out of the tube. One other wonderful application is filigree fusing. Many enamellists, who do plique azure, use this formula extensively since they do not have to worry about other elements destroying the enamel. In the past, people have made their own and spent much time doing that. We have just streamlined the operation by producing this formula on a commercial basis.
As for granulation, that is a eutectic bonding, not a soldering operation. Again, it is when the metals reach a point of bonding that is lower than either metal will melt at, it is bonded. If you are doing gold granulation, it is advised to copper plate the granules first so that you lower the temperature point of the fusing or bonding.
Would it be all right with you if I posted this email and the answer on my web site? I will only use a first name and if you want me to keep your email unlisted, I will. I think if you had a question, then others will have a question as well.
I do hope this answers the question.
Eutectic and IT Q & A to the Orchid Forum April 7, 2004
You have stated "that you've piqued my curiosity, and you have looked over my website".
Well, there are things that we are made aware of each and every day. There are always new things to learn. Among these is the use of paste solder. It is not taught by many schools and therefore, many are not familiar with this form of solder. It is an easy way to get the solder into exact placement and to also keep from having to go through several steps before you can be ready to solder. You eliminate the sanding of the sheet solder, cutting the pallions (chips), fluxing the pallions and fluxing place where you are going to join with the solder, placing the pallions, drying the flux so that the pallions do not jump off the project and then finally applying heat to make the solder flow. With paste, it is a point and shoot approach if it is in a syringe. Decide where you want to place the solder, apply to
the piece and then add heat from the torch to make the solder flow. Paste solder is not for each any every application, but most will work wonderfully well with paste solder.
We have eliminated all the work in making your own powder solder. Isn't that wonderful!!! It comes already to use.
You said "Please help me understand a couple terms: IT and Eutectic. Why and how are
these solders used. (I'm familiar with the ranges of easy through hard solders.) With my own silver work, I mostly use hard. I use the easy on repairs because I have no idea of what was used initially."
The terms IT refers to a formula that melts at a certain temperature, in this case the flow is at 1475 degrees F. It is the solder we carry that has the highest melting temperature. Many enamelists (those using high temperature vitreous enamels) use this formula for doing the findings on their pieces. Many enamels will melt below that temperature allowing a temperature difference that will allow the finding intact.
The other formula that you asked about, Eutectic, is also for vitreous enamel work as well as many other applications. This formula is one that vitreous enamel can be applied right over and the enamelist will not have any problems with bubbling or cracking of the enamel after it is fired. It is the temperature where two metals (copper and silver) melt when used together (alloy); it is a lower temperature than either metal will melt at when used alone. The flow and melt temperatures (F 1435) in Eutectic (for silver) are exactly the same. Eutectic is used for filigree work when a person wants to enamel over that work, or make a plique azure piece. You can enamel over the solder without any problems. I used the Eutectic to solder my findings onto the pins that I recently exchanged at the SNAG conference is St. Petersburg, Fl. I had copper with a brass finding.
I do hope this has answered some of your questions. Please feel free to ask if more remain.
Could you please explain how Eutectic (IT) aids enamelists.
Aren't the silver settings fabricated before the enamel piece is set into it?
Are you saying that soldering can be done after the enamel piece is put into silver or gold?
The formulas that you are questioning are two different formulas. There is the Eutectic and there is the "IT". They have different applications.
You are thinking of the finished enamel as a stone. That is just one way to handle enamels. You fabricate the "bezel" setting and then add the enamel and then set it just as you would do for a stone.
IT- The other way, it to make the piece, solder on the findings with the "IT", THEN do the enamel work. This will works as long as the IT solder is not where the enamels are to be placed. The formula is not the kind that should have enamel placed over it. The melting temperatures of the solder is high and if you are using enamels that melt at 1400F then you will not have any problem with the solder on the findings melting, since the temperature will have to be reached that exceed the melting point of the IT solder. Once solder has melted, then next time it is going to be melted, you will have to apply more heat the second time around, thus increasing the temperature of the melting point. You place all your findings onto the piece before you do the enamel work. SO...... if you want an pendant with a jump ring on the top, you can place that jump ring on the piece before you enamel.
Eutectic- This is they type of solder that you can enamel over. This is formulated especially for enamellists for this purpose. This is the type of solder that is used for plique a jour. There will be no adverse reaction to the solder from the enamels. The enamels will not bubble. The only thing you may encounter is if you are applying transparent enamels over the fine silver. The solder contains copper and you may see shadows if you are enameling over with that with transparent. You can either file off the shadows before you start or put on a thin, thin layer of opaque enamels to counter act that shadow. If you are using opaque enamels then go for it!!! No problems. Unique Solutions is the only company currently making these formulas in both the powder solder and paste solder. I like to do a pod shaped object. I solder the seams with the Eutectic, then apply the enamel directly over the seams. It works like a charm. It will also work for bead forms!!!! So, if you like to make bead forms, get your circle, dap it to the depth you want, cut small holes where you want them, solder it together with Eutectic, enamel. Beautiful pieces have been made this way!!!If I can answer any other questions, please feel free to ask.Beth
USING FLUX WITH PASTE SOLDER
Beth - I was very interested in your explanation. I have just taken my first silversmithing class, and the designs in my head require precise placement of solder to hold various, often quite small and linear, shapes in place. The instructor only uses sheet solder, and while I made it work, I question whether that is the best solder for what I want to create.
I've looked at the syringes in the catalogs, but being a newbie am a bit confused. Our instructor had us cover everything in flux before soldering - how does that work with paste or other methods? He said this prevented firescale. Also, I need to get a torch - we used acetylene in the workshop. It seemed rather hot. Would butane or propane be better for delicate work?Thanks!
Beth in SC
You can solder with any torch. It is the touch. The hottest oxy acetylene I would not recommend for what you are describing. Use the smallest tip available for the setup that you are going to buy. I use both a plumbers torch (Prestolite) and a Smith. I prefer the Smith since it has a smaller handle. I use the Prestolite when I need to do bigger pieces, faster. If I had only one torch, it would be the Smith with the smallest tip available and also one size up to start. This is the set up for the air/acetylene. Your instructor is using the chip or sheet solder since they are not familiar with the paste. He/she learned that way and continues to do that method since they are familiar with that technique. People need to grow and experiment. Feel free to do your own thing as long as you are not endangering others.
I use acetylene/air for my soldering and also a oxy/propane for my mini torch... that one is hot and better for gold.
I do not think you will be able to control the propane or the butane to your satisfaction.
As for the use of flux on the piece. Yes, a lot of people work like this. You can also use a super saturated solution of boric acid mixed with alcohol (the kind that is used in marine stoves) that can be purchased at a home improvement center such as Home Depot. This is what I use. It is a type of flux and does protect the surface from fire scale. You can use this to coat your piece, then use the paste solder where you want it placed. It will not interfere. The paste solder is all self contained with the flux included. BUT... they will work together, no problem.