I have attempted to solder glass and ceramics with both pure indium and a approximately 50:46:4 mix of indium tin and silver. the best results i have got is a kind of stuck blob, that is easily removed with moderate pressure. so how do i actually do this? do i need some kind of flux to clean the glass? what is the best temperature? how do i apply the stuff? (i have been using a soldering iron)
Oliver
how does one solder glass with indium?
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Richard Hull
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Re: how does one solder glass with indium?
No flux is needed, however a process of cleaning and indium tinning in preparation is a must.
http://www.indium.com/documents/applica ... /97753.pdf
This should give all the info.
I clean in pure lye solution (very nasty business) then super rinse 6 times in distilled water. Next, they are dipped in acetone and hot air dryed. I place the pieces to be joined in an oven and take them way over melting temp. I, next, take them out hot and jig them using heat resistant gloves and quickly tin the surfaces with either pure indium or 50:50 tin indium. ( I can often solder directly right here). From here just a normal light flame is used that never touches the pieces and indium wire is fed to the joint. Works every time.
I prefer often to tin with pure indium and solder with 50:50 as the joint is stronger mechanically but will not flex as much as pure indium. Even a tiny amount of silver with make the joint super hard and the tensile strength and melting point can go through the roof!
I have a friend who only cleans as above and tins immediately with no preheat after cleaning (save for a small propane flame to warm the piece) and he has good results.
Preheating warrants a warm piece, overall, and soldering and tinning goes a bit faster and adhesion is better.
Richard Hull
http://www.indium.com/documents/applica ... /97753.pdf
This should give all the info.
I clean in pure lye solution (very nasty business) then super rinse 6 times in distilled water. Next, they are dipped in acetone and hot air dryed. I place the pieces to be joined in an oven and take them way over melting temp. I, next, take them out hot and jig them using heat resistant gloves and quickly tin the surfaces with either pure indium or 50:50 tin indium. ( I can often solder directly right here). From here just a normal light flame is used that never touches the pieces and indium wire is fed to the joint. Works every time.
I prefer often to tin with pure indium and solder with 50:50 as the joint is stronger mechanically but will not flex as much as pure indium. Even a tiny amount of silver with make the joint super hard and the tensile strength and melting point can go through the roof!
I have a friend who only cleans as above and tins immediately with no preheat after cleaning (save for a small propane flame to warm the piece) and he has good results.
Preheating warrants a warm piece, overall, and soldering and tinning goes a bit faster and adhesion is better.
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Re: how does one solder glass with indium?
I use an Ultrasonic Soldering Iron at ordinary heat for tinning or joining single crystal silicon slabs. Cleanliness is important and a matte finish usually gives a stronger bond.
You can join with regular rosin flux-core solder after the indium "tinning" process, but either indium-tin or silver alloy solder works better. With regular solder you may "un-tin" the surface, and then you have to start over.
Dave Cooper
You can join with regular rosin flux-core solder after the indium "tinning" process, but either indium-tin or silver alloy solder works better. With regular solder you may "un-tin" the surface, and then you have to start over.
Dave Cooper
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Todd Massure
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Re: how does one solder glass with indium?
I'm also interested in joining glass and ceramic, but how are these materials (indium etc.) in vacuum application? I would think one would want to stay away from the rosin flux. I was planning to use Torr seal or equivilent and keep the exposed area very small, but some of the areas might get too hot for that.
Todd
Todd
Re: how does one solder glass with indium?
Thanks thats very helpful!
do i have to worry about differential expansion when soldering glass/ceramic to metal, or are the temperatures low enough for it not to matter? should i design to do end to end joints or can i (for example) solder a glass piece into a close fitting recess (to make a view port)?
Oliver
do i have to worry about differential expansion when soldering glass/ceramic to metal, or are the temperatures low enough for it not to matter? should i design to do end to end joints or can i (for example) solder a glass piece into a close fitting recess (to make a view port)?
Oliver
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Richard Hull
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Re: how does one solder glass with indium?
The beauty of using pure indium is its adhesion qualities and its flexibility in the face of different expansion characteristics of joined pieces. If expansion is extreme, use a loose fit and fillet with pure indium. Always keep the soldered areas to a minimum in large differential expansion zones.
I do not like to use any flux with indium solder operations as such operations should already offer up hyper cleaned tinned and soldered surfaces, thus, flux is almost never needed.
NEVER, EVER, use tin-lead or tin-silver solder with any indium solder operations. Use only pure indium, tin-indium, or tin-silver-indium solders. Never use a tin-lead soldering iron to solder indium. Dedicate an iron to indium solders only. Note... copper is highly miscible in indium and the tip of the iron will quickly erode in molten indium. The result is copper poisoning and hardening of indium joints. Just like silver, copper, in even a few parts per thousand will really harden the alloy in a pure indium joint. This is why I prefer to use a small, special torch flame in indium soldering with preheated pieces. As always, never let the torch flame touch any indium alloy..... only the workpiece.
Cold welding of special indium coated items is stunningly amazing. Check it and the preparations out on the URL I gave earlier. I have tried it and it blew my mind.
Richard Hull
I do not like to use any flux with indium solder operations as such operations should already offer up hyper cleaned tinned and soldered surfaces, thus, flux is almost never needed.
NEVER, EVER, use tin-lead or tin-silver solder with any indium solder operations. Use only pure indium, tin-indium, or tin-silver-indium solders. Never use a tin-lead soldering iron to solder indium. Dedicate an iron to indium solders only. Note... copper is highly miscible in indium and the tip of the iron will quickly erode in molten indium. The result is copper poisoning and hardening of indium joints. Just like silver, copper, in even a few parts per thousand will really harden the alloy in a pure indium joint. This is why I prefer to use a small, special torch flame in indium soldering with preheated pieces. As always, never let the torch flame touch any indium alloy..... only the workpiece.
Cold welding of special indium coated items is stunningly amazing. Check it and the preparations out on the URL I gave earlier. I have tried it and it blew my mind.
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Re: how does one solder glass with indium?
I should have clarified about the solder and particularly the rosin flux. We never use the flux or lead based alloys in areas that will be under hard (<10-7 torr) vacuum. Removal of the flux can be done successfully, but it takes some patience and thoroughness in the cleaning.
Indium O-ring type seals have been used successfully as THE high vacuum seal. The key is the cleaning process. Chemically cleaned indium will adhere to just about everything, and will require serious scraping when you go to remove parts. Definitely a consideration for things that have to be disassembled.
The application to which I referred involving regular soldering, was to join a grounding lead to silicon plates which had been joined with indium. We have seen little or no attack on the soldering irons, but then the ones we use are temperature regulated and usually have tinned iron tips.
Copper tipped soldering irons experience pitting and dissolving (actually it is an amalgamation process) in almost any type of solder, which is why the soldering techniques recommend touching the solder to part to be soldered, and not to the soldering iron. Saves the tip.
Indium is truly an amazing metal.
Dave Cooper
Indium O-ring type seals have been used successfully as THE high vacuum seal. The key is the cleaning process. Chemically cleaned indium will adhere to just about everything, and will require serious scraping when you go to remove parts. Definitely a consideration for things that have to be disassembled.
The application to which I referred involving regular soldering, was to join a grounding lead to silicon plates which had been joined with indium. We have seen little or no attack on the soldering irons, but then the ones we use are temperature regulated and usually have tinned iron tips.
Copper tipped soldering irons experience pitting and dissolving (actually it is an amalgamation process) in almost any type of solder, which is why the soldering techniques recommend touching the solder to part to be soldered, and not to the soldering iron. Saves the tip.
Indium is truly an amazing metal.
Dave Cooper
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SteveHansen
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Re: how does one solder glass with indium?
Alexander Roth has a some material on using indium for glass/ceramic to metal seals in his "Vacuum Sealing Techniques." This book covers about every seal known to man (at least up to the mid 1960s). If it's not on your shelf, get a copy. I'll shamelessly promote the Amazon link from my vacuum books page: http://www.belljar.net/books.htm
He suggests, in addition to the other methods of cleaning the glass, a corona final treatment (e.g. with a small Tesla coil).
He suggests, in addition to the other methods of cleaning the glass, a corona final treatment (e.g. with a small Tesla coil).