Coin Mokume Ring Liner issues

[MrMaelstrom]

Hell all,

Being that I am waiting to get my new regulator, I decided to try making some mokume out of quarters. Made little trinkets and stuff, so I decided to make a ring for the girlfriend. 

I dont want to turn her finger green from the copper, so i wanted to put a silver liner in. I got some sterling sheet, cut the liner and pressed it into the interior of the ring. I heated it up, got my borax and applied it, waiting for it to wick into the gap between the mokume and the silver. Never really started to get fluid and when it finally did, I ended up alloying the solder with the sterling band and melted the band right out of it. Im using an easy silver solder because I figured that the lower the temperature, the better to avoid the exact problem I am having. Thankfuly I didnt end up cleaning the ring very well, so I was able to just pop out the melted mess inside, but I am not sure what I am doing wrong with the solder. Sense says I was too hot, but it wouldnt wick at the lower temperatures. 

Am I missing something?

 

[Frosty]

Try tinning the ring with the solder, then inserting the liner and bringing to heat. It won't need to flow and if you put a teeny little dab on the inside of the liner you'll be able to see exactly when it wets and is done.

Just buy a commercial paste or liquid flux. Borax works but using it to silver solder requires some preparation or the flux grains will widen the gap needing filler which is a BAD thing.

To get a very close fit, flux and chill the 2-3 thousandths over sized silver liner in the freezer or better yet on dry ice. After tinning, reflux the ring and start heating but before it reaches soldering temp slip the COLD liner it. The liner will expand into an interference fit as it warms, the solder will make it permanent.

Frosty The Lucky.

[MrMaelstrom]

Hmmm, never would have thought of that. I will certainly give that a shot. Along those lines: I have some silver plumbing solder as well. Would that theoretically work as well or would it be too weak of a bond?

 

Thanks Frosty!

[Frosty]

I have no idea how plumber's silver solder would work in a, silver, copper, nickle joint. Strength isn't a real issue, it's a ring liner, not a tow hook. The closer the joint is matched, the thinner the solder, the stronger the bond is a general principle for solder joint, soft, hard, etc. Experiment with solders on something you don't have so much work and time invested in, just buy some jewelers solder and flux.

Just making this stuff should be experiment enough. Remember one of the PRIME tenets of experimentation and trouble shooting, change ONE thing at a time and test, log the method particulars and results before you change anything else. Change more than one thing at a time and you'll NEVER know what did what or why.

And just so you know I'm not a jewelry guy, I just pick a thing up here and there. I read something and the strings of words just won't go awayyyyyyyy! Has it's percs though. <wink>

Frosty The Lucky.

[ThomasPowers]

borax works at way too high a temp for low temp silver bearing solders like staybright. Use the proper flux!

[Chinobi]

Thankfuly I didnt end up cleaning the ring very well, so I was able to just pop out the melted mess inside, but I am not sure what I am doing wrong with the solder.

 

This leaps out to me as perhaps the biggest problem.  You want the cleanest, closest fit you can create for a good solder joint.  If it was so contaminated that you could just pop it out afterwards you were going to have issues with that joint regardless.

i won't claim to be a professional but I have melted my share of projects over the years and have a few suggestions based on your descriptions and some inference:

quarter mokume and sterling do not need to be babied, you can use any temperature solder, if you have multiple joints to make then you need to consider the order of operations, but otherwise don't feel like you need to use a low temp because it's easier or safer.

I find that lower temp solder (the 1100 degree one, not used the specialty stuff like staybright or other super low melts) tends to tarnish more readily than the higher temps like medium and hard, so if it's just one joint I usually go for hard.

i prefer to add flux before I start heating, rather than waiting for the metal to come up in temperature while in full contact with atmosphere, borax and water have treated me well, I have some boric acid that is supposed to be amazing, but yet to test it.  Stuff like handyflux (IIRC) is pretty good too, but hard to beat borax on a bang for buck basis.

not knowing what plumbing solder you have access to I would be inclined to stick with jewelers silver solder, but if you look it up and there's nothing unpleasant in the alloy and the melting point is below that of sterling (they already use it on copper) then go nuts

I like Frosty's recommendation to tin one side first and then sweat solder them together, much easier to get penetration than adding solder from the edge and trying to wick it in, not saying you can't do it that way, just easier.

even heating is very important, if you melted your liner but the ring was undamaged (you didn't specify so assuming there) I can only assume you were focusing all your heat on the liner (or that it is extremely thin relative to the ring and you were not favoring the thicker material) and melted it out.

it is very frustrating to watch that solder bead sit there on your joint all shiny and melted but refusing to penetrate.  Could be a problem of cleanliness or joint fit, but when I get it the cause is usually heat management.  Don't torch the solder itself on the way to the metals to be joined, that itty bitty chunck of solder will be at melting temp in seconds and your project is still (relatively) stone cold, so no joint.  Instead try heating from the opposite side, you want the project to be hot enough to melt the solder, at that point it will wick in by capillary action because the interior is hot enough, rather than only the surface just beneath where you placed the solder.

 

ok, too much thumbtype, I hope something in there makes sense and is useful to you  and if you are able, get some pictures up! Much easier to see problems than type them, and it's cool to see the projects that people put together here!

Good luck!

[MrMaelstrom]

Update:

I had a very hard time tinning the inside of the ring with the high-temp solder. Heating with the torch, although gradual, was not very precise. Getting the solder to melt without overheating it was tricky, and spreading it was a nightmare. As such, I decided to try and use the low-temp pipe solder after getting some flux paste. The results are below, and I am pretty happy. Not bad for my first time, I think. Also, I went with some ferric chloride  for the patina. 

The only real gripe I have with it is that I wasnt able to get a perfect seal between the band and the mokume, so there are some areas where there is a bit of pitting. The ferric only really made it look worse, but 

 

Thanks for the help guys, I really appreciate it. 

 

[LastRonin]

Coming from the perspective of someone trained in microminiature repair on electronics, solder flows toward heat, so if you heat where the solder is it sits there. You need to apply solder from opposite the side the heat is applied. 

 

But your ring looks beautiful to me and I am sure she loves it.