ToolSteel Posted January 22, 2012 Share Posted January 22, 2012 Hey everyone. I hope this is the place for repair questions. I've worked quite a bit with copper, but never with silver. As luck would have it, I've been given a 12" tall silver vase and asked if I can repair it. The bottom has come off. I cleaned up both vase and bottom last night. To me, it looks like it was soldered together long ago with lead. The original bonding material is greyish and was easy to carve off. Where I cut into it with a razor, it was bright silver. When I was young, I had far more experience with lead than I care to admit, so it looks familiar to me. In the center of the bottom is a thick disk of something that looks like bronze or brass. It's raised about 1/8th of an inch and surrounded by a flat shelf of the same size. Sorry, but I don't know the technical terms. The vase fits over this disk. If you turn it all upside down, it's like the vase is a bottle and the bottom is a cork that fits inside. Now to my question: What material should I use to repair this? I have plenty of silver plumbing solder. I have a bar of 50/50. I know that 50 percent is lead and I think the other half is tin. I also have some braze, but it's bronze and not silver... although I could buy silver braze. I know braze is very strong but I worry about melting the silver. Any pointers would be appreciated. ToolSteel Link to comment Share on other sites More sharing options...
pkrankow Posted January 22, 2012 Share Posted January 22, 2012 Look up your melting temperatures of these various fillers and the believed material of the item being repaired. Choose your filler based on this information. They likely used lead because it has a much lower melting point than the silver. If this is a decorative or non-food item, then I would not think too hard against using lead to make the repair, since lead was used in the original. Phil Link to comment Share on other sites More sharing options...
bigfootnampa Posted January 22, 2012 Share Posted January 22, 2012 Personally I would not use ANY sort of soft solder for silver work. Easy solder (which is a hard solder of the lower melting point type and contains silver with no lead or zinc) is as soft as I would use. Easy solder is quite a few times stronger than soft solder. Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 23, 2012 Share Posted January 23, 2012 Lead and silver do NOT play nice together---any lead contamination on silver can lead to pitting and other nastiness. I would suggest a low temp silver bearing solder like stay-brite that is lead free! Link to comment Share on other sites More sharing options...
Rich Hale Posted January 24, 2012 Share Posted January 24, 2012 If none of the seam is visable have you considered JB weld? Link to comment Share on other sites More sharing options...
ToolSteel Posted January 27, 2012 Author Share Posted January 27, 2012 "If none of the seam is visable have you considered JB weld?"I never even remotely considered JB Weld until I read your post, Rich. What a brilliant solution! Last night I used a scrap piece of wood and a hammer to tighten the seam a bit, then applied a thin bead of JB Weld to the inner rim. I gently twisted the vase and the bottom back and forth a few times to make sure I had 100% coverage. This morning, I checked the seam: It's invisible and hard as steel. Once again, JB Weld has saved the day. I absolutely love the stuff. Thanks for recommending it.ToolSteel Link to comment Share on other sites More sharing options...
Bentiron1946 Posted January 28, 2012 Share Posted January 28, 2012 Silver Solder does have zinc in it. If you look at the numbers associated with silver solder you will see that those number are related to the percentage of zinc in the alloy. Say that you purchase HARD silver solder it will be listed as #75, this indicates that it is 75% silver and 25% zinc, MEDIUM silver solder is #70 and EASY is #65. There are also other silver solders that are used in the air conditioning industry such as EASY EASY which is #56 and not often used in the making of jewelry or silverware because it is a bad match color wise to sterling silver but great for copper fittings that need the extra strength. The melting temperature of Sterlilng silver is something like 1640F and the HARD solder melts at 1360F and flows at 1450F so you need to watch you heat very carefully if using HARD but if you drop down to EASY you get some more leaway in temperature with a flow point of 1360F which is just where the HARD is starting to melt. That gives you almost 200F to play with while the solder is flowing rather than sitting there waiting to get to the flow point. On a large piece this can make a big difference when just a little more heat can turn the whole thing into a puddle of molten silver. There is just a little over a two hundred degrees between each grade of hard silver solder. It is difficult for some folk to grasp that "silver solder" can come in so many different grades and one can be called easy or "soft" and still be "hard". All silver solders are actually a form of "brazing" not true soldering with is done at lower temperatures. Lead, tin and such metals that melt in the 400F to 800F range are usually referred to as true soldering. Link to comment Share on other sites More sharing options...
azurefire Posted March 19, 2012 Share Posted March 19, 2012 when possible avoid using leaded solder on silver. it causes a eutectic reaction at a very low temperature and can destroy the piece during later repair attempts if you have a few pictures of the piece before you jb welded it it might help. you can test to a certain degree the solders makeup using acids and a reference piece and watching the reaction. chances are unless it was a extremely poorly crafted piece it would have been made using a silver solder. i have actually seen a beautiful silver hollow bracelet ruined because the refractory bed it was being soldered on contained a small piece of leaded solder( which burned a hole through it) so if you post a pick we could help you a bit more Link to comment Share on other sites More sharing options...
ToolSteel Posted March 28, 2012 Author Share Posted March 28, 2012 Where are my manners? I just came back to this site after a long time away and realized I never gave any update on my project. I put the two pieces back together with JB Weld. It worked like magic. The woman for whom I did this project was amazed at my silverworking "skills". Since this was a freebie for a friend of a friend, I saw no reason to change. Thanks to everyone who pitched in. ToolSteel Link to comment Share on other sites More sharing options...
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