Repairing stained glass
January 7, 2023 9:50 AM Subscribe
I've got a small stained glass piece my late Dad made many years ago. The lead channel around the perimeter has pulled up and away (It appears to have stretched as well) and the adhesive backed copper foil wrapped around the edges of the glass has also pulled away. What's the best way to fix this? I'm a skilled solderer (electronics and plumbing) but don't have much stained glass experience.
Didn't MeFi's own cortex recently complete a stained glass project started by his late grandfather? What a coincidence. OP, I'm going to link you to cortex's Projects post where he posted the detailed step-by-step process he used. Hope you can find something of use there.
posted by MiraK at 12:59 PM on January 7, 2023 [2 favorites]
posted by MiraK at 12:59 PM on January 7, 2023 [2 favorites]
Here is a little video. She is using foil and solder to edge. You might want to use lead channel, and attach it with solder, at every point the lead channel meets a solder line between pieces.
posted by Oyéah at 2:58 PM on January 7, 2023 [1 favorite]
posted by Oyéah at 2:58 PM on January 7, 2023 [1 favorite]
Best answer: AzraelBrown pretty much has it on the repair approaches.
Sorting out how to remove and replace the exterior channel won't be super difficult if you want to learn, but it's a little futzy so be prepared to be patient and probably curse a little at first. I've only ever done soldering in a stained glass context and everyone I've showed it to who was bringing in soldering experience form electronics/engineering has been like "huh, that's completely different", so definitely watch a video or two.
The main challenge is melting the solder enough to get the lead channel to come away. It's harder to take solder off than put it on in this context. It can be a little bit of a tricky three-handed problem: soften the solder near the edge of the piece while gently pulling and slightly rocking the lead channel with a pair of pliers to pull it away from the now-melted solder. You'll need to do that connection by connection all the way around to get the entire frame off. Don't be afraid to snip off bits of detached lead channel as you go to make it less to fiddle with. Possibly melting the solder connection to the lead channel on one side of the window and rotating the lead away, and then turning it over and doing likewise for the solder on the other side at that connection.
Lead is soft and a bit flexible; focus on deforming and pulling it while avoiding putting any pressure on the glass itself, which might break under significant angular pressure.
For putting new solder on: as AzraelBrown says, you apply flux prior to soldering; you don't want to use flux-core solder because part of the end goal is to avoid having any extra flux left around when you're done since it can mess with the patina and potentially etch some glass surfaces. You'd apply flux, apply solder to connect the existing solder lines on the interior of the piece to the zinc, and then when you're all done wash those edges with a water ammonia mix to neutralize the remaining flux. I give a piece a scrub with soap and water and a small stiff brush when I'm done as well.
Zinc's a good solution if the piece edges underneath are reasonable straight, which for this piece looks like the case. I agree it's much more durable than lead channel, especially as pieces get larger. It's by design far less flexible so if any of the glass in the piece is extra wide you could run into trouble fitting it on (with lead channel you can widen it easily just by sticking e.g. the nose of some needle-nose pliers in there and squishing), but I think it's a good plan.
You could also replace the frame with new lead channel; it may have the same problems if it hangs up for a few decades hence, since lead is lead, but one thing that would I think make a significant difference: relocate those hooks that it hangs from to the corners. The trouble spot here is conspicuous: the hook on the right was being held in place only by the lateral horizontal support of the lead channel where it connects to the edge of the piece and that glass intersection farther in. No vertical support at the hanging point itself is going to lead to easily stretching the lead under load. The hook on the left looks fine, and it's right on top of an intersection of solder from the interior of the piece: that's not a coincidence! Personally I'd prefer to move both hooks to the corners where the vertical strength of the whole frame is taking the load, but it'd also work to relocate the right-side hook to the nearest interior intersection ala the left side hook's current position.
For a zinc frame (or a wood frame) this hook-placement consideration doesn't really matter because the frame is going to effectively take all the load. But this piece doesn't look huge so better hook placement and a new lead frame would also likely do the job just fine for a long time.
And, yeah, a wooden frame is a real nice possibility too if you don't specifically want to learn to futz with repairing or replacing the existing lead channel frame, for a few reasons:
- it's going to be durable under hanging stress to the same degree as the zinc channel would
- you can get away with a somewhat looser fit: the piece just has to be *inside* the frame, doesn't have to marry up snugly the way a lead or zinc channel frame does
- you don't need to remove much if any of the existing lead frame, just use pliers/snips to remove the existing hooks probably to make framing easier
So, yeah! You have choices, and you can make this as much or as little about familiar with stained glass solder removal as you like. (And if ultimately you find the whole thing frustrating or dispiriting, this is something you could definitely hire a local stained glass person to do as a small repair job, if you can find one.)
In any case: it's a lovely piece and I'm glad you're taking care of it.
posted by cortex at 9:59 AM on January 8, 2023 [2 favorites]
Sorting out how to remove and replace the exterior channel won't be super difficult if you want to learn, but it's a little futzy so be prepared to be patient and probably curse a little at first. I've only ever done soldering in a stained glass context and everyone I've showed it to who was bringing in soldering experience form electronics/engineering has been like "huh, that's completely different", so definitely watch a video or two.
The main challenge is melting the solder enough to get the lead channel to come away. It's harder to take solder off than put it on in this context. It can be a little bit of a tricky three-handed problem: soften the solder near the edge of the piece while gently pulling and slightly rocking the lead channel with a pair of pliers to pull it away from the now-melted solder. You'll need to do that connection by connection all the way around to get the entire frame off. Don't be afraid to snip off bits of detached lead channel as you go to make it less to fiddle with. Possibly melting the solder connection to the lead channel on one side of the window and rotating the lead away, and then turning it over and doing likewise for the solder on the other side at that connection.
Lead is soft and a bit flexible; focus on deforming and pulling it while avoiding putting any pressure on the glass itself, which might break under significant angular pressure.
For putting new solder on: as AzraelBrown says, you apply flux prior to soldering; you don't want to use flux-core solder because part of the end goal is to avoid having any extra flux left around when you're done since it can mess with the patina and potentially etch some glass surfaces. You'd apply flux, apply solder to connect the existing solder lines on the interior of the piece to the zinc, and then when you're all done wash those edges with a water ammonia mix to neutralize the remaining flux. I give a piece a scrub with soap and water and a small stiff brush when I'm done as well.
Zinc's a good solution if the piece edges underneath are reasonable straight, which for this piece looks like the case. I agree it's much more durable than lead channel, especially as pieces get larger. It's by design far less flexible so if any of the glass in the piece is extra wide you could run into trouble fitting it on (with lead channel you can widen it easily just by sticking e.g. the nose of some needle-nose pliers in there and squishing), but I think it's a good plan.
You could also replace the frame with new lead channel; it may have the same problems if it hangs up for a few decades hence, since lead is lead, but one thing that would I think make a significant difference: relocate those hooks that it hangs from to the corners. The trouble spot here is conspicuous: the hook on the right was being held in place only by the lateral horizontal support of the lead channel where it connects to the edge of the piece and that glass intersection farther in. No vertical support at the hanging point itself is going to lead to easily stretching the lead under load. The hook on the left looks fine, and it's right on top of an intersection of solder from the interior of the piece: that's not a coincidence! Personally I'd prefer to move both hooks to the corners where the vertical strength of the whole frame is taking the load, but it'd also work to relocate the right-side hook to the nearest interior intersection ala the left side hook's current position.
For a zinc frame (or a wood frame) this hook-placement consideration doesn't really matter because the frame is going to effectively take all the load. But this piece doesn't look huge so better hook placement and a new lead frame would also likely do the job just fine for a long time.
And, yeah, a wooden frame is a real nice possibility too if you don't specifically want to learn to futz with repairing or replacing the existing lead channel frame, for a few reasons:
- it's going to be durable under hanging stress to the same degree as the zinc channel would
- you can get away with a somewhat looser fit: the piece just has to be *inside* the frame, doesn't have to marry up snugly the way a lead or zinc channel frame does
- you don't need to remove much if any of the existing lead frame, just use pliers/snips to remove the existing hooks probably to make framing easier
So, yeah! You have choices, and you can make this as much or as little about familiar with stained glass solder removal as you like. (And if ultimately you find the whole thing frustrating or dispiriting, this is something you could definitely hire a local stained glass person to do as a small repair job, if you can find one.)
In any case: it's a lovely piece and I'm glad you're taking care of it.
posted by cortex at 9:59 AM on January 8, 2023 [2 favorites]
A couple other thoughts:
1. you may end up mussing a bit of the solder near the interior edges by the frame; you will definitely disrupt the existing patina a little bit at those spots as you remelt the solder, and any new solder you put on will not have a patina on it. This is not a big deal, it's easy to reapply patina: the two common formulations for lead solder are a copper and a black, available from multiple sources, and from the image this looks like black patina. So buy or borrow a bottle of that and once you're totally done soldering and washing the flux off the piece, apply the patina with a brush or cloth to recreate that consistent black look.
And while you're at it, anywhere else the patina looks a bit worn you can also touch up if you like. I scrub any solder I want to put (or refresh) patina on with some steel wool or copper wool, to get it back to its default shiny state so it will take a chemical patina well. You can just spot-do this as needed, no need to scrub and re-coat the entire piece if most of the interior patina is fine.
You could also choose *not* to redo the patina at the edges and instead leave it the shiny grey that, with lead solder, will fade over a not very long time to a more matte grey of its natural oxidization. Nothing wrong with that structurally and conceptually it's an interesting record of the piece and its repair across generations.
Note that if you use a zinc frame, lead patina products will probably not have any effect on it: the solder will turn black but the frame will stay shiny grey. Different metals, different reactions. If you were to really, really prefer that uniform black patina look, go with a lead channel frame.
2. The solder I use and most stained glass people I'm aware of use is 60/40 tin/lead alloy, with no rosin/flux core. I've used 50/50 as well and it's fine too. Depending on your usual soldering setup, you may need to switch to a much broader head (vs. the wee pinpoint heads I see folks use for electronics stuff). Look at what folks do in videos.
posted by cortex at 10:13 AM on January 8, 2023 [2 favorites]
1. you may end up mussing a bit of the solder near the interior edges by the frame; you will definitely disrupt the existing patina a little bit at those spots as you remelt the solder, and any new solder you put on will not have a patina on it. This is not a big deal, it's easy to reapply patina: the two common formulations for lead solder are a copper and a black, available from multiple sources, and from the image this looks like black patina. So buy or borrow a bottle of that and once you're totally done soldering and washing the flux off the piece, apply the patina with a brush or cloth to recreate that consistent black look.
And while you're at it, anywhere else the patina looks a bit worn you can also touch up if you like. I scrub any solder I want to put (or refresh) patina on with some steel wool or copper wool, to get it back to its default shiny state so it will take a chemical patina well. You can just spot-do this as needed, no need to scrub and re-coat the entire piece if most of the interior patina is fine.
You could also choose *not* to redo the patina at the edges and instead leave it the shiny grey that, with lead solder, will fade over a not very long time to a more matte grey of its natural oxidization. Nothing wrong with that structurally and conceptually it's an interesting record of the piece and its repair across generations.
Note that if you use a zinc frame, lead patina products will probably not have any effect on it: the solder will turn black but the frame will stay shiny grey. Different metals, different reactions. If you were to really, really prefer that uniform black patina look, go with a lead channel frame.
2. The solder I use and most stained glass people I'm aware of use is 60/40 tin/lead alloy, with no rosin/flux core. I've used 50/50 as well and it's fine too. Depending on your usual soldering setup, you may need to switch to a much broader head (vs. the wee pinpoint heads I see folks use for electronics stuff). Look at what folks do in videos.
posted by cortex at 10:13 AM on January 8, 2023 [2 favorites]
Response by poster: Follow up! It's all fixed. I re-copper foiled the edge of one piece where it had torn away, replaced the lead came with some new lead came with a much thicker profile and, perhaps most importantly, redesigned the hanging loops so that the vertical component of the hanging force is transferred into the side pieces of came, rather than having the force pulling on the top piece of came. The load is much better distributed now. Pulling off the original came revealed some irregularities in the glass cutting but, like my ancestors before, I was able to conceal the wonky-ness with a little bit of fudging of the came. Thanks to everyone who took the time to reply!
posted by Larry David Syndrome at 5:06 PM on February 11, 2023 [1 favorite]
posted by Larry David Syndrome at 5:06 PM on February 11, 2023 [1 favorite]
Response by poster: I forgot to add a tip- in case anyone finds themselves in a similar situation. I used electronics desoldering braid to wick up some of the surplus solder when detaching the old came. It contains rosin, so it does require some cleanup, but any one of a number of solvents or purpose made rosin type flux removing chemicals will get it off. It might be possible to get rosin-less braid and use stained glass acid type flux with that instead.
posted by Larry David Syndrome at 6:51 PM on February 11, 2023
posted by Larry David Syndrome at 6:51 PM on February 11, 2023
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Watch a few videos on soldering stained glass and you'll see it's not really similar to soldering electronics other than the equipment. In stained glass you generally flux the area you want the solder to go, then essentially drip the solder onto the flux, causing it to bind to it, you don't significantly heat up the area you're trying to solder, the flux and heat of the melted solder takes care of it.
So, you would cut 45s on the ends of four pieces of zinc came u-channel, fit the stained glass inside, solder the corners and wherever the existing lead touches, and then there's a stained glass putty, like a grout, which is forced into the came to set the stained glass inside it so it doesn't move around.
If you're handy with woodworking, a non-stained-glass method would be to just mount it in a wood frame, again taking the weight off the stained glass itself.
posted by AzraelBrown at 10:48 AM on January 7, 2023 [3 favorites]