I have repaired my post and mount for the bulb horn on my 1914. Quick Steel didn't hold, brass brazing didn't hold, 3 types of J. B Weld didn't hold. I noticed in one of the hobby catalogs that it says to use silver solder. Is that supposed to be 27% silver? 5% silver?, most are 1-2% silver, mostly tin and copper. What will hold these brass mounts and posts from breaking loose?
I use 15% (brown tip) silver solder for refrigeration work. It's self fluxing and fills any gaps. The copper tubing will fail before the silver solder does, so sounds like it would be ideal for this application. An ordinary butane blowtorch is usually not hot enough to work with it; you'll need oxy/propane at a minimum to do a decent job with it.
Clean, clean, clean...Any solder joint that is any good at all must be very clean! no oil, grease, or debris of any kind. Solder needs a clean area in order to stick.
Marvin, as far s I know the low percentage silver content rods are what we call plumbers grade solder. It requires greater heat to work with. I go all the way up to 40% silver when working on thin radiator shells. It's more than $10 a stick but it requires much less heat to work with, essential for this amateur working on thin material.
Dennis makes a good point on cleanliness.
If you have one of the reproduction mounts, it will never be really solid. There is just so little contact area between the post and the foot of the bracket. When I take mine off again I will make up a collar with a wider base and a hole drilled through it to accommodate the post, the idea being to spread the load at the joint.
Hope this helps.
Allan from down under.
If you plan to use silver solder with a torch get you a piece of thin brass or some type of material that's similar to your bulb horn parts.
Practice to get the feel of using the torch and learning how to control the heat and learning how to apply the solder. Using the right kind of solder is one thing BUT knowing how to apply it is another.
It takes a little practice but you will be glad that you did.
Harris Safety Silv 45 is a true silver solder or more accurately a silver brazing alloy. It melts about 1100 f and is 45 per cent silver.
All great information! This will give me some good direction. Thanks to everyone!
A company called Micro-Mark sells a product called TIX solder and flux. It is rather expensive, but is the best solder and flux I have ever encountered. If you have something that you want to fix that is valuable, I would highly recommend it. All you need to do is clean, clean clean, then apply the flux and heat with a very small torch and touch the solder stick to the joint and it will flow into the entire joint from one point.
Sometimes this is "Silver Solder"
This is an interesting thread for me as I have 5 of the 26-27 shells in my shop.All of them need some restoration,and replating.
Jack, are any of them for sale?
Allan from down under.
I have used what Ted D. is talking about for years on brass repairs. There is a white paste flux for it too. If it dries out, you can add water to thin it down. This will "wick" in to a joint and creates a strong joint. On a crack in a lamp, you can repair it from the back side and it will wick out to the top side. It flows amazingly well into a clean joint.
Marvin, I'm wondering why the brazing didn't hold up. In fact, it should have been as strong or stronger than it was originally. Did the bracket break again in the same spot, or on one side or other of the repair? If the brazing was done correctly, there should be no reason for it to fail, unless of course it was "overstressed", as in bumping it or something. JMHO Dave
If you have one of the spindly, fragile, reproduction bulb mounts that fall apart, you may want to replace it with the much stronger mount that R.V.Anderson makes.
By the way, what is the going rate to get one of these shells replated--and where to get it done?
sorry for the drift. Thanks, Joe
Silver Solder is the best way to repair the horn mount. I have tried all kinds of solder.
People try to blow the horn on my 11 T and pull down on the bulb and break the mount!!!
David, this is an original stem and mount. According to R.V. it is the wrong one for an inside mount because it is a little longer for outside mount, but it keeps breaking in the same spot. When i would squeeze the bulb it would fall off the bracket at the point of attachment. CHUCK, I am going to keep your idea of silver solder in case other things do not work. Red Green would love your idea of fixing this problem. I want to stay with original if possible, but it needs to work. I am going to try silver solder to see if will work. Thanks all!
They aren't cheap to replate. I did one paid to have it chemically stripped, repaired the small tear and ding I found, spent three days polishing it perfectly smooth and shiny, then had it nickel plated. I don't think I made a dime when I sold it. Send me a pm if you want to know more.
I just had one nickeled for $350.00 They did a great job! Ramos plating in okc. Plating is not cheap.
American Silver Plating in St Louis nickel plated the shell for my 1927 T last summer (2015) for $280. This included polishing it prior to plating. They did a really good job.
Oops...the company is American Plating Company on Park Ave in St Louis.
This is the tin silver phase diagram -
You can see that the solidus is about 220C and the eutectic is around 5% silver.
Anything above 5% is wasting money unless you want to get to 500 C which will require 72% silver.
Tin silver copper solder is also know as SAC and is the replacement for lead based solder for electronic assembly.
The eutectic has a solidus of 217 C at 3.9% silver and 0.7% copper.
Most people are using SAC 305 that has a solidus of 217C and liguidus of 221C.
Fred: I'm with you on your observation regarding eutectic melting point and Ag composition, but might increasing the %Ag enhance the mechanical properties of the alloy for a non electrical application and thereby justify the higher cost? The phase diagrams on their own tell us little about mechanical strength of the alloy. And for electrical apps mechanical strength may be less of a concern than say a silver solder repair of a brass horn bulb mount. respectfully, jb