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Hi!

I need to hardsolder some broken parts of a saxophone. Will my blazer ES1000 give enough heat?
Silver alloy soldering rods melts at 1275 degrees Fahrenheit (691 Celsius)... and the blazer gives maximum 2500-degree F....
So there should not be any problems.

I've done a lot of soft soldering but no hard soldering before. Any advices?

Thank you!
 

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The temperature is not the only issue. The important issues are both how fast the flame can prove heat to the work, and how fast that heat is draining away form the work.

The hotter the work, the more quickly that heat escapes into the environment and by conduction through the work.
(The escape of heat from a hot place to a cold place is proportional to the difference in temperature of these places.)

So a small flame at 2500F will not be enough to supply heat to a large item quickly enough to overcome the escape of heat. The work will never get up to the red-heat needed for the brazing rod to run onto the work.
Yes, the Blazer will be OK to get the work up to a red-hot silver-brazing temperature providing the work is quite small.
For a larger item being brazed, in order to reach the silver-brazing temperature you will either need a larger flame or a hotter flame or both, in order to beat the escape of heat.

If you don't reach red-hot fairly quickly then the flame is unsuitable.

Even a candle flame is 1670F, but you wouldn't be able to silver-braze an instrument key with it.
However a candle flame could silver-solder two needles together, because there is so little mass of metal involved, so red heat is easy to achieve.
 

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Among many torches I also have the same Blazer you mentioned. I've used it for soft and hard soldering. I'd say that statistically, 90% of the time I can't use this Blazer for silver soldering woodwinds parts. 10% of the time it works but takes an absurdly long time. It works fine for silver brazing some rings (like what jewelers do, etc.). All for the reasons Gordon mentioned. I guess you could build a "shelter" (blocking the area as much as possible) and this would make it more likely to work.
 

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Grafton alto | Martin Comm III tenor
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The temperature is not the only issue. The important issues are both how fast the flame can prove heat to the work, and how fast that heat is draining away form the work.
Correct me if I'm wrong but in addition to taking a long time to get to a working temperature, the longer it takes due to heat draining away can be a very major issue, because the longer the draining away time, the further the draining away heat will travel. This cmay mean that this heat reaches parts of the instrument where posts etc. are soft soldered and could those to unsolder.

Hence you need something hot enough to be as quick and local as possible. Obviously also taking precautions such as heat sinks whenever practical. But then heatsinks themselves will potentially cause more draining away but at least they can divert that heat from the vulnerable soft soldered parts.
 

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For heavy stuff... you'll probably need what jewelers use: a hydrogen torch.
With this thing you go up till around 2,800 °C (5,100 °F)... but you need to be very very skilled and careful.
 

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I use a acetylene torch, they get the parts hot fast with the right tip. Pete I have never seen a key hard soldered on a instrument. The key is removed and soldered in a jig usually, so posts and other soft soldered parts are not an issue. What can be an issue with a torch that does not heat quickly enough is that other hard soldered parts of the key may come loose during the repair. Either way the blazer is not the proper tool for the job.
 

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No, you need a blue flame not a yellow one.

Blowlamp is the sort of thing.
Some charcoal blocks or heat resistant block are useful for putting around the piece to concentrate the heat.
You'll need pickling solution too.
Make you you have the right kind of solder.
 

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I thought brazing used a brass/bronze alloy rod and silver solder small pieces cut from a strip with some silver content.
 

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Grafton alto | Martin Comm III tenor
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Pete, brazing (silver soldering) is almost always done off the instrument, so that is not really an issue.
Thanks that makes sense of course but I am sure I have seen posts here where people have had to do it on the instrument 🎷
 

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I thought brazing used a brass/bronze alloy rod and silver solder small pieces cut from a strip with some silver content.
Actually brazing is temperature related term. Bonding two metals with a filler metal above 850°F. Soldering is same but below 850°F.
Welding is when the base metal is melted joined/ filled.
So yes a nickel bronze would be brazing but really hot for brass on a sax. Silver solder is available in different content.

Gordon what do you recommend on silver/ tin % content?

@Repairman, temperature control and technique take experience. Find something to practice on first. Find a local craftsman to help teach you.
 

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Actually brazing is temperature related term. Bonding two metals with a filler metal above 850°F. Soldering is same but below 850°F.
That should read “filler metal MELTING TEMPERATURE above 850°F“.

That is likely what was intended so thank you, PigSquealer, for getting the conversation on track.



P.S. For those looking for a true citation, see the American Welding Society (AWS) for guidance. The actual definition there is a melting temperature of 450°C (I’ll leave the correct value conversion as an extra credit problem for the engineering students among the audience).
 

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Not sure about the alloy I use, but it goes plastic or melts at 1240f and flows at 1325F. I've used others that melt at 1145 and flow at 1205. It just depends on who I am ordering from. Kraus, JL smith, Votaw, etc...Jewery supply shops also sell various hard solders that would work well.
 

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That should read “filler metal MELTING TEMPERATURE above 850°F“.

That is likely what was intended so thank you, PigSquealer, for getting the conversation on track.



P.S. For those looking for a true citation, see the American Welding Society (AWS) for guidance. The actual definition there is a melting temperature of 450°C (I’ll leave the correct value conversion as an extra credit problem for the engineering students among the audience).
Yes Dr. G you are correct. Thanks for the backing.

@Saxdaddy, acetylene torch is great tool with lots of practice before attempting thin brass. I’m concerned the OP would burn a hole through the horn before noticing the color change in base metal. On the flip side de-soldering an area from lack of proper heat is why I suggested seeking a fellow craftsman to learn.

I have 3 spools all rosin core with no labels. Radio Shack closeout buy. Think it’s 70 or 80% silver. Works on small areas(posts/ Wire guards) with various electric irons and guns 600 Watt and Less. It takes a little time and finesse. Sometimes I’ll flash the part with a micro torch to smooth the joint. Haven’t had China syndrome or adhesion problems. Cosmetically acceptable and I’m fussy.
The pictured repair was executed using a 600 W heat gun applying the heat from the outside of the joint. I left small fillet of metal to the inside for additional strength . The key was not removed for the repair. Note the proximity of the post. Yes I could’ve used the micro torch but I don’t take chances.
 

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Correct me if I'm wrong but in addition to taking a long time to get to a working temperature, the longer it takes due to heat draining away can be a very major issue, because the longer the draining away time, the further the draining away heat will travel. This cmay mean that this heat reaches parts of the instrument where posts etc. are soft soldered and could those to unsolder.

Hence you need something hot enough to be as quick and local as possible. Obviously also taking precautions such as heat sinks whenever practical. But then heatsinks themselves will potentially cause more draining away but at least they can divert that heat from the vulnerable soft soldered parts.
Having done a lot of soldering of electronics and also some work with copper water pipes I'd be concerned about exactly what Pete describes. The longer it takes to build up heat the farther the heat travels. It could possibly travel far enough to melt the solder holding posts or keyguards.
 

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What does that have to do with silver soldering, and why are you using rosin core and soldering irons on horns? The reality is that if you take a pair of smooth jaw pliers and give that soft solder you did that way a little tug, it will likely fail. You have to get both parts hot enough and that pad is too close to the heat if you do. I might seem new here because its been a couple of decades since I've been vary active, I'm usually fixing horns all day. I am pretty aware of what my torch can do, I've been at this awhile now. I do not use an oxy/acet torch, but the type that is the industry standard. It's about the right tool for the right job. The honest and easy answer to most questions asked like this would be , if you have to ask, bring it to a pro, but no one learns anything from that. The OP asked about hard soldering, your pics are what is known as soft soldering. Hard solder, know as silver solder or silver brazing in my profession is what I have described. It requires a lot of heat, put in the right place in the right amount of time. Both parts need to start glowing red before it makes a proper bond. Now for the soft soldering you were doing I would want a 60/40 or 63/37 solid wire, no rosin.
 

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I get good results using a small MAP with oxygen torch for small silver soldering work. It is a bit pricey considering how fast the oxygen is used up. I really don't have space in my small shop for a big acetylene tank set-up, nor do I use it often enough to justify the expense.
 

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When I made jewelry a million years ago there were 3 types of silver solder each with a different melting temp so that multiple jobs could be done on one piece, still very tricky.
As I said before it came in thin sheets and was cut up on the spot to order with snips.
 

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...G ordon what do you recommend on silver/ tin % content? ...
The rod I use is 42% silver. What is important (for most key work) is that it flows well into small gaps at close to the melting point. Mine melts at 610C and flows at 620C.
The components other than the silver are also pretty significant. Lower silver content silver-brazing rod flows at higher temperature. The much higher silver content rods that silversmiths use for jewellery flow at a considerably higher temp. They use this in part because it looks closer to silver.
Cadmium has traditionally been included in the alloy to lower the melting point of the rods we use, but the health police are putting an end to it. I know very little about the cadmium-free rods. They probably have a higher flow temperature.

BTW, although there are better options, for decades I have got by quite satisfactoriliy using an LPG setup (mostly propane) similar to this: https://www.google.co.nz/search?q=l...w=1707&bih=820&dpr=1.13#imgrc=KSues5g0HQkzpM:

If one tip does not provide enough heat I change to a larger one. A disadvantage with a hotter flame eg fuel/oxygen for the inexperienced is that it introduces the possibility of melting a key. With my setup it is pretty much impossible to melt a key.

BTW another issue is that if the job takes a very long time because heat is not supplied quick enough, then the base metal can gradually alloy into the brazing-rod, increasing the flow temperature of the rod.
 
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