Free Shipping!

Bench Notes #14


Issue #14 - April 2013


Welcome Home from NAPBIRT and the Musikmesse!

Curt returned from yet another successful Musikmesse in Germany this week and had tons of pictures to share from his fun trip.

Before we get to the pictures, a thank-you goes out to Ken Coon, who proved to be a tremendous help setting up the booth and pitching in throughout the whole show, and to Sylvia Nooteboom, who manned the booth for countless hours and bridged the language gap on many occasions.

Thank you also to everyone who attended the Messe and came to our booth this year! We were overwhelmed with orders and barely had enough neck checkers with us to go around. The multi-tool was a surprise hit and we are working on getting it produced. Here are some of the highlights from the show:

The week before Curt, Rich, and the guys from the Sax ProShop all attended the NAPBIRT conference in Virginia. Both Curt and Rich enjoyed giving clinics at the convention, catching up with old and new friends, and spending time in Virginia.

This year, the guys from the Sax ProShop had a special new service to introduce: Silver Plating. In this industry it is normal to repair saxophones mechanically, and then buff, sandblast, engrave, and plate them. So basically, a horn gets repaired, damaged, and then plated. It will look fantastic, but not be functional anymore.

Because the ProShop works in an assembly line style, we can choose to do or leave out various jobs along the way. We can also add in the steps of the plating procedure. After a lot of research and hard work, we developed a practical process to get the repair and the plating done together. The body of the instrument never gets buffed at all. In the end we have an instrument that is not only beautiful, but also mechanically correct. When we send the horn to the plater, the keys are fit, the tone holes level, the body straight, and it is ready to be assembled the minute it comes back to us.

This is a service we believe is not available anywhere else. It is the only refinishing service that extends the life of an instrument rather than reducing it. And the best thing is, it is available to players and technicians alike! If you are interested in this service, contact Matt at SaxProShop@MusicMedic.comfor more details.


Skype Lessons with the Sax ProShop - Video

If you are a player, technician, or manufacturer and wish to further your studies in saxophone repair techniques, you will be interested to hear that the Sax ProShop including Curt are now offering Skype Lessons! Simply schedule an hour or two with the technician you want to learn from and we'll create a lesson plan according to your needs. Check out this video for more details and email Matt at SaxProShop@MusicMedic.com to schedule.


Soldering Basics

Soldering is the process of bonding one piece of metal to another by melting and flowing solder into the joint. Solder is a metal that melts at a lower temperature than the metal of the workpiece. In instrument repair, there are several types of soldering that are applicable. Soft soldering occurs at a lower temperature and it creates a semi-permanent bond between two pieces of metal. You will often find that posts and bow guards are soft soldered to the body of a saxophone. Hard soldering, or brazing, occurs at a higher temperature and creates a more durable bond. The different pieces of brass that make up a key are hard soldered together. This article will explain the basics of soldering and help you to choose the best soldering products for a particular job during your repairs and modifications.

As a general rule in instrument repair, soft solder is only used to connect pieces of the body and attach parts directly to the body. All other connections are hard soldered.

Soft Soldering
Soft solder is composed of tin and another alloy. Traditionally, solder was a combination of tin and lead. These types of solder were labeled as 63/37, 60/40, 50/50, and so on, with their tin-to-lead ratio. The temperature at which these solders melt is around 360°F (182°C).
Due to environmental concerns, lead-free solders are increasingly more popular. These solders are composed of tin and silver and found under such names as 94/6, 96/4, Stay-Brite, or simply Lead-Free. These solders have a higher melting point of around 430°F (221°C). Additional benefits of lead-free solder include a higher tensile strength and the solder retains its silver color as it ages instead of darkening like lead-based solders.

In order to solder two parts together, the surface of the brass must be clean and free of oxidation. As heat is applied to the workpiece, however, the brass begins to oxidize. This necessitates the use of flux: a liquid or paste that slows the oxidization of brass and allows the solder to penetrate the surface of the metal.

Your end result should be that upon examination, solder is visible around the entire perimeter of the joint but no excess solder is dripping out of the joint.

Choosing a Soft Solder and Flux
Lead Free Solder is similar in properties to the traditional 50/50 lead/tin solder. All lead-free solders flow at a slightly higher temperature than their leaded counterparts, so extra care to protect lacquer or plating is important. Use with Tix Flux.

Stay-Brite Solder is slightly stronger than standard soft solder and is very good for joining two parts that have slight gaps between them. It does not tarnish the way standard solder does (hence the name Stay-Brite) so a cleaner looking joint is possible when the work will not be lacquered. Stay-Brite requires slightly more heat than Lead Free Solder, so it would not be the best choice for trying to re-solder a broken joint without burning the lacquer. Only use Stay-Clean Flux with Stay-Brite solder.

Hard Soldering
Hard soldering, which is also called silver soldering or silver brazing, creates a much stronger bond between two parts than soft soldering by using a silver alloy. These processes require heat around 1200°F (650°C). Brazing also refers to a higher temperature, higher strength process which uses a brass alloy as the filler metal.

Hard Soldering is useful for bonding small parts where strength is very important. Hard soldering requires a much more precise fit between the parts, so care must be taken when preparing the workpieces that there are not gaps in the joint. The flux used during hard soldering and brazing is generally a borax-based paste. Because lacquer will burn quickly at the high temperatures required, it is best to remove the lacquer near the joint on the workpieces first before soldering.

Choosing a Hard Solder and Flux
Easy Flow Silver Solder Wire is the standard silver solder used in instrument repair. Whenever the parts to be hard soldered are thicker than 1/16 inch and there are not multiple joints close together, Easy Flow Wire is a good choice. The Medium and Hard wires flow at higher temperatures and are used when several joints need to be hard soldered close together. In that case, start with the highest temperature silver solder and use the next one down for each successive joint. Be very careful with the hard and medium flow silver solder wire, as the temperature required for them to flow is very close to the melting temperature of brass. Use Creamy Silver Brazing Flux with all three silver solder wires.

Silver Alloy Soldering Rods are excellent when repairing a broken part rather than fabricating a new one. These rods contain a flux core so no additional flux is needed. The strength is slightly lower than Silver Solder Wire, but the flowing temperature is much lower as well. Brazing a cracked part back together or attaching an arm to a hinge tube are perfect times to use this silver solder. It is not as good for large joints or joints where maximum strength is needed.

Solder Paste with Flux is the same silver solder as the Easy Flow Silver Solder Wire, but mixed with flux in a paste form and contained in a syringe. You simply apply the paste to the solder joint before heating and then heat the parts up. Once the parts reach the flowing temperature, the silver solder particles in the paste flow and fill in the joint. It is extremely useful for attaching feet or flanges to posts, braces and guards. It is not as good as Silver Solder Wire for large joints or joints which require a lot of wicking, such as attaching an arm to a hinge tube.

Soldering Safety
Before you get started, it's important to know a few things about soldering safety.

1. Ventilation
It is necessary to have proper ventilation when soldering because of the fumes given off by flux when it is heated. Be sure to solder with adequate air flow and an overhead vent when possible.

2. Protect Your Body
Since you're working with open flames and chemicals, you need to take care to protect your eyes and body. Always wear protective goggles when using an open flame. If you will need to hold the part near to where it is being heated, use a non-marring tool like Large Brass Jawed Parallel Pliers or a glove or rag. After soldering, be sure to wash your hands. Avoid contact with flux on your skin.

3. Protect Your Workspace
Because you are using high heat and flame, you'll need to protect yourself and the area around you. Do not solder next to flammable items and do not solder items directly on top of your work bench. Use a Soldering Board or a Ceramic Soldering Block. If you are soldering directly onto the body of the instrument, secure it in a jig, or on a peg that is secured in a floor-mounted vise.

Preparing Your Solder Joint Surfaces
The two pieces that you plan to solder together must be clean, free of oxidation, and fit together well. This maybe involve shaping the pieces with dent working tools, or filing and shaping a modification to fit well with the piece it will be soldered to. There will need to be some space between the two pieces for soft solder to flow, but it should be less than .010" or about the thickness of heavy paper or cardstock.

If you are reattaching something that has already been soldered before and has old solder on it, you'll need to remove the old solder. Begin by heating up that piece until the solder flows and wiping the solder off quickly with a rag. The workpiece will retain a silver color even after the solder has been wiped away. This is known as "tinning", and it is solder that has permanently bonded with the brass. Tinning can be removed by buffing.

After your piece is shaped and tinned, if necessary, clean and polish to remove any surface oxidation. If either of your workpieces has lacquer over the solder joint, you'll need to remove that lacquer first before attempting to solder.

Securing The Solder Joint
In most soldering applications, it will be helpful or necessary to hold the two pieces together while you are soldering a joint. This can be done with the help of Soldering Clamps, baling wire, or a jig with clips to hold the two pieces. Some pieces can be soldered while resting on a Ceramic Soldering Board. If you are soldering something that is very near to other solder joints, such as a post on a saxophone, you will need to secure other posts in that area so that when the body of the instrument heats up, those solder joints will be held securely in place.
If using a paste or brush-on flux, it should be applied to the joint at this time, before securing it in place.

Protecting the Area Around the Solder Joint
If the workpieces you are soldering are bare brass, you need only to secure the solder joint in place and secure any other soldering joints directly around it, if applicable.

For lacquered instruments, there are cooling gels that can be applied which will minimize burnt lacquer around the joint. It can also help to cover surrounding areas with aluminum foil to protect the lacquer.

Solder flows more freely on gold and silver plating, so it is advisable to create a barrier around the joint to prevent solder from bonding with the plating. You can create a barrier with Tix Anti-Flux, or by using pencil lead or contact cement.

Choosing A Heat Source and Applying Heat for Soft Soldering
There are several heat sources that can be used for soft soldering. Most common is an acetylene torch. Those come in several varieties, anywhere from an Acetylene Torch with a tank to a simple hand-held torch, like the Roburn Micro Torch. In the Sax ProShop, we have also used the Vortex Air Torch™ for smaller soft soldering jobs in order to avoid burning lacquer. This method takes a little more patience but can yield good results.

Have everything you need handy: your parts which are secured together, your torch, your torch lighter, solder, flux, and tools to help you hold the parts once they are hot, if applicable.

If you are using a paste flux, it should already have been applied to the workpiece surfaces which are to be soldered. Concentrate the flame several inches from your workpiece, focusing more heat on the part with a greater mass, but applying it evenly around the area to be soldered. If you are using a liquid flux, apply some to the edge of the solder joint and it will flow into it. Continue evenly heating the solder joint area. Touch the solder to the joint: if it is at the right temperature, the solder will melt and flow into the joint. If it doesn't, continue applying heat and testing again every few seconds. Once at the melting point, the solder will flow into the joint. Continue to feed solder into the joint until you can see that the solder has filled in around the perimeter of the entire solder joint.

Remove the heat source and let the solder joint cool. Once it has cooled, neutralize the flux by spraying or applying soapy water. At this point, if there is any excess solder around your joint (it is not uncommon for there to be a small amount at the point at which you fed solder into the joint), it can be removed by applying a direct flame to the excess solder. Once it has reached melting point, it can be wiped off with a rag. Be very careful to not overheat your solder joint in the process.

Choosing A Heat Source and Applying Heat for Hard Soldering and Brazing
Because of the high temperatures needed for brazing, you'll need an Acetylene Torch that allows you to control the amount of oxygen that mixes with the acetylene. If using Easy, Medium, or Hard Flow Soldering Wire, your Creamy Silver Brazing Flux should already have been applied to the workpiece joint. Solder Paste With Flux and Silver Alloy Soldering Rods contain flux and are ready to use.

After lighting the Acetylene or Oxy-Acetylene Torch, you'll need to adjust the flow of acetylene and oxygen until you have a flame shaped like a bright blue comet with a tail. Begin heating the workpiece until it is red-hot. Apply the solder to the joint and once it has flowed into the joint, remove the heat source. Remember that when soldering at high temperatures, the solder melting point is very near the melting point of the brass, and care must be taken to not overheat the workpiece.

Dowse the workpiece by placing it in soapy water. If there is excess flux at the joint, it should be scraped off once the part is cool.
To remove the heat varnish, which is oxidation that occurs when a part is heated over 800°F (427°C), soak it in acetic acid (vinegar) for 10 minutes. The workpiece can now be shaped or polished according to your intended results.

Un-Soldering a Joint
Un-soldering a joint will require the same heat as the part would require to be soldered. Apply the heat to the joint which is to be unsoldered, and when the solder reaches flow temperature, the joint can be separated. Flux can also be applied to the joint when heating.

Experimenting with Soldering
Soldering is a skill, like many others, that can be honed through practice. If you have never soldered before, it is best to practice on some scrap pieces of brass or other metals rather than your prized instrument. There are many different approaches to soldering and many different solders, fluxes, and torches and we recommend experimenting to find out what works best for you.

If you have any questions about the soldering products or any other products at MusicMedic.com, please don't hesitate to ask.


New Products:

Woodwind Screwdrivers
Double Sided Pad Slick
Saxophone Pearls
Woodwind Screwdrivers Double Sided Pad Slick Saxophone Pearls