Week 10- Soldering, Lathe Projects, and More

The next lathe project was creating a trumpet main tuning slide mandrel.  Made of brass, the mandrel is sized to the most common diameter of main tuning slides (0.458").  The mandrel can be used for forming, burnishing, and even some swedging type repairs. 

First, I faced one end of the brass rod.  Then in a few consecutive passes, I turned the diameter of the brass rod down to the 0.458" measurement. The next step was center drilling and tapping the rod to allow a handle to be inserted into the mandrel.  A final cut and facing of the opposite side produced the final product seen below.

Alongside the lathe project was a soft solder job.  After filing a brass rod down to fit the arc on a bare trumpet bell, soft solder was used to attach the rod to the trumpet bell.  After the initial solder, I had to wipe to tin and hand buff the bell and brass rod brace.

The end result produced a high shine finish with nearly all traces of solder removed from the area surrounding the brace.

Week 9- Welcome to Brass Lab

The halfway point of the semester means that we move workshops.  We are now in the brass lab.  Immediately we went to work on trumpet nomenclature.  We took apart our trumpets, learned about the various parts and the metals they were made of.  In order to do any work on aligning the piston valves, Greg Beckwith helped us make a porting tool.  

This was our first time silver soldering.  I was successful in soldering my part at a 90 degree angle.  After sanding and buffing, I was able to use my porting tool for the first time!

Using plastic tubing, I can mark the height of the knuckle to the valve threads.  From there, I am able to make sure the down stroke of the piston lines up precisely between the port and the knuckle.

Piston valves are an extremely interesting system.  By simply lining up ports with their respective knuckles, specific lengthening and shortening of tubing on the instrument produce different notes.  The tolerance between the piston and the valve casing is only 0.010".  With measurements this small, it is important to be extremely precise with our maintenance and repairs.

To finish off the week we marked trombone bells with marker to show the direction of the buffing wheel.  After completing the buffing of my trombone bell I am looking forward to a lathe project, a soft soldering project, and more practice on repairing and maintaining brass instruments next week.

Week 8- Finishing Flute Repairs

After soft soldering a post back together on my Music & Arts flute, I had some clean up to do.  After wiping to tin and using a very small amount of Light Green Compound on blue cloth, I used a silver polish to buff away the excess material.  While there were some surface scratch marks remaining, I was able to remove the majority of the cosmetic damage.  

 I then finished the repad on the body of the flute.  Once the pads were seating and I put the flute in the oven, I was able to cork the body and regulate it.  I was able to eliminate all lost motion. Finally, I polished the body and keys for a final product that I was very pleased with.

Week 7- Gemeinhardt Flutes

This week we started in on our complete flute repads.  I am completely fascinated by the flute.  There are quite a few intricate regulations to make the mechanics run smoothly on the instrument.  This allows a flute to be adjusted to have zero lost motion! The mechanics are so sound, and the addition of stop plates and regulation screws is so smart!  I'm really impressed with the mechanics overall.

After completing an initial inspection, I began removing keys from the flute.  Above, with the keys removed I was able to move on to taking apart the keys that are attached by knock pins.  This was a tricky procedure, and I would love to have more practice at it on other flutes.  Getting a needle-shaped, tapered object out of a conical hole is not easy!  I did manage to remove the six knock pins necessary for cleaning my keys.  Although my flute had been poorly taken care of, I saw improvement after cleaning the body and keys.

I am very interested in the foolproof method of padding for flutes.  With the pad and washer system, adding shims underneath the pad can create the exact coverage needed over the tone hole.  Ironing the pad removes any wrinkles on the pad skin, and a nearly perfect result can be produced on every pad.  I wish this existed on other woodwinds!

I started my key fitting and pad replacement on the foot joint.  Once I had a quality seal, I clamped the keys and baked them in our oven for 15 minutes.  The impression made on the pads was not severe, but was visibly indented.

When I moved on the the body, I was met with a most unwelcome surprise.  One of the posts on the double G Key was broken!  Lucas and I took immediate steps to fix the post, however the process of soldering and cleaning the work was time consuming.  If this was an instrument I was working on in a shop, it would have added a fair amount of time to the complete job.

I placed the flute on a wooden dowel so I could tighten it into a vice.  I angled the flute so that the broken post was within easy reach for holding a torch and soft solder up to it.

With Lucas' help, we applied flux to the intended area.  The next step was to heat the flute body up so that when the soft solder touched the post, it would melt into the opening.  This would ensure the most cosmetically friendly repair job.

The soldering procedure only took about one minute.  However, the process of cleaning the dirty metal was another story.

I first wiped off the body with alcohol.  Getting rid of a reasonable amount of the discoloration, I then switched to a green rouge compound to buff away some of the minor imperfections around the site.  I was able the remove most of the excess solder.  Using silver polish, I buffed the surrounding rib, tone holes, and posts to ensure the the repair job would be nearly invisible.

Next week's post will include the completed flute repad pictures as well as the final product of the post repair.

Week 6- Rosewood Clarinet Project

As an additional project while we begin flute repair, I am going to be working on a mystery rosewood clarinet.  The post work has Conn style pivot screws, however, there is no clear portrayal of a specific make of clarinet.  There is a serial number that has been nearly worn away, however, I am not sure how I would use a serial number to deduce a make of clarinet.

Upon first glance the piece is pretty exciting.  Unfortunately, after an initial assessment, it was obvious that there is a long road ahead for me and this clarinet.  While the choice of rosewood is a beautiful cut of wood, there is a severe double crack down the barrel and the bell.  The double crack that continued through the lower joint had an even worse result.

As you can see, the clarinet has run through the gauntlet of repair work already.  The top quarter of the lower joint was removed and replaced with a grenadilla wood clarinet joint.  While the original repair may have been sound, the new grenadilla wood piece also cracked down the entire piece.  The repair for these cracks was at best a job that was done on a limited budget and definitely without access to additional rosewood.  I can only assume that the key work from the original instrument was maintained in the piecing together of a new lower joint.

According to the engraving, 'Mpls. Bd. of Edu.', this was a school instrument at one time.  Probably poorly maintained, I would assume it was eventually donated for lack of funding to repair or maintain the work needed on the clarinet.

After assessing the tenons, I noticed some other repair work that I may need to remove before reevaluating. Shellac was used on the tenons.  Because of Minnesota's extremely varying climate of intense dry spells and very humid summers, I have elected to use contact cement as my base for the new tenons.  However, with the extensive cracking on the instrument, other repairs have included using what looks to be epoxy and a colored oil to get a brownish color that somewhat masks the repair work.  A considerable amount of shellac is found inside the lower joint tenon, which will no doubt lead to intonation issues.

A thorough cleaning of the tenon corks was necessary to ensure that as much shellac as possible was removed from the tenon grooves.  The end result shaped up nice.  In removing the key structure additional work was discovered.  Many of the hinge rods were damaged, two posts were stripped, two pad cups were damaged, and the A/D ring key had been noticeably swedged to the point of cosmetic failure.

Even after running the keys through a degreaser, acid bath, and silver soak, the tarnish and wear on the keys was very noticeable.  After polishing hinge rods, I began to assess lateral and end play in the mechanisms.  Unfortunately nearly all hinge tubes had severe lateral play.  Many also had severe end play.  While swedging could potentially be an option, the severity of these cases leads me to a second option: I will fabricate oversized hinge rods for all existing hinge rods.

It looks to be a daunting task, but with time and effort, the instrument can most definitely be improved to be used as a show piece for the BIR program.

Week 5- Final Touches on the Clarinet Repad

 After finishing the the corking and regulation on the lower joint, I had to replace the tenon corks.  I was hesitant to use my torch to quickly melt the paraffin wax over the cork to seal out any cork grease oils, but I was successful.

Once the upper joint tenons were corked, I was able to fit the two joints together to ensure that the 3 ring key regulation with the A/D ring key was sound.  I then had to make the final touches on the instrument.  I cleaned up the keys, replaced the thumb rest cork, and got ready for a play test.

My first full repad was a success.  The instrument plays freely and there are no mechanical issues or major intonation issues that would be due to the instrument itself.  I'm excited with the result, and I can't wait until we are able to fix even more instruments.  Next on the list: FLUTE!

Week 4- Key Adjustment, Padding, and Corking

Finishing out the repad week, I have been spending a lot of time eliminating lateral and end play.  I had a particular challenge with my clarinet's Throat A key.  The posts were not in alignment, and after a cost-benefit analysis, it was obvious that removing and resetting the post was not my best option.

As seen above, I then flared an opening on the hinge tube to allow for some lateral play when the hinge rod entered the non-aligned post.  While the fix didn't eliminate the problem, given the student model clarinet and the cost of resetting the post, I learned a very real-life approach to solving my problem.

After adjusting the key fitting I installed and set the pads on my clarinet.  Above are the upper joint keys before setting the pads on their tone holes.  Especially concerning the upper joint, I found that as you assemble the instrument, pad fitting becomes more difficult.  Fitting one pad at a time and then removing the key seemed a better option and less likely to burn a surrounding pad by accident.

While setting the pad for the C trill key, I had trouble getting a seal.  Upon closer inspection, I found that the tone hole was not level. Using my new tone hole leveler, I was able to sand a level surface and obtain a quality seal on the tone hole.  The same process was repeated when I found the Alternate F# tone hole was also uneven.