Tuesday, February 17, 2015

Another Saxophone Leak that a Light Can't Detect.

I wrote a prior blog about using air for leak detection rather than the usual leak light.  I now use the leak light to chase down leaks, but to do overall testing, and to find leaks that go undetected with a light, I'm using the air suction test as my initial check.

I just found another leak that would have gone undetected had I not used a suction test.  I know that's the case because the person I purchased the horn from, as well as the technician(s) that worked on the horn had not figured out that there was an odd leak.

When UPS delivered the horn, a 1955 Buescher Aristocrat, I unpacked it and took it for a test toot.  I immediately noticed that there was something odd.  The low end seemed weak, 2nd D was stuffy, and the key heights on the lower stack were extremely high.  The pads looked new, but something wasn't sealing.  These horns have a great reputation and I was expecting something on par with my Martin tenor.

As per the prior post, I put plastic wrap over the bell, fingered low Bb, and slowly inhaled through the neck.  The plastic wrap could be sucked in, but I could basically breath through the horn almost like one of the pip vents was open.  And I could hear a hissing sound.  Something was really wrong for a horn that had new pads and recent servicing.

Starting at the neck, as in the prior blog, I sealed off the neck tenon, and sucked.  I could hear a distinct hiss, so I put pressure on the octave pip pad to make sure that it was sealing.  That wasn't the problem.  I looked closely at the neck cork for any weird splits.  Nope.  I had a Martin that had a pinhole leak in the tenon solder, but that wasn't the case here.

I could see that the neck brace, which is soldered up against the underside of the neck, had a little split in it.  I could also reach in through the tenon just far enough to feel a ridge or split on the inside of the neck.  So I put soapy water on the neck and blew air into it.  It was like a kid's bubble pipe.  You can hit the "full screen" icon to view this video.  

The leak created a tiny "ghost vent" right between the upper and lower pips.  It was always open, which caused several odd things that weren't immediately apparent (the prior owner gigged with this horn, so it is possible to "practice, practice, practice" and live with the problem).  Here is a picture of the tiny split along only one side of the brace.  It was about an inch (2.5cm) long.

You can see that the neck has plenty of tiny dents and the lacquer is not great (about the same as the rest of the horn).  The neck tenon was a perfect fit, which on a 1955 horn means that it was probably adjusted at some point. I suspect that the neck received a sharp knock of the kind that "shocks" a solder joint open.  Closer examination of the neck showed that it was slightly out of round and the tiny dents may have been the result of somebody putting the neck back closer to round.  Don't know.  That's when the neck tenon may have been adjusted back to perfect. What they didn't do, clearly, is check that the neck still sealed.  

The horn had a stuffy 2nd D, a common indication of a leak, but this leak was high enough on the horn so that it really effected the entire horn.  The horn had a "spread" sound common to vintage American saxophones, but that was in part because the tiny ghost vent was adding high partials to the entire lower register.  In fact, the lower stack keys were the the highest that I had ever seen.  Really open pads flattens the notes and tends to keep the low end from "jumping register" (because the ghost vent is like pressing the octave key a tiny bit).  

I first sealed up the leak using some sticky clay stuff commonly called "blue tack," although mine isn't blue.  This showed me that the leak was in fact causing some problems.  It also showed me that the neck leak wasn't the only problem.  More on the other problems in another blog.

Once the leak was fixed, I actually doubled the thickness of the lower stack corks to reduce the heights.  It had 1/32nd inch thick cork of the key feet.  I put on 1/16th inch thick cork, which lowered the pads about 1/8th of an inch.  That's a huge difference.  It makes the lower stack feel much quicker (maybe it is) and it tunes just fine.

Probably the worst thing a little leak does is that it sucks power out of the horn.  You can mess with key heights for intonation issues and you can get some more power out of the horn by maximizing pad heights, but there's only so much that can be done if there's a little leak high on the horn.

Since this wasn't a pristine horn, I had a go at resoldering the neck brace.  I was hoping that there would be enough solder already in place that, once fluxed (using a needle to apply), heat would be all that was necessary.  I had some solder handy just in case that didn't happen.  And it didn't.  I had to add a touch of solder.  Careful as I was, it shows a little outside of the brace.  
Once the solder tarnishes a little, it was disappear, as it will be camouflaged by the general condition of the vintage horn.

I could have taken this to a specialist to completely remove the brace, reshape the neck better (maybe), and re-solder the neck seam before re-installing the brace.  I could also pay to have the neck really cleaned up and re-lacquered.  It would cost me about 50% of what I paid for the horn and it would be so pretty that it wouldn't match the funky finish on the horn.  No thanks.  I'm happy with a player. 

After finishing up by chasing down the "regular" leaks on the pads, the horn is back in business.  I should write another blog about the other things I found, just because it should be standard operating procedure for DIY horn tinkerers and, just as important, players should know what to look for when buying or getting a horn back from their tech.  In the meantime, what a nice difference the "suck" method of leak detection provided for this old horn.

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