Valve Oils- My recent experiences
Posted: Mon Oct 15, 2018 1:36 pm
I'm sure this horse has been sufficiently beaten but I just want to share my recent experiences with my new Wessex Chicago York and the various valve oils/ combinations that I have tried.
As a disclaimer, the statements that I'm about to make are based on my experience as a degreed chemical engineer with all of my work experience being in polymers. If you don't want to read all of this, skip to the TLDR at the bottom
I'll start by saying that, as someone who is really anal about maintaining anything mechanical, the very first thing I did with this horn when I took it home was take it apart and clean it. Overall, things looked fine. The slides were almost dead nuts true on my surface plate and had very very minimal alignment issues. Everything pulled smooth out of the box, but with a little extra work they're even better. In my opinion, the 5th rotor could have been cleaner out of the box. Everything was thoroughly cleaned, polished, and measured with a micrometer for my own reference before re-assembly. I also used telescoping gauges to check the ID of the valve casing. The fit between the piston and the casing comes out to right around 0.0011" per side. This is larger than some of the instruments that I've played before. However, based on having played the horn for many hours at this point and consulting several professionals about the clearance, the valves were all sufficiently tight enough to provide stable and in-tune slotting. Based on this clearance I began formulating an oil to appropriately take up the space.
After reading a lot of positive posts about UltraPure lamp oil, I purchased a bottle of the stuff and began thickening it up with 30W motor oil. This is where I'd like to discuss my first point here- UltraPure lamp oil is a paraffin oil. Yes like paraffin wax.... but an oil instead. Paraffin wax candles are (essentially) made up of the same building blocks as what's in the UltraPure lamp oil bottle. But it's not what blocks we're building with that makes a valve oil become "gummy" or "sticky" over time. Rather, it's how many of those building blocks are strung together. Paraffin wax candles, being solid at room temperature, are made unsaturated hydrocarbon chains that are likely around 30 carbons long (plus or minus a few). It's this chain length that determines the melting temperature of the substance. A longer chain paraffin will remain solid at elevated temperatures, whereas a shorter chain paraffin will melt sooner at elevated temperatures. If your paraffin chains are short enough, they'll be liquid at room temperature. Such is the case with the UltraPure lamp oil. These molecule chains are, according to the MSDS, between 5 and 20 carbons in length. Based on my experience, I would guess that this is a bell curve figure with the center about 12 carbons in length. That being said, under that bell curve, are molecules that are 20 carbons in length. 20 carbons is a substantially different situation than 12 carbons. I haven't done the research, but I imagine 20 carbons would be nearing a waxy substance. In the event that you're really bad about oiling your valves regularly, you might just end up washing away some of the shorter chain molecules with your saliva and leaving behind some of the longer chain molecules. The shorter chain molecules will be more easily dissolved by the partially non-polar parts of your saliva. With this in mind, if you oil your valves regularly with some mixture of UltraPure and another thicker petroleum based oil, I cannot understand how you'd ever end up gumming up your valves. I I thickened my mixture up to the point where I felt the slightest drag on the piston and that worked very well for me for over a month of playing ~5 days out of the week.
At this point, I had more or less settled with this mixture being 'good enough' but I was curious as to how airtight it was holding my valves. After a fresh coat of oil, I removed my first slide, plugged the outboard side with my palm and blew down the leadpipe of the instrument. I could feel a slight leak in the air pressure. I wasn't really concerned with this as, like I said, the instrument played very well. I did however, want to try something different after consulting with Dana Hofer in Palatine, IL. He mentioned that University of Illinois professor Mark Moore uses an oil stabilizer on his pistons that he then washes down with valve oil. He does this on all of his piston horns. After reading into the idea, I understood more of the logic behind it. Oil stabilizers create a thin film 'slick' on motor piston seals that doesn't drain off as easily when the engine is shut off and the oil drains down to the pan. It essentially prevents wear upon startup.
In my head I imagined my tuba pistons having a bi-layer lubrication of oil stabilizer, and my UltraPure concoction. The bottle I purchased (HyperLube) indicated that the formulation was 100% Petroleum based. Dana advised using Al Cass as a good oil to wash down that slick layer. I don't think this was coincidental. This is where I'd like to talk about a second point- mixing synthetic and conventional oils. From a chemical standpoint, there is no reaction that will take place between a synthetic and a conventional oil. They're made of the same building blocks and are both petroleum distillates. Yes. They're the same thing, just different carbon lengths. The only thing that makes these valve oils different from the aforementioned paraffin oils is degree of saturation. Find a good educational resource if you'd like to know more about this topic. Synthetic oils are all petroleum based molecules that are exceptionally uniform in length. They might span 10-13 carbons in length instead of 5-20 in length. You need those 5 carbon long molecules to balance out your 20 carbon long molecules. If you mix in synthetic oils, you can end up shifting the peak of the aforementioned bell curve and end up with something wax-ier than you'd like. That is my hypothesis on the rational behind this heuristic.
TLDR: I took Dana's advice and put a very thin coating of this oil stabilizer on my pistons and re-inserted them into the casings to see how airtight the seal was. I think my eyes would pop out before I could blow past the valves at this point. Playing a few notes yielded a slightly more stable slot than what I was getting before. I then began to wash down the heavily lubricated valves with my lamp oil mixture until they moved freely. I checked for airtight-ness and it was still there. I swear I can feel a marginal difference in the stability of the horn with this method. Like I said, the horn played well enough for me to shell out 10K to buy it before I did all of this. I just like it even more now! My friend also tried it on his old Martin Mammoth and felt a noticeable difference in his lower register response. Based on our experiences, I felt I had to share this method with the TubeNet community. Now, please enjoy a few photos of these two aforementioned horns.
As a disclaimer, the statements that I'm about to make are based on my experience as a degreed chemical engineer with all of my work experience being in polymers. If you don't want to read all of this, skip to the TLDR at the bottom
I'll start by saying that, as someone who is really anal about maintaining anything mechanical, the very first thing I did with this horn when I took it home was take it apart and clean it. Overall, things looked fine. The slides were almost dead nuts true on my surface plate and had very very minimal alignment issues. Everything pulled smooth out of the box, but with a little extra work they're even better. In my opinion, the 5th rotor could have been cleaner out of the box. Everything was thoroughly cleaned, polished, and measured with a micrometer for my own reference before re-assembly. I also used telescoping gauges to check the ID of the valve casing. The fit between the piston and the casing comes out to right around 0.0011" per side. This is larger than some of the instruments that I've played before. However, based on having played the horn for many hours at this point and consulting several professionals about the clearance, the valves were all sufficiently tight enough to provide stable and in-tune slotting. Based on this clearance I began formulating an oil to appropriately take up the space.
After reading a lot of positive posts about UltraPure lamp oil, I purchased a bottle of the stuff and began thickening it up with 30W motor oil. This is where I'd like to discuss my first point here- UltraPure lamp oil is a paraffin oil. Yes like paraffin wax.... but an oil instead. Paraffin wax candles are (essentially) made up of the same building blocks as what's in the UltraPure lamp oil bottle. But it's not what blocks we're building with that makes a valve oil become "gummy" or "sticky" over time. Rather, it's how many of those building blocks are strung together. Paraffin wax candles, being solid at room temperature, are made unsaturated hydrocarbon chains that are likely around 30 carbons long (plus or minus a few). It's this chain length that determines the melting temperature of the substance. A longer chain paraffin will remain solid at elevated temperatures, whereas a shorter chain paraffin will melt sooner at elevated temperatures. If your paraffin chains are short enough, they'll be liquid at room temperature. Such is the case with the UltraPure lamp oil. These molecule chains are, according to the MSDS, between 5 and 20 carbons in length. Based on my experience, I would guess that this is a bell curve figure with the center about 12 carbons in length. That being said, under that bell curve, are molecules that are 20 carbons in length. 20 carbons is a substantially different situation than 12 carbons. I haven't done the research, but I imagine 20 carbons would be nearing a waxy substance. In the event that you're really bad about oiling your valves regularly, you might just end up washing away some of the shorter chain molecules with your saliva and leaving behind some of the longer chain molecules. The shorter chain molecules will be more easily dissolved by the partially non-polar parts of your saliva. With this in mind, if you oil your valves regularly with some mixture of UltraPure and another thicker petroleum based oil, I cannot understand how you'd ever end up gumming up your valves. I I thickened my mixture up to the point where I felt the slightest drag on the piston and that worked very well for me for over a month of playing ~5 days out of the week.
At this point, I had more or less settled with this mixture being 'good enough' but I was curious as to how airtight it was holding my valves. After a fresh coat of oil, I removed my first slide, plugged the outboard side with my palm and blew down the leadpipe of the instrument. I could feel a slight leak in the air pressure. I wasn't really concerned with this as, like I said, the instrument played very well. I did however, want to try something different after consulting with Dana Hofer in Palatine, IL. He mentioned that University of Illinois professor Mark Moore uses an oil stabilizer on his pistons that he then washes down with valve oil. He does this on all of his piston horns. After reading into the idea, I understood more of the logic behind it. Oil stabilizers create a thin film 'slick' on motor piston seals that doesn't drain off as easily when the engine is shut off and the oil drains down to the pan. It essentially prevents wear upon startup.
In my head I imagined my tuba pistons having a bi-layer lubrication of oil stabilizer, and my UltraPure concoction. The bottle I purchased (HyperLube) indicated that the formulation was 100% Petroleum based. Dana advised using Al Cass as a good oil to wash down that slick layer. I don't think this was coincidental. This is where I'd like to talk about a second point- mixing synthetic and conventional oils. From a chemical standpoint, there is no reaction that will take place between a synthetic and a conventional oil. They're made of the same building blocks and are both petroleum distillates. Yes. They're the same thing, just different carbon lengths. The only thing that makes these valve oils different from the aforementioned paraffin oils is degree of saturation. Find a good educational resource if you'd like to know more about this topic. Synthetic oils are all petroleum based molecules that are exceptionally uniform in length. They might span 10-13 carbons in length instead of 5-20 in length. You need those 5 carbon long molecules to balance out your 20 carbon long molecules. If you mix in synthetic oils, you can end up shifting the peak of the aforementioned bell curve and end up with something wax-ier than you'd like. That is my hypothesis on the rational behind this heuristic.
TLDR: I took Dana's advice and put a very thin coating of this oil stabilizer on my pistons and re-inserted them into the casings to see how airtight the seal was. I think my eyes would pop out before I could blow past the valves at this point. Playing a few notes yielded a slightly more stable slot than what I was getting before. I then began to wash down the heavily lubricated valves with my lamp oil mixture until they moved freely. I checked for airtight-ness and it was still there. I swear I can feel a marginal difference in the stability of the horn with this method. Like I said, the horn played well enough for me to shell out 10K to buy it before I did all of this. I just like it even more now! My friend also tried it on his old Martin Mammoth and felt a noticeable difference in his lower register response. Based on our experiences, I felt I had to share this method with the TubeNet community. Now, please enjoy a few photos of these two aforementioned horns.