Tech/maintenance SHWoodwind Updates

[Ivan]

You've been watching too much tennis.

Unavoidable

Any tennis is too much tennis

 

[vries1]

Forte, 'FOR-tay"

vs

Forté, 'for-TAY'

Mebee it depends on how you hear it in your noggin while you type

Feeling flamboyant or transatlantic? Forté every time

I thought the water that separates the UK from the EU continent had a different name...

 

[vries1]

Of late I have become rather familiar with, if not to say entrenched in, the topic of leaks.

The handy hints of Steve's website contain, quite exactly as the title says, a lot of handy hints. Anyway, I found a subtle issue regarding statistical vocabulary in the leaklight article Making and using a leaklight :

"This, combined with other factors such as the condition and cleanliness of the pad, the profile of the tonehole rim and the state of wear in the action can lead to 'false positives' when checking the pad seat with a leaklight." (the term false positives is later re-used in the same sense)

Statisticians would call a signal found a positive, and no signal found a negative. In the context of leak checking, a leak would be a positive. And 'false positive' means, using this (generally accepted) convention, that a leak is found where none is present. I am rather sure that this is the exact opposite of what Steve meant. The correct wording for not finding a real leak would be 'false negative'.

(And a small typo in the left column with navigation links: there is a superfluous space in " Making and using a leaklight", just before Making)

 

[Stephen Howard]

I tend to take the view that a non-leaking pad is a positive thing, and that as much as the term is 'checking for leaks', the actual object of the exercise is checking for a good pad seal. This is why the sentence says 'when checking the pad seat'.

I'm not seeing the superfluous space in my browser, or in the web software. Maybe it's specific to your browser?

 

[vries1]

Yes, it may be a statistician's thing - catching a signal (typically, "something bad" - like a leak!) is counted as a "positive". A "false positive" is just a "false signal". For laymen this may seem counterintuitive. For the formal definition, you could check out, for example, False positive rate - Wikipedia

As for the left navigation link. It does render correctly in Chrome, but not in Safari. I inspected the web page code and I found that there is a spurious empty reference to the "Oiling the Action" page. Here's the html code for the Leaklight entry. The first <a> ... </a> part shouldn't be there. The content is just <b> </b> ("start bold - end bold")

CODE SNIPPET:

<li><a href="/HandyHints/oilaction.htm"><b></b></a> <a href="/HandyHints/leaklight.htm"><b><font face="Trebuchet MS, Verdana, Arial" size="2" color="#800040">Making and using a leaklight</font></b></a></li>



After this <li> ('list item') </li>, I see the expected and correct entry for oiling the action.

<li><a href="/HandyHints/oilaction.htm"><b><font face="Trebuchet MS, Verdana, Arial" size="2" color="#800040">Oiling the action</font></b></a></li>

 

[Stephen Howard]

An excellent catch!
Must've been a bit of leftover code after shuffling things around in my WYSIWYG website software. It has a 'clean-up' function, but you have to initiate it manually (which I rarely remember to do). When I did so it detected and deleted two unwanted tags...so there must have been something else invisibly lurking in the code.

 

[vries1]

The "Low A bari extension" in the same column has (or had) the same type of issue.

<li><a href="/HandyHints/Springhook.htm"><font face="Trebuchet MS, Verdana, Arial" size="2" color="#800040"><b>
</b></font></a><a href="/HandyHints/Bari_extension.htm"><b><font face="Trebuchet MS, Verdana, Arial" size="2" color="#800040">Low
A bari extension</font></b></a></li>

 

[vries1]

And in the soprano review section, same issue on the Boosey & Co Regent entry.

 

[vries1]

This is getting addictive.

Oiling the Action : "it collects in a small 'reservior'" (reservoir)
"Such oils are usually offered in a choice of grades (i.e light, medium and heavy)." (i.e.)

 

[Stephen Howard]

Fantastic! Cheers!

The html errors in the menus will appear in all articles in the relevant section, as the menus are library items (a single source shared by a number of articles).

Good catch on the i.e. - I suspect there'll be a fair number of those dotted around, as well as the odd malformed e.g.

 

[Stephen Howard]

Another Benchlife Blog update - I have a ream...

A rolling blog of everyday life on and around the workbench

 

[Ivan]

Another Benchlife Blog update - I have a ream...

A rolling blog of everyday life on and around the workbench

View attachment 9230

Next time I'm hungry at dinner time I'll order Fish and Swarf

 

[Stephen Howard]

Next time I'm hungry at dinner time I'll order Fish and Swarf

"D'you want cutting fluid on that, luv?"
"Nah fanks...I'll just stick with a dollop of Trefolex, ta"

 

[David Dorning]

Another Benchlife Blog update - I have a ream...

A rolling blog of everyday life on and around the workbench

View attachment 9230

Here's a bit of info about Nitromors and Maxolen gel paint strippers which bears out Stephen's observations. The formula of Nitromors gel changed a few years ago. It originally contained dichloromethane (aka methylene chloride) which is an excellent solvent for old paint layers where the oil binder has crosslinked. Crosslinking involves the oil molecules chemically reacting together and joining to form much bigger (and therefore much less easily soluble) molecules. It is why old paint layers or lacquers are hard to remove. Dichloromethane is good at breaking them down because it is chemically very similar to those paint layers.

Unfortunately the habit of decorators to cover large painted surfaces with Nitromors gel and then inhale the fumes for the rest of the day led to safety concerns, and the dichloromethane in Nitromors was replaced with a different (and perhaps inevitably) less effective solvent.

Googling “Nitromors gel” today I found: “Non methylene chloride formula. New Formula Nitromors All-Purpose paint and varnish remover is a new double strength, faster acting paint stripper suitable for use on wood, metal and masonry (no mention of saxophones!). New Nitromors is the direct replacement for Original Nitromors paint stripper”.

Double strength (as Stephen noted) or faster acting? The “strength” of a solvent is a relative quantity. Water is a “strong” solvent for salt, but a very weak one for old paint layers; whereas dichloromethane is a “strong” solvent for paint layers and a very weak one for salt. I’m sure the new Nitromors will be strong relative to some materials, but it certainly isn't strong to paint layers. Stephen’s experiments show it isn’t much cop on saxophone varnish either. The active ingredient is 1,3-dioxolane which chemically is in a different class from dichloromethane.

But looking at the Safety Data Sheet for the Maxolen Powerstrip Stephen used successfully shows it is a “Thickened blend of dichloromethane and methanol with surfactant and paraffin wax”. So it is a paint stripper that does contain dichloromethane, as did the old Nitromors. It obviously works nicely on saxophone lacquer and probably also on paint layers........ It's probably virtually the same formula as old Nitomors. The gel is essentially wallpaper paste with a little detergent added to help the dichloromethane mix in.

 

[Stephen Howard]

Dichloromethane - that's the stuff. The 'goodness' - just like the Toluene that used to be in Evo-Stik.

And yeah, it's exactly the same as old Nitromors - right down to the classic 'aroma', the faint hissing when you wash the gloop off, the way it eats through rubber gloves and makes your hand tingle...and the slow stinging pain when you fail to notice you've spilt a drop on your skin.

 

[David Dorning]

Dichloromethane - that's the stuff. The 'goodness' - just like the Toluene that used to be in Evo-Stik.

Ah toluene. Happy/hazardous days...!

 

[Targa]

Ah toluene. Happy/hazardous days...!

Happy Hazardous daze.
That and cellulose thinners.

 

[Tenor Viol]

I remember organic chemistry lab sessions for A Level chemistry - we used to use toluene, benzene, acyl chloride, acetone, ether. I doubt if any of those are allowed now 🙁

 

[vries1]

One can do worse.

In my Ph.D. thesis time, we cleaned stainless steel vacuum chambers for molecular beam epitaxy in the following way.

First, bathe in aqua regia to get rid of all metallic contaminants; don't forget to add a shot of hydrofluoric acid to be on the safe side. Then, bathe in pure trichloroethylene to remove organic material. Dry with pure nitrogen. The result is VERY clean, but don't apply this process to a saxophone, or your horn will just dissolve (and not just the lacquer)...

 

[kevgermany]

I remember organic chemistry lab sessions for A Level chemistry - we used to use toluene, benzene, acyl chloride, acetone, ether. I doubt if any of those are allowed now 🙁

I burnt myself with a mix of conc nitric and conc hydrochloric doing A level chemistry. I was so worried about breaking the glass flask that I didn't do the clamp up tight enough and so the flask dropped on the bench and smashed. The acid mix sprayed across the bench, wrecking my blazer and drew a neat line across the tops of my legs where the blazer stopped.