Pumice for slide cleaning?

[bigbandbone]

A young repair guy told me he learned from NAPBIRT to use a slurry of Lava Soap and water to clean trombone slides. I cringed!
Has anyone else heard of this or actually uses the technique?
I repaired for 44 years and don’t think I’d ever use this. Pumice is far to abrasive. And if you leave even 1 grain behind it would score both inners and putters.

[Posaunus]

[MTbassbone]

Makes me think of when a young student came to a lesson with a very scratchy sounding trombone slide, and when I asked if anything happened to his trombone he told me his little brother put "moon sand" in his slide. Ugh...Even after I snaked it out it was scratchy. I am guessing either there was still sand in there or permanent damage was done. Not sure what happened because summer break happened and they never came back.

[hornbuilder]

That is called a Texas Flush. It is NOT meant for handslides!!

It is used for the inside of "Tuning Slides"!!

[BGuttman]

I would certainly hesitate to use Lava Soap pumice to clean anything in a trombone. The pumice is pretty coarse.

When we used to clean circuit boards we used FFFF grade pumice, which is a fine powder. It's probably still too coarse for a trombone slide, but it's no more abrasive than UF Scotch Brite. I don't know where you would buy FFFF pumice except from an industrial supplier, and it comes in 50 pound (20 Kg) bags. You'd have to be someone like Matt Walker to use that much stuff.

[Doug Elliott]

"Abrasiveness" is a function of both the hardness of the abrasive and the grain size, and maybe whether the grain breaks down smaller in use.
Brass is pretty soft so any large grains are going to score it. I would think that Lava soap, to do its normal job on hands, would have large grains - that doesn't change just because you dilute it to a slurry.

[hornbuilder]

PS. I have used Texas Flush for instrument service work. Back in a previous life. The soap is chopped up into little pieces, then dissolved in water, with some added dish soap. You then use a plastic bristle brush in a drill to scrub the insides of tubes. It really didn't make obvious score marks in the brass, but did have enough "oomph" to get the insides of the tube back to a bright brass color, if you went at it long enough. (And as long as you had properly cleaned the part chemically before hand)

It is not spoken of.much in the repair industry these days...

[modelerdc]

I have one of those inexpensive Jin Bao Alto trombones that play better than they should for the price. Purchased new when they could be had for $150, mine had a scratchy sounding slide. I put some ordinary toothpaste on the outside of the inner tubes and worked the outer slide in and out for about 15 minutes. It took longer to clean all the toothpaste out, but when lubed up, the scratching sound was gone, and he slide worked well. I wouldn't do this with an expensive slide, instead I'd take it to a good slide tech. But for the Jin Bao alto it worked well.

[baileyman]

There's a tech in the north west (Ober-something?) who had a terrific video of slide servicing that involved some rather shocking procedures. Wish I could find that.

[OneTon]

Dan Oberloh is out in the south part of Seattle.

[Doug Elliott]

There's probably nothing wrong with using lava soap in the way that Matt described, with a brush, and wash it out afterwards. It's when you add metal to metal contact that it's going to scratch one or both surfaces.

[OneTon]

When I lived in North Africa it seemed like grains of sand were constantly getting into the hand slide. It did not seem to matter whether there was a ghibli blowing or not. The saving grace was that Libyan sand had been blown around by the wind so much that the edges of the sand particles were rounded off. Thus, for construction grade concrete, sand had to be imported from Norway to achieve the proper lattice. The rounded off Libyan sand did not ever seem to do damage to the slides. It was merely extremely annoying. Murphy’s Law says that pumice used for cleaning will always find someplace to lay up, and turn loose at the least opportune moment.

[brassmedic]

The Allied Catalog has an article on this, written by Hal Hall. He claims the pumice "breaks down as you use it". I have never tried this method of cleaning.

texasflush.png

[brassmedic]

By the way, does anyone still use "soap bark"? I don't even know what that is, but all the old-timey repair sources talk about it.

[BGuttman]

Pumice is a crushed volcanic rock, mostly silica. It really doesn't "break down", although it does have sharp edges that flake off, much like the Libyan sand OneTon talks about. I still say that the grade of pumice in Lava Soap is pretty coarse. I would suggest a much finer grade for this flush process.

[OneTon]

Just thinking about it gives me PTSD.

[tbonesullivan]

This does bring up a question I have had before though: just how clean should the inside of the horn be? Is there any benefit to pretty much buffing the inside of the horn? Does it mean that it will take longer for corrosion and deposits to build up?

I also have heard of some people using lamp oil or similar oils to coat the inside of instruments after cleaning to help prevent future corrosion.

[Crazy4Tbone86]

This does bring up a question I have had before though: just how clean should the inside of the horn be? Is there any benefit to pretty much buffing the inside of the horn? Does it mean that it will take longer for corrosion and deposits to build up?

That is an interesting question! You can use this information to start a data bank……the inside of my late 1990s YSL-683 has, by far, the most polished and shiniest interior horn of any horn I own, at least in the bell section. Yet, it seems to accumulate mineral deposits faster than all others.

Back to the Texas Flush. I do still keep a canister of the stuff around. I must add water, stir it vigorously and allow it to soften up about 2 hours before every use. I find it best for removing stubborn gunk on the inside of inner slides (must be careful around the leadpipes), straight goosenecks and long tuning slides on large horns (euphoniums and tubas).

If a student trombone comes in and has EXTREME calcium build-up in the slide, I will use it on a circular rod/brush (sometimes chucked in a lathe) combined with a chem clean on the inside of the outer slide. The end results are pretty good but the labor is increased because it takes several wash/swab cycles to get the grit out of there. The grit does break down, especially when the lathe is used. It starts with the larger grains and ends with a fine black silt……almost silky to the touch.

[timothy42b]

That Texas Flush article says on trombone handslides? That sounds pretty scary to me, probably not for DIYers.

[Crazy4Tbone86]

That Texas Flush article says on trombone handslides? That sounds pretty scary to me, probably not for DIYers.

I was taught the Texas Flush technique back in the 1990s and I think it faded away with techs over the next 10-15 years. Again, I use it, but only for extreme situations.....maximum of once or twice a year.

I used it on a trombone back in June. To give you an idea of how extreme the trombone was....when I took the instrument out of the case and pulled the inner and outer slides apart, a small cloud of white powder (calcium) went into the air. The instrument was used by a parent back in the late 1990s and then stored for 20+ years. He wanted to resuscitate the trombone for his kid. This particular trombone slide turned out rather well.....it was a miracle that there was no red rot!

The biggest problem with doing a Texas flush on a trombone slide is NOT the potential for damage. The hassle is the cleaning process.....that gritty silt gets in all the nooks and crannies of the slide and takes a lot of effort to remove. Wash, swab, lube the slide, move the slide up and down for 15-20 minutes, repeat. Sometimes you must repeat the process a dozen times or more. For a technician, it is NOT a cost effective way to clean/polish the inner parts of a slide. That's why I only do it on those rare slides that are really bad.

[Cush]

My tech has used Lava soap and a brush on a drill as the final stage of a slide cleaning for years. He starts with cheesecloth on a rod, then an ultrasonic cleaning, then a short dip in etch cleanse then the long brush on a drill, then thorough rinsing, then compressed air through tie slide tubes to speed up the dry time (and perhaps purge any remaining grit/sediment? after the rinse?), then left to hang to dry.
I have watched him do this countless times and do not know how long it took him to master the routine. It only takes him a few seconds to create his “slurry” and he does it in real-time with each cleaning by holding the big bar of Lava soap to the spinning handdrill-mounted brush under some running water over his cleaning vat. The “slurry” is formed on the brush to whatever sudsy thickness his 50 years of experience have taught him feels right.
There may be some cringe-worthy risk to pumice for slide cleaning as a DIY exercise, but I know I am in good hands when my guy performs his magic.

[timothy42b]

There was a thread awhile back about taking a little bit of brass off the top of the outer slides, because that area was catching on the stockings and causing slide action problems in long positions. I looked for that thread but couldn't find it.

Is that one of the things this Texas flush is used for?

[Crazy4Tbone86]

There was a thread awhile back about taking a little bit of brass off the top of the outer slides, because that area was catching on the stockings and causing slide action problems in long positions. I looked for that thread but couldn't find it.

Is that one of the things this Texas flush is used for?

I have had a few slides that were tight in 7th position and I used the spinning pumice brush a little longer up near the end of the outer slides. It made a subtle difference.

I think it goes without saying that a tech needs to be careful with any tool that has the potential to remove metal. It only takes 1 or 2 thousandths of an inch to go from a fantastic slide to something that doesn’t respond well because the clearance between inner and outer slides is too much.