Question: *NOT* Bore Honing at Home

[Pipion]

Hey all,

I have a Bach student trombone (I think a TB301, but I can't find a number on it) that I got from a friend who played it in high school. Being a school instrument, it has a fair amount of damage. It is functional, but the slide bore is incredibly sticky.

My question is this: What type of cylinder hone should I use to clean up the inside diameter of the slide? Is there anything I should know about before/while/after honing the bore? Any and all advice is appreciated.

Edit: See more detail in reply below

[JohnL]

Please, put down the flex hone and step away from the trombone.

The tubes (inners and outers) need to be checked and, if necessary, straightened. The outer tubes need to be de-dented, cleaned, and polished. Honing is a last resort, if it's a resort at all.

If you look around, you'll find information on polishing outer slide tubes.

[ghmerrill]

I'll attempt to answer the original questions ...

Honing can be accomplished with one of a number of abrasive compounds. You of course want "non-embedding" compounds, and my favorites are Brownell's J-B Bore cleaning compound or one grade or another of Timesaver (TM) Lapping Compounds. (You can always try toothpaste, of course.) For the Timesaver products you'll want the "Yellow Label" varieties designed for soft metals such as brass. Just use the J-B Bore paste directly or make a kind of slurry (oil or water) with one of the Timesaver Compounds, apply it to the inner slide, work that back and forth in the outer slide until you get tired of it, and then rinse it off thoroughly. Check the result.

You very likely (almost certainly) will have ruined your slide for any use in a musical instrument, but it probably will work slick as a whistle -- unless, of course, it's bent! (In full disclosure, I have lapped some instrument tubes in this manner, but only under very specific conditions, and only very carefully. I have never lapped a trombone hand slide in this manner.)

An alternative is to take the slide to a competent repair tech (preferably one who specializes in hand slides) and see what he can do about fixing it. He'll have all the tools and experience, and it will probably cost you less than getting the compounds necessary to ruin the slide itself. This is especially true if the slide is bent -- in which case the problem can still often be quickly and inexpensively remedied by an experienced instrument tech, but can never be remedied by "lapping".

Just some thoughts based on experience.

[brassmedic]

Yes. The magic cylinder hone that fixes everything. Available from....

[BGuttman]

The "hone" I've seen used on slides is called a "slide rod". It comes in a variety of diameters generally a few thousandths less than the nominal bore of the tube. You can grease it up and as a final touch after pounding out dents just ream the slide with it. But the slide has to be de-dented and straightened first.

A set of rods can set you back a few hundred dollars. Just perfect for that $30 garage sale special instrument

[ghmerrill]

Yes. The magic cylinder hone that fixes everything. Available from....

Doesn't Ferree's or Allied sell one of those? It's been a while since I looked.

[ghmerrill]

But in place of snarky comments, this may be useful as an educational resource: (Ferree's) Basic Slide Straightening https://www.ferreestoolsinc.com/pages/b ... b153&_ss=r

And given the original description, for all we know, the problem may be that the slide is just dirty and needs a good cleaning.

[hornbuilder]

The "hone" I've seen used on slides is called a "slide rod". It comes in a variety of diameters generally a few thousandths less than the nominal bore of the tube. You can grease it up and as a final touch after pounding out dents just ream the slide with it. But the slide has to be de-dented and straightened first

All of this is a BIG NO!! This is NOT how slide mandrels are used!!!

Handslide tubes are not "honed". There are several processes involved in correct slide repair that are performed in a particular sequence. (The first of which is diagnosing what the actual issue is!) This is something you learn in Band Instrument Repair training. If you don't have that training, or experience in the field of BIR, please don't offer "advice" on instrument repair. You're not helping.

[hornbuilder]

And given the original description, for all we know, the problem may be that the slide is just dirty and needs a good cleaning.

Yes, this is absolutely correct. Unfortunately with an Internet public discussion forum such as this, there is no way to physically evaluate the slide in question. But it is certainly the case that a lot of slide performance issues are attributed to how clean the slide is, and how well it has been cared for.

[ghmerrill]

I was actually planning on cleaning my bass trombone today. At least it's a LOT easier than the tuba.

[CharlieB]

I'm guessing that this is the horn connected your below post from last August ??

Back to Basics
Post by Pipion » Thu Aug 24, 2023 3:14 am
Hey all, new member here, and I'm looking for some advice.
I picked up trombone as a secondary instrument about a year ago, and have made progress towards becoming proficient.

If it makes you feel good, you can swab the outers with some non-aggressive brass polish, but NO abrasive honing.!!!
Given that the horn's former life was as a "student beater," odds are that the slide is either dented or bent. I would get a quote from a good slide tech for the cost to evaluate the slide and (maybe) proceed with repairs.
A sticky slide can lead to frustration and bad habits, especially for beginners. Not good.

[brassmedic]

Yes. The magic cylinder hone that fixes everything. Available from....

Doesn't Ferree's or Allied sell one of those? It's been a while since I looked.

They sell a "flex hone", but it's not really a hone. It's a bunch of little abrasive spheres attached to the end of a flexible rod. I have a couple, but I don't use them. I think it's way too aggressive for a trombone slide. And it could be disastrous in the hands of an untrained person.

[ghmerrill]

I'm guessing that this is the horn connected your below post from last August ??

Back to Basics
Post by Pipion » Thu Aug 24, 2023 3:14 am
Hey all, new member here, and I'm looking for some advice.

If it makes you feel good, you can swab the outers with some non-aggressive brass polish, but NO abrasive honing.!!!

Not only non-aggressive, but non-EMBEDDIING (two different properties). Non-embedding brass polish is really hard (impossible?) to find outside of industrial supply or "specialty" sources. If it's a readily available commercial abrasive (as opposed to purely chemical) brass polish that you can find (in various stores), it is almost certainly embedding. The J-B Bore Cleaner I mentioned is non-embedding and also highly non-aggressive. I have used it for "polishing" hand slide action. It's probably the easiest non-embedding abrasive polish to get (it's on Amazon), but it's not cheap.

But, as several people have pointed out here. You don't want to even think about such an approach until you know that the slide is otherwise "correct".

[ghmerrill]

Doesn't Ferree's or Allied sell one of those? It's been a while since I looked.

They sell a "flex hone", but it's not really a hone. It's a bunch of little abrasive spheres attached to the end of a flexible rod. I have a couple, but I don't use them. I think it's way too aggressive for a trombone slide. ...

Well, my question there was a joke. I haven't seen the one you mention, but so far as I've previously seen, the only genuine hones they sell are for cylinders on valved instruments.

And it could be disastrous in the hands of an untrained person.

WOULD be, I think. I'm sure we've all totally ruined things in learning to use various abrasives. I know I have.

[hornbuilder]

Yes. Honing is a precision operation where parts are brought to very specific, repeatable dimensions

The flex hone is far from a precision tool!!

[Pipion]

Thanks for the replies all, some more info:

I'm certain now that I'm using the wrong terminology. I said I need to hone the bore, but really I just need advice on how best to repair the bore, not necessarily honing. For reference, I'm a machinist by trade, so the process of honing is familiar to me, and I just assumed its the process used to accomplish the fit of the slide.

Otherwise, the slide itself is straight and dent free (aside from any micro-dents that I have no way of detecting), and it has been rigorously cleaned multiple times to try to fix the issue. I assumed the only recourse I had left was re-finishing the bore - eg. honing. There may be something I missed though, I haven't gone as far as chemical solutions, just a soft bristle brush snake, dish soap, and elbow grease. I'm not sure if it'd make much of a difference, but the next step for cleaning would be here: https://www.ferreestoolsinc.com/pages/b ... e-cleaning. I'm sure the recommendation will be to do this regardless, just keep in mind that this isn't my first attempt.

As for the damage, the inner slide had a couple minor burs that I have been able to gently remove, but the outer slide has proven more troublesome. After some finagling with a flashlight, I can tell there's some orange-ish spots close to the open end (maybe exposed brass?). The most stickage occurs at the bottom of the travel (1st position, let me know if there's better terminology), which I can't see at all. I'm hoping this isn't an issue with the plating, as that might blow away any hope of doing this myself.

My goal here is to not spend too much time/money on this instrument, as I'd rather save up to just get a better trombone, so I'm looking for anything to improve its condition, not a complete refurbish. Thank you all for the advice so far, I hope this cleared up some of the confusion.

[Pipion]

You very likely (almost certainly) will have ruined your slide for any use in a musical instrument, but it probably will work slick as a whistle -- unless, of course, it's bent! (In full disclosure, I have lapped some instrument tubes in this manner, but only under very specific conditions, and only very carefully. I have never lapped a trombone hand slide in this manner.)

Sounds like you're advising against this course of action, so I won't pursue it. However, I am curious as to why this would ruin the instrument, if you could explain.

[ithinknot]

Otherwise, the slide itself is straight and dent free (aside from any micro-dents that I have no way of detecting)

Do you know that you know that? What have you done to check straight and parallel in all planes (inc the relationship between the stockings and the main length of the inner tubes)?

There may be something I missed though, I haven't gone as far as chemical solutions, just a soft bristle brush snake, dish soap, and elbow grease.

... so it's not clean at all. Descaling through chemical means is mandatory. You can snake with dish soap until the end of time without shifting significant calcium deposits. White vinegar, 15-20 mins, then snake/soap/etc. If that's not enough, multiple short rounds with brushing between is the way to go; don't just let it sit for longer.

the outer slide has proven more troublesome. After some finagling with a flashlight, I can tell there's some orange-ish spots close to the open end (maybe exposed brass?) [...] I'm hoping this isn't an issue with the plating, as that might blow away any hope of doing this myself.

Outer slides aren't plated.

There are still some significant knowledge gaps and misconceptions here.

I don't doubt your competence as a machinist, but in this case you're looking at a system, not just a surface.

Without the correct procedural order and diagnosis, further actions are - at best - a waste of time, and potentially destructive.

(It's also quite possible that the instrument you're describing is Not Great... not only can a good tech diagnose it properly, they can also tell you if you'd be throwing good money after bad. Either service would be worth the fee.)

[ghmerrill]

Sounds like you're advising against this course of action, so I won't pursue it. However, I am curious as to why this would ruin the instrument, if you could explain.

I'm sorry, but I think I'm going to withdraw at this point. I honestly felt that you were likely a young trombonist with little or no experience with instruments, their care, or their repair. Now you say that you are a machinist by trade -- which means that you should have a great deal more knowledge than I do about these issues. But you seem totally unfamiliar with some of the fundamental issues, problems, materials, products, and techniques of dealing with something as simple as cleaning a precision-made tube. And you've misused fundamental terminology.

This is not a coherent picture, and I don't think I can possibly be of any help.

[CharlieB]

You very likely (almost certainly) will have ruined your slide for any use in a musical instrument........

[/quote]
Sounds like you're advising against this course of action, so I won't pursue it. However, I am curious as to why this would ruin the instrument, if you could explain.
[/quote]

To answer your question about honing ruining the instrument.....
The working clearance in a trombone slide has to be very tight, or the horn will not respond well.
As an example, if you hold an assembled (good) trombone slide vertical, cover both open ends with your thumbs and allow the outer slide to fall by gravity, a good slide will take seven to ten seconds to fall its full length. It is very nearly air-tight. Opening up the working clearance between the inner and outer tubes, say by honing, will allow more air loss, decrease that drop time, and allow bad acoustic things to happen.

[Blabberbucket]

Please take your slide to a competent musical repair tech. That is all.

[tbonesullivan]

Please take your slide to a competent musical repair tech. That is all.

Seconded. There is no "machinist friendly" tool that fixes slides. It's not the liner of a cylinder in an engine block. Outer slides are made from unplated brass or nickel silver alloys. The inner slides are usually made from nickel silver alloy which is chrome plated on the exterior.

What you need to fix slides is years of experience and knowledge, a perfectly flat leveling stone, sunlight, steel rods of various thicknesses, some burnishing tools, and a bunch of other things I haven't even thought or heard of.

This reminds me of my current youtube fix: guitar amplifier repair videos. One very well regarded tech mentions that this amp he is working on is owned by a friend of his who does HVAC system repairs and such, and as such can do some minor things, but also realizes that there are things he really can't do, and when he knows it's above him, he brings it to the tech. The tech also says that when he has an HVAC problem, he usually will call his friend as he's not an HVAC expert. There are some similar skill sets, yes, but vastly different implementations.

[Kbiggs]

… a good slide will take seven to ten seconds to fall its full length. It is very nearly air-tight.

Except a Bach slide!! #%$&@!!

[Burgerbob]

Except a Bach slide!! #%$&@!!

My Bach slides seal very well.

[ghmerrill]

There are some similar skill sets, yes, but vastly different implementations.

You mean to say that even though I've got some wire cutters and strippers, and know how to use wire nuts, I shouldn't attempt commercial 3-phase power repairs? That's pretty elitist of you. What could go wrong?

I've seen a slide straightened. You have to wonder how many practice sets were damaged/ruined in order to acquire those skills.

[hornbuilder]

Even after working in this field for 30 years, with high quality slide work being one of the skills I pride myself on, it still happens that tubes will fail in the process of straightening. It's just the way it is. Surprises you every single time, too!!

[Kbiggs]

Except a Bach slide!! #%$&@!!

My Bach slides seal very well.

Mine are okay. That is, they are good for a Bach, not as good as a Conn, a King, or a Yamaha.