Dented slide crook. Is it worth fixing?

[JCBone]

My old yamaha came with a dented slide crook. As I understand, this is not always an easy fix. So how much does it really affect the sound and is it worth it to fix?

[BGuttman]

Really depends on a lot of things.

Mostly, how bad is the dent. If it's just a small depression you may never notice the effect. If the crook is crushed nearly flat you may have to do a repair. If the dent has a hole in it (even a crack) it needs to be replaced.

The other factor is how sophisticated you are. If you are a beginner or even a moderate player you may not notice the problem. If you are a top pro (and if you were you probably wouldn't be asking this question) you may notice the effect.

Slide bow repairs require unsoldering the bow, doing the repair, and then rebuilding the slide. If the bow is too damaged it needs to be replaced. It's an expensive repair for a modest amount of damage, but it could be necessary.

[Matt K]

Yamaha crooks are pretty cheap and also pretty readily available. Many techs require you to do a full slide service if you replace it but you're still possibly under $150 or $200 all-in, including a replacement crook and the slide will also probably be in better shape one way or the other too.

[JCBone]

Here is an image of the damage

[BGuttman]

Looks like a "stood the trombone on the slide and used it as a support" type of damage. It doesn't look too bad. If you are using it in hazardous duty (Marching Band, "dive" gigs) it's probably not worth the effort. If you need it to be perfect for appearance, you may find that it needs to be replaced. If it's a school horn, don't waste any money on it.

[Elow]

Yamaha sells the crook assembly for $25.72, so that plus tech labor, which probably wont be too much. The site says contact for availability so might have to wait a bit, not sure how long but im waiting another 5 months for a tuba rotor part.

[tbonesullivan]

I would replace it. That is enough constriction to merit it. It will probably be cheaper to replace it than to go through the trouble of trying to get that end bow back to the correct shape.

[Burgerbob]

Only worth it if you have a good slide tech around. The whole assembly will have to be aligned afterwards. Torching it off is the easy part!

[robcat2075]

That is such a common dent I'm surprised someone hasn't made a tool to grab that stub and pull it out.

[BGuttman]

That is such a common dent I'm surprised someone hasn't made a tool to grab that stub and pull it out.

You really need to push it out from inside. The knob is soldered to the outside of the crook and you will probably just pull it and the guard off the crook.

[timothy42b]

Slide bow repairs require unsoldering the bow, doing the repair, and then rebuilding the slide. If the bow is too damaged it needs to be replaced. It's an expensive repair for a modest amount of damage, but it could be necessary.

We had a slide tech talk to a group of us at a trombone day a couple years back. He had a beater horn and a torch and completely disassembled it, also showing us how damage occurred. Very interesting.

He addressed slide crook dents and why they are expensive. You have to unsolder the outer slide and rebuild it. But then to do it right you also have to unsolder the inner slide and get that distance and alignment perfect. It takes a lot of skilled technician time.

[hyperbolica]

My tech told me that the threshold for repair of that sort of thing is 1/3 occlusion of the crook. The repair usually means removing the end pin plus the end guard, flattening/straightening/rerounding and then reassembling it all in addition to pushing the dents out of the crook tubing.

That's one of the damage items I look for on used horns that might disqualify a horn. It's a sign of abuse, and the rest of the slide can't be in good condition if the end has been smashed so hard (and probably more than once).

In the end, if you play it, and it seems ok, then it's ok. I personally wouldn't buy a horn like that unless I intended to replace the crook.

[robcat2075]

That is such a common dent I'm surprised someone hasn't made a tool to grab that stub and pull it out.

You really need to push it out from inside.

That would be ideal. But given the above-noted complexity and cost of doing that, a hand tool that would get 90% of the result in 1% of the time would be a handy thing for the school band director with multiple cases of this every year.

The knob is soldered to the outside of the crook and you will probably just pull it and the guard off the crook.

Maybe. Or... it might work.

If the knob did come off, you could tack it back on with some temporary glue until it can go to the repair tech.

[Crazy4Tbone86]

On most Yamaha models, the crook is very close to or the same exact bore as the outer slide. If the crook bore is the same as the outer slide or smaller than the outer slide (I just did a Bach TB300 last week that had that situation), the crook dents can many times be removed without removing or replacing the crook. However, if the crook bore is larger than the outer slide (Bach 42 and other .547 bore horns with a bass crook), the crook usually needs to be removed to completely remove crook dents.

There are three or four techniques and some specialized tools that can be used for removing crook dents without removing the crook. For crooks that look like the photo, I can usually repair those about 80-85% of the time without removing/replacing the crook. One huge variable that can change everything is excess solder. If there is a lot of excess solder on the inside of the crook-to-slide ferrule connections, if can be impossible to access the crook with dent tools.

I usually only need to replace the crook if there is a crack/tear in the metal or the metal is extremely work-hardened (for the work hardened crooks, I sometimes remove them, anneal the metal and then reinstall them). The one thing that I frequently replace is the crook guard. I would definitely replace the crook guard for the trombone in that photo.

Note: Please DO NOT attach parts to brass instruments with glue! Technicians (at least all the technicians I know and myself) really hate that. Depending on the adhesive, you can really create a mess and extra work for your technician.

[robcat2075]

Here's another idea...

A long cable, long enough to reach down the slide, around the crook and back up the other side. It would have a threaded end that would screw into a steel ball that you would then pull back through the crook.

The balls would come in a set of gradated sizes. You'd start with the smallest one and work up to something that approached the proper inside diameter.

A jig would hold the slide by the crook to your work bench so all you have to be doing is pulling the cable straight on your end.

Ta-Dah!

CrookBallCable.jpg

[BGuttman]

Actually, there are dent balls that go on flexible rods. Imagine having to take a dent out of a French Horn. I'm sure Crazy4 has one of these tools. Moderate dents can be fixed this way, and it's not too different from what you are suggesting.

Again:

School horn: don't bother.
Marching Band horn: don't bother
1930 Conn Fuchs: bother.

[Crazy4Tbone86]

There are actually similar tools that already exist on the market. I like to use cable tools for graduated tubes like horn, baritone and tuba leadpipes.

Using such a cable tool for dents in trombone slide crooks could present certain problems:

1. If the dent ball is stuck at any point in the slides, ferrules, or the crook, the torque of pulling it either direction can easily bend the slide tube(s).

2. You will need a set of about a dozen or more jig blocks for all of the different size crooks.

3. Removing a dent is not just a process of pulling a dent ball through the dented area. A technician must also tap on the dent (a specific way) with a special dent hammer with the dent ball under the dent (the metal bounces off of the dent ball and moves outward). If such a tool were used, the technician would need to remove the slide from the jig repeated in order to tap the dents out with a dent hammer. A large crook dent might require the slide to be removed from the jig dozens of times....that's quite labor intensive compared to techniques that are commonly used.

Robert, I don't want to burst your bubble. I definitely admire your ingenuity!

[Matt K]

The cost/benefit depends greatly on what is being fixed too and in this case, being a Yamaha, the part is so cheap and the labor probably is too... if it has that issue it probably has other issues too with alignment so soldering on a new one and having it aligned, etc. will cost almost the same including parts and labor. But if like Bruce mentioned... this was an older horn or the crook were expensive to replace, that equation certainly changes. A new Shires part is like $300 which is probably 2x the cost of the entire operation on a Yamaha.

[Crazy4Tbone86]

Very good point Matt K. When I worked in a retail music store repair shop, the rental trombones would come through by the hundreds. The crooks on King 606 trombones were notorious for being smashed in. For that particular model, it was no-brainer. We would replace the crooks almost automatically because the cost of labor for removing the severe dents was higher than the cost of replacement parts + shorter time it took to replace them.

For some other models, it was the opposite. If the crook was an expensive part, we would spend 30-60 minutes removing the dents because the labor was cheaper than replacing the part.

[Doug Elliott]

Replace the crook and use the old one to practice dent repair on.

[CharlieB]

The sound/feel of the horn will be affected some by the dent. Probably not enough to be of concern for most uses.
Slide action is a more important consideration..
Nothing is more frustrating to both experienced and beginner players than a slide that catches or drags.
It is possible that the damage to he crook has distorted its shape, resulting in poor slide alignment.
How does the slide action feel ? If it's OK, doing nothing may be the best option.
On the other hand, money spent to make the slide "nearly perfect" would not be wasted on a Yamaha (354?). They are good horns.

[robcat2075]

The need for a different jig for every possible crook could be eliminated by immersing the crook in some solidifying liquid. Water is easily solidified. Cement with a divider left in is another possibility.

To prevent solidified liquid from blocking the expansion of the dent, the exterior of the dent would be first filled in with a solid that will keep out the liquid but is easily collapsible otherwise. Something like the expanding foam one sprays out of cans

Or perhaps a packing peanut sculpted to shape, then sealed over with tape.

IceJig.jpg

Robert, I don't want to burst your bubble. I definitely admire your ingenuity!

You don't need to worry that I intend to pursue this. There is no "bubble." I'm not the one with horn that needs fixing.

But until I posted, the prevailing response was that the crook HAD TO BE TOTALLY REMOVED or nothing at all.

That didn't sound right.

And it turns out it isn't right.

[BGuttman]

Not quite. It's a matter of economics.

If the crook costs less than the labor to remove the dent, replacement is preferred. Remember, dent removal takes time and a good repairman deserves to be paid for it.

Replacement or repair is not free. If the slide can function as is, that is the most economical solution. I played a gig with a slide with a real bad bow dent and it worked out fine. School owned horns are the responsibility of the School, and kids should not be responsible for damage committed by others.

[brassmedic]

Sometimes I can grab the knob in a vise and pull the dent out enough to then get dent balls in. But this one was smashed so hard, the knob is almost flush with the surface of the crook. How do you even do that?! There's no way just resting it on the slide bow did that. It's almost like kids are TRYING to do major damage. On this one I would take off the guard for sure. Or just replace the whole crook.

But for less severe damage, there seems to be a myth that it's impossible to repair dents in a crook without removing the crook. Not true. You don't need a cable either. You run a dent ball down the slide tube into the crook and use a smaller ball (or multiple ones) as a driver to tap the dent ball under the dent. Then you can hammer around the edges of the dent so that the dent is pushed out. There is usually a bit of constriction where the crook is soldered to the slide tubes, but the dent ball doesn't need to be the absolute exact size of the ID of the crook. A skilled tech can do a satisfactory job of taking out a dent with a slightly smaller dent ball. This even works if the crook is a larger bore, like Bach 42. I like to think of taking the slide apart as a last resort. Sometimes it's necessary, but it's not automatically the first thing I would try.

[brassmedic]

The need for a different jig for every possible crook could be eliminated by immersing the crook in some solidifying liquid. Water is easily solidified. Cement with a divider left in is another possibility.

To prevent solidified liquid from blocking the expansion of the dent, the exterior of the dent would be first filled in with a solid that will keep out the liquid but is easily collapsible otherwise. Something like the expanding foam one sprays out of cans

Or perhaps a packing peanut sculpted to shape, then sealed over with tape.

IceJig.jpg

Robert, I don't want to burst your bubble. I definitely admire your ingenuity!

You don't need to worry that I intend to pursue this. There is no "bubble." I'm not the one with horn that needs fixing.

But until I posted, the prevailing response was that the crook HAD TO BE TOTALLY REMOVED or nothing at all.

That didn't sound right.

And it turns out it isn't right.

Seems like a lot more work than just taking the crook off. How much does a freezer large enough to accommodate a trombone slide cost, how much does it cost to operate, and how much space does it take up in your shop? And I'm not even sure that would work. They do use soapy water to bend tubing, but I believe they have industrial freezers that are colder than commercial ones designed for food, and I imagine those are REALLY expensive. At some point you have to consider whether the cure is worse than the disease.

[Elow]

I just replaced a trashed crook, it cost the shop like $40 for parts, and i would much rather just have a new crook than fixing a banged up one.

[timothy42b]

Hmm. What about dent ball on the inside, neodymium magnet on the outside?

[BGuttman]

Hmm. What about dent ball on the inside, neodymium magnet on the outside?

This would work great on a small dent. On the slide shown by the OP I think it's like trying to fight a tsunami with a tablespoon.

[brassmedic]

Hmm. What about dent ball on the inside, neodymium magnet on the outside?

This would work great on a small dent. On the slide shown by the OP I think it's like trying to fight a tsunami with a tablespoon.

In my experience, magnets work great for big tuba bows, but when you get down to a little ball bearing that's 1/2 inch diameter, it just doesn't generate enough magnetic force to take out a dent.

[timothy42b]

This would work great on a small dent. On the slide shown by the OP I think it's like trying to fight a tsunami with a tablespoon.

In my experience, magnets work great for big tuba bows, but when you get down to a little ball bearing that's 1/2 inch diameter, it just doesn't generate enough magnetic force to take out a dent.

On a related idea, BBs for cleaning. I haven't done this on an instrument but several times I've needed to clean crud out the inside of some object where I couldn''t reach a brush in, and just pouring water through didn't work. So I throw in a spoonful of regular .177 airgun BBs, a little water and dish soap, and swirl around until clean. Pour the Bbs into a colander and rinse them off.

With a trombone I'd worry about one getting stuck in a valve though. Might want to count how many you put in, if you try that. I don't intend to.

[boneagain]

In my experience, magnets work great for big tuba bows, but when you get down to a little ball bearing that's 1/2 inch diameter, it just doesn't generate enough magnetic force to take out a dent.

On a related idea, BBs for cleaning. I haven't done this on an instrument but several times I've needed to clean crud out the inside of some object where I couldn''t reach a brush in, and just pouring water through didn't work. So I throw in a spoonful of regular .177 airgun BBs, a little water and dish soap, and swirl around until clean. Pour the Bbs into a colander and rinse them off.

With a trombone I'd worry about one getting stuck in a valve though. Might want to count how many you put in, if you try that. I don't intend to.

Sounds a lot like "balling out" a curved part. That would be quite a stack of balls down the outer slide tube. OR a long driver down there. Something to hold it it place.... AND the bow guard STILL has to come off, or the balls will just make a reverse curve in the insided of the bow.. in fact, it is likely to with ANY balling that does not have an "opposing force... so you COULD make a die, to preserve the inside shape while forcing the outside....

I think you get the idea. Some seriously clever people over the years have thought of MANY alternatives, and keep coming back to taking the lower slide apart, removing the outer reinforcement, reaching around to redistribute the stretched metal to less acoutically problematic spots, then realigning the slide.

And how did I come to this conclusion? By suggesting things like your good and reasonable idea to a master craftsman, who kinda laughed and ALMOST said "go ahead and try it" before taking pity on me and walking me through all the bits and pieces.

[Crazy4Tbone86]

I just replaced a trashed crook, it cost the shop like $40 for parts, and i would much rather just have a new crook than fixing a banged up one.

Let us all remember that $40 is not the actual cost of this repair. There is the labor cost of replacing the crook, soldering on the water key parts, drilling the water key hole, soldering on the crook guard (because many replacement crooks are supplies as just a blank crook), realigning the slide tubes and possibly needing to adjust the inner slide width. Many repairs require a chemical cleaning prior to the solder work. All of these labor costs really start to add up. Let's say that the slide has several "other small issues" and the total time to get the slide in great order is 1.25 hours. In my area of the USA, the average labor cost for instrument techs is in the $65 -$70 per hour. That would put the crook replacement in the $121.25 to $127.50 range.

Now let's say that the technician chose to keep the original crook and remove the dents. The technician only needed to replace the crook guard at a cost of $6.00 (I'm just throwing a number out there). The total time for the repair was 45 minutes and there was a $3.00 mandatory shop lacquer touch-up fee (just to make the story more spicy). At $65 - $70/hour labor, the total cost of this repair is now only $57.75 - $61.50. Sure, the crook might have slight scars from the dent work....but, the total cost of the repair is half of the other option. These are the choices that repair technicians must make constantly.

[brassmedic]

In my experience, magnets work great for big tuba bows, but when you get down to a little ball bearing that's 1/2 inch diameter, it just doesn't generate enough magnetic force to take out a dent.

On a related idea, BBs for cleaning. I haven't done this on an instrument but several times I've needed to clean crud out the inside of some object where I couldn''t reach a brush in, and just pouring water through didn't work. So I throw in a spoonful of regular .177 airgun BBs, a little water and dish soap, and swirl around until clean. Pour the Bbs into a colander and rinse them off.

With a trombone I'd worry about one getting stuck in a valve though. Might want to count how many you put in, if you try that. I don't intend to.

Somebody stole your idea.

https://www.ferreestoolsinc.com/product ... aner-balls

[Matt K]

I would suspect that you would want to realign the slide with a dent that bad. The cause of that was either hitting something really hard... by... extending the slide??? Or by leaning on it so there is probably some misalignment either way. So in this context, again especially Yamaha, the cost of the part will probably be totally or nearly totally absorbed by the other stuff that also needs repairing. Yamaha parts usually come with the bow guard and water key pre-installed so it is just a matter of the other two solder points.

Is it possible that it could not need a cleaning/alignment? Sure. But it's the primary mechanism that we interact with the instrument and even if you did ~$150 a year it's a drop in the bucket compared to other instruments maintenance costs (reeds anyone?) and it makes quality of playing sooooooo much better.

[Crazy4Tbone86]

I cannot speak for all techs, but doing a slide alignment after a crook repair/replacement is automatic for me. All of the parts of a slide are so closely related.....doing work one part almost always impacts another part, even if it is only a few thousandths of an inch. It is just like getting a new set of tires for your car. If you don't get a 4-wheel alignment, you are probably not going to get the most out of the new set of tires.

[brassmedic]

I would do it during the crook replacement. Having the crook off is an ideal time to straighten the slide tubes without one tube affecting the other. Then I would measure the alignment with the crook pressed on. Get everything right before soldering. Then check it again after soldering.

[elmsandr]

On a related idea, BBs for cleaning. I haven't done this on an instrument but several times I've needed to clean crud out the inside of some object where I couldn''t reach a brush in, and just pouring water through didn't work. So I throw in a spoonful of regular .177 airgun BBs, a little water and dish soap, and swirl around until clean. Pour the Bbs into a colander and rinse them off.

With a trombone I'd worry about one getting stuck in a valve though. Might want to count how many you put in, if you try that. I don't intend to.

Somebody stole your idea.

https://www.ferreestoolsinc.com/product ... aner-balls

Cliff never stole ideas... he borrowed them until he decides to get out of the business. Then we'll never speak of it again.

Cheers,
Andy

[Crazy4Tbone86]

The cost of those Ferree's cleaner balls is ridiculous! I like Ferree's because they have some highly specialized tools and many of the tools are of high quality. However, they also overcharge for many items that a creative person can find elsewhere for a fraction of the price.

Those "cleaner balls" look like they are about 1/8 inch in diameter. Here is a site where you can get a similar product for a price that is 70% lower:

https://pgnbearings.com/products/500-1- ... gIvK_D_BwE

Yes, the Ferree's balls are brass and the "cheaper set" is chrome. But the alloy shouldn't not impact the effectiveness of the tool when the balls have so little mass. As a matter of fact, I would prefer the chrome ball bearings because they will not tarnish/corrode.

[BGuttman]

Watch out handling those little balls. If you spill them on the floor they make a BIG slip hazard!

[timothy42b]

https://www.walmart.com/ip/Crosman-BB-s ... 67/9222903

https://www.walmart.com/ip/Daisy-Precis ... t/15729973

Or 6,000 of these for even cheaper. And they stick to a magnet when you spill them on the floor. DAMHIKT.

[Crazy4Tbone86]

https://www.walmart.com/ip/Crosman-BB-s ... 67/9222903

https://www.walmart.com/ip/Daisy-Precis ... t/15729973

Or 6,000 of these for even cheaper. And they stick to a magnet when you spill them on the floor. DAMHIKT.

Now that's a good deal! You could buy the 6000 Daisy BBs for $7.89, keep 600 for yourself, divide the remaining 5400 into 9 lots of 600 each and sell those lots at the Ferree's price of $42.90 each. That would be a profit of $378.21!