Brass Horn Repair With Ice

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Intro: Brass Horn Repair With Ice


Use the power of ice to remove dents in a horn. If you live in a cold climate, you know frozen pipes bursts. That is because water expands about 9% when it freezes. You can use that property to pop out dents and expand crushed tubing in brass instruments with a little luck. I had a crushed leadpipe on my old horn that I couldn't reach with a pushrod (out of a V8 motor, worked like a charm with its rounded end!) So I filled the leadpipe with water, sealed both ends at the mouthpiece receiver and first slide with a rubber balloon (or fingers cut out of a latex glove) and pipe clamps loosely tightened. Put horn into freezer for 4-5 hours or until your sure the ice is solid. Take out with a towel and set bell down so it will drain out. You will notice that the ice has expanded out of the leadpipe. The amount of expansion out of the leadpipe is proportional to the amount of outward force it exerted, ie, if no ice came out, your leadpipe will probably have burst, or at best straightened out completely!   Remove seals and let water drain. With any luck, your dents or crush zone will have been pushed out by the expanding ice. If it didnt work, you can try sealing the ends with a more rigid device like a cork or hard plastic cap. Be advised that if the water has nowhere to expand, it may rupture your leadpipe or brass tubing, so keep that in mind. Hope it works, you really have nothing to lose and your horn will be cleaner than when you started.

38 Comments

This helped for me! I have a dented and somewhat flattened leadpipe on a Yamaha horn, but I unsoldered it before doing this process. 45-60 minutes of freezing, checking in on it halfway in, was enough to regain the shape of the pipe. There are still some hard dents that need mechanical work, but they are only aesthetically problematic now, the hand guard will cover them up.
This is a really terrible idea! Cold on brass causes the metal to harden and become brittle. Hence people are splitting the tubes. Brass is a very soft pliable metal and the brass on your horns is very thin. You are better off taking to a professional to fix. However, if you are dead set on doing it yourself, you are better off annealing the dent with a butane torch enough to soften the metal a touch and carefully working the dent out with a steel ball and rod or V8 pushrod.
Try that on a blind bend that is unreachable. Seeking professional assistance in fixing something goes beyond what this site is about. This may not be for everyone but it worked for me.
Take your panties out of a bunch. You want to talk scope of the site, well I do not believe it is the scope of the site to recommend doing something that will cause people more grief than they already had either. So this bad idea worked for you. That's good, however it still doesn't make it a good idea. The internet is full of crazy ideas. Some are good some are bad. As a responsible adult, when I see a bad idea that can cause more problems than solve, I will say something. Yes this is a do it yourself site. However, something's are out of the scope of do it yourself. For example you might be a burger flipper at the local burger palace. You read an internet page on how to build a homemade rocket out of cardboard tubes and 500 gallons of gasoline. So the rocket scientist that you are follows the instructions and builds yourself a rocket. Do you think it's a good idea to try and launch yourself into space?
We have a be nice policy.
Be positive and constructive.

Panties in a bunch? There is another instructable on that, unless you think its outside the scope of this site. Then seek professional help.
A way to potentially improve this method would be to anneal the dented area first and just keep an eye on it. Like check it every hour. Maybe even glue some plugs on the ends of some flexible wire and use less water. When you're jury rigging you really have to think about what you're doing.
DONT do this! I did it with my French horn and two pipes burst open.
I wish I could do this with my instrument...if only I didn't have one the size of my fridge. One of the bad things about being a tubist.

This seemed like a really good idea, but I can now confirm that it can go badly wrong.

I tried this today, to attempt to remove a dent from my Eb tuning slide - my single French horn came with an F tuning slide, and an Eb one, which is the one I like to use. It fell off while I was emptying water out, a few days ago, and made a dent.

I did this with fingers cut off an old thin silicone rubber glove, and rubber bands. I more or less filled the slide with water, and put it in the freezer.

The slide split in two places. The dent wasn't removed or even noticeably improved.

Since I didn't want to be without it, I've patched it with blobs of lead free solder, and a blow torch. Really, it needs mending properly, which means I'll probably be deprived of it for some time - that's what normally happens when I take an instrument to be repaired or serviced, which is why I rarely do.

It was actually playing just fine with the dent. It would have been far better to just leave it.

Sorry it didnt work out. Im wondering if the volume of water is a variable that should be addressed?

It's probably a factor, yes. The problem is, in a curved tube, there's often going to be nowhere for the ice to expand to as the water freezes. Obviously, that's what you're exploiting to try to push out a dent, but if it expands too much, it will split the slide. In my case it split it in two places, but left the dent alone.

The ends and outside surfaces of the water will freeze first. The frozen ends form plugs, which won't move easily, especially when the slide has taken a knock making the cross section vary.

The outside edge of the curve on a slide can be very thin, where it's been stretched to make the shape, so that will sometimes be the easiest route for the ice to escape.

I see Dawkes (UK shop) sell a selection of different sized metal balls with holes through them, for taking out dents. I guess you string them on a wire or strong fishing line and pull them through. That's probably a lot safer.

yes, the balls. You use them to broach the dent out. problem is the curve may be tapered so the balls are a multi size operation. To get the ball around a curve you use a small cable and a slide hammer to pull the ball through the dent. That is production work as the precision ball collection is expensive and is beyond the DIY approach. Suitable for an expensive instrument repair.

Those balls are certainly not cheap. Given my record on taking instruments to be repaired, and not getting them back for a couple of months, I'm inclined to DIY a little more than most people might.

I'd consider buying a few balls around the right size and trying it. I don't want to split the crappy soldering I did to patch it up though, so I'll just leave it, for now.

How much time would you guess a second valve trumpet slide would take?
Took about 4 hours, or just long enough to freeze water. Brass offers no insulation.
Thank you! I appreciate it

enough to fill to first bend or wherever you can cap it, first valve?

There's a kink in my leadpipe and was wondering how much water is safe to use for something like this?

I have a trumpet and It had dents in it so i followed this ible and it worked great! Thank you!
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