Ovular bell bow

[Pablopiccasso]

I've been offered a good trumpet but noticed the bow of the bell (the bit that curves from bell back to the valves) is off round, it's a bit oval. No ripples, creases, dings or scratches. Do you suppose it was like that new? It's not obvious looking at it but running your fingers over it one can definately feel it

Thoughts, it seems a good trumpet otherwise.

[Don Herman rev2]

Probably as intended. What trumpet maker and model?
_________________
"After silence, that which best expresses the inexpressible, is music" - Aldous Huxley

[Pablopiccasso]

[oxleyk]

The word you want is ovate.

My guess is that the trumpet was dropped, possibly on a carpeted floor. If it didn't severely flatten the tubing it may be OK. I don't know if this can be fixed of if it would be better to replace the bell.

[shofarguy]

If the horn has a bow with a flatter stretch between two radii, we usually call that "D" or square. If it is one sharp bend that looks like half an ellipse, we call that ovate.

The first one is most likely what your horn has, right? It's normal, unless it's been flattened by dropping. Old Chicago Benge horns have that D-shaped bell bend.
_________________
Brian A. Douglas

Flip Oakes Wild Thing Bb Trumpet in copper
Flip Oakes Wild Thing Flugelhorn in copper


There is one reason that I practice: to be ready at the downbeat when the final trumpet sounds.

[ghelbig]

[Tritone]

Some people consider this a manufacturing defect or anomaly, without any trauma to the horn.

In my experience, it's not tremendously unusual in Strads. For example, I noticed this out-of-round condition in two nice Strads that I've had, a B-flat and a C. Had them both rounded and noticed a nice improvement in intonation. I'm aware of other players who have done the same and had similar results.

James Becker refers to "bell bow ... cross section correction" on page two (about halfway down) in a previous Horns forum thread entitled, "Osmun blue printing service" - others, too, mention this issue in that thread:

https://www.trumpetherald.com/forum/viewtopic.php?t=130066&start=0&postdays=0&postorder=asc&highlight=round+strad+bow[/url]

[James Becker]

Thank you Tritone for mentioning our trumpet blueprinting service http://www.osmun.com/blueprint and correction of out of round bell bow cross sections. It never ceases to amaze me how pinched some bells are from the factory. It's more commonly found on double radius or "square" style bell crooks, but also on some shepherds crook cornets. Quite often the result of the bending technique and the filler used.

Traditionally bending is done with either lead or pitch as a filler. Lead holds it's shape better but is highly toxic. Pitch/tar/resin mix is more sensitive to the room temperature, too cold and the tube buckles, too warm and the tube collapses. When all conditions are right pitch is an excellent filler but requires a strong, highly toxic, solvent to remove residue.

An alternative to lead is Cerrobend http://www.csalloys.com/products-cerrobend-alloy.html with it's lower melting point and lower lead content, it cleans out nicely and can be re-used over and over again.

Frozen soapy water has become one of the favorites in our indusatry due to how efficient it is to clean out, not to mention being far less hazardous than the others.

Regardless of method, there's always the possibility for the tube to get flattened out, especially at the corners of sharp bends.

And because high and low pressure points reside at different places along the length of a tube, pinches on cross section can have an adverse effect on particular notes.

The cumulative effects of eliminating all forms of irregularities, be it burrs or excess solder, valve misalignment, or pinched tubing allow an instrument to play as intended. This is our goal when blueprinting trumpets. Play testing before and after corrections are performed are often striking.

I hope this is helpful.
_________________
James Becker
Brass Repair Specialist Since 1977
Osmun Music Inc.
77 Powdermill Road Rt.62
Acton, MA 01720
www.osmun.com

Our workshop is as close as your nearest UPS store https://www.ups.com/dropoff?loc=en_US

[LittleRusty]

James,

The details are great. It helps one understand why some services are worth the money.

[Pablopiccasso]

[Pablopiccasso]

Ah. I understand now. Fill The bend with cerabend or low temp alloy, and use "rounding tools" to correct the problem. Would need to be annealed first. Seems a bit involved and well beyond my skill level.

The tools and comments are under 'Auspocheisen' on page 10

http://www.boehmtools.de/fileadmin/Assets/boehmtools/2017/Catalogue.pdf

Very interesting

[Pablopiccasso]

[shofarguy]

[Pablopiccasso]

[boog]

I have some trumpets and cornets with dented up bell bows, and they all play good to me. But, I have not had the opportunity to play the same model without dents, with the exception of my Olds Ambassadors, and that could be tempered by variations in the respective horns. Not serious dents, mind you, but minor dents (IMO). Of course, it is always preferable to have NO dents.

I used to play in an orchestra with a friend that had an early (4-digit serial number) Schilke C trumpet that he bought directly from Mr. Schilke himself. The bell bow was severely damaged in an accident, and was repaired with evidence of the dent removal, as you would expect. The horn played wonderfully, and he said that it played as good as it did before the accident.

Since the "air" column is essentially immobile in a trumpet playing a single note, or a string of single notes, consists of standing wave "nodes" (or areas of increased pressure) within the tubing, a dent or crease or "out-of-roundness" may have consequences on the playability, or the intonation, tone, etc., or not. Who knows?