Fix up a Conn 36K

[P@rick]

Hi all,

I few months ago I bought me a Conn 36K fixer upper. The 36K didn’t show any signs of leakages, it only had a few small dents, the valves and slides looked fine, but it played very stuffy. I was pretty sure it could be fixed and bought it for a few bucks. I removed the brass part from the fiberglass body and put a hose in the body…result…one happy Teddy …


Now it played fine and next step was cosmetically. The 36K had its original paint covered with green paint and then white paint again. The green shined trough the last white layer. The bell was sprayed black and flames were painted inside which looked more like a flower . In short…it looked terrible.

I stripped the fiberglass body from its paint and a friend who is a spray painter will make it shine again.
He is experienced in spraying all kind of materials including fiberglass. His advice on spraying the body and bell is:
- Spray putty to smoothen the sanded fiberglass “snake skin” like body and bell.
- Primer
- Basecoat. Automotive lacquer. Maybe using 2-pack systems (hardener and thinner).
- Clearcoat.

Knowing his work (from motorbikes to vintage refrigerators) I’m pretty sure that the result will be perfect.

Nevertheless I’m interested in repair tech’s view or anyone who has experience with spraying fiberglass sousaphones:
- How would you do the paint job on a “naked” fiberglass sousaphone body and bell?
- Would you only spray the fiberglass part of a 36K bell or also the plastic part from the bell?
- What is the original color and finish of an original Conn 36K? (white, off white, matte, gloss)

Thanks!

[nycbone]

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[nycbone]

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[Dan Schultz]

As a side-note... the 36K cluster is compatible with the 14K cluster and most of the other models of Conn sousaphones going back for many years. About the only difference is the branch that connects to the fiberglass body... and I think even that part is the same except it has the O-ring groove feature soldered to it.

Don't know for certain but I think the 36K was in production all the way up until 1987 when the 'Cyborg' made the switch to rebadge Kings as Conns.

[nycbone]

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[nycbone]

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[nycbone]

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[nycbone]

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[nycbone]

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[nycbone]

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[P@rick]

great.

Don't neglect the replacement of the two O-rings where the 4th branch inserts into the 3rd branch.

They are in good condition, but while I'm at it it would indeed be good to replace them.

[P@rick]

Can you post a picture of the scary paint job in the off topic paint job thread?

Already started sanding


Look at that ugly paint job


Finished the body


The back was black


The front still had to be done

[nycbone]

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[P@rick]

Those flares are plastic and (when new) were as white as the finish on the adjacent fiberglass. Over the years, those plastic bell flares (as Ian has noticed) have yellowed.

I noticed this also while sanding the plastic flare. After removing the black paint I ended up with a yellowish plastic flare. While smoothening the plasic flare with fine sandpaper it became white.

[Dan Schultz]

I am also working on a 'project' 36K. I discovered yesterday that 'Aircraft Stripper' does a bang-up job of removing the heavy paint on the fiberglass Conns. One coat of the stripper and that heavy 'pebble-finished' paint comes off like sheets of rubber leaving behind the very hard polyester fiberglass base. The stripper has no affect of the fiberglass base since polyester is a thermoset material.

With that heavy layer of paint/gelcoat/whatever gone... what is left reminds me of the old Reynolds/King sousaphones. In my opinion... those horns played much better than the 36K and it could have been due to NOT having that thick outer material. Sort of like the raw brass/heavy lacquer argument.

HOWEVER... I would not use the stripper on the bell flare... which is a thermoplastic material... probably ABS. That stripper contains methylene chloride and other solvents that I'm sure will attack the plastic flare.

[P@rick]

I am also working on a 'project' 36K. I discovered yesterday that 'Aircraft Stripper' does a bang-up job of removing the heavy paint on the fiberglass Conns. One coat of the stripper and that heavy 'pebble-finished' paint comes off like sheets of rubber leaving behind the very hard polyester fiberglass base. The stripper has no affect of the fiberglass base since polyester is a thermoset material.

Wish I new that before I started sanding

How do you do the paint job? What layers will you apply and do you intend to paint the plastic bell flare?

[Dan Schultz]

I am also working on a 'project' 36K. I discovered yesterday that 'Aircraft Stripper' does a bang-up job of removing the heavy paint on the fiberglass Conns. One coat of the stripper and that heavy 'pebble-finished' paint comes off like sheets of rubber leaving behind the very hard polyester fiberglass base. The stripper has no affect of the fiberglass base since polyester is a thermoset material.

Wish I new that before I started sanding

How do you do the paint job? What layers will you apply and do you intend to paint the plastic bell flare?

I just used satin-white quick-dry enamel from a spray can. Nothing special. I think the age of the fiberglass has something to do with being able to just apply paint without primers or base coats. I worked on Corvettes for several years and getting a good paint job over fresh fiberglass is sometimes a real challenge. Painting the 36K once the top layers of paint were removed didn't seen to present any problems.

I couldn't believe that the paint and top coats came off like sheets of rubber! I must've thrown away a couple of pounds of material!

Excuse the 'fuzzy' images. I need to ditch the phone and go back to my trusty old Panasonic digital camera!

[Dan Schultz]

Oh.... by-the-way... I spoke with the parts guru at Conn/Selmer/Steinway today. Production of the original Conn 36K actually ended two years EARLIER than I thought. Production of the Conn 36K sousaphones halted when the Abilene, Texas plant closed and all Conn 36K sousaphones that left Eastlake from 1985 on were actually rebadged 2370 King sousaphones.

I think you can put that one in ink and forget anything else that may be lingering on The Internet. Of course... there is always the possibility that some of the Abilene 36K sousaphones were sold after then but they would have had to have been 'old stock'.

[nycbone]

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[MvHooft]

Hi Patrick,

That's funny to see my old sousa here on this site!

I'm looking forward to see the result of you fixing up, maybe I will regret that I sold it and didn't fix it up myself.

Mark