How to fix minor crack in horn

[Roger Fisher]

A friend found  an original plain horn with a minor crack and air leak.  How to fix from inside w/o yanking the end plug?   The horn will be used.

A slurry method

[smokinbuck]

Roger,
It would seem to me that anything that you put inside, "slurry", whether it is a parafin etc. would possibly contaminate the powder if it deteriorated. If the crack is open enough I think I would apply a colored epoxy with a small hypodermic needle.
Mark

[A.Merrill]

    Would bees wax work? Shave off some wax, place wax in horn, heat horn with paint stripper gun. (Be careful not to burn horn) While horn is hot rub wax on outside of crack.  Sounds good to me.     Good Luck    AL

[Longshot]

A couple of applications of spar varnish, slurred around a bit and poured off would probly tighten things up.  Sodium silicate would do likewise.

[RonT]

I would repair the same way i repair screw holes in drywall... a hypodermic filled with drywall compound.  in the case of this horn, a mix of powdered horn form a donor and E-pox-E forced into the crack. 
Wipe off the excess with an alcohol soaked cloth and finish to match the rest of the horn.  Just my $.02
R

[mjm46@bellsouth.net]

Careful if you have an origianl horn that may have any value as an antique or collectable, anything you do to seal it will probably ruin its value. If that's not an issue go for it. I have a buddy who had an original F&I map horn who put a little epoxy in the base to seal a crack so he could use it. Years latter he wanted to sell the horn and got $3000 for it but the appraiser said without the epoxy the horn would have been worth about $15000