horn restoration

-
pyrojim

pyrojim

Well-Known Member
Joined
Feb 4, 2013
Messages
1,163
Reaction score
39
Location
Chesterton, Indiana
I want to clean and restore the horns from my 66 Dart. Is there any reason I cant just drop them in a bucket of purple power? Whats on the inside??? What's the best way to get them all sparkly and clean?
Thanks.
Jim
 
There's some variety of diaphram in the horns to make the sound. What exactly it's made of it probably the big question. Guessing they're mostly metal, but could possibly have some rubber in there as well. The main concern I'd have would be making sure they were good and dry before putting any power to them.
 
You don't want to immerse the horns in any liquid.

Horns work just like a buzzer. They are in fact sort of a modified relay. What you have in there is an electrical magnet in series with a normally closed ELECTRICAL CONTACT.

When power is applied the armature of the "relay" (buzzer) is pulled down by magnetism against the core of the electromagnet. As the armature is pulled down, it itself opens the electrical contact, breaking the current path, and stopping the magnetic pull. Either a separate spring, or the spring action of the horn diaphragm mechanically pulls the armature back up the other way, back to it's starting place, the electrical contact closes, and "things happen" all over again, over and over.

Meanwhile, the armature is mechanically attached to the horn diaphragm, which amplifies the noise of the buzzer, and the resonance of the cavity of the housing causes the trumpet sound, so to speak

Normally there is an adjustment screw which actually moves one of the contacts to control tone

So what you have in there is electrical wiring, mechanical movement, and electrical contacts, all of which may be damaged by solvents or corroded from liquids

http://www.cvel.clemson.edu/auto/actuators/horns.html

http://en.wikipedia.org/wiki/File:Car_horn_in_use-tag.svg
 
Iv'e done four of these. Easiest way is to jam some foam tied to a string or zip tie into the cavity as far as you can go without damaging something then sand blast them. The string is so you can pull the foam back out.

They look like brand new when done and you can clear them or paint them to finish.

Here is a shot of the last ones I did. I chromed the mounting brackets to add a bit more bling factor.

Good luck.
 

Attachments

  • 100_5016.jpg
    51.7 KB · Views: 419
there is a small breather hole in the diagram and if you immerse them you will damage the contacts. If they don't work you can clean them with most anything you like because either the contacts or the coil is burnt up.
 
I just got done restoring my 68 horns a couple weeks ago. There isn't anything hard about it...It just takes some time. There is cardboard inside so if you soak it, you will destroy it. Here's what I did...your horns may be different.

First I ground off the heads of all the rivets and took the horn apart. Then I drilled and tapped the rest of the rivet for an 8-32 allen head bolt.


You can see the three pieces that make up the horn. If your horn doesn't work, you need to clean the contacts. Fold a piece of sand paper in half...open the contacts with a screw driver and insert the sand paper. Then all you have to do is pull out the paper. Do this a few times to make sure the contacts are clean.


If the center diaphragm is rusted, you can soak it in EvapoRust. Do not blast it...you will ruin it. Next, I made two new gaskets out of a non corrogated Christmas box. There is a gasket on either side of the center diaphragm. I used some C-clamps to hold the horn together while I tested it. One horn worked fine...the other didn't. I had to adjust the screw on the second horn to get it working again. Once they tested good, I screwed them together and painted them.




 
Cool info and nice work guys! I never knew you didn't want water inside them so now I know to never soak them....thanks!
 
great thread. I might have to go mess with my horns when I get home. I was wondering if it would be a bad idea to powder coat them? I know its got cardboard in it, but would 400 degrees for about 10 minutes really hurt it?
 
That tear down is about as far into the details of a horn as you can go.

I've never seen the inside of one and I know why now.

Great work on the rebuild.

Mop
 
bluetrane said:
great thread. I might have to go mess with my horns when I get home. I was wondering if it would be a bad idea to powder coat them? I know its got cardboard in it, but would 400 degrees for about 10 minutes really hurt it?
Click to expand...

No, it won't hurt it at all. But that's because you're only curing it for ten minutes ... that's not enough time to even get the powder to flow out let alone cure properly. The PART has to be at 400 degrees before your cure cycle starts, NOT your oven. :-D God I hate Eastwood ..............

But if you open it up completely for a rebuild like Burdar did (nice work btw), I see no reason the rest of the housing can't be coated.
 
momoparman said:
Eastwood don't mind you though....:D

Mop
Click to expand...

LOL! Yes, they do. So much so, in fact, that I got fired by the office manager Kathy after 19 loyal years of being a customer. Everything they sell you can find somewhere else under its own label, and usually a lot cheaper.
 
Nice work, burdar. I'm sure that your post will help a number of people.
 
Thanks Burdar! Very nice work.

Leanna whats wrong with Clint??
 

Attachments

  • Clint-Eastwood-Movie-Poster--53544.jpg
    84 KB · Views: 240
I can't take credit. Mike Ross from BE&A wrote a how-to on another site. One of my horns didn't work so I had nothing to lose.
 
You must log in or register to reply here.
-

Back
Top