[68ragtop]

Wondering if you guys would put a light coat of paint over the diaphragm of the horn during a rebuild? I cleaned them up but over time I am sure they would rust. Was planning on reassembling them & leaving the diaphragms like I have them in the picture, but now I am thinking a coat of paint might hall them last a really long time.

But, would that effect the sound? I have no idea......

[300deluxe]

maybe a light coat of rust convertor, not sure if the sound would change....maybe it will play Dixie

[68ragtop]

Thanks! Thats what I did. Never thought of that. Probably never be a rust issue going forward, but hate to skip a simple step while i'm in there......

They are all back together. just have to let the sealant cure, tune them & paint them black.

Thanks for the idea. Soooooo many parts like this to work on yet.

[68ragtop]

They are tuned & epoxy primed. No dixie, but they do sound strong. I tested them without a new gasket or sealant. makes a big difference having them sealed up. very loud & clear!

Now the question is what sheen? I have been searching google images & it looks like most NOS horns are more of a satin, low gloss finish. But restoration shops are painting them semi/medium gloss.

Any thoughts?

here are a couple examples I found:

http://www.ebay.com/itm/NOS-GM-Delco...BW5vm0&vxp=mtr

http://www.ebay.com/itm/55-64-CHEVY-...ZXFOpv&vxp=mtr

[68ragtop]

here's a horn restoration shop.

Too much gloss?

http://www.carhornrestoration.com/proc6a.jpg

I am trying to use either different paint, or sheen, or both on all the parts that are black & are bolted together so it doesn't look like everything was painted at one time. more like the way they came from GM. many paints, many suppliers. But if I change I want to error towards the correct sheen.

If I go by the "restoration" bibles. Everything is either zero gloss or 60%.

[bkmont]

Originally Posted by 68ragtop

They are tuned & epoxy primed. No dixie, but they do sound strong. I tested them without a new gasket or sealant. makes a big difference having them sealed up. very loud & clear!

Now the question is what sheen? I have been searching google images & it looks like most NOS horns are more of a satin, low gloss finish. But restoration shops are painting them semi/medium gloss.

Any thoughts?

here are a couple examples I found:

http://www.ebay.com/itm/NOS-GM-Delco...BW5vm0&vxp=mtr

http://www.ebay.com/itm/55-64-CHEVY-...ZXFOpv&vxp=mtr

Woow! Those look great. So tell me the steps you took to rebuild the horns.
Is it that easy? Where did you get the rivets?
Thanks,
Bryan

[68ragtop]

Originally Posted by bkmont

Woow! Those look great. So tell me the steps you took to rebuild the horns.
Is it that easy? Where did you get the rivets?
Thanks,
Bryan

Thanks! Really wasn't bad. I had 4 horns & upon testing them, none of them worked. All showed open circuit with my meter. So I drilled out the rivets & found the points/contacts were the culprit. My feeling is they corrode & go bad from lack of use. But thats just a guess. I slid i piece of folded over 400 grit paper between the contacts, sanded until I could open the gap & see they were cleaned up. then passed 800 grit through to smoothen them out. That alone was the culprit of why they didn't work.

They do have a gasket between the diaphragm & the mechanical side of the horn, buts not a good seal. moisture no doubt leaked past the gasket & into two of the horns I took a apart. I re-assbembled them to test & then bead blasted. took them back apart, made new gaskets & sealed all mating surfaces with ultra black RTV.

I took the rivets to my local hardware store & found a small allen headed threaded fastened that was the same head size as the rivets. On the nut side I put standard nuts in the lathe & cut them down to the same od size as the rivets. so I basically had threaded sleeves. so, they are not like the original rivets, but they will trick the eye when you first look at them. IF you put seam sealer in the heads of the bolts, they would look really good imo. I decided not to do that because it looks so close to the original & if for some crazy reason they ever need to come apart again its still an option.

Now I really need to decide how much gloss these should have. my window for top coating the epoxy primer is going to be closing soon

[tekheavy]

Learn something new everyday. I never realized they come apart and you could rebuild them.

[bkmont]

Originally Posted by 68ragtop

Thanks! Really wasn't bad. I had 4 horns & upon testing them, none of them worked. All showed open circuit with my meter. So I drilled out the rivets & found the points/contacts were the culprit. My feeling is they corrode & go bad from lack of use. But thats just a guess. I slid i piece of folded over 400 grit paper between the contacts, sanded until I could open the gap & see they were cleaned up. then passed 800 grit through to smoothen them out. That alone was the culprit of why they didn't work.

They do have a gasket between the diaphragm & the mechanical side of the horn, buts not a good seal. moisture no doubt leaked past the gasket & into two of the horns I took a apart. I re-assbembled them to test & then bead blasted. took them back apart, made new gaskets & sealed all mating surfaces with ultra black RTV.

I took the rivets to my local hardware store & found a small allen headed threaded fastened that was the same head size as the rivets. On the nut side I put standard nuts in the lathe & cut them down to the same od size as the rivets. so I basically had threaded sleeves. so, they are not like the original rivets, but they will trick the eye when you first look at them. IF you put seam sealer in the heads of the bolts, they would look really good imo. I decided not to do that because it looks so close to the original & if for some crazy reason they ever need to come apart again its still an option.

Now I really need to decide how much gloss these should have. my window for top coating the epoxy primer is going to be closing soon

Thanks for the lowdown on the horn rebuild. I have a set of 68s and 70s that need a rebuild. I think I'll try your method.

[68ragtop]

Originally Posted by bkmont

Thanks for the lowdown on the horn rebuild. I have a set of 68s and 70s that need a rebuild. I think I'll try your method.

The one thing I learned was you have to drive the rivets out with a center punch. they are pressed in. With exception to the rivet that is in the "bell" of the horn. take a smaller drill bit & drill that one all the way through after removing enough of it to separate the halves. Then drill & tap that hole so you can just thread a new bolt into the alloy side. I ruined the the first horn before realizing that rivet is different than the others. you'll have to shorten that bolt if you don't want it sticking out into the bell. the other bolts I used were an off the shelf length. I can measure them if you need that info.

[68ragtop]

So what do you guys think on gloss level? Semi gloss, or something closer to semi flat?

Here are a couple of contrasting picts from google by searching delco horn images:

[tekheavy]

To me, the first pic looks right. The other pics seem way too glossy.

[68ragtop]

No doubt the last ones in the last photo were spray bombed with high gloss. they don't look good at all.

I am probably going to start another thread on some gloss level questions I have, but do you know if the headlight brackets & mechanisms are the same gloss level at the core support? I took the headlight assemblies apart today & media blasted all the parts. Looked like they were pretty glossy, 60% for sure in area that were protected. Looks like all the parts where dunked in paint rather than sprayed. Every bracket had a heavy run off of paint that was a little harder to remove with the glass beads. headlight buckets look galvanized.

I think I will paint the horns a little more to the satin side.

[68ragtop]

Thanks again, here the final paint on the horns. The satin looks good, thanks for all the advise & opinions.

Yes, the green is my pool table felt. It's turned into a temporary staging center of small parts.

[bkmont]

I agree, the satin finish looks right.

[Greg Reid]

Wow..I wish I'd thought of that. I had an original set of horns I took off a '68 Lemans in the junkyard. They didn't work and I think I finally threw them away during one of my cleanups. Never thought about drilling the rivets out.

[68ragtop]

Originally Posted by Greg Reid

Wow..I wish I'd thought of that. I had an original set of horns I took off a '68 Lemans in the junkyard. They didn't work and I think I finally threw them away during one of my cleanups. Never thought about drilling the rivets out.

I had three 68 horns, two highs & one low. one of them I know worked years back. then I looked into rebuilding services & decided to take one of the duplicates apart to see what made them tick. Once I saw how simple they are it was game on.

[charles bledsoe]

Thanks for posting! It just so happens I'm getting ready to do the samething. Great timing