The Ford Barn

alexiskai · 07-31-2019, 09:18 PM

I'm getting ready to put a Sparton horn together and I'm confused about the drain hole feature. I have the following parts:

A horn bell of uncertain age with no drain hole
New repro gaskets and diaphragm with a drain hole centered between two of the bolt holes
A presumed-original motor housing with no drain hole, but it has a tiny raised nub between two of the bolt holes

The problem is that the nub is not at the same offset between the bolt holes as the drain holes on the diaphragm/gaskets, so not only does it not line up with the drain hole, it's going to mess with the seal if I try to bolt the whole thing together.

How is this whole assembly supposed to go together? Do I need to drill a hole in the bell? Where is the water draining from and how does it get to this hole in the gasket? What's with this nub?

I've looked at all the part diagrams I can find and no one seems to have drawn this part of the system; there is no mention in Les Andrews of this drain hole arrangement.

Tudortomnz · 07-31-2019, 11:56 PM

Of course the drain hole is at bottom of horn assembly. There will be the hole in diaphragm disc, paper gasket& mounting flange of horn trumpet. That nub you mention would be for aligning the motor cover which ,if it is correct to the horn motor, has a corresponding nick out of the edge. Bear in mind, early [1928] covers do not interchange, but '29 '31 ones do. An original trumpet flange will have the hole, but sounds like you may have to drill one in what you have. Clear as mud? Cheers -- Tom in NZ.

alexiskai · 08-01-2019, 08:40 AM

I know the nub you're talking about that aligns the motor cover, but this is not that nub, this is a tiny one that is on the flange portion of the motor housing at about 150° offset from the alignment nub. I guess most likely someone decided to add it with a punch for some reason in the past. I can just file it off.

The one thing I'm still not clear on is how these holes are supposed to work if they're located inside the flange/gasket. Wouldn't the gasket seal the water into the horn? Is there supposed to be a ridge or something in the horn trumpet that lines up with the hole?

alexiskai · 08-01-2019, 08:45 AM

Ah, OK, I see on this page where the hole in the horn projector is supposed to be. I guess somehow the water is supposed to migrate through the diaphragm and come out this hole. So I'll need to drill that hole in mine.

Brentwood Bob · 08-01-2019, 11:29 AM

You don't need to drill a hole and ruin an OEM diaphragm.
The bell has a weep hole. I sent you a couple of pages out of my journal that should get you thru this restoration. Ask more questions before drilling any extra holes.

rotorwrench · 08-01-2019, 12:21 PM

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An open face horn projector will catch a pretty good amount of rain water if a person gets caught in the rain with their A-bone. It just need a place to drain the projector out. No water should get past the front face of the sounding diaphragm. A bug screen will slow it down some but not all horns of the era came with bug screens.

alexiskai · 08-01-2019, 02:14 PM

Quote:

Originally Posted by Brentwood Bob

You don't need to drill a hole and ruin an OEM diaphragm.
The bell has a weep hole.

Sorry for the confusion, I meant that my horn projector doesn't have a weep hole and that's where I may need to drill.

Brentwood Bob · 08-01-2019, 04:03 PM

You are on track. Thought the diagrams would help.

07-31-2019, 09:18 PM	#1
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,353	Horn drain hole assembly I'm getting ready to put a Sparton horn together and I'm confused about the drain hole feature. I have the following parts: A horn bell of uncertain age with no drain hole New repro gaskets and diaphragm with a drain hole centered between two of the bolt holes A presumed-original motor housing with no drain hole, but it has a tiny raised nub between two of the bolt holes The problem is that the nub is not at the same offset between the bolt holes as the drain holes on the diaphragm/gaskets, so not only does it not line up with the drain hole, it's going to mess with the seal if I try to bolt the whole thing together. How is this whole assembly supposed to go together? Do I need to drill a hole in the bell? Where is the water draining from and how does it get to this hole in the gasket? What's with this nub? I've looked at all the part diagrams I can find and no one seems to have drawn this part of the system; there is no mention in Les Andrews of this drain hole arrangement.

07-31-2019, 11:56 PM	#2
Tudortomnz Senior Member Join Date: May 2010 Location: Canterbury, New Zealand Posts: 1,242	Re: Horn drain hole assembly Of course the drain hole is at bottom of horn assembly. There will be the hole in diaphragm disc, paper gasket& mounting flange of horn trumpet. That nub you mention would be for aligning the motor cover which ,if it is correct to the horn motor, has a corresponding nick out of the edge. Bear in mind, early [1928] covers do not interchange, but '29 '31 ones do. An original trumpet flange will have the hole, but sounds like you may have to drill one in what you have. Clear as mud? Cheers -- Tom in NZ.

08-01-2019, 08:40 AM	#3
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,353	Re: Horn drain hole assembly I know the nub you're talking about that aligns the motor cover, but this is not that nub, this is a tiny one that is on the flange portion of the motor housing at about 150° offset from the alignment nub. I guess most likely someone decided to add it with a punch for some reason in the past. I can just file it off. The one thing I'm still not clear on is how these holes are supposed to work if they're located inside the flange/gasket. Wouldn't the gasket seal the water into the horn? Is there supposed to be a ridge or something in the horn trumpet that lines up with the hole?

08-01-2019, 08:45 AM	#4
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,353	Re: Horn drain hole assembly Ah, OK, I see on this page where the hole in the horn projector is supposed to be. I guess somehow the water is supposed to migrate through the diaphragm and come out this hole. So I'll need to drill that hole in mine.

08-01-2019, 11:29 AM	#5
Brentwood Bob Senior Member Join Date: May 2010 Location: brentwood, ca Posts: 4,241	Re: Horn drain hole assembly You don't need to drill a hole and ruin an OEM diaphragm. The bell has a weep hole. I sent you a couple of pages out of my journal that should get you thru this restoration. Ask more questions before drilling any extra holes.

08-01-2019, 12:21 PM	#6
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Horn drain hole assembly Sponsored Links (Register now to hide all advertisements) An open face horn projector will catch a pretty good amount of rain water if a person gets caught in the rain with their A-bone. It just need a place to drain the projector out. No water should get past the front face of the sounding diaphragm. A bug screen will slow it down some but not all horns of the era came with bug screens.

08-01-2019, 04:03 PM	#8
Brentwood Bob Senior Member Join Date: May 2010 Location: brentwood, ca Posts: 4,241	Re: Horn drain hole assembly You are on track. Thought the diagrams would help.