Split Dome Beacons

Skip Goulet

Passed Away
How are the dome halves attached? Glue or some type of plastic welding process?
I had a friend in Lubbock who had bought a TwinSonic that came with red domes. He ran a service that did roadside assistance and couldn't have red to the front but could have red to the rear. Blue or amber forward was o.k., so he got a blue dome and took it and the red dome to a plastics manufacturer in Lubbock and they were able to cut both domes and put them back together with blue to the front and red to the rear. Seems like they used some kind of clear silicone in the process.


Veteran Member
I never really thought about it, but that was probably the shortcoming of the Twinsonic and similar lightbars.  The inability to show one color to the front and another color to the rear.  Federal certainly addressed that problem with the Aerodynic and Jetsonic series.


Veteran Member
Here's something quite unique: a split red-amber Dominion Auto 357.

The dome is pretty old and the amber side spider-cracked but since it is the only one I know to be so far in existence, I guess I can share it all the same.




Site Minion
Platinum Supporter
This is what Dietz used to do to create their amber/red domes for the 7-11, 7-40, and 7-61 beacons. I believe those were their only "split" colored domes offered.
Interesting. I can't imagine that it was the most effective and would cut down the output.

Ben G

Premium Member
Dominion  Automotive made them specifically for the Ontario Ministry of Transportation Highway Patrol units.  Those units were non law enforcement, and patrolled the major 400 series highways in the Toronto / Niagara Corridor. They assisted at MVC's, provided traffic control and first aid, and assisted disabled motorists. And I guess I will have to post a picture of the NOS one I have.     Ben


Veteran Member
Please do, Ben. I'd like to see.

This one came from New Bruinswick and was owned in the 60's by a fire station, according to the person who traded it to me.


Site Minion
Platinum Supporter
Awesome grab for $15!!! There was a thread or post on here that someone discussed a plastic specific adhesive that did not leave residue. I will try to find it. I believe Rob was the one talking about it.

Skip Goulet

Passed Away
Yesterday I just picked up this Federal Signal Model 173. Its in rough shape but works perfectly. Not bad for $15.00 huh?

P.S. the original glue used has failed. Can someone tell me what glue I should use to fix it?
A good clear silicone should work well.


Site Veteran
Digging around, I found some pictures of a few of these for the FB3's from inventory photos. They were produced to comply with our state laws requiring red to the driver's side and blue to the passenger side on LE vehicles. These would have been a necessity when using the UF7 flash mirror assembly to meet this statutory requirement versus the front/rear red/blue split which produced a smorgasbord of red/blue flashes...

And an FB4, dual speed, utilizing one of those split filters;



Last edited:

Skip Goulet

Passed Away
You are correct, it was terrible.
That reminds me of an ambulance I used to see as a little kid. It was a '51 Chevy sedan-delivery. It had two clear driving lights mounted on the front corners of the roof which were painted red. The only "real" red light on the ambulance was the spinning PropelloRay light on the fender-mounted siren. It belonged to Ellis Funeral Home here originally, and when it was replaced by a '54 Ford wagon, the Chevy was given to the predominantly black funeral home. Something you'd like, Dan, a red BR2 was added to the rear roof, but the nice big siren/light was replaced with a tiny Federal VL siren. The guy just couldn't understand why people weren't seeing and hearing him!


I got the other one. Nice light. I trashed the box. Smelled. Light is gorgeous. It shows they had blue red and blue amber options. Wonder if those had actual split domes. This one is red sprayed. Looks brand new

Online statistics

Members online
Guests online
Total visitors

Forum statistics

Latest member
Top Bottom