Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

How to fix broken horns

654 views
8 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    November, 2016
  • 128 posts
How to fix broken horns
Posted by khier on Wednesday, May 09, 2018 12:32 AM

While fitting the couplers to my brand new Walther's F7 I damaged the horns. They are two pieces now. Replacement was my first thought, however, some remains are still inside the mounting hole. I will not clear it without damaging the paint. Hence, gluing is my only option.

 

Any hint or advice?

 

Regards

 

Walid

 

  • Member since
    July, 2006
  • From: Bradford, Ontario
  • 8,278 posts
Posted by hon30critter on Wednesday, May 09, 2018 1:07 AM

Hi Walid,

First thing to do is get yourself, or make yourself a foam cradle like this if you don't have one already:

https://www.walthers.com/foam-cradle-locomotive-and-or-rolling-stock-work-holder

I made mine out of soft foam that came from a cheap mattress pad:

As far as fixing the horn, I don't understand why you feel that the paint will get damaged if you drill out what is left of the stub in the mounting hole. If you have the right sized drill and it is sharp, you should be able to drill the broken stub out without doing anything to the surrounding paint.

If you are going to try to re-attach the original horns you might want to consider drilling a small hole into the bottom of the horn bracket and using a piece of stiff wire as the mounting post (I recommend .015" phosphor bronze wire from Tichy). If you use a #78 drill bit the hole and the wire will be close to the same size, and you can use the same drill bit to open up the hole in the shell. That means that you will not be removing all of the original horn mounting stub, but instead drilling a smaller hole in the middle of the stub. What is left of the stub will act as a shim so that the hole matches the size of the wire.

Just a suggestion.

Dave

  • Member since
    November, 2016
  • 128 posts
Posted by khier on Wednesday, May 09, 2018 4:03 AM

hon30critter

 I don't understand why you feel that the paint will get damaged if you drill out what is left of the stub in the mounting hole

 

Because the remaining bit is protruding out of the shell. If it were inside the shell the hole would have been a guide to the drill.


BTW, I had the engine in the Styropor packing, so it was resting on a soft surface (or so I assumed). I did not have it upside down on the floor of course.

Each time I had to mount a coupler to a Walther F-unit (4 units made by myself), I have wondered who on earth make a coupler pocket out of three parts held by a screw? Each time I will have to remove the shell I will have to remove the coupler first and repeat these tedious installation because there are wire (probably piping) passing under the coupler.

 

But this is a different story.

 

Regards

 

Walid

  • Member since
    February, 2005
  • From: Vancouver Island, BC
  • 21,300 posts
Posted by selector on Wednesday, May 09, 2018 10:06 AM

Walid, this type of repair is actually fairly straightforward.  That bit of pipe still sticking out of the mounting hole?  Nip it off flush.  Use a sprue cutter or a sharp Xacto knife blade.  Now you can place the tip of the drill bit directly onto that spot and gently begin to tap the hole clear.  

From there, you drill a small hole in the bottom of the body of the horn, maybe a mm or two deep at most, and use that bit of styrene piping or brass wire that seems to be a good fit.  Later, once it's all done, use a very fine tipped artist's brush with some suitable paint for careful touch-up.

  • Member since
    May, 2004
  • 5,023 posts
Posted by 7j43k on Wednesday, May 09, 2018 10:29 AM

Get your replacement horn, first.  Then you will know what size hole to drill.  You may not be able to obtain a drop-in piece.

Also, consider getting a replacement horn in brass.  For obvious reasons, I think.

 

Ed

  • Member since
    July, 2004
  • From: Weymouth, Ma.
  • 5,179 posts
Posted by bogp40 on Wednesday, May 09, 2018 10:54 AM

If you feel that drilling will cause damage(drill bit walking before starting to drill the broken stem out), use a sharp #11 blade to mark the center and give it a spin. This give you a perfect detent exactly in the center that the drill bit can follow. Even odd, ragged broken surfaces can still be center marked this way. By angling the xacto blade to creep to the center before bringing it up to vertical for the center mark/ divit.

As to the repair/ reinstallation of the horn, I would follow recomendations previously mentioned. Drilling out for a small piece of wire to locate and act as a reinforcment of sorts. I perfer brass wire. just try to drill as close to the center of the mounting "nub" on both mating pieces. Dry fit for alignment, then CA. just a touch with a toothpick and wick up any excess withh piece of paper towel. should have no problem or damage to paint. If all else fails, replace the fragile horn with brass. Don't drill out the roof mounting until you have the brass replacement to size the proper mounting hole. Detail West, Cal Scale and others offer a variety of horns for replacement. You may also check your prototype for the exact horn that the unit should have. many times manufacturers will use an as built or some generic (fit all roads) horn for application. I generally end up replacing almost all the horns on my Chessie EMD and WM diesels. Even if the factory one is close the replacement is far better quality in detail.

Modeling B&O- Chessie  Bob K. http://www.ssmrc.org/

  • Member since
    July, 2006
  • From: Bradford, Ontario
  • 8,278 posts
Posted by hon30critter on Wednesday, May 09, 2018 11:30 PM

Hi again Walid,

I didn't realize that the stub was still protruding, but as others have said, a #11 blade would cut it down to the surface so you can drill it out.

khier
Each time I had to mount a coupler to a Walther F-unit (4 units made by myself), I have wondered who on earth make a coupler pocket out of three parts held by a screw? Each time I will have to remove the shell I will have to remove the coupler first and repeat these tedious installation because there are wire (probably piping) passing under the coupler.

I have installed quite a few of the smaller Kadee couplers with the same problem. Gluing the parts is a recipe for disaster so I use my soldering iron to 'weld' the coupler box pieces together. It doesn't take much at all to get the pieces to stick together enough to make handling and installation easier. The tiny welds can be fragile so handle with care.

Dave

  • Member since
    November, 2016
  • 128 posts
Posted by khier on Saturday, May 12, 2018 11:05 AM

Dave,

I will probably discard Kasse couplers in my all US locomotives and use ROCO couplers instead to avoid the hassle with coupler installation/removal.

 

Regards

 

Walid

  • Member since
    July, 2004
  • From: Weymouth, Ma.
  • 5,179 posts
Posted by bogp40 on Saturday, May 12, 2018 3:52 PM

khier

Dave,

I will probably discard Kasse couplers in my all US locomotives and use ROCO couplers instead to avoid the hassle with coupler installation/removal.

 

Regards

 

Walid

 

You should be able to retrofit any of the Kadee series whether in the standard #5 draft gear box or the 30 series. Even though the 30 series "tortion spring" box can be a real pain to work with, they have supurb operation of the knuckle. Learned this many years ago with installing the Kadee #450 in all my Stewart F units. Have used that box on many conversions since,

Modeling B&O- Chessie  Bob K. http://www.ssmrc.org/

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!