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(Solved) How do I repair this brass engine frame?

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  • Member since
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  • From: Pennsylvania
  • 1,048 posts
(Solved) How do I repair this brass engine frame?
Posted by Trainman440 on Sunday, November 21, 2021 6:50 PM

Hi guys, I recently acquired this Sunset NYC K5 with by far the best paint job Ive ever seen. Problem is upon disassembly I realized something was loose as I can easily push the pilot up and down. Upon further inspection I realized one of the core solder joints on the frame broke off, leaving me with a broken frame. Given that all I have is a basic soldering iron which kinda struggles and soldering large brass pieces, Im asking how do I repair this? Am I forced to strip the frame and make a proper solder connection repair? Or can I get with a solder joint without ruining the paint? Or should I just give up on solder and use glue to hold it together? 

Any advice is appreciated!

Photo of damaged frame next to an intact frame from another model of the same loco:

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Modeling the Santa Fe & Pennsylvania in HO

Youtube Channel: https://www.youtube.com/channel/UCLb3FRqukolAtnD1khrb6lQ

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
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Posted by gmpullman on Sunday, November 21, 2021 7:03 PM

The only reliable solution is to strip the frame around the solder joint, clamp everything into a solid fixture to retain alignment and resolder the original joint.

A Paasche "Air Eraser" would be ideal for cleaning up the joint area.

At least being the frame you sould be able to get a decent paint finish just as good as the original. Since you're not doing any decal work on the frame the Scalecoat 1 locomotive black, matte finish, should give good results and you can bake the finish in a warm oven a few hours.

When I was faced with some brass repairs I did a little research into butane torches and found this Dremel model. It has lived up to my expectations very well and can handle a job like that frame with ease.

https://us.dremel.com/en_US/products/-/show-product/tools/2000-versatip-precision-butane-torch

[edit] Forgot to mention, you might want to invest in a perforated, ceramic soldering block. You can use copper wire (passed through the small holes) to tie down the frame pieces and hold them in alignment, shimming where necessary, and help insure to keep everything in tram while you apply heat.

https://www.amazon.com/Honeycomb-Ceramic-Soldering-Jewelry-Jewelers/dp/B08RBSHRHS/ref=pd_ybh_a_4?_encoding=UTF8&psc=1&refRID=TTQKQZSXTPE3HVNH7P3D

A few heat sink clamps or moistened towels to keep the heat from migrating will help, too.

Good Luck, Ed

  • Member since
    January 2004
  • From: Canada, eh?
  • 12,257 posts
Posted by doctorwayne on Monday, November 22, 2021 12:25 AM

A friend living in the U.S. had a DM&IR Yellowstone with a broken frame, and asked if I could repair it.  After seeing a couple photos of the break, I figured that it wouldn't be too difficult to do, so he sent it to me via mail.  Unfortunately, he listed its value at around four figures, and when it came through Canada Customs, I was on the hook for the duty. 
I instigated for an exemption, and had to explain to Customs that what was sent was the loco's chassis only - no superstructure and no tender, either.  I also noted that it was broken (photos provided) and while it's value might be as stated, what I had was a part that was unuseable, and none of the other parts that would make it that valuation. 
It took some back-and-forth before Customs accepted my arguement that what I had was of almost no value as it stood, and would be of limited value after repair, as the other parts were still in the States.

I don't recall what part of the frame had broken, but it was easy to access without too much disassembly.


I cleaned-up the mating pieces, then tinned them both, draping not-too-wet paper towels over nearby soldered joints and clipping them in place using alligator clips.  I'm not sure which soldering iron I used, but it would have been fairly large...at least 100 watts, but it might have been my 200 watt one. 

Anyway, I got the repair done with very little difficulty, re-boxed the assembly, and sent it back to the owner. 

I was required to provide photos of the repaired frame and photos from the owner, showing the chassis and the re-assembled loco, along with a newspaper showing the date that he had received it.

I also had to state that I was not accepting payment for the work done - I wasn't, nor would I have accepted it if offered - I simply wanted to help a friend.

A couple weeks later, I did receive a token gift...no Canada Customs involvement at all....

As best I can recall, that locomotive was sold a year-or-so later.  I hope that he got his money's-worth for it.

Wayne

 

  • Member since
    August 2006
  • From: Franconia, NH
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Posted by dstarr on Wednesday, November 24, 2021 8:01 AM

I went to E-Bay and bought an old 250 Watt Craftsman soldering iron to solder up some failed solder joints on this brass locomotive.  My 30 watt soldering station and my 100 watt soldering gun just did not throw enough heat. 

  • Member since
    March 2002
  • From: Milwaukee WI (Fox Point)
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Posted by dknelson on Wednesday, November 24, 2021 9:50 AM

At one time I did a fair amount of soldering, nothing sophisticted, so I felt reasonably comfortable when a brass locomotive had some parts that were not broken per se, but soldered joints were giving way, including the locomotive pilot.  Probably "cold joints" that visually look OK but are fatally weak.  I sweated some  bullets because I could see evidence that I was weakening other soldered joints as I did my work.  Too small an iron probably, although I am aware that the artisans who assemble brass locomotives use solders of varying melting points and use them in a sequence. 

But it seems to have turned out alright.

But that was then.  If I was faced with the OP's issue right now -- after some years of no soldering other than feeder wires to track now and then -- I think my first instinct would be to find a friend who is more adept at it than I am.  If not a model railroader then certain jewelrs and metal artists are very good solderers by necessity. 

Dave Nelson 

  • Member since
    February 2001
  • From: Wyoming, where men are men, and sheep are nervous!
  • 2,963 posts
Posted by Pruitt on Wednesday, November 24, 2021 11:02 AM

When soldering the parts back together, you might want to put thin brass doublers across the joints, if there's room to do so. That will dramatically increase the strength of the repair.

  • Member since
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  • From: Pennsylvania
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Posted by Trainman440 on Thursday, November 25, 2021 7:14 PM

Hi all! Thanks for the replies! I've been considering upgrading from my 40W soldering iron for a while now, it just doesnt output enough heat. Ed convinced me to buy a soldering gun, I ended up getting a 140W one from Weller. That thing has now made soldering brass locos a breeze! 

I used to have problems (along with not getting enough heat) where the heat was dissapate so quickly throughout the model to the point where other solder joints would melt before the one in question would. This gun heats up so quickly that the problem no longer exists!

Anyways, I gave up on avoiding repaint and stripped the paint, resoldered the frame, and gave it all a repaint before reassembly...as seen below.

Note the solder joint may not look amazing but it is SOLID. I used flux and sanded the brass areas to make sure the area was clean. I held the frame and whacked on a (towel covered) table with it and it didnt snap :)

I used model master black and a 30/70 mix of dullcote/glosscote in an airbrush to match the satin finish seen on the rest of the frame. It may not look like it in the pictures (due to odd lighting), but the paint was blended evenly into the old paint to make a gradient. 

I also had to replace the drive tubing, cleaned and added fresh lubricant and added some cardboard between the gearbox and frame to reduce vibration. 

Now I got a perfect looking and running engine!

Thanks again for all the replies!

Charles

---------------------------------------------------------------------------------------------------------------

Modeling the Santa Fe & Pennsylvania in HO

Youtube Channel: https://www.youtube.com/channel/UCLb3FRqukolAtnD1khrb6lQ

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
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Posted by gmpullman on Thursday, November 25, 2021 9:55 PM

Very nice repair, Charles!

You just added very valuable skillsets to your repertoire.

Regards, Ed

  • Member since
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  • From: Bradford, Ontario
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Posted by hon30critter on Thursday, November 25, 2021 11:10 PM

Trainman440
Now I got a perfect looking and running engine!

Hi Charles,

You did a great job on the repair! Your investment in a 140 watt iron will pay off (as it already has).

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

  • Member since
    August 2020
  • 282 posts
Posted by Southgate 2 on Friday, November 26, 2021 12:03 AM

Nice job on the brass repair and paint. What a handsome engine! Don'cha love acquiring a new tool and the skill to use it? Dan

  • Member since
    May 2014
  • From: Pennsylvania
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Posted by Trainman440 on Friday, November 26, 2021 10:31 AM

Thanks for the kind words all!

Yea its nice to finally have a powerful soldering gun..makes brass repairs SO much easier.

Now all Im missing is a resistance soldering iron, a drill press, a sand blaster, and a lathe :)

(and a million dollars LOL)

Charles

---------------------------------------------------------------------------------------------------------------

Modeling the Santa Fe & Pennsylvania in HO

Youtube Channel: https://www.youtube.com/channel/UCLb3FRqukolAtnD1khrb6lQ

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