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Need suggestions for dealing with a strange problem

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  • Member since
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Need suggestions for dealing with a strange problem
Posted by John-NYBW on Thursday, February 20, 2020 5:25 PM

I only work on my layout in the cold weather months and this year I haven't done much running or operating due to some long overdue layout maintenance projects. I've finally gotten to the point where I am ready to start running again and I just pulled a Bachmann Consolidation out of the roundhouse only to discover the metal components at the rear of the tender hand become badly tarnished and corroded. The track leading to that stall also had some tarnish. I have no idea how this could have happened. My first thought was maybe I had spilled something on the floor above and it had seeped through but looking at the subfloor from below doesn't show any signs of leakage and the loco was under a roof anyway. On top of that there isn't a seam directly above either the roundhouse or the turntable. The only thing I can think of is that maybe something leaked through and landed in the turntable pit and splashed on to the rear of the loco.

Anyway my problem is now how to deal with the tarnish and corrosion. The brass piece which connects to the axles to pick up current, if I remember this is called a wiper, had a thick green layer of tarnish on it as did the brass screw that holds it in place. The trip pin on the KD coupler is badly corroded as are the axles on the rear truck. The front truck had a minimal amount of tarnish and corrosion. I also want to look inside the tender to see if there is damage to the electrical components. The loco will not run at all as is. 

My plan was to remove the damaged parts and soak the brass pieces in Tarn-X and then figure out a way to remove the corrosion from the axles and the trip pin. I ran into a snag trying to remove the rear truck. The tarnish was so thick the screw wouldn't budge and the truck did not swivel freely. I dabbed some Tarn-X onto both the wiper and the brass screw with a small paintbrush. That removed most of the green tarnish but I still couldn't move the screw despite trying three different sized flathead screwdrivers. I dabbed on a little more Tarn-X and after a few minutes I finally got the screw to turn but very stubbornly. I managed to get about 3 rotations before I began to strip the head head of the screw. I don't think I can continue to turn that screw without stripping it further. I have one of those drill bits that digs out stripped screws but it is too big to use on such a small screw. It might not be necessary to remove the truck. I can pop the axles out and that will allow me to apply more Tarn-X to the wiper so maybe I can clean that without removing it. I need suggestions what to use to remove the corrosion from the axles and the coupler. Also, if it does become necessary to remove the rear truck, are the any suggestions for how to proceed with that stripped screw head? 

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Posted by BigDaddy on Thursday, February 20, 2020 5:43 PM

I don't know about your model but some Bachmann tender trucks are held by a nut, which is underneath and in the middle of the circuit board.  I've never been a happy camper when I removed that nut.

You can probably spread the sideframes and drop the wheels.   A dremel with a wired brush, or wet dry sandpaper will clean the axle up.  If the axle ends are boogered up by corrosion you should replace them.  I assume parts would be available from Bachmann or ebay.

KD trip pin, wire brush if you are cheap or just replace it.

The brass pickup on my Shay and 4-4-0 only sit on top the screw, removing one axle lets it fall out.

If that truck is now too loose...there is no easy out for screws that small.  I would take the tender apart and the circuit board out.  To drill the screw head off, the drill only needs to be as wide as the external diameter of the treaded portion, however it needs to be in the exact center of the now boogered up head.  I don't have any suggestions for that.

It might be possible to use a cutoff disc from the inside, but be careful and wear eye protection.  You don't want to cut through the tender floor or wallow out the hole in the tender floor.

 A more descriptive title, than Strange Problem (and it is)  might get you someone who had a similar problem

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by BATMAN on Thursday, February 20, 2020 5:54 PM

The corrosion could be rodent urine, Google how corrosive that stuff is. 

Brent

It's not the age honey, it's the mileage.

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Posted by SeeYou190 on Thursday, February 20, 2020 6:00 PM

John-NYBW
I only work on my layout in the cold weather months

.

If I did that I would literally NEVER work on my layout!

.

Laugh Laugh Laugh Laugh Laugh

.

-Kevin

.

Wink Happily modeling my STRATTON & GILLETTE RAILROAD. A Class A line located in a personal fantasy world of semi-plausible nonsense on Tuesday, August 3rd, 1954.

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Posted by RR_Mel on Thursday, February 20, 2020 6:40 PM

If you backed the screw out enough to grab it with pliers try that.  I have a pair of long nose vice grips that really help get out stubborn screws.
 
 
Worse case I’ve grabbed the screw or in this case the truck and worked it back and fourth to break it then redo the hole.
 
If that is the only place the corrosion has occurred Brent could be correct.  Nasty stuff!!!
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
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Posted by BigDaddy on Thursday, February 20, 2020 6:52 PM

If this is the schematic, https://www.bachmanntrains.com/home-usa/dwg/dwgs/HOBaldwin2-8-0DCCSoundValue(2of2).pdf

It may not be underneath the the circuit board, but it is a machine screw and nut.  That implies there is corrosion on the nut too.  I don't know if the screw backed out enough to get any kind of grip on it with the vise grip or even small needle nose pliers. 

Rodent vandalism, who knew?  I better shut up before the moderation police catch me.

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by herrinchoker on Thursday, February 20, 2020 6:58 PM

You might try Marvel Mystery Oil, apply with a Q-Tip, let stand overnight, and then try. It will also help remove corrosion. Hardware stores, or auto-supply. Have used it many years on marine electronics with satisfactory results.

herrinchoker

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Posted by John-NYBW on Thursday, February 20, 2020 11:47 PM

BATMAN

The corrosion could be rodent urine, Google how corrosive that stuff is. 

 

I thought about that because I do have a problem with mice but how would it get on the underside of the truck?

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Posted by John-NYBW on Thursday, February 20, 2020 11:59 PM

RR_Mel

If you backed the screw out enough to grab it with pliers try that.  I have a pair of long nose vice grips that really help get out stubborn screws.
 
 
Worse case I’ve grabbed the screw or in this case the truck and worked it back and fourth to break it then redo the hole.
 
If that is the only place the corrosion has occurred Brent could be correct.  Nasty stuff!!!

Unfortunately, I didn't get the screw loose enough to where I can grab the head of it. I have a small needle nose pliers but I can't get enough of a grip to turn it. 

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Posted by PC101 on Friday, February 21, 2020 12:48 AM

Deleated my post. Better idea posted below.

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Posted by doctorwayne on Friday, February 21, 2020 8:51 AM

Simply take the body shell off the tender (one screw near the front, accessible from the underside), then carefully lift the front of the shell to disengage two interlocking tabs connected to the bottom edge of the rear wall of the tender's cistern, as shown on the modified tender below...

If the tender still has its original circuit board (mine all have it removed, for better DC operation), remove the small screws holding it in place, then lift the board out of the way to reveal the nut into which that recalcitrant screw is threaded.

After the screw has been removed you can take the wheels and axle wiper from the truck to clean them.  I'd suggest some fairly fine wet/dry sandpaper for the axle wiper (use it dry), and perhaps try some baking soda, made into a paste with a little bit of water, to remove the build-up from the wheels and axles - don't use the sandpaper there, as it may remove the plating from the wheels and axles.

When you re-assemble the tender, make sure that the wheelsets for the rear truck are installed with the insulated wheels on the opposite side of the truck to those of the front truck.

Wayne

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Posted by John-NYBW on Sunday, February 23, 2020 2:06 PM

As per doctorwayne's  instructions, I was able to remove the tender without having to remove either truck on the tender so I was able to proceed without having to loosen the problem truck screw. I don't think I would have found that front screw had he not told be about it since it is partially hidden by the front truck. I would have probably assumed it was the truck screw itself holding the body on the chassis. I was able to open up the tender and to my relief, there didn't appear to be any internal corrosion. I soaked the tarnished wipers in Tarn-X over night and that seemed to clean them off. I removed all four axles from the truck and cleaned them. I replaced the corroded coupler with a KD whisker coupler which is an upgrade I  should have done anyway. The screw holding the coupler plate in place was so badly corroded I had to use a needle nose pliers to remove it rather than a Phillips screwdriver.

The fun began when I went to reassemble. When I went to reinsert the wipers and axles, one of the wipers sprung loose and shot across the room. I looked all over the floor with a flashlight and never found it. But that was minor compared to what happened next. In putting the body of the tender back on the chassis, I broke off the tiny two pronged recepacle on the front of the tend that the loco plugs into. Replacing it would require soldering skillls which I do not possess. I will have to send it back to the factory for repair. This Consolidation is one of my favorite locos and usually is assigned to my peddler freight. I have three of the Bachmann Consolidations but this is the only one that has sound. I have no idea what the expense will be to fix it. It's days like this that make me wonder why I ever got into this hobby.  

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Posted by RR_Mel on Sunday, February 23, 2020 3:26 PM

Sounds like a normal day around my hobby.  If anything goes right I’m happy.
 
If you have a soldering iron practice using it, it really isn’t very difficult.  Get some scrap wire some soldering paste or flux and do it to it.
 
Good Luck
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    January 2019
  • 213 posts
Posted by John-NYBW on Sunday, February 23, 2020 3:54 PM

RR_Mel

Sounds like a normal day around my hobby.  If anything goes right I’m happy.
 
If you have a soldering iron practice using it, it really isn’t very difficult.  Get some scrap wire some soldering paste or flux and do it to it.
 
Good Luck
 
Mel
 
 
 
 

I have a soldering iron and I'm able to do things like solder rail joints and feeder wires but that's about as challenging a task as I can tackle. My problem is getting the solder to flow where I want and only where I want. The part with the broken receptacle is a small circuit board about a half inch wide with six fine wires leading to very small closely spaced terminals. The chances of me successfully getting that right are about the same as me making two holes-in-one in the same round. It's possible but the odds aren't very good. 

I've already destroyed one decoder with a bad soldering job and that was a piece of cake compared to this. 

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Posted by John Busby on Monday, February 24, 2020 5:09 AM

Hi all

Ratsak or a mouse trap sounds like a rodent problem.

regards John

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