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Discussion Starter #1
There have been any number of approaches to straightening out a bent cab roof on a steam loco. Most or all of them result in a broken roof. I have just successfully straightened a bent roof on a 2025 loco. I bought the loco for $30 without a tender. In order to straighten it out, I needed one piece of data: Zinc has an elastic limit of zero. What does this mean? It means that zinc will cold flow. Put a stress on a piece of zinc, and it will deform to relieve the stress. So I bought a clamp at Harbor Freight and used the clamp to put a stress on the bent part and I left it alone for 24 hours. This got the process started, but with the clamp I was not able to get the roof completely straight. I then clamped the end of the bent part to my work bench and added the motor and steam chest to the shell to increase the torque to straighten the roof. After a couple of days, the roof was nearly straight. Right now, the clamp is back on the roof for the final straightening. I should have a good report in a couple of days. This is not something that can be accomplished in a few minutes or hours. Anything that is die cast should be able to be straightened using this technique.:thumbsup::)
 

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Good tip! I straightened the fatigued cast frame of my '49 Lionel 622 the same way. Tightening the clamp a quarter turn a day over six days gave me a straight frame with no damage.
 

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Servoguy,

Interesting approach! Thanks for the info.

Question, though ... I have a prewar 1668 cast shell that has bent cab SIDES ... down low, near the cab entry steps. To correct this, I was thinking (???) of stripping the shell (planned for repaint, anyway), and then HEATING the cab section with a plumber's torch. Then, with the metal hot, slowly work it back into place.

But as I said, I've only been thinking about doing this ...

Any opinions? Anyone???

TJ
 

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I am thinking that with both heat and torsional stress the metal should react quicker. But how much heat and how much stress? Interesting thread I am interested to read more.

Bud
 

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Discussion Starter #7
I don't think heat is a good idea. Zinc is not like steel. It will melt instantly before you realize what is happening. Since the slow approach works, I am going to stay with it. If the part has zinc disease, I think you are out of luck.
 

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Ok what is zinc disease ? And if you have to heat it how about a low heat in the oven. Just a little bit. Like before you paint them? But if servoguys way works what's another day or two?
 

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Discussion Starter #9
sjm, don't go dropping your locos just to try out this approach. But you can buy locos cheap if they are bent. Recently I bought a 2065 with a nice whistle tender for $65. The loco was pretty well scratched up, but I touched it up with a fat sharpie. The tender needed lubed and a wire fixed, but it whistles really good. It is in very good condition.
 

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Like I said before, everything I buy is cheap. I dont know enough about trains yet to spend a lot of money! Maybe I never will. But I will take your advice , sharpies recently purchased (large size). I looked for paint brush size applicators. They were not avalible ( just kidding, maybe) . I dont drop things on purpose ( i sometimes throw them in frustration now and then) on the ground. So you can see why I need to try this out!
 

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By the way , the 2065 is a very nice engine. I like the side ( drive )rails. Very detailed. Thats why I originally liked the 1666 ( im not a fan of its slide pick ups) You will have to school me on wistle tenders, I have a few that are non working at the moment.
 

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Discussion Starter #12
First thing to check on a whistle tender is the wires from the pickups to the whistle relay. If they are bad (insulation missing or broken off) the whistle isn't going to work well

Second thing to check is the relay to see if it picks up when you operate the whistle control. These relays are very reliable. I don't think I have ever seen a bad one.

Third thing is to lube the motor. There are two bearings, one on the brush plate which is very easy to see, and one below the armature which is somewhat hidden. You do not need to disassemble anything to lube the motor. I use a pin oiler or toothpick to lube the lower bearing.

Fourth thing is to check for bugs building nests in the whistle and blocking the air flow.

Take one of your tenders apart and we will walk you through the servicing.
 

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Discussion Starter #14
I buy stuff cheap, also. I enjoy fixing things and making them work again. One of my specialties is 022 switches. I soon will have 100 of them. I wrote a long post "022 and 711 switch operating pblms" which you can find using Google. After I get done servicing them, they work better than new and will probably last 100 years.
 

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Ok what is zinc disease ? And if you have to heat it how about a low heat in the oven. Just a little bit. Like before you paint them? But if servoguys way works what's another day or two?
It's more correctly called Zinc Pest. It happens due to impurities in the die-cast material. Stuff produced in the pre-war and earlier post-war period are more likely to develop it. Once it happens, there is no going back.
 

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Hello verybody. I'm new to this forum however I have straighten 50 or so bent roof Lionel castings.

I put the engine casting in the oven at 175 degress. Let it sit there for 5 or 10 minutes. Then remove it, using my wifes pot holders to pick up the casting. then, Using a set of smooth jawed pliers very slowly pull up on the bent roof. It may take a few times but it does work. And the casting will not break.

jack
 

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OK ... dumb question ...

How do I know if my Lionel prewar 1668 loco shell is zinc-based, or some other alloy, instead???

TJ
 

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I have straightened cab roofs by making oak molds that match the curvature.--a concave one for the outside and a convex one for the inside and then slowly clamping them together. the oak is hard enough to take the stress.
 
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