Unsoldering PSC bolsters for Protocraft trucks

this.... UGH

You want to remove the car bolster?  The whole thing?

And hen put what in its place - got a photo of that replacement bolster?

Not the whole thing, only the part where the truck screw goes.

http://www.protocraft.com/cate...145&Categoryid=6

If you just want to remove the threaded mount from the bolster you need high heat. I would use a mini torch but a 100 watt or greater iron would work too (not soldering gun). Keep the screw in place. Apply heat to mount while pulling up. High heat minimises heat transfer to the whole bolster.

Pete

I'll try that Pete, thanks.

 

I would use a mini torch...........

Keep the screw in place. Apply heat to mount while pulling up.

Seems right.

If you can put something to block/shield the rest of the underbody, I would - couple of smaller ceramic tiles....

Some small pieces of cloth soaked with water, then draped over the tapered sections of the bolster as well as on the floor of the car will help block the heat flow and confine it to the threaded insert that you are trying to remove.

B Smith posted:

Some small pieces of cloth soaked with water, then draped over the tapered sections of the bolster as well as on the floor of the car will help block the heat flow and confine it to the threaded insert that you are trying to remove.

Ever try to unsolder copper water pipe that still had water in it? The solder will never melt. I would not use any type of heat shield but if you are nervous about the car returning to kit form use a heat resistant insulator as MWB suggested.

Pete

Well, all I can say is that I have had very good success with this method of  using a small bit of damp cloth as a heat sink. It's quite different from trying to solder a copper pipe that still contains water, because you have to raise the temperature of the whole circumference of the pipe in order to get a good joint, whereas in this example it is only necessary to get a small area of the bolster hot enough to melt the solder. The pieces of damp cloth prevent the rest of the bolster from getting hot enough to come apart. Heat sinks are often used to protect parts that have already been attached if you are building up an assembly. What can I say? -- it works.

Santiago, have you tried to tap the old hole for the new screw size? If there is enough material I would think that would be the easy way to do this.

Charlie

Drilling a new hole of the correct diameter and tapping it for the replacement screw sounds like a good solution if there's enough material , as Charlie said. You could drill right through the floor and then tap the hole with a regular tapered tap, or you might be able to use a bottoming tap to finish the threads if you don't want to drill all the way through.

I got a 100 watt gun and it did the job, barely but did it. Could have gone for a bigger one. 

Tapping is not an option as it requires a smaller screw, not a bigger one. 

Thanks for the input guys, I'll post a few pics when I'm done.

Pretty sure the PC king pin screw is quite a bit smaller.

Jay

Next time just run a brass screw in there, drilled and tapped dead-center?  If you are brave, you can run the screw in with Loctite, then drill and tap.

I have had very good results in situations like this from using a very small jeweler's torch such as the one illustrated (uses regular propane and oxygen cylinders with valves and adapters for the small hoses), sold under the brand name "Smith's." You can put a lot of heat on a very small area very quickly with one of these, but you do have to be careful.

Yes Smith torches are very good for this, have used one for years. But the were made for the medical and dental trade, so they are expensive. torch tanks and tips can set you back about 400.00 dollars.

This is one of the micro torches I use. Solder It PT 220. About 45 bucks. This would have been my first choice. I also have a resistance soldering set, homemade, that I am sure would have worked as well. The key here is concentrated heat.

Pete

I bought mine from a local jeweler's supply store about 25 years ago, but a recent Google search yielded some outfits for around $140.00. The oxygen and propane tanks are not expensive and can be found at local hardware stores. I did see a Smith's torch with a caddy for the tanks and some extra parts and tips/nozzles for around $400, but it isn't necessary to purchase all the bells and whistles. Even 25 years ago the equipment, although cheaper back then, did seem expensive, but the torch is very well made and I have gotten a lot of use out of it over the years building kits from CLW and Electric Shop and other fallen-flag suppliers of O-scale stuff, and repairing old engines with large castings.

Santiago,
Another option is to enlarge the hole in the Protocraft truck bolster to allow the original PSC screw to be used with the Protocraft truck. Replacing the carbody bolster center is a frustration you only do once. Then you realize you can't see the screw even if you turn the car upside down.

George I'll def try that on the protocraft car, I'm actually swapping trucks between PSC and PC.

all great ideas guys, thank you!

Here is the PSC w protocraft trucks installed, love the ball bearings! 

Seems the car sits quite high in this arrangement.  How is the coupler height?

BH

You may be right, I'll check tonight

Maybe a bi yeah, easy fix tho

Very, very close actually.  I guess these cars sat higher than I realized. I looked online at some actual cars and based my comment on the amount daylight between the top of the truck and the underside of the body; the model looked to have quite a bit more. But, it sure looks fine sitting in the train including the roof height. 

BH