Making a brass tank car comments (to GRR article)

[FJ and G]

The latest article in GRR on using brass is nice & gives me ideas for the many future projects I've got on my endless list.

I've worked with brass and copper in the past building a variety of switchstands as well as installing plumbing in my basement. That said, I'm no metallurgy expert and would classify myself as a beginner.

Two comments on the good article. Before sealing the tank, you might want to add some weights inside the tank (if you think U need them).

Secondly, the biggest problem that I have when soldering, whether with the large propane tank, small butane torch or soldering iron, is when I'm soldering one part and the other part already soldered nearby melts.

This is particularly irksome when doing window mullions for industrial buildings, using copper wire grid patterns.

I know that heat sinks such as alligator clips help, but still, I find that the most difficult and frustrating part of working with metals.

One other comment. You can use a form and bang out a variety of shapes using a mallet, then go back and fill in the crevaces with auto body filler or the stronger JB weld and then sand.

Oh, one more comment. The author used a dremel grinding tool bit to smooth unwanted solder around the top. I've used that method before, esp. for making switch frog flangeways, and that too has frustrated me b/c when you do the grinding, it tends to remelt the solder and make a big mess. I find better success using simpler mechanical means such as a file and in the case of frogs, a hacksaw.

It takes longer and uses more calories, but that's my experience.

[kstrong]

Dave,

All good points. Thanks for writing.

A few additional notes about this particular car. The copper end caps are HEAVY, so there's no reason--in this instance--for additional weight. (that little tank weighs as much as a common Aristocraft tank car.) Their mass is also the reason why none of the other solder joints melted when the assembly was heated. They're incredible heat sinks themselves, taking a lot of the torch's heat output just to get to melting temperature on the joint being worked.

If melting joints presents a problem, try using a wet sponge or cotton ball as a heat sink. They're far more effective than lightweight alligator clips, especially when working on items this large.

Heating the metal to the right temperature without destroying everything else is one of the tricks of soldering. In the next installment, I discuss using smaller heat sources for smaller jobs. Some electronic irons have variable heat settings, so you can tailor your heat output to the piece being worked on. Torches have a small degree of variability as well. I usually start with a low flame, and turn it up as needed.

The trick with using dremel tools is to tread lightly so not to build up too much heat. Again, given the heat absorbtion of the copper used in the tank, this was very much a non-issue, but it could be for smaller assemblies. The same sponge or cotton ball trick will work in this instance as well. Generally speaking, though, I've been able to use a rotary tool and continue to hold the workpiece in my hand. It never really gets that hot.

The rotary bit has the advantage of working around details such as rivets which a file would remove very effectively. Files, on the other hand, are less prone to clog up with solder, so if you can get away with a file, that makes just as much--if not more sense. (And who among us can't afford to burn a few extra calories?)

Later,

K

[dwhellum]

Hi,
I used to work making aluminium boats. When we ground or cut the aluminum with abrasive tools we had a block of wax we would rub on the surface of the cutting tool first, this prevents the aluminium from clogging the tools. I'm sure this would work with lead and copper as well. We had a lasrge block of parrafin wax but im' sure candle or bee's wax would work also. [;)][:D]