Oxy - Propane Torch

One of my projects (The Pennsylvania A3 Switcher, a live steam locomotive in 3/4" scale) requires a considerable amount of silver soldering. So I did some research and came up with the Mircoflame 6002 from SRA. I chose this one because the fittings are for the disposable propane (or Mapp etc.) and oxygen cylinders that are available at most hardware and home outlets. And I thought it would have a large enough flame. Mine came with 3 tips: 2, 4 and 6. Others are available, plus some with special 2 tips forming a half circle (or so).

Using Firebrick for Safety

Safety ..Safety .. Safety .. is a must so I have a small portable enclosure using firebrick, this is to help keep a wandering flame from torching the place. It looks like I need a few more bricks to complete the job.

Silver Soldering the Column

So far I have been using the #6 tip (looking for a #7) for my soldering. It puts out a very nice 5" by 3/4" flame. See photo on right. Here I am soldering one set of columns. Notice that the column is orange red and just ready to melt the solder. I have to be very careful that I don't stay in one place very long otherwise the brass will melt or pit. The top piece is only 1/16" thick and since I'm using a flame that is over 3000° F, you must move around a lot!

After cooling down and cleaning it, I noticed that there was not enough solder. Repeated the heating process and added more solder. You guessed it ... now a little too much. But still a good joint.
 

Columns at various stages

The photo on the right show the various stages for the columns. Notice that the middle one has a lot of red oxide from the heating process. It comes off during the cleaning, forming and final sanding. The one on the right is the finished product (except for final drilling).
I am very happy with the results so far and hoping the remaining 2 will be the same.
 

Conclusion...
The Microflame worked very well for what I have done so far. I had very good control of the flame and the amount of Oxygen I wanted. From a large flame to a small one. I controlled the temperature by moving around and keeping a safe distance from the inner flame. The #2 and #4 tips will work for the small joints and the #7 tip probably will do for larger jobs.

But if I were to do it all over again ... I would not buy it.

It is too small for the larger items (especially the boiler), where a large (but not excessive) hot flame is required. This one is greater than 3000° F but the flame is just not that large.

Additionally, I may want to use the larger propane tanks (17# ones), but I haven't been able to find an adapter yet ... I may have to make one.

I will make due and if needed I will add additional torches to spread the heat around while the Microflame heats the joint. We will see.

Take a look at the Turbo Torch LP-1 Swirl Air Propane Kit from J&R Welding Supply Co.

See Dan's review click here it's under Workshop.
 
Thanks Dan ... for your inputs.

Review - Silver Solder Torch