Soldering Brass

[Attuvian]

I am in the midst of assembling a Precision Scale Delta trailing truck for an upgrade to an old MDC 2-6-2 Prairie.  As this item is going to take some wear and tear over time (if only because of its relative weight), I'd like to solder it together.  But because of its mass, especially at the aft end booster, I can't expect any standard pencil iron to do the job.  Perhaps not even a soldering gun as the booster is large enough to be its own virtual heat sink!

I ran across a small, self-contained butane torch at a tool store and wonder if that might be too much in terms of temperature, even though its only about the size of a hefty pencil.  I will definitely start at the back end as that's going to require the most heat and I don't want to wipe out any earlier work on smaller parts in the process.  Observations and suggestions, please.  And while we're at it, is there a flux to avoid in this application?

I'm certainly willing to consider some sort of adhesive or epoxy as long as it would be sturdy enough and take well to a jeweler's file and paint.  Thanks, all.  JB

[gmpullman]

Attuvian

I ran across a small, self-contained butane torch at a tool store and wonder if that might be too much in terms of temperature, even though its only about the size of a hefty pencil. 

After studying torch options I settled on this Dremel model:

https://www.dremel.com/en_US/products/-/show-product/tools/2000-01-versatip-precision-butane-torch

It has the heat and control that I needed to solder heavier brass parts onto several locomotive projects that I had going.

Shop around. I bought my kit at Amazon in the neighborhood of $40. Some torches seem like they are geared toward making creme brulee and other desserts. They may be OK, I really can't say. The ten dollar one at Harbor Freight might be good, too. I have not used it. I'm happy with the Dremel model, though.

YMMV.

At the same time I was looking for a reliable solder to use. This is what I am using and have had great success with the flow and strength of:

http://www.micromark.com/Tix-Solder-Pkg-of-20-Three-Inch-Sticks

Tix solder and their liquid flux made the job of soldering hassle free. I used it to build a tall, etched brass yard light tower and had to solder each of the four, very long corner joints, and had no problems with warping or solder flow.

The Dremel torch kit comes with a bit of solder, too, but it is not labeled as to the content and I didn't try it yet. I'll have to contact them to find out what the specs on that solder is, mainly the melting temperature.

I bought my Tix which came with a bottle of flux and "anti-flux" which is supposed to resist solder from Amazon, too, but there are other vendors out there.

Good Luck, Ed

[Attuvian]

Thanks, Ed.  My small torch is from Harbor Freight.  I guess I should not be too concerned with warping or damaging the brass as long as I back off as soon as the solder flows . . .  I used to solder brass occasionally when building electronic test equipment but that was stiff sheet stock - and 45 years ago.  And I have my own money invested in this job!  That and the affection for the project itself generates a tad more care.  JB

[RR_Mel]

I do a lot of brass soldering and I have soldered several Precision Scale trucks too.  Many years ago I bought a 150 watt American Beauty iron for the purpose.  It came with a spare ½” tip, I turned the ½” tip down to ¼” and it works great.  I’ve never needed the ½” tip so it’s still my spare.

 

Using a paste soldering flux allows the solder to flow quicker with less heat.

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[doctorwayne]

Clean all of the areas to be joined using a wire brush in your Dremel.  If you don't have those items, you can do the job manually using steel wool. Brush or blow-away any residue, then apply a paste flux to all areas to be soldered, then assemble it completely, using soft iron wire to hold things in place.  Do the heaviest work first, and use wadded, wet paper towels to keep the other areas from heating up too much.  Once you've completed a joint, protect it with more wet towelling, and move on the the next.
I assembled this cast-brass cab using this method with a plumber's propane torch.  It was then protected with wet paper towels, and attached to the boiler using a 200watt soldering iron:

Wayne

[hon30critter]

Always amazing work Wayne, with a plumbing torch yet!!

Dave

[doctorwayne]

Thanks, Dave, but I was sorta stuck as to how to accomplish things, so thought I might as well give 'er a shot.
That was after I'd removed the original cab and then used a cut-off disc in my Dremel to "prepare" the boiler for it's new cab...

I actually learned lots of useful stuff re-building that locomotive, and one of the most useful was that sometimes, ya just gotta jump in and see how it goes.  It wasn't my loco, anyway, so what was there to lose?  

Wayne (still good friends with the guy who owns it)