One of the main issues many people face when scratch building farm toys, particularly out of brass, is to not only have a toy that is pleasing to the eye, but also one that will hold together for years to come. It may sound pretty straight forward, but I would like to share with you some tips on methods of effectively joining brass, as well as various products that I have found to work very well, and the different equipment needed. This will be Part One of a two-part series, and the first will deal exclusively with methods of soldering and soldering equipment.

First when soldering, always remember to wear proper eye safety wear, and even hand and/or skin protection if necessary to prevent burns, and be aware of the surface your work is on. Wooden surfaces, for example can ignite under the intense heat produced when soldering. Be sure to work in a ventilated area and avoid breathing fumes that can be produced. Also, never apply heat to areas that already contain any type of epoxy, as excessive heat exposure to almost any type of epoxy will produce toxic fumes.

While there are more ways than one to effectively solder brass parts and come up with a sturdy piece, following are methods I use that have proven to work very well. First of all, different jobs require different levels of heat to get the brass hot enough to let the solder become liquid and fill in the void areas between the pieces you are joining to form a strong bond. For small jobs, such as soldering pieces of 1/16” brass that are relatively small, for example, I use a 30 watt pencil-grip iron that can be purchased at any hobby store for $3 to $5. This wattage can usually disperse sufficient heat through smaller pieces. For jobs where something like 3/16” tubing is used for example, I use a 100-watt soldering gun, which effectively disperses the heat in what would be considered medium pieces. For larger pieces, such as sheets of 22 guage brass which one might use to build a wagon or other such items, I use a refillable butane pencil torch that produces a lot of heat for heating up large pieces of brass quickly. These can be purchased at hardware and hobby stores for as little as $5. There are other types of butane torches that can be purchased for up to $50 that are self-igniting, have a pistol-like grip and may stand up to longer use. It is just up to the buyer as to how much is spent and what quality one it looking for in a torch. There are also soldering guns out there that are of great quality that can even be considered professional grade, but I have found that the lower cost guns work well also, especially for occasional building.  I typically use lead-free tinning flux and lead-free silver solder. Other types can probably be used, but I first tried these and they proved to work, so there was no need to change, and there were no potential health hazards of working with lead-containing products.

Before beginning to join the pieces, make sure they fit together the way you want. Next, make sure the surfaces are clean by either wiping them off, or by gently “roughing up” the surfaces with a Dremel tool. Then apply a thin coat of tinning flux with a brush to the pieces you are working with. If needed, one can apply extra flux to make sure there is sufficient flow when heat is applied. The next step can be quite a challenge, but if there is a way, clamp the pieces together to prevent them from moving while soldering. It can become frustrating when the pieces end up joined together out of proper position. If clamping will not work, laying a heavy tool such as a wrench or pliers to help keep the pieces in place on a flat surface can work also.

Once you have the pieces secured and tinning flux applied, begin applying heat to the pieces with whatever equipment you are using. If using an iron, make sure to have the tip touching both sides of the metal joint. Sometimes it may take several seconds or even a minute to let the pieces heat up. Once the flux has really had a chance to melt and begins to “sizzle” pretty good, touch the solder to the brass itself, not the tip of the soldering iron. If the brass is hot enough, the end of the solder will melt and begin to flow throughout the joint rapidly. Once this has happened, remove both the solder and heat source from your work and let cool. This should result in a nice strong metal joint.

Some problems people run into that result in an ineffective metal bond are not having enough heat applied to the work in order for the solder to melt and flow through. This may be the result of too small of an iron for the size of metal you are working with, or it may result from solder deposits on the iron tip, which will hinder the iron from reaching full heating temperature. Make sure to keep the tip clean. To accomplish this, I will let the iron heat up, then clean it by rubbing it on a steel wool pad, then apply a small amount of tinning flux to the tip. If some of the solder “beads” up on one side of the joint, then there was not enough heat to disperse it effectively. This can be remedied by applying heat back to that spot in order to re-heat the solder and melt it completely. One other problem one might run into is when using sheet brass, having a spot right in the middle of the sheet get hot enough to bond another piece to it can be a real challenge. Again, it all comes back to having enough heat. When trying to heat up the middle of the sheet, there is much more room for the heat to travel throughout the piece, thus when that heat is spread out over a greater area, it becomes more difficult to reach full bonding temperature at the very spot you are trying to work on. If you find this happening, you might need a larger torch or iron, or try brass that is a bit thinner.

 It can take several times to get a feel for what it takes to accomplish a good strong joint, but once that is achieved, it becomes easier with time. To build practice without making your custom or scratch built project be the guinea pig, use scrap and try soldering it together in different ways such as angles, butted together, lapped, etc. Once you get it down you will find that it is very effective to get the desired strength in a model.

Part II will cover joining brass with epoxy and some of the different epoxy products available.