Bench Tips
This selection of Bench Tips is generated through experiences and challenges my students faced in their training. It started 2011 and will over time become an info spot for my web guests on issues and perspectives generally unavailable in jewelry books and publications.
SOLDERING
If you are having trouble here’s what works
Flux is an oxidation protector used for gold and silver soldering. Without flux the solder will not connect with your piece. It comes in different forms, dry, liquid or as a paste.
Working with silver and low carat gold soldering:
You can buy flux in powder form {i.e. Borax} from the grocery store. The pasty, borax based composition products, from tool suppliers are slightly better.
Working with higher carat gold:
Use Fluoride flux. The powder is orange and turns green when dissolved in - preferably - distilled water. You can find it ready mixed at tool suppliers.
Working in white gold, with nickel content:
Because white gold needs complete protection, use alcohol based Boric Acid, Borax and little fluoride flux addition in the mix can improve the results. (More info further down)
Solder is a special metal alloy created to melt, before the metal’s melting point is reached. While being heated, it will penetrate and connect the surfaces, without the risk of melting the entire work piece. Mostly Cadmium and sometimes Zink are used to reduce the solder’s melting interval, and those metals will evaporate in the soldering process while liquid.
Balling up Solder
Withstand the temptation to ball up solder! Your solder has lost half of its capacity to connect before you begin. That means, about half the distance to run and a lesser willingness to merge with your piece. The simple reason is that the tiny portion of cadmium, to reduce the melting point, partly evaporated already while creating the ball. You also need to know, that once it is gone completely, your solder will not run again. That can be seen as an advantage in the construction process if you know how to use right!
Flux - Solder Relationships
Most people don’t pay enough attention to temperature ranges and how to combine both Solder and Flux right. See the two most common problems as follows.
1. When solder flows before the flux
Imagine your solder is melting before the flux forms a liquid glaze, unable to connect through to the piece, even balling up. You will have unwanted cadmium losses plus oxidation on the solder, while the solder still can’t sink through the pasty cover. This will lead you to overheat the solder, until the glazing is liquid enough to finally let the solder sink through and connect to the metal. Overheating solder causes shorter running distances, porosity; lesser stability and often unevenness of the solder line and unwanted clean ups.
2. When flux gave up before the solder runs
The other variation is that low temperature flux gives up, before your high temperature solders come to run, which will leave your solder and surfaces unprotected, oxidizing. Once the solder liquefies, oxidation which had meanwhile developed in the seam as well will limit or stop your solder from running. The outcome for your work pieces shows similar results like the above, porosity, poor stability, eating into the surface when pushing the heat and lots of unwanted clean ups will make for the major issues.
Boric acid-covers protect the entire piece
Harmless on your skin, boric acid is a white powder that makes for a great protection against surface oxidation. Two common solutions are studio proven. The paste form, mixed with water applied with a brush or dipped. The downside is, it is thick and it distracts the view while the solder also tends to float inside the paste. Second choice, Boric Acid dissolved in Methylhydrate until saturated for finer distribution over the piece. With this method you can also mix in 30% - 50% Borax to help the protection to set in at lower temperatures, which is important for silver and the running distances of your solders (read Martinus on fire scale). This mix works fine for white gold with nickel contents as well. It is absolutely necessary since nickel oxides can’t be removed with regular acids. Apply Fluoride Flux on seams prior to dipping twice into the boric acid solution and burn off the alcohol each time. Then apply the solder with fluoride flux. Please note: Easy solders have a tendency to float on the boric/borax-cover. Push those through with the pick before they have lost their cadmium content!
Make sure to use an unbreakable container and a lid that can shut down an accidentally caught-on flame.
Best Solder/Flux matches will be provided in a diagram soon!
The Titanium Pick
An investment for life and in quality seams for the rest of your life! Don’t be cheap to use steel. Our fluxes will dissolve steel oxides and give them off into the solder seams. You don’t want them there!!!
back to top