My experience leads me to say that the tip of the iron should be in contact with the surface of the material being soldered. If the metal is not hot, it will not take the solder well. In the case of copper foil, the metal is so thin it will heat up almost instantaneously. The solder should be added to the heated metal to obtain a good joint. All the advice to hover just above the surface and allow the molten solder to heat the metal below seems to make for hard work suspending the iron, and for possible cold joints.
The principle is that both metals should be hot for a good join. In leaded work you can sweat a joint and get as good (and in some way a more lasting) joint as by having a bead. That is because by adding the minimum of solder (sweating) you will have to get the base metal hot for the thin layer of solder to flow. I feel that many people do not understand the principles of soldering, but look only to the finish. It is possible to have a beautiful joint, or bead and have the joining of the metals technically weak.
It has bothered me for a long time that only the bead finish is considered when people evaluate soldering. I do a lot of work using foil. It amazes me I have only read one time that the foiled pieces should not be tightly jammed together, solidly held in place with nails and soldered. It seems to me the Tiffany method allows for finer detail and yet at the same time it is imitating the creation of lead came. If you tightly pack the pieces together you are only soldering a bead top and bottom and no "heart" is created. Worse yet I have seen pieces soldered where the flux has caused an air pocket and the solder is simply buttered over the top failing to burn out the flux and failing to fill the void. In an effort to create a narrow thin high top bead we are forgetting to teach strength and longevity.
ReplyDeleteI subscribe to your blog and find your insights to be well thought out. Thank you for sharing with us of lesser experience.
Sincerely,
Art
Art, I agree with you on the soldering of copper foil. We are creating a "came" by having a "fin" of solder joining the top and bottom beads. Without that we are relying on the temporary strength of the adhesive to provide structural integrity for the piece. We already know that the adhesive is mostly compromised by the heat of soldering.
ReplyDeleteIt is because we are creating a "H" section with the solder that it is important to have beads on both sides of the piece, unlike the far east imports and a number of western produced items.
I'm glad you find the blog useful. Continue to add comments as they will make the blog better.
Thanks.
I agree!
ReplyDeleteI have also heard people say that "capillary action" will pull solder into even the smallest space between pieces of copper-foiled glass. I know this isn't so because when I do repairs, I often run into glass with no solder between it.
And one last one - I have heard people say that the reason you have spitting and bubbling on the second side of a copper-foiled piece is that you use too much flux. One person recommended using a sponge dampened with flux so that flux won't get into the space between the glass. Sorry - that's incorrect. Try putting solder on copper foil without using flux. It wipes right off. YOu need to get some flux on the foil between the glass or no solder will stick.
Rebecca
I agree that teaching needs to emphasise the proper technique more than just the beauty of the bead. In leaded glass you cannot spend so much time on the joint, because you will melt the lead. Perhaps starting people on leaded lights would make soldering better, but that's another discusson
ReplyDeleteStephen