Tell Me How to Solder Stuff

October 7, 2007 6:25 PM

What can you tell me about soldering? Not the electronic kind, but more for crafty/domestic purposes. Bonus if you know anything about metalwork.

I checked this thread, but I don't think the question or answers apply to what I want to do.

The overview of the project is that I want to permanently affix some silverware to a wire frame. This is strictly a décor thing, so I am not worried about it being able to support weight, or be food-safe, etc.

I could use smaller-gauge wire for attaching, but I think it will look ugly and bulky, and make the project look more rustic when I want a clean, streamlined look. Plus, then the pieces will wiggle ever so slightly, and I want them to be firm. I think soldering is what I want, but what I know about soldering would fit on the head of a pin.

Do you have any suggestions for websites that might offer tutorials? Suggestions on equipment, stores, anything? I'm a total novice at metal crafting, so all help is appreciated!

posted by pineapple to home & garden (9 comments total)

First thing you'd need to do, is to determine what kind of metals you'll be trying to join. You say you want to hang "silverware" on "a wire frame." But there are many metals used for "silverware," from actual fine sterling silver, to plated silver over base metal, to common stainless steel for every day kitchenware, to combinations of pot metals and various platings for the cheapest of common every day knives and forks. And there are many kinds of "wire frames," the most common material probably being drawn mild steel, although copper and aluminum are also frequently used in "wire frames." To, make a long story short, the metals you are trying to join will determine whether you can join them by soldering, silver soldering, brazing, or welding. And actually, you might find that something as simple as hot glue, or epoxy would be equally fixative for your application, without the difficulty of heating the pieces, or your wire frame to temperatures sufficient for any form of metalurgical bonding.

If you want to join common stainless steel tableware to drawn mild steel wire, you could rough up the tableware at the point to be joined and silver solder it, or braze it to the wire, according this primer on working with food grade stainless steel. You might see some slight discoloration from the heat needed to melt the brazing rod or silver solder, and you'd need to be careful and use a small torch tip. By that, I mean you'd probably use a normal oxy-acetelyne tank rig, with fine brazing tip, to provide heat for the joint. You put most of the heat into the tableware piece to be joined, and only flow heat to the wire frame as needed to carry filler out on it, for the joint.
posted by paulsc at 7:12 PM on October 7, 2007

Did you look on Craftster.com? I've found lots of good info there. Also, Glitter.
posted by sugarfish at 7:12 PM on October 7, 2007

Make has a useful collection of links, but I think paulsc has it - any decent epoxy will join what you're trying to join, and you won't have to worry about discoloration from heat.
posted by ersatzkat at 7:19 PM on October 7, 2007

Basically, you use a very hot iron tip plugged in to a socket to melt a thin soft strand of solder without burning your fingers. The solder usually comes ready to go. It melts instantly and hangs onto your tip in drops. Be exact, never sloppy. Try not to get the smoke in your lungs or eyes. The solder can be spread with the hot tip, but once it's on, you can only flatten it, not remove it easily. It dries in minutes, but never use your fingers to see it if is dry, because you can never tell, it might be molten instead. I don't see any harm in experimenting with it to learn if it works. It's great for joining electric wires. An electric iron or gun can be bought for about $10 and a coil of solder goes a long way. Be careful to properly place the hot tip in a holder when not in use.
posted by Brian B. at 7:21 PM on October 7, 2007

A stained glass store can answer your questions and you can buy the equipment there as well. Here's one in Dallas.
posted by Eringatang at 7:31 PM on October 7, 2007

The silverware is silverplate, and I don't have a plan yet for what kind of wire to attach it to. I was going to buy a roll of something at Home Depot. ("Ill-conceived" is the most accurate way to describe my craft projects, you might have noticed.)

Thanks for all the info. I knew MeFites would have good resources. Keep 'em comin' if anyone else has ideas.
posted by pineapple at 8:02 PM on October 7, 2007

I could be wrong, but I don't think you're supposed to actually touch the solder to the tip of the iron--you touch the iron to the stuff you're joining and then when that's hot enough, the solder will flow onto it. It's such an easy and clean process that I can easily solder wires together over any surface without having to put paper or anything down--and I have almost no experience with it.

Things could be different with crafts, of course. I found a pretty good guide on Instructables about it, and that helped me a bunch...unfortunately, I can't seem to locate it now.
posted by DMan at 8:08 PM on October 7, 2007

I am an MFA student who builds metal sculpture and jewelry.

You want to braze the two pieces together. "Sliver soldering" is a colloquialism that refers to using a silver filler for the braze. Actual soldering takes place below 800 degrees F and will not bond your silverware.

The torch you will need to get the "silverware" (I am assuming it is actually steel) to brazing temperature will probably be the biggest obstacle. It's most likely going to have to burn acetelyne or oxy propane in order to get hot enough. Ottofrei sells the acetelyne/air Smith kit for about 150 dollars. The tip that comes with it is not big enough. You will need to get an additional tip, like a #0 or #1. The propane torch you buy at home depot will never get hot enough and you will end up with discolored metal that never bonds. In a pinch I have used a mapp gas canister to braze 1/8th in steel rod, but I doubt it will get hot enough for your application.

Brazing is not easy. You will need to practice. The differences in masses of the two objects you want to attach together will make it even more difficult. Both pieces needed to be heated evenly for the filler to flow between the two. Silver does not form a eutectic bond with steel and when the steel inevitably corrodes, you are left with a weak joint. I know you don't need it support weight, but if you want it to stick around for a while, you will better off using a bronze filler and braze welding.

You will need a flux. You cannot use the low temp flux sold at most home supply stores. You will need to visit a specialty welding shop. For steel I recommend the Superior Black Flux. Everything needs to be clean and tight fitting for caplliary action to bring the filler into the seam. You coat everything in flux on a fire brick or soldering board and heat like mad. When the flux goes clear you are ready to add filler. Coat the filler with flux and touch the parts. Control where the metal flows with the heat, but don't boil the filler, this leads to contamination. Keep adding filler until you build up an adequate fillet. Air cool and clean. You can do this mechanically or chemically with a heated solution of Sodium Bisulfate and water.

If the silverware is actually silver, use a copper or silver armature and silver braze. The technique is very similar but takes even more fine control. You will use a white flux and not need to build up a fillet because of the eutectic bonding. Be careful. Silver reticulates then melts very quickly. The key is heating quickly to the right temperature and not over. Silver will also pick up firescale if overheated. This can be combated with a little boric acid mixed with denatured alcohol.
posted by fair_game at 8:16 PM on October 7, 2007

I have a unique method. I use a 24 inch fresnel lens as my torch. I use silver solder wire pounded flat, cut into pieces that fit between the parts i want to join. I hold things in place with soft iron wire and coated in stay-silv brand flux. I stick copper to stainless this way. You will need a lens from surplus, flux and solder from a refrigeration supply, and dark sunglasses to see when the solder wets. If the sun isn't shining a 'presto lite torch' works very nicely,available from the refrigeration repair supply place. Very neat results, no solder flowing around outside the joint.
posted by hortense at 11:54 PM on October 7, 2007