Last updated: 10/10/21
Nancy LT Hamilton
Soldering and the danger of fire, explosion, and physical damage must be treated with respect and extreme caution. YOUR actions and improper use of materials and equipment can result in death or serious injury. Never work when mentally impaired, in any way, and follow all safety precautions, manufacturer’s instructions, and the material’s safety and datasheets. (What is MSDS?) There are multiple sources for finding MSDS sheets. Most companies have these sheets available. It is recommended that you check with the manufacturer before using any products that you are unfamiliar with or unsure of. Here is only one source for finding a variety of MSDS sheets: EHSO (Environment, Health, and Safety Online). You can also check with OSHA – Occupational Safety and Health Administration – if you are unsure of safe practices.
BIG NOTE: The type of soldering discussed below, involves the use of a torch.
What’s the difference between a soldering iron and a torch?
Generally, Soft soldering uses a soldering iron. Soldering irons can range from about 300 degrees to about 900 degrees Fahrenheit. The wattage only determines the size of the join it can solder – not the temperature.
This is a soldering iron: A soldering iron operates on electricity. Ya plug it in and it gets VERY hot. Soldering with this tool involves heating up the solder until it melts and running the “solder” over the parts to be joined – holding them together like tape. The solder is usually composed of a tin/lead alloy (low melting metals). Silver Soldering or “Hard soldering” uses a torch. A torch uses gas plus air or oxygen to create a flame. It can reach temperatures well over 900 degrees Fahrenheit. Soldering with this technique involves melting a “filler” metal and, by the process of capillary action, the “solder” joins the parts together. The solder contains silver and other metals. The same holds true for gold soldering with gold being the primary metal in the solder.
Setting up a soldering area
Prices current as of Jan 11, 2010So, you’ve read the warnings above and now I’ve scared you to death, right? Just remember to follow all safety precautions and to adhere to them religiously and you will embark on one heck of an exciting adventure! Good Luck!
1. Ventilation (VERY Important) – Now, I have a kitchen vent over my soldering area but when I started out I used an open window with a fan that had a forward and reverse airflow switch. Make sure that the air is being pulled OUT of your studio and away from your face! If you don’t have a window, set up a fan to blow the fumes away from you – hopefully out a door or a window or even up a chimney.
2. Fire Extinguisher. (Also VERY important) – Make sure that it is of sufficient size for the area. Check with your local fire department if you are unsure.
3. A fireproof area to solder on. I use Durock to protect my walls and soldering surfaces. Durock is easy to cut (wear a mask – the product contains Crystalline Silica see MSDS sheet ). Durock is a gypsum board made with portland cement and aggregate. It is available at hardware stores such as Lowe’s or contact the manufacturer. I don’t solder directly on the Durock but it is a non-flammable product that protects my wood and drywalled surfaces.
4. A soldering pad. There are MANY different types of soldering pads. I will only discuss what I use.
Charcoal Soldering Block – I work with a dense, close-grained charcoal. I like it because it lasts longer and doesn’t fall apart easily. Charcoal offers a heat-reflective surface which means, when you solder, the heat from the torch is absorbed by the charcoal and reflected back onto the work. It is especially useful when soldering heavy pieces, where you want to achieve an even heat. But, I use it for most soldering tasks. You can find them at Rio Grande, Amazon, and Otto Frei among other suppliers. Charcoal blocks can be shaped with burs and drill bits to create wells or divots to solder or melt metal in. I use several different blocks for different purposes.
The wheel that my soldering “stuff” is sitting on is a sculpting wheel turntable or a decorating wheel. It is usually used by potters. I like it for soldering because I can keep my work hot and reach all areas easily.
Solderite Pad – Another type of soldering surface. This is also heat reflective, like the charcoal pad but, it also has the added advantage of a surface that is soft enough to push soldering pins into (especially if you choose the soft variety). It can also be modified with burs and drill bits. Available at these and other locations: Rio Grande, Amazon, Otto Frei, and other suppliers.
Honeycomb Ceramic Block – This block dissipates heat away from your work. This can be very useful when you don’t want a piece to overheat as when soldering small, delicate pieces. You can also find these at Rio Grande, Amazon, and Otto Frei.
Annealing pans and pumice. These are used for annealing your metal. I don’t recommend them for straight soldering as it’s almost impossible to line up parts to be soldered. Also, small pieces (not to mention errant solder snippets) get lost in the rubble. Available at these stores and many others: Rio Grande, Amazon, Otto Frei, and other suppliers.
(Goss Torch handle, hose and tips) 5. Torch, regulator, flashback arrestor, hose, torch tips. There are many different types and styles of torches. Your first decision is what type of gas and air mixture that you are going to use. I use Acetylene and air for most of my work. I chose this setup because it isn’t as hot as an oxygen setup. I didn’t want to teach soldering to new students and have them melting everything. It’s a good trainer gas. I have been using it since day one and got used to working with it. I do use a small oxy/acetylene torch system for quick, hot solders. Rio Grande sells a Little Torch setup for small disposable tanks. The product name and number is OX2550 KC -Cutting, Welding, and Brazing torch kit made by Bernzomatic.
There are also Butane torches that work very well and are great for small soldering jobs or for beginning jewelers. They are inexpensive and are great if you are just trying out the craft. But, as your skills grow or your techniques change you may find that you need a more “permanent” solution. The initial cost is small (generally under $30.00) but, those Butane refills get pretty pricey after several years of daily soldering, not to mention the environmental impact. These canisters are not recyclable at this time.
Rio Grande has several different Butane torches starting at around $40.00. Amazon has a ton too – starting at around $20.00. Others have purchased crème brûlée torches and have been very happy with their results. I do not use a butane torch so, can’t recommend one over the other – read reviews!
Acetylene is a dirtier gas than propane but it is hotter. If you decide on propane, I advise that you choose to go with an oxygen and propane set up. Oxygen differs from air in that the oxygen is supplied by a tank, while the air is pulled in, by the torch, from the surrounding atmosphere. You need an oxygen regulator and hose (green) and a propane regulator and hose (red). The torch tip has both hoses coming into it. The gas is lit first, then the oxygen is turned on. Slowly, open the gas line. Don’t open it too much, just a tad, and light it. If you have a blow torch effect, lower the gas. When the gas is a manageable size, then slowly open up the oxygen valve on the handpiece. It will start to hiss and turn blue. You don’t want too much hissing or too long of a flame. The flame type depends on what you are doing. It’s a little trickier, using an oxygen/gas setup than a plain acetylene/air setup where the handpiece pulls the surrounding air into the torch and does the air mixing for you. There is also less equipment with air/gas as there is only one tank, one regulator, and one hose.
WARNING: NEVER LET THE REGULATOR GO ABOVE 15 PSI (pounds per square inch) WITH ACETYLENE. The gas polymerizes over 15 PSI – which WILL likely cause an explosion. I set my regulator to 10PSI. The tanks MUST be strapped to a solid surface (like a wall) so that they don’t fall over. Use either straps or chain on the top and bottom of the canister – don’t forget to make changing the tanks easy – make sure you can open the straps when the tank gets empty. Acetylene is a very dangerous gas. Leaks are deadly. Don’t store the tanks near open flames or electrical appliances. Check for leaks every time you change your tank out. Please see the Safety Hazard Information at MSHA (US Dept. of Labor -Mine Safety and Health Administration) for safe handling information and warnings.
If you have a regulator with only one dial – one that only shows the amount of gas – you won’t have to adjust the PSI. The regulator is designed to not exceed 15 PSI for acetylene. Check with the manufacturer and your instruction manual. Don’t assume!
Don’t forget: oxygen is not the same as air. I just read a book on enameling that interchanges the words. Believe me, the difference between oxygen/gas and air/gas torches is a difference of many hundreds of degrees. The words are not interchangeable!
A torch that utilizes both oxygen and gas burns very hot and is great for doing fast solder jobs where the whole piece doesn’t get heated up. It is very useful when you want to make repairs or when you need to solder an item that has a heat intolerant object in the design.
If you are using a small tank soldering unit, that involves small disposable tanks of propane or Mapp gas mixed with air, choose Mapp gas as it burns much hotter than propane. I have found it difficult to solder larger pieces and to melt scrap metal (to make ingots), using the propane/air mixture.
Safety Information on Propane/Mapp Gas and Butane (LP gas)
These gases are heavier than air. If there is a leak, the gas will accumulate in low places. Before lighting the torch, check these low areas for the odor of rotten eggs. The gas smells like rotten eggs because, ethyl mercaptan (an odorant), is added to the gas. The gas itself is odorless. If you smell rotten eggs, have people leave the area, turn off the tank, ventilate the room, don’t smoke, don’t turn on electrical appliances or switches, don’t use your phone – call for assistance from a safe distance. Call either a service professional or the fire department.
Rarely, but occasionally, propane will lose its odor. This is called gas fade and can occur when rust, water, or air gets into the tank. Installing a gas detector in your studio is one way to guard against this type of leak.
When picking up tanks from the dealer, be sure to check the tank for odors or hissing sounds. I once had a brand new acetylene tank leak in my truck. If I had left that tank in my closed vehicle, overnight, I would likely have blown it up when I clicked “unlock”!
Don’t rely solely on hearing or smelling the gas to determine if there are leaks – do the soap test (see below) – every single time you change your gas tanks.
Below, is an image of the valve stem/packing nut. Image courtesy of Thomas K. Thank you, Thomas!
Please see the NFPA website for more information.
A note on Hoses: Oxygen hoses are green and gas hoses are red! Always.
Tip: I recommend buying your torch in a kit. That way there is no guesswork. Rio Grande Jewelry Supply and many other companies sell kits. Discuss any problems or questions regarding set-up with these vendors.
Precautions and safety procedures
One big rule, when choosing a torch head, is to NEVER use torch tips from another type or manufacturer in the handle. It can explode, catch on fire, or other horrible things. This happened to me in jewelry class. The tips looked identical but were from another manufacturer. It even fit the torch body and screwed in easily. When I lit it a ball of fire burst out of the handle. If not for the quick thinking of another student, who shut off the gas main, I could be dead. Luckily, the flash was so fast, I didn’t get burned. If you use different torches keep all the parts separate!
I recommend that you read the instructions that come with your torch, carefully. I buy my supplies and gas from Airgas and they were very helpful in teaching me all about setting up my torch and tanks. Soldering is safe if you follow the rules.
After you attach your hoses, torch handle, regulators, etc. to the tank, either purchase a commercial product for leak detection or mix up a very soapy mixture of water and dish detergent. I use a little water and a few big squeezes from the soap bottle. Don’t make bubbles. Stir gently. Take a medium-sized artist’s paintbrush and paint the soapy mixture all around the connections. If you see any bubbles forming, tighten the joints and re-check with soapy water. I clean off the soapy water after testing. There may be small bubbles present from the application process which you don’t have to worry about. The differences between application bubbles and a leak are obvious – the bubbles will grow and multiply. If you’ve got a lot of bubble activity – you have a leak!
You can suspect a leak if, while the tank is on and the torch handle is turned off, the pressure on the regulator drops. The pressure will always drop a bit when you are using the gas but, it shouldn’t drop when you aren’t. Check for leaks and if you don’t find any, bring the regulator in for servicing. As I said earlier, DON’T use plumbers tape to fix gas leaks!
Another important step is to check your hoses for cracks and holes. I do this religiously; every time I get a new bottle of gas. Never use plumbers tape to fix leaks at the connections. Never repair holes in your hoses – buy new! Have your regulators serviced and cleaned at least every few years – depending on the amount of use. I have an annual clean-up where I check the hoses, get the regulators spruced up, and clean my tips with the tip brush. I have a backup regulator for when my other one is getting serviced.
*Don’t forget to check the valve stem and packing nut for leaks too!
Keep the key, that turns on the gas, attached to the tank. It is important to be able to shut off your gas supply quickly and by leaving the key in place you will always know where it is. Tip: Don’t forget to remove the key when you take your tanks in for a refill – they never get returned!
- All About Solder – You need to understand what you are working with!
- Annealing Wire – Want broken wire? How about melted wire? Need your wire soft and bendable? These tips will help you to avoid these problems and work with ease!
- Creating Consistently Sized Spheres – how do you make perfectly round spheres? You might need to know!
- DIY Fume Extractor for the Studio or Shop – One of the BIG ONES for studio safety. Learn to make your own!
- Flat Square Edges on Metal – Important techniques for creating square edges like on ring shanks, tubing, settings, etc. – pretty much any two pieces that you want to solder together!
- Getting Ready to Solder – Important steps before you solder.
- How to Anneal Silver Sheet – an important skill to have otherwise, you can damage your metal and work twice as hard!
- How to Set Up a Torch – have a torch, need to set it up? Here’s how.
- Identify Wire Solder – Mark your solder before confusion reigns!
- Jewelry Studio Safety – Extremely important information that every jeweler should know! Don’t risk your life or your health! Know the dangers of metal dust? If not, don’t sand anything – yet!
- My YouTube Soldering Playlist – A list of all my soldering videos on YouTube.
- Soldering 101, part one and Soldering 101, part two
- Soldering Jewelry: How to solder settings, bails, and wire. – We solder dissimilar shapes and sizes of metal together, all the time. Want to stop melting your settings or bails? Can you solder wire without melting it?
Related Web Pages
- The 4 Steps for Successful Soldering – The 4 steps will help you to achieve soldering success!
- About Solder – Learn all about the material you use.
- Acetylene, Torch, Tanks, Safety – A huge page with so much more than info on Acetylene! Learn all about torches, soldering, and how to protect yourself!
- Charts – Soldering related charts. Includes things like annealing temps, compressed gas valve sizes, what temperature does your gas burn at, what are the melting points of your metal. Also, there are wire gauge charts, millimeter to fractions and inches charts, drill bits to wire gauge charts. Lots of information!
- Cleaning Metal – nice to know if you plan on soldering anything!
- Identifying Wire Solder – How to mark your solder so that you always know what type it is.
- On Pickle, Acid, Crock Pots, and Baking Soda – How to remove the schmutz left from soldering, how to make your own pickle, how to use pickle, and how to neutralize pickle. Tons of info!
- Oxidation, Flux, and Fire scale – Why does oxidation occur? Why do you keep getting fire scale, how do you get rid of it? Learn the whys of what is happening when you solder and the solutions.
- Recipes: They aren’t just for cookin’ anymore! Find pickle recipes, how to remove copper flashing, how to remove broken drill bits, etchant formulas, etc.
- Soldering in a Nutshell – my list of basic necessities for soldering.
- Torch/Gas Questions – Portable vs. regular torches, problems with the torch, butane torches, water torches, setting up a torch safely, buying torches.
- Torches – Learn more about the individual gases and about the torches that go with them.
- Using an Oxygen Concentrator for Soldering – Just started using my new concentrator and disposable propane. Come see what I’ve learned so far!
- What Torch to Buy: Trying to figure out what type of torch you need? Check out this information before you buy!
Questions and Answers About Soldering
- Q&A: Annealing – How long to hold your annealing temps. Kiln annealing.
- Q&A: Firescale/Firestain – See what others have had problems with and find solutions!
- Q&A: Soldering Questions – You are not alone! This is a HOT topic!
- Q&A: Wire Questions. Balling up wire, tapering wire, work hardening wire, straightening wire, and more!
Note: Nancy L. T. Hamilton and any affiliates are NOT responsible for any injury, damage or health issues resulting from or even remotely related to these posts! You understand that you and only you are responsible for your decisions and actions! Take care and USE COMMON SENSE when working with any material or following any procedure that is even slightly a health risk!!!!!!!!!