Any amateur or professional blacksmith can come to a point when they must learn how to use a blowtorch to finish a metalworking project. These handheld, liquid-fueled, super fun devices allow for pinpointed heat application great for projects from making jewelry to pipe soldering. Blowtorches are even used by chefs to apply a direct flame to tasty dishes. This guide will walk you through the different types of blowtorches and how to use them to shape metal and glass.
Before you can learn how to use a blowtorch, you need to understand how to use one safely. If you don't already own them, it's crucial to equip yourself with the right safety wear, a fire extinguisher, and a water bucket for dousing. It's an open flame that you have in your hands, that is used to melt metal. Stay safe.
All blowtorches use flammable gases as fuel, so make sure your space is well ventilated. If you are not familiar with turning on or lighting your torch, the last thing you want is a build-up of invisible gas in your workspace. Open a window, turn on a fan, and get that fresh air circulating!
The two main types of blowtorches are gas and liquid. Gas is typically easier to use, with the fuel options of butane and propane gas, which are more common for household torches. Professional models use hotter burning fuels, such as acetylene is used mixed with oxygen.
Different types of torches will burn at varying temperatures, so you want to make sure you have the right tool for the job you are doing. Most people want to use their torch to heat metal or glass without causing combustion, so a little research will go a long way when you are learning how to use a blowtorch.
Butane and propane blowtorches are easy to use, sometimes designed with a built-in igniter. Otherwise, you will need to use a friction igniter to light the flame once the gas is flowing. Follow the instructions on the torch, and familiarize yourself with the basic parts of a blowtorch that are listed below:
Professional grade blowtorches have a lot more parts, and steps needed to create a super hot flame. The basic steps are outlined below, but your best bet is to follow the directions for the specific device you have:
Here is a good explanatory video on all the basics you need:
Learning how to use a blowtorch to melt and shape metal is not too different from using a furnace or forge. Pliers, an anvil, and hammer are all helpful tools to pull and pound the hot metal into the correct shape.
If you are planning to melt it down to a liquid, you will need a crucible and mold to finish your project. You should also consider using borax to help clean the metal of impurities and protect the crucible from damage.
In both cases, you will need to find the correct flame size and heat required for the metal. Metals have different melting temperatures, so be sure you understand the material before you try to melt it. Keep some extra fuel handy, so you don't run out of the gas part way through your project.
Blowtorches do not burn as hot as a furnace or forge, it will take longer to fully melt the metal. You may also need to keep applying direct heat to your metal while pouring, to make sure it stays in liquid form. A well-designed pouring device might help you keep one hand free to hold the torch, but an extra set of hands would also help.
Safety should always be first when you start figuring out how to use a blowtorch and always start a project prepared to finish it. Have the molds ready, keep your safety and emergency equipment on hand, and know how your blowtorch will affect the material you are melting.
Depending on the project you are working on, you will need to adapt your methods while you are learning how to use a blowtorch. Glass, for example, can be shaped slowly, and usually doesn't need a crucible. The biggest difference between melting glass vs metal is that you cannot use cold water to cool the glass. This will cause the glass to shatter dangerously, so make sure you have space and time to allow the project to cool fully before handling. Also, you will need the right tools, such as pliers and wire, to effectively shape the heated glass.
Glass is fragile, so protect your eyes and hands with heat-resistant protective gear. To melt and form glass evenly, you will need to be constantly rotating the object while applying heat. Once it's red-hot, the glass can be pulled or pinched into the desired shape. Always use your steel pliers to form the hot glass. You will need to keep applying heat evening to the glass while you are forming it since it cools much faster than metal.
With the right tools and a bit of open flame, you should be ready to learn how to use a blowtorch on art projects, at home welding and soldering, or to try your hand as melting things. Remember to stay safe, and have fun!