How to use a blowtorch

Blowtorches are often be used to heat up metal pipes so that they will solder more easily. You might have seen a plumber use this technique at your house, or maybe you’ve read about it in an article online.

But what happens if you try to use a blowtorch on a chrome pipe? Will it work the same way or will using any type of flame near or on the surface of chrome cause it to discolour and corrode?

In this article, we are going to cover whether you can use a blowtorch on chrome and if not, we will explain the best way to get the soldered finish you require.

What is Chrome?

Chrome or Chromium is a shiny metal finish that is often used in items such as car bumpers and bathroom fixtures.

Although chrome is a metal, you will never find it in pure solid form. When you hear that something is ‘made of’ chrome – what they really mean to say is that there’s a thin layer of plating on the object.

Almost anything can be chrome-plated, but some common materials often used are aluminium, brass, copper, and steel.

Can You Have Chrome Heating Pipes?

Yes, chrome heating pipes are becoming more and more popular these days. Chrome makes a great alternative to painting your pipes or even hiding them completely.

Chrome heating pipes are just copper pipes that have been dipped and finished with chromium, giving them a stunning silvery look.

Can You Bend Chrome Pipes?

Although chrome pipes can be bent, we do not recommend bending them as bending often causes the chrome plating on the inside of the bend to become distorted.

Chrome will usually be fine with shallow bends, but it makes more sense if you need a 90-degree bend to use a chrome-plated elbow joint instead.

Can You Use a Blowtorch on Chrome?

In the simplest terms, no you cannot use a blowtorch on chrome. The metal coating is simply too thin to withstand serious heat and will get damaged if exposed to it for an extended period of time.

If your goal is to solder two pieces of chrome together – then there is a way to do it that involves a little heat but does not involve using a blowtorch.

How to Solder Chrome

If you are looking to join 2 pieces of chrome, truth is that the flux (solder) will not stick to the chrome itself so read on for our technique for soldering chrome.

What You Need

  • Chrome pipe
  • Chrome Elbow Fitting
  • Heat gun
  • Stanley Blade
  • Small Paintbrush
  • Wire Wool
  • Liquid Flux

Step 1 – Mark Your Pipe

Insert your pipe into the elbow joint and then pull it out again by about 3mm. When you have done this, make a small score in the chrome where the pipe meets the joint.

By pulling the pipe out before scoring ensures that you will get the finish that you require. Score in the wrong place and that length of pipe could be ruined.

Note: Be careful not to score the chrome too deep – just enough so you can see it.

Step 2 – Remove the Chrome

Now take your wire wool and remove all the chrome from the end of the pipe below your score mark.

The chrome will have to be completely removed and the pipe polished back to the bare copper.

Also, rub the wire wool around the inside of the fitting to ensure that it is clean and only bare copper is exposed too.

Step 3 – Apply Liquid Flux

Generously apply your liquid flux all the way around the exposed copper at the end of your chrome pipe.

You can do this with a small paintbrush or something similar.

Step 4 – Solder

Now insert your pipe into the fitting and using a heat gun, heat the joint until you begin to see the solder coming out of the joint all the way around.

It is possible to use a blowtorch here but do not apply the flame directly to the chrome. The torch must be kept far enough away to provide heat but not too much.

Step 5 – Clean

As we mentioned earlier, the solder will not stick to the chrome so any solder that has become visible at the bottom of the joint will easily rub off.

Once this is done, you should have a nice clean soldered joint with no copper visible at all.

Can You Use Compression Fittings on Chrome?

Yes, compression fittings can be used on chrome. Personally, I follow the same process as if I was soldering and remove the chrome plating before using compression fittings with chrome.

Also, if you choose not to, it is a good idea to make sure that the olives you are using are brass and not copper as the copper ones are a little tough and has a hard time biting into the chrome plating.

Conclusion

As you can see, it is possible to solder chrome pipes although the chrome does have to be removed from the area you are soldering first.

As for whether or not you can use a blowtorch on chrome, the answer is no, the chrome plating will not hold up for any length of time when extreme heat is applied. Using a blowtorch on chrome will only end up damaging the plating or tarnishing the shine which cannot be fixed.

Plumbing Wizard Tips

“Use a heat gun and liquid flux when soldering chrome pipes!”

“Do not apply your blowtorch directly onto chrome as it will ruin it and be a costly mistake!”

“Make sure all of the chrome has been removed before attempting to solder – solder will not stick to chrome!”

“Solder chrome instead of using compression joints – why go to the expense of using chrome and then having bulky elbows!”

Frequently Asked Questions

Can chrome be soldered?

Chrome cannot be directly soldered. To solder chrome pipes, the chromium plating will need to be removed and the solder applied directly onto the copper!”

Can I have chrome heating pipes?

Yes, heating pipes are now available with a chrome-plated finish. Chrome heating pipes are just copper pipes that have been finished with chromium for added shine.

Do chrome pipes look good?

Yes, having chrome pipes looks great and means that they can become a feature of your room rather than something you want to keep hidden.

Fire: Is there anything it can’t do?

How to use a blowtorch

How to use a blowtorch

No need to wait until your next soldering project to fire it up. We put together a list of torch-worthy jobs.

How to use a blowtorch

Stubborn nuts and bolts are annoying, and what’s worse is when the wrench slips off and you smack your knuckles against the wall or the side of a truck engine. A mechanic’s trick is to heat up the fastener with a torch before cranking on it with a wrench. The heat causes the metal to expand and the rust to crack loose, making the nut or bolt easier to turn. Just make sure there’s nothing flammable, like leaking fuel, near the fastener before turning the flame on it.

How to use a blowtorch

Fire lets you give metals and wood a distinct appearance. Run the flame over wood for a distressed look, which is a popular trend in furniture that makes the surface appear aged. Or torch copper and other metals for a vintage or antique feel. The surface will transform after only a couple of seconds under the flame, so keep the torch moving to avoid burning or melting the materials.

How to use a blowtorch

The same techniques plumbers use for soldering pipes can also produce attractive outdoor structures for the lawn and garden, such as a trellis. Use copper piping, fittings, and wire for your building materials since they’re user-friendly for soldering. Assemble the components to form your trellis, then solder the connections. If you’ve never soldered before, then don’t worry too much about making mistakes. The trellis will be covered with climbing vines or flowers that’ll hide imperfections.

How to use a blowtorch

You know how annoying it is when you cut a rope and then the end unravels? A simple way to keep the end together is to zap it with a torch. The flame melts the end slightly, causing the individual pieces to bond together. This same melting method also works on landscaping fabric. When you cut a hole in the fabric for your plants, singe around the cutout to prevent frayed edges.

How to use a blowtorch

Forget chemical killers or getting down on your hands and knees to pull weeds only to have the roots live on and continue growing. Burn those weeds growing between the pavers in your walking path or the cracks in your driveway. Torching weeds works—just make sure to scorch only weeds that aren’t near flowers or grass in your yard to avoid damaging plants you didn’t mean to harm.

How to use a blowtorch

After you burn the weeds growing through the cracks in your asphalt or concrete driveway, use the torch to fix the cracks. There are crack and joint fillers designed for use with a torch, such as Pli-Stix, which costs about $12 for 30 ft. at The Home Depot. Clean any debris out of the crack first, then insert the filler and torch it. Bam, you’ve got a watertight, self-leveling seal.

How to use a blowtorch

The torch can take the place of a heat gun for warming up paint to make it easier to remove. Hold the flame about 6 inches from the finish and apply heat until the paint bubbles. Again, always keep the torch moving so you don’t burn a single spot. Then use a scraper to remove the softened paint. This approach works on other finishes such as varnish, and also for removing caulk.

How to use a blowtorch

When the mercury dips below freezing, it can take more than a key to unlock a padlock. And nobody wants to have to shovel the driveway because the snow thrower is stuck in a padlocked shed. If your metal lock is frozen shut, heat the padlock with your torch until the mechanism work properly. (Also works on frozen plumbing, as seen above.) Just be very careful about heating metal—don’t touch until it has the chance to cool down.

How to use a blowtorch

Craftspeople know that when you’re making or working on jewelry, heating the metal with a small torch lets you easily bend it into the exact shape and fit you want for your rings, necklaces, and bracelets. You can use your torch if you decide to take up DIY jewelrymaking, or if you want to make jewelry repairs by joining together broken pieces.

How to use a blowtorch

Yes, really. After cooking my first steak with a torch, I was hooked. It tasted better than when I use my grill or what I can get in most restaurants. I’ve talked to several people who torch their steaks and not surprisingly, everyone has his or her own method. Mine is to torch both sides until the meat turns brown (what chefs call the “Maillard” reaction) to seal in the flavor, then grill on a low temperature until the inside is medium rare. I torch the stakes on my grill after learning the hard way that torching them in my kitchen sets off my smoke detector (which is odd because there’s hardly any smoke). If you want to really impress your dinner guests, you can find myriad recipes online for foods and desserts that can be cooked or set ablaze with a torch.

How to use a blowtorch

The presence of a culinary torch in a kitchen is the sign of a truly accomplished home cook. It’s a must-have for making perfect crème brulee, but it can also be used for so much more if you think outside the box.

Culinary Torch Uses

Brûlée the Sugar on a Crème Brûlée

Sprinkle an even layer of sugar on the top of a ramekin of chilled crème brûlée custard. Work the culinary torch back and forth to melt the sugar until it melts and turns pale amber. It will set in a glossy, crisp crust.

Brown the Topping on Mac and Cheese

If you don’t have time to make macaroni and cheese in the oven, you can still fake the crispy, oven-baked crust with a culinary torch. Try this easy recipe: combine two parts whole milk and two parts elbow macaroni in a saucepan. Bring to a simmer, reduce heat to low, and cook until the macaroni is cooked through but still firm to the bite, about 10 to 12 minutes. Turn off heat but leave on the burner and stir in 1 part grated sharp cheddar cheese and 1/2 teaspoon Dijon mustard per cup of cheddar cheese. Add more milk if needed to achieve a creamy consistency and season to taste with salt and cayenne pepper. Spoon into bowls, sprinkle lightly with breadcrumbs, and brown the breadcrumbs with a culinary torch until the cheese bubbles and the breadcrumbs are lightly browned.

Make a Tuna Melt or Patty Melt

If you don’t have a toaster oven and don’t want to turn on the broiler of your oven, you can still make a tuna melt or salmon melt. Assemble the melt, then use the culinary torch to melt the cheese on top until it bubbles. Hold it a little further away until the cheese melts, then bring it in closer to make the cheese brown and bubble.

Roast Peppers

Roasting peppers is easier with a culinary torch than in a broiler or on the stovetop because you can direct the flame with more precision. Place a pepper on an aluminum foil-lined sheet pan. Have a large glass or metal mixing bowl and some plastic wrap ready. Beginning with one small area, work the flame of the culinary torch back and forth over the pepper until the skin blackens and blisters. Use a pair of tongs to turn the pepper to reach the other sides, working the torch over the surface of the skin until all of it is blackened. Immediately place the pepper in a bowl and cover the bowl tightly with plastic wrap so that the pepper can steam in its own heat. After 10 to 15 minutes, when the pepper has had a chance to cool, uncover the bowl and remove the pepper. Under running water or using a paper towel, rub off the blackened skin. Cut away the stem and scrape the seeds off the inside.

Brown Meringue

A culinary torch will perfectly caramelize the peaks of the meringue topping on lemon meringue pie or baked Alaska. When you’ve topped your dessert with the meringue, simply work the flame of a culinary torch lightly over the topping until it is lightly browned.

Brûlée a Grapefruit

For an elegant way to serve grapefruit at breakfast or brunch, cut a grapefruit in half and sprinkle it lightly with brown sugar. Use the culinary torch to broil the surface of the grapefruit, melting and caramelizing the sugar.

Finish a Gratin

Get a crisp, beautifully browned crust on Au Gratin Potatoes with a culinary torch. After it is completely cooked in the oven, sprinkle the gratin lightly with finely grated parmesan cheese and perhaps a light drizzle of truffle oil. Work the culinary torch back and forth over the surface of the gratin until the cheese and potatoes begin to crisp and brown.

Toast Marshmallows for S’Mores

If campfire season is way too far away, use a culinary torch to make some indoor s’mores. Have graham crackers and pieces of milk chocolate bars ready. Spear a marshmallow on a metal skewer and use the culinary torch to brown it evenly, beginning with the torch further away so that it has a chance to heat through without getting burnt, then bringing the flame closer to finish the browning. Immediately transfer the marshmallow to a chocolate-topped piece of graham cracker, using another graham cracker to scrape the marshmallow off the skewer, topping it with the cracker.

Make a Perfect French Onion Soup

French onion soup is not complete without a gooey layer of cheese-covered crouton. A culinary torch can melt and crisp the cheese much more easily than trying to navigate a sheet pan of brimming soup bowls into the broiler. Ladle soup into bowls, float a toasted piece of bread on top, and drape a slice of Gruyere cheese over the whole bowl (tradition dictates that the corners of the bread hang over the sides). Use the culinary torch to melt and brown the cheese on top, just before serving.

Are you like me?

  • With a temperamental broiler in your kitchen/oven? The net effect of which is no broiling?
  • Without a blow torch for reasons of border control and air travel rules & regulations?
  • Yet with a deep desire to crack a sugar glass crust? Specifically creme brûlée, restaurant-style…….in your own kitchen.

Never has burnt cream been so appealing. To me! Say it with me (French accent et al). Creme Brûlée. crem broo lay.

How to use a blowtorch A cracked crust is the best kind for a creme brûlée

That luscious dessert of just-set custard, with a wonderful chapeau (topping) of crackable caramel.

According to Wikipedia, Discs of caramel may be prepared separately and put on top of the creme brûlée just before serving, or the caramel may be formed directly on top of the custard, immediately before serving. To do this, sugar is sprinkled onto the custard, then caramelized under a broiler / salamander or with a blow torch.

So fair enough you can make the caramel separately but would you want to do that? And if so, do tell why. For I think it is so much trouble to do. Hence my ‘other’ option.

Use a spoon! Yes, a spoon. A heated spoon.

Technique: A large cooking spoon is heated on the stove top/flame. This is pressed down on the ‘sugar-top’ of a cold, set custard to create a crust that can be cracked with a spoon, to reveal creamy custard underneath.

Application: Creme Brûlée! The iconic dessert.

Results: A well-defined, ‘breakable’ caramel top which is exactly how you want your Creme Brûlée

Level: Easy

Why I like it: If you don’t have a functional broiler in your oven, or a blowtorch, this dessert is still accomplishable!

A few weeks ago, on the Food52 Hotline, I asked a question, desperate to buy a blow torch to make creme brûlée. The question was ‘How to get a blowtorch across continents? I’ve decided to get a blow torch when I’m in the US in the summer. How can I get it home with me to Nigeria. Anyone travelled on an airplane with one? or cargoed it? Help!’

The responses over a few days brought me lots of laughter and finally a solution to my brûlée dilemma.

A dilemma I was in because of a delicious lemongrass creme brûlée I had in Edinburgh at my sisters spring wedding.

How to use a blowtorch Dessert deliciousness

Served with a whiskey granite, summer berries and a mixed sesame seed snap, it brought joy and freshness to the palate and plate.

How to use a blowtorch Totally cleaned ramekin!

With a towering pot of lemongrass gracing my front yard, I felt the custard was no big deal. The crackling top of burnt sugar would be the real challenge.

So on to the hotline it was. I got varied advice from using plumbing blowtorches meant for welding copper pipes to being careful to avoid trouble by going against safety regulations. We had a plumber from Frankston plumber agency come in to fix a few of our sinks because the water pressure was to high and we almost had him try to use his blowtorch.

But one tip held promise and that came from Cris aka Mensaque, from Brazil.

She wrote ‘Here’s another idea for you…….on how to brûler your crème: spread the sugar over the custard,take a big metal spoon or a spatula,heat it on your stove burner and and press it on the sugar till brown. Works like a charm!’

I was thrilled. There was the possibility of success and sooner than I hoped!

Cris writes more: “Hey, KB. How kind of you to send me a message…thank you. I’m glad I could help. I’m from Brazil, and over here (at least in my hometown) it is almost impossible to find a good blowtorch small enough to be considered practical in the kitchen, so I feel your pain, hahaha!

I learned the “hot spoon technique” from a chef (can’t remember his name) on a culinary TV show in Brazil and it works very well,vlike your photos prove. All the best,
Cris. (aka mensaque)”

I wasted no time in whipping up a custard and trying out the heated spoon method which worked to the book. And letter.

Cris and I, bound by history, culture, place….and the inability to find blowtorches have conquered the brûlée and so can you!

Directions

(This assumes already made ‘custards’, which have been chilled for at least 4 hours in the refrigerator)

Remove custards in ramekins from the refrigerator.

Dab the tops with a paper towel to remove any water or condensed liquid.

Evenly sprinkle caster sugar over the top of each custard – I used 1/2 – 1 teaspoon of sugar for a normal-sized ramekin.

How to use a blowtorch

Heat up a large cooking spoon, being careful to protect your hand from a handle that could get hot. I held mine with a kitchen pad, though it didn’t get extraordinarily hot. BE CAREFUL.

I used a ladle – as I have 2 ladles, I have decided to dedicate one to a life of caramel, knowing the bottom may be darkened forever.

How to use a blowtorch

Place the heated spoon over the sugared top of custard and listen for the sizzle, smell the caramel and watch burnt sugar being made….right before your eyes!

How to use a blowtorch

A work of art! And it only takes a few seconds for the magic to happen!!

How to use a blowtorch

You can repeat if not all parts have been heated.

How to use a blowtorch

Truth is, you will be rewarded with an impressive, restaurant-style brûlée! Made in your kitchen……without fire and brimstone! And yes, with blackened spoon in tow.

How to use a blowtorch

Get stuck in. Crack that crust. Thank me, thank Mensaque. Enjoy yourself!

How to use a blowtorch

Now to perfect that custard! Coming soon to a screen near you!

Have you ever come across this idea? Do you have other top tips for creating a brûlée?

It’s all about nailing that Maillard reaction, where cooking and chemistry meet.

How to use a blowtorch

How to use a blowtorch

It turns out that one of the best ways to get that perfect, brown, crisp, roasted flavor on the outside of a steak while preserving the succulent meat within is to fire up the blowtorch. The chemical reaction that takes place when sugars and proteins are heated to form that delicious char is known as the Maillard reaction. With a blowtorch, it’s much easier to achieve this reaction without cooking the meat on the inside of the steak.

Chefs actually blowtorch steaks all the time, sometimes after the steak is prepared sous vide—a method of cooking that involves sealing the food in an airtight plastic bag and placing it in a water bath at a specific temperature for an extended period of time. A blowtorch can be particularly useful for thin steaks that you don’t want to cook all the way through.

In a new clip of Food Science with Dave Arnold, the founder of the Museum of Food and Drink in New York demonstrates how you can use an attachment called the Searzall to easily cook a steak with a blowtorch. The Searzall has two metal screens that distribute heat over a wide area so the intensity of the torch is not so focused.

If you’ve already got a blowtorch lying around, might as well give cooking a steak a shot to see how it turns out.

How to use a blowtorch

Related Articles

  • How to Clear an Overgrown Gravel Driveway
  • How to Get Rid of Weeds in a Pachysandra
  • How to Kill Kochia (Bassia Scoparia)
  • How to Kill Weeds & Grass on Patios & Driveways
  • How to Use Vinegar Near Raspberry Bushes

Flaming technology has existed since the 1940s, and home gardeners can use flamers — portable gas torches that create intense heat — to kill weeds. Though this method of weed control lost popularity once herbicides came to market, gardeners are once again showing interest in flamers since they require no chemicals, don’t contaminate groundwater and leave no chemical residue. When operated properly, flamers are a safe and time-effective weed killer.

Contact the fire department and obtain a burn permit if one is required in your area before torching weeds.

Water the soil around the weeds thoroughly before torching in order to aid in heat conduction.

Open the flame-adjusting valve — the round knob — of the flamer by giving it a 1/8 turn or until a small amount of gas can be heard escaping. Ignite the flamer using a flint lighter. Turn the flame-adjusting valve to adjust the size of the flame to a low pilot flame that will keep the flamer burning. A small flame is adequate for torching weeds.

Torch weeds in the spring or early summer as young weeds emerge. Young, tender weeds require less heat and therefore less fuel than large, mature weeds. Torch weeds in the early morning before the heat of the day for safest results.

Hold the flamer and walk at a slow rate of 1 to 2 miles an hour along the weeds. Pass the flamer over each weed with a sweeping motion, touching each weed with the flame for no more than a split second (1/10 of a second). You need only apply enough heat to wilt the weeds but not burn them. When you apply the right amount of heat to a weed, the water in the cells boils, causing the plant to atrophy.

Torch weeds once every two to three weeks in ongoing applications or as needed until the next frost. Flaming kills annual weeds completely but does not completely eradicate the roots of perennial weeds. With multiple treatments, however, you can deplete a perennial weed’s stored root energy, killing the weed.

  • National Gardening Association: Kill Weeds With Heat
  • Lee Valley: Flame Weeding Tricks
  • Weed Dragon: Operating Instructions and Parts Manual
  • Before torching weeds, contact the fire department to ask if the weather conditions in your area are suitable for burning weeds.
  • Hold a spade between weeds and desirable plants to protect them from the flame. It is easy to accidentally torch and kill desired vegetation, so be careful to keep the flame at a safe distance from nonweeds.
  • Do not disturb the soil as you torch, as this can bring weed seeds to the top and promote germination.
  • Have a fire extinguisher handy in case of emergency.
  • Do not torch weeds if there is a drought or burn ban.
  • Do not attempt to use a flamer if you smell a gas leak.
  • Never use a flamer on poison ivy or any other poisonous plant. The smoke from burning poison ivy releases fumes that are harmful if inhaled and can damage the skin and eyes.

Based in Fort Worth, Sarah Mason has been writing articles since 2009 on topics including nutrition, fitness, women’s health and gardening. Her work has appeared in “Flourish” and “Her Campus.” Mason holds a Bachelors of Arts in economics from the University of Florida.

Soldering enables you to join two metal segments into one piece, using a torch and a softer metal as the adhesive. Before you start a soldering project, it’s important to set up a well-ventilated, clean work space. The following important tips will help to ensure that your soldering project is a success.

Step 1 – Organize a Safe Work Space

Place your tile on the surface of your work space. Put your fire brick on top of the tile. Place your torch and tools on the space around the tile. Take any items that might be flammable out of the area where you are working. If it’s not possible to remove a flammable item, be sure to use a heat shield to protect it from the heat of your soldering torch. Place your overhead light so that it shines over your work space. Put on your gloves, goggles, and apron.

Step 2 – Sand the Metal Edges

Use your sandpaper to smooth the edges of the two metals you would like to join. Be sure not to overly file the edges. You will get a stronger bond if the edges of the metals are slightly rough. It’s also crucial to make sure that the two edges are joined as closely as possible so that there are no gaps between them.

Step 3 – Clean the Metals

Clean the two metal pieces you’re using. Carefully immerse them in the acid cleaning liquid to get rid of any impurities that could weaken the bond between the two metal pieces.

Step 4 – Apply the Flux

How to use a blowtorch

Apply a generous amount of flux to the joint you are soldering. Be sure the flux is applied sufficiently to the entire bonding area. The flux will increase the solder flow and remove oxidation from the metals.

Step 5 – Secure the Metal Pieces

If necessary, position the two pieces into a vice so that they cannot move when you begin to use the soldering torch.

Step 6 – Remove Moisture From the Metal Surface

Make sure there is no moisture on the surface of the metals you are joining. The soldering process can create a dangerously hot steam if the torch heats any moisture in the metal. Moisture can also weaken the bond between the two metals.

Step 7 – Get Your Torch Ready

Attach the head to your soldering iron tank. Open the valve. When you hear the hissing sound of the gas, turn on your torch. Your flame should be around two inches. If necessary, make adjustments to the valve.

Step 8 – Heat the Metal Surface

How to use a blowtorch

Use the torch to heat the joint between the two metals. Move the torch closer to the joint area. Begin by applying the heat onto the metal a small distance away from the joint. Carefully move the flame, applying an even amount of heat to the area.

Step 9 – Apply Heat to the Joint

Once the areas outside of the joint have been properly heated, apply the flame directly to the top part of the joint area. Make sure the flux is flowing and is no longer bubbling. After the top part of the joint is complete, continue with the bottom of the joint. The heat from the torch should force the solder into the joint. This will ensure a strong bond. If more solder is needed, it can be applied at this time.

Step 10 – Turn off the Torch

Remove the torch from the joint area and turn off the heat. Inspect your joint for a clean, strong bond.

Step 11 – Clean the Metal Joint

Apply water to the joint area to cool the metals. Clean all areas of the joint to remove any flux residue from the metal surfaces. Smooth the joint with your filing tool or sandpaper.

Learn how to braze a joint using a blow torch and brazing rod with these step by step instructions. This project features clear, animated illustrations and diagrams showing you every step you need to make a solid join with a blow torch or brazing rod.

1. Two pieces of steel sheet are to be brazed. The steel must first be cleaned so that grease and dirt is removed. Wire wool or emery cloth are the most suitable abrasives.

A borax flux (powder) is mixed with water to produce a paste which is brushed along the joint. Flux prevents oxidation taking place on the metal surfaces as this would prevent brazing being successful.

How to use a blowtorch

Clean the faces of steel properly to remove dirt and grease using Borax

2. The compressor is turned on and this pressurises the gas and air. As the gas-air control is slowly turned on, gas is fed through the nozzle and this is ignited by a pilot light on the nozzle or by a match.

3.Once alight the gas-air control is turned to allow more air/gas through the nozzle which gives a longer, more fierce flame. The length of the flame can be adjusted with the control until the desired type of flame is achieved. As a rough guide, a blue section of flame will appear near the nozzle, the end of this is the hottest part of the flame.

How to use a blowtorch

Adjust gas and air control of brazing torch to get the required flame strength

4. The two pieces of steel should have already been placed on the rotating table. Fire bricks are used to raise both pieces slightly off the surface of the table so that heat can flow all the way round it. Fire bricks should also be placed at the back and sides of the metal so that heat does not escape and is reflected back.

The steel is given a gentle overall heating first which raises the temperature slowly. This allows the steel to expand slowly and for the water in the flux to evaporate without moving the steel out of position. The flame is moved around the joint fairly quickly throughout this first stage of heating.

How to use a blowtorch

Fire bricks used to position steel plates and torch used to gently heat steel plates

5.The flame is then moved forward with the blue tip of the flame nearly touching the steel. The focus of heat should now be on the joint or the sections of steel being joined, as the flame is slowly moved backwards and forwards along it. The joint/steel will eventually become so hot that it becomes red in colour.

How to use a blowtorch

Steel being heated until red hot

6. A brazing rod (copper-zinc alloy) is then pushed gently against the joint and if the temperature is right the end of the rod will melt and begin to run along the joint. The rod is fed into the joint until a brazed joint is complete.

The steel is allowed to cool slowly. If cooled quickly, such as quenching in water, the joint can crack or become distorted.

How to use a blowtorch

Brazing rod pushed up to joint and melted along the join

The image below shows how the copper-zinc alloy (brazing rod) forms a joint between the two pieces of steel.

How to use a blowtorch

Brazing rod melted and forming joint along the 2 sections of steel

Extra Safety

Using a brazing hearth and soldering/brazing is potentially dangerous as high temperatures are reached. Serious burns can result if safety procedures are ignored.

Leather aprons and gloves will offer good protection if you accidentally touch hot metal. Goggles are essential as ‘splashes’ of hot flux or brazing rod (solder) could damage eyes permanently. Furthermore, if there is a need to pick up materials that have been heated on the hearth, always use steel tongs and place the hot material on a steel plate/block. The steel block/plate will conduct the heat away from the material without cooling it too quickly.

All project content written and produced by Mike Edwards , founder of DIY Doctor and industry expert in building technology.