Among the many types of welding, hot air welding can often provide a stronger, tear-proof seam. If you’re looking to add hot air welding to your skills, you’ll need specialized hot air welding equipment so that you can perform this welding type.
Whether you are a professional welder or hobbyist, getting the right equipment is crucial to master the skill and make the welding experience all the more enjoyable. Luckily, hot air welding equipment is extremely affordable and easy to find.
It’s normal to want to find the best welding equipment overall. You don’t want to purchase equipment twice if it breaks, or purchase multiple items when you could have just purchased one item. Here’s what you need to know about hot air welding equipment and the best items to choose.
Before we dive into the best hot air welding equipment, here’s some information on hot air welding, techniques, and the benefits of hot air welding.
What is Hot Air Welding?
Also known as hot gas welding, hot air welding is a type of welding where heat and pressure are applied to connect materials together. This type of welding is typically for thermoplastic materials (i.e., plastic).
Hot air welding is common in plastic fabrication. Using heat, speed, and pressure, hot air welders join thermoplastic industrial fabrics and films together. The main way that hot air welding works is through the correct combination of these three parameters.
Instead of other types of plastic fabrication, hot air welders use heated air to melt two materials together, typically using a thermoplastic material that melts and cools as a hardened resin. In fact, hot air welders can only be used on thermoplastics, such as polypropylene/thermoplastic polyolefin (PP/TPO).
Hot air welding is often used on smaller plastic items, chemical tanks, heat exchangers, plastic plumbing fittings, and water tanks. It can also be used on plastic webbing and films, but you’ll be using a slightly different process for this (i.e., no filler rod).
How Do Hot Air Welders Work?
Hot air welding usually requires a heat gun, also known as a hot air welder, to produce a steady stream of hot air. When you turn on a hot air welder, it blows compressed air across the heating elements to reach the right temperature (700°F to 1,350°F; 400°C to 730°C). The machine then directs this heat out the injection point so it can be directed and used properly.
When directed at the two pieces of plastic that you wish to be joined, it will soften the plastic. A filler rod is also added to provide extra welding material throughout this process. Using either a rotary machine or manual pressure, the hot air welding equipment will heat materials to perform a permanent seal between them, making this seal resistant to air and water pressure.
Once the desired softness is reached, the materials are pressed together with the material rod and clamped to cool.
It’s important to use a high-quality filler rod as this can impact the final outcome of the weld. You also want to use a filler rod that is of a similar material as the thermoplastics that you are using (although, you can weld PVC to acrylic, and this is the only exception to this rule). A filler rod with high porosity can lead to air bubbles and voids in your weld, which weaken the weld overall.
Techniques for the Best Hot Air Welding
There are several different techniques for welding thermoplastics together, and one is using a hot air welder. Most hot air welders are built similarly, which involves heating up pressurized air to be directed out of the injection point.
No matter which plastic welding technique you use (i.e., lasers, solvents, or hot air) for melting thermoplastics, all techniques follow three steps:
- Surface preparation
- Application of heat source and pressure
- Final cooling
Welding With a Filler Rod
If you are welding with a filler rod, then you’ll want to tack before you place your weld. Tacking should be carried out wherever you intend to place the welding rod. Tacking provides a slight swaging for two materials.
Next, set the right weld temperature on the welding tool. You can use different techniques depending on the length and application of your weld.
There are two main techniques for hot air welding with a filler rod:
- Hand welding
- Speed welding
Pendulum Technique – Short Hand Welds
The pendulum hot air welding technique is used for short welds. With this technique, you will have placed tack at the desired weld point and then you start by placing your plastic filler rod at the start of the weld point. The heat gun is then directed toward the weld point, where the filler rod meets the tack; move it back and forth slowly in the direction of the filler rod in a pendulum motion. You’ll notice that as you make the pendulum movement, the filler rod will start to melt down into the tack. Keep moving the weld gun along the filler rod and along the direction of your weld. The filler will appear to lie down.
The pendulum action allows the correct heat to be applied to the welding rod and the attachment material.
Filler Rod – Simple Hand Weld
If you have a simple weld like a crack that needs to be filled, then you can hold your filler rod in one hand and then the hot air plastic welder in the other. The pendulum technique is not always necessary, especially if the weld does not need to be so precise.
No matter what, your filler will need to be pressed down into the weld for a better seal, and the gun should at least be held at a 45-degree angle.
Speed Welding Nozzle – Fast Weld
For faster welds, you’ll need to use the speed nozzle attachment to apply the filler rod. With this nozzle attachment, the rod will slide into the shaft, which will place the rod directly in the line of the heat injection point so that the hot air gun can move faster along the weld point.
The filler rod requires about 2 kilograms of pressure to be applied downward into the weld juncture. This is the only way to push the welding rod down into the welding area. With this nozzle, you can move faster along the weld edge, but you need the attachment to complete this.
This technique can also be used for longer welds.
Welding Without a Filler Rod
You can perform hot air welding without filler material. This type of welding is called autogenous welding, and the only materials used are your main welding materials. This technique is typically used for webs and films.
In the case of webs and films, a filler rod may not be used. Two sheets of plastic are heated via a hot gas (or a heating element) and then rolled together. This is a quick welding process and can be performed continuously.
Should You Add Hot Air Welding to Your Services?
Many professional welders prefer to use hot air welding because it eliminates the need for buying tooling equipment to make the weld work. Additionally, if you work in plastic fabrication, it may be required.
Benefits of Hot Air Welding
Hot air welding is used primarily due to its simplicity, speedy welding technique, and affordability. There are a few other benefits of using hot air welding:
- You can join long, continuous panels
- You can join a variety of materials of the same thickness
- The resulting joint is stronger than the parent material
- The seal is watertight and airtight
- No special tooling or dies are required
Hot air welders can be adapted to the material size and shape. So, with hot air welding, you can weld complicated shapes, intricate contours, and eliminate the need for buying expensive tools.
Is Hot Air Welding Easy?
With the right welding equipment, hot air welding is relatively easy. If you work in a trade that involves plastic repairing, you may want to consider hot air welding to simplify repairs and installations.
Welding Equipment Needed For Hot Air Welding
If you want to perform hot air welding for thermoplastics, then you’ll need some equipment. Luckily, you only really need two things:
- A hot air welder, or hot air gun
- Filler rods
What To Look For In A Hot Air Welding Gun
There are a few things to look for when buying hot air welding equipment.
For starters, look into the brands available. You want to be sure that you purchase a reputable brand. And ideally, a brand with an excellent warranty and customer support. Read customer reviews wherever possible to find out what other welders are saying.
Next, think about what you will be using the welder for. Are you going to be professionally repairing hot water tanks, or do you have more casual, at-home uses in mind? If you aren’t going to be using the welder frequently or in heavy-duty applications, it is not likely necessary to purchase the biggest, baddest, most tricked-out welder on the market. Taking the time to think about how you will the hot air welding gun ensures that you will get the one that is perfect for you.
Finally, you will want to look into what is included with the gun. Are there attachments? Does it come with filler rods? This information can factor into your budget and how much you are willing to spend. If a welding gun has attachments and filler rods to start, you may pay a little more but it may also work out to be cheaper than purchasing all of those items on their own.
Research is the key to finding the right hot air welding gun.
Sourcing Filler Rods
Oftentimes, you’ll find filler rods included in your purchase of a hot air welding gun. But as you use the filler rod material, you’ll need to buy more rods. Filler rods are extremely affordable, and you can often purchase a starter pack (mix-use pack) so that you have a range of material types.
Be sure to buy high-quality filler rods made with high-grade resin, and the filler rod material of the items you are welding together. Unless you know exactly which materials you are using, you may want to purchase a mixture of filler rod types. You can purchase plastic welding rods in bulk in materials like HDPE, PP (polypropylene), PVC, and HMW HDPE.
You’ll also need to look at the dimensions. Filler rods come in different sizes, ranging from 3mm up to 15.8mm, depending on the width and material type. For example, you can purchase 3mm round (⅛ inch) rods or 7mm profile (flat) rods. Some materials only come in certain dimensions.
Once you find a product that you like and use often, consider purchasing a spool of the rods; for most professional welders, spools up to 30 pounds can be used for a long time.
9 Best Hot Air Welding Guns
Choosing a high-quality plastic welder and filler rod can be difficult when there is so much to choose from. Here are Welder101’s choices for the best hot air welders:
- Best for Big Jobs and Professionals: WELDY 3400W Handheld Hot Air Plastic Welder
The WELDY handheld plastic welder is an affordable option for big welding jobs. With a voltage of 230V, and a power output of 3400W, you’ll want the WELDY on your side when you have large jobs to get through.
The EX3 handles only Pe/PP and welding rods of 3 and 4 mm, though, so you may be limited with the range of welding types that you can do. However, if you know you have a lot of welding, you most likely won’t be switching welding materials often.
- Best Small Heat Gun: Leister Triac ST 1600W
The Leister Triac plastic welder is a great hand-held heat gun, perfect for those professionals who regularly travel for their plastic welding jobs. The Leister comes with a range of styles, for example, with pencil tip and 5 mm nozzle, to no pencil tip and 20 mm nozzle.
Leister is a very reliable brand, so you know that this heat gun will last a while. Leister comes with a ton of accessories and nozzles, so you can purchase one air gun and customize your requirements with attachments and overlapping nozzles. This is one of the best tools on the market.
- Best for Newbie: Polyvance 5700HT Mini Weld Model 7 Airless Plastic Welder
Polyvance Airless Plastic Welder is the perfect beginner piece of welding equipment.
Not only does the manufacturer provide a QR sheet with instructional videos, but this hot air welder also comes with 8 types of welding rods that can be used for most types of plastics, especially those used in automotive applications.
With a 200 watt element and two changeable welder tips, this tool is the perfect place to start.
- Strongest and lightweight: Beyondlife Plastic Hot Air Welder
A portable hot air welder allows you to work anywhere and at any time. Weighing less than 3 pounds, this is one of the strongest, lightest, and most compact hot air welders available.
This piece of welding equipment has adjustable heat and power so you have the flexibility you need to complete any project.
This welder comes with a spare heating element, one 40mm flat slit nozzle, one Pencil Tip Nozzle, one triangle speed welding nozzle, one round speed welding nozzle, one pressure silicon roller, manual and some PE & PVC plastic rods
- Most Reliable: Steinel Heat Gun Kit
Steinel is one of the most renowned brands for manufacturing welding guns. You can completely rely on this brand.
Delivering 1600 watts, this tool comes with a variety of welding rods, a 39mm reflector nozzle, a 9mm reduction nozzle, a welding Nozzle, shrink tubes, a 75mm spreader nozzle, and a 14mm reflector nozzle.
- Budget-Friendly: Hobie – Kc Welder Pro With Rod Stock
Hobie’s model is one of the most inexpensive and budget-friendly hot air welding tools. If you are setting up a home shop, or have a few projects you’d like to complete, this welder can give you what you need without blowing your entire budget.
This hot air welder has a 80 watt element, a flat tip, and comes with a selection of colored welding rods.
- Easy to Use: Poly Welder Pro 200 Watt Plastic Repair Kit
With its flexible structure, the Poly Welder Pro 200 is one of the easiest pieces of welding equipment to operate!
Included with this welder are detailed instructions for use, a 200-watt element, welding tip, 10 feet of polyethylene repair sticks, a 5″x10″ sheet of stainless steel reinforcing mesh, and a welding stand.
With this product, you can handle just about any polyethylene repair or weld with no trouble at all!
- Versatile and advanced control: Master Appliance ProHeat Series Plastic Welding Kit
You can repair almost all types of plastic with this versatile and advanced control welding tool.
This hot air welder is compact and lightweight allowing you to weld both rigid and flexible plastics, tarps, liners, covers, tents, and inflatables!
With an LCD display monitor, you can control the welder’s heat output. Including with your purchase will be five tips and an assortment of welding rods.
For more heavy-duty jobs, like plastic bumper repair or flooring work, this welder is a great choice.
- Overload Protection: DEWALT Heat Gun with LCD
To complete your welding project effectively and ensure its safety, DEWALT Heat Gun comes with overload protection. This means that the heating element will automatically shut off, preventing burn up.
This particular piece of welding equipment also has an LCD display that allows the user to adjust the heat in 50-degree increments, a number of different tips and an ergonomic handle to make every job a comfortable job.
Improve Your Hot Hair Welding Technique with Welder 101
Now that you have an idea of what welding equipment you need to complete your hot air welds, it’s time to learn more about and improve your technique!
Welder 101 is a comprehensive training program that you can follow at home, in your own time, and at your own pace. Membership grants you access to an ever-growing library of easy-to-follow video tutorials, private community support through your Facebook group, and discounts on some top welding gear. And the best part, it is a lifetime membership so you can always be honing your skills whenever you see fit!
Don’t wait any longer, get started with Welder 101 today!
