1. Five tips for aluminum welding
1. The wire drawing welding gun is most suitable for welding aluminum.
If you can’t use this kind of welding gun, try to use the shortest welding gun to keep the welding gun straight;
Only argon can be used as shielding gas; When welding aluminum (automatic pipe welder), only push gun can be used.
2. If you find a wire feeding problem, you can try a conductive head one size larger than the welding wire.
3. The most commonly used welding wire for aluminum welding is the softer standard welding wire.
The other is harder (easier wire feeding), which is mainly used in welding operations with higher hardness and strength requirements.
4. Before welding, the oxide layer on the aluminum surface shall be removed, and a special stainless steel brush shall be used to remove the oxide layer.
5. Fill the crater at the end of welding to prevent cracks. One way is to keep the welding gun in the molten pool for several seconds after welding.
2. Precautions for aluminum profile welding
1. Welding of aluminum
Welding characteristics: aluminum and aluminum alloys have the characteristics of strong thermal conductivity, large heat capacity, large linear expansion coefficient, low melting point and low high temperature strength. It is difficult to weld.
Certain measures should be taken to ensure the welding quality.
For the cleaning of pipe fittings and welding wires, the surfaces within 50mm on both sides of the welding wire and the break shall be cleaned with acetone, and the surface oxide film shall be brushed with stainless steel wire to expose the metal luster.
The cleaned break must be welded within 2 hours, and the cleaned welding wire must be put into the unused cylinder and used up within 8 hours, otherwise it shall be treated again.
Cerium tungsten rod shall be selected as tungsten rod, the argon blunt mass shall not be less than 99.96%, and the water content shall not be greater than 50mg / m .
The ambient temperature shall not be lower than 5 ℃, otherwise it shall be preheated to 100 ~ 200 ℃ before welding, and the relative humidity shall be controlled.
2. Required equipment
You need at least a $4000 welder and excellent welding skills to weld aluminum;
The welding operation with good effect can be completed without practice;
You need to buy expensive welding guns suitable for aluminum welding.
3. Successfully welded aluminum
The fact is that after training, using suitable welding equipment and setting correct parameters, the compact small MIG welder can also carry out temporary aluminum welding.
You will be able to use MIG welding machines to weld all kinds of materials in your home, such as barbecue grills, backyard storage rooms, docks, and even decorative parts.
Even home welding enthusiasts who often weld steel will find it a great challenge to weld aluminum.
The reason is that the aluminum wire is very soft and it is very difficult to feed the wire.
In addition, the wire diameter and welding machine setting commonly used for steel may not be suitable for welding aluminum.
3. To successfully weld aluminum, you need to understand the following problems
1. What kind of equipment do I need?
The first decision to be made is what kind of equipment is needed to achieve the goal.
Keep in mind that the 115 volt wire feeder can handle welding of sizes 22 to 12, and with proper preheating, you may be able to weld 1 / 8 inch thick material. Be careful.
However, that the maximum preheat is limited to 250 degrees Fahrenheit.
The other is a 230 volt machine that can weld materials from size 22 to 3 / 16 inch. Proper preheating can increase the range to 1 / 4 inch.
If you need to weld plates of different thicknesses, consider a 230 volt welder.
Remember, if you are going to do very regular aluminum processing, you will need a heavy welder.
115 and 230 V compact MIG welders can be used for occasional aluminum welding, but they are not recommended for complex and heavy aluminum welding, otherwise welding equipment with an output of more than 200 amps should be considered.
After you have determined the input voltage, another question you usually ask when choosing a welding machine is, do I need a continuous voltage regulation model or a tapped coil model?
The continuous voltage regulation model allows you to steplessly adjust the set voltage within the voltage limit of the machine, with stronger adaptability, more effective adjustment and accurate control.
This allows you to adjust more easily during welding operations.
2. What kind of shielding gas?
The shielding gas required for MIG welding aluminum and steel is different.
For welding aluminum, 100% argon should be selected. However, steel welding requires mixed gas or 100% carbon dioxide.
The good news is that we don’t need any special equipment – your existing regulator (except carbon dioxide regulator) and gas pipe can be used in pure or mixed gas.
3. What polarity is set?
All MIG welding, including aluminum welding, requires positive electrode, while flux cored welding process typically uses negative electrode.
If you want to switch the welding machine in different processes, first determine the switching polarity. This is a common mistake for novices.
4. What kind of aluminum alloy electrode should be purchased?
If you try to use steel electrodes when welding aluminum, you will get poor results.
Instead, we recommend that the compact MIG welder use 4043 aluminum alloy filler metal limited to 0.035 inch diameter.
5336 aluminum alloy electrode may be generally recommended to retailers and distributors because it is harder and easier to feed wire.
However, if this wire feeding welder is used, the current of 5356 aluminum alloy is usually not enough to achieve good welding effect.
Although the 4030 is soft, good wire feeding performance can be guaranteed by following the appropriate steps described below.
Do not use welding wires of other diameters. In particular, avoid 0.030 inch welding wire (wire feeding is quite difficult) and 3 / 64 inch welding wire (compact small welding machine can not provide enough current to reliably melt the welding wire of this diameter).
5. How can I set up my welder to weld aluminum?
Now that you know the types and performance / limitations of welding machines, the next very important step is how to set parameters.
Follow the following tips: buy a set of aluminum wire feeding tools;
Note that wire feeding is more important when welding aluminum, so it is strongly recommended to buy a set of special aluminum wire feeding tools, which will include the following items:
Non metallic liner – designed to minimize feed
Wire friction 2 U-groove driving roller – used to avoid breaking or deformation of soft aluminum wire.
These drive rollers will not scratch the aluminum wire like V-groove rollers.
If the V-groove roller is used, the welding wire will scratch the liner and cause blockage, resulting in wire feeding failure.
Inlet and outlet guides – designed to avoid wire scratches.
Contact – the contact head used in aluminum welding has a larger diameter opening, because when the aluminum wire heats up, it produces more expansion than the steel.
Therefore, the size of the special contact head for aluminum wire is small enough to maintain electrical contact and allow expansion at the same time.
Load welding wire to welding machine
Here is a trick to correctly load aluminum wire (also applicable to steel welding wire). It is very important to load aluminum welding wire and avoid welding failure.
Hold the welding wire shaft safely with one hand to ensure that it will not loosen.
Once you unpack the cellophane package, hold the loose end of the welding wire with the other hand – do not let go before putting it into the drive roller.
Inexperienced people usually fail to hold the loose end, resulting in the whole bundle of welding wires beginning to loose and spread.
If this happens, there will be no remedy, and the welding operation will be greatly affected – you have to buy another bundle of welding wire.
Set the tightness of welding wire brake
The tightness only needs to ensure that the welding wire will not loosen just, but it cannot be too tight, otherwise it will drag the welding wire.
To set it correctly, first adjust the tightness to the minimum, and then install the welding wire and let it pass through the driving roller.
If the roller of welding wire is moving and other parts stop, it means it is not tight enough.
Be careful when operating, because too tight will cause too much force on the welding wire.
In addition, don’t be nervous when the last few rounds of welding wire can’t be fed; It is usually because the welding wire is too hard to loosen easily.
Set the tightness of the drive roller
This is probably the most important step in the entire setup procedure.
Experts recommend placing the wire head at a small angle 1 inch from the surface of the insulating material.
Then, set the roller tightness to almost minimum.
Press the switch on the welding torch and observe its operation – the welding wire should slide when it contacts the surface of insulating material.
From that point, adjust the tightness until the welding wire stops sliding.
Again, it should be noted that too tight will lead to the fracture of the welding wire.
This means that the welding wire stays in the welding gun, and the welding wire driving roller is still rotating.
The final result is that the welding wire breaks after running out of the roller, or backlogs, resulting in a mess of welding wires, including guide liner, welding gun liner, etc.
Remember, when you set the roller tightness according to the above contents, press the switch of the welding gun, and the welding wire sent out is hot, so always wear high-quality welding gloves.
Ensure a good power connection
First, the welding fixture should be safely clamped in the area where the welding workpiece is not painted and polluted.
To clean the workpiece, use degreasing solvent to remove all grease. Before welding, ensure that the workpiece surface is dry.
At the same time, do not weld containers with combustible materials nearby, such as solvents or paints.
Step 2: clean the oxide on the surface of aluminum with a clean stainless steel wire brush.
Positioning is very important
During welding, try to keep the welding gun cable straight to minimize wire feeding constraints on soft aluminum wires.
The bending of the torch cable will cause the welding wire to knot, resulting in poor wire feeding.