When you start learning a new technique it is important to know the basics and the major dos and don’ts related to the craft. when it comes to arc welding thin material, a lot of sources will try to convince you to buy some extra equipment or tell you a straight no, but the truth is a bit more complicated than that. I will try to get into the details surrounding the topic and the different points of view related to stick welding sheet metal.
Stick welding is not the preferred method of welding thin sheet metals but if you have no other option then it can be done. The first thing you need to keep in mind is to select a thin electrode and work on a low amperage. Rods like the 7018 and 6013 are preferred. You can also try the whipping method to reduce heat build-up.
WHAT’S THE THINNEST YOU CAN WELD WITH SMAW?
There is no hard and fast rule with the thickness under which you shouldn’t use stick welding. But there is a fair idea of what constitutes a thin metal and below which using stick welding might become difficult. A lot of people consider anything less than 3/16” to be thin so below this thickness stick welding can start creating problems or can become difficult to handle. But remember that there is no particular thickness under which it can’t be used.
To my knowledge 12 to 14 gauge (2mm) can be done with 6013 3/32″ rods. Anything thinner like auto body panels MIG would be a way to go. However, there is another way to go even thinner, and I have seen it done numerous times. This will not get you welds pleasing to the eye, but if you need to do some repairs ASAP you can try.
For that, I would recommend trying out a rod with a more violent arc, that penetrates fast, deep, and strikes easily, like 6011. More about that in the next section.
HOW DO YOU WELD SHEET METAL WITH A STICK WELDER?
Before you begin the process of welding a very thin sheet, there are a few things you must have. The first is a DC welder which can go as low as 20-25 amps.
The second thing is lots and lots of practice, the first thing you will need to master is striking an arc at very low amps and avoiding making holes in the sheet. You can also try padding to avoid making holes in the base metal. The trick to striking an arc is to use the matchstick method rather than the tapping method as the chances of the rod sticking to the base metal is much higher when using the tapping method.
You should set up your arc welder to straight polarity (DCEN), doing this will keep the heat on the rod rather than the sheet. When you are setting up the sheet, try to place it in the air, or use a copper backing plate that will suck in the heat from the base metal.
Once you have mastered striking an arc, you can start placing a series of tack welds side by side forming a uniform bead. As I said, it will not be pretty, but it will get the job done. Check out the video.
If you keep blowing holes in the work, dial down the amperage and try again.
Some people also prefer whipping motion when it comes to welding thin materials. This involves using a whipping motion with the welding rod following the same direction of the weld, it basically means a back-and-forth motion. The reasoning for using this method is to prevent the accumulation of heat on one spot which can happen if you drag the rod too slow.
CAN YOU WELD BODY PANELS WITH ARC WELDER
The popular sentiment about this subject online is a big no-no. a lot of people say that as the material is thinner than the rod itself, it will end up melting first. Some random comment on a post online states that using arc welding on body panels is a good idea if you are working on a tank. The truth is that yes, it is not ideal to use arc welding on body parts if it is the only alternative you have then it can be done.
If you are looking to work on mild steel, for example, the 6013 rods would be suitable for the job, make sure you are selecting a thin rod. The 0.093” would do the job, even thinner than that would be better. Make sure that your amperage is low, and you are working with DCEN which will provide less penetration.
WHAT’S THE BEST ROD FOR THIN METAL
The best rod to be used depends on a couple of factors like the thickness of the base metal being used. If you are using a new 1/8” material, then you should probably go for 3/32” 6013 rods. On the other hand, if you are going to be working on a 14 gauge that has been rusted or painted then you should go for a 1/8” or 3/32” 6013 rods. You can choose to grind the rust off if it is just surface rust but if it is pitted out you might end up grinding away all the material away before you get it cleaned. Plus, if you are going to do a simple repair job then it will be better to do a quick weld if the material is that bad as the weld will far outlast the material anyway.
ALTERNATIVE WELDING METHODS TO WELD THIN METAL
The truth is that most people out there will prefer using the MIG and TIG welding methods when compared to stick welding for thin metals. but the issue which arises is that of affordability and the learning curve. If you are just starting your welding hobby or if you are a beginner you might not want to spend extra money on a whole new welder and the accessories which come along with it.
The problem of using the TIG method is the steep learning curve that beginners might face in the beginning. A lot of people spend a lot more time learning the TIG method when compared to MIG or stick welding. Otherwise, TIG welding is preferred by professionals looking for a finer weld and low splatter.
MIG welding on the other hand is relatively easy to practice but has the disadvantage of limited application. It does not work great on rusted materials, nor can it weld as thick materials as with a stick welder.
HOW NOT TO WARP METAL WHILE WELDING?
First, let’s address what is warping? When you are welding the weld bead, the filler metal is at a higher temperature which is above the melting point of the metal. As the welding goes on, the base metal conducts more heat. After welding, it wants to cool and shrink. The thing is, the more heat you apply to the area, the more it warps because of the tension created in the welded area.
These distortions can be controlled through the following techniques.
- Avoid over welding, correctly sizing the weld will minimize the heat, thus distortions will be smaller.
- The second thing you can try is intermittent welding, using this technique can minimize the amount of weld metal.
- Use backing plates that such up most of the heat from the base metal.
When it comes to thick materials. fewer welding passes may also help in the situation as the distortions increase with increase in number of welding passes, a smaller number of big passes may result in less distortions when compared to large number of small passes.
FREQUENTLY ASKED QUESTIONS
This is one of those topics which consist of a lot of opinions and no right or wrong answers. A lot of people might have different experiences which provide different suggestions. I tried to provide a common ground on which most people agree with. It is obvious that you might have questions related to the topic. I will try to go through some of the most common queries that people have related to the topic. Hope it helps.
A lot of people a say that stick welding is not ideal for welding exhaust pipes and that is true to some extent but it is not impossible to use the method. The first step to select the best rod for the job. Make sure that you are selecting the thinnest 6011 rod you can get your hands on. This rod will help you during spot welding before welding around the muffler’s circumference. It is recommended to use lower amperage value before you start welding. You also might end up using several electrode during the process.
The main goal while welding thin metals is to avoid problems caused by excess heat. MIG and TIG welding processes provide the best and most control over the heat to address these problems. Stick welding, although can be used, but is not recommended for this process.
Avoid over welding, correctly sizing the weld will minimize the heat, thus distortions will be smaller.
The second thing you can try is intermittent welding, using this technique can minimize the amount of weld metal.
Use backing plates that suck up most of the heat from the base metal.
To sum it all up, keep in mind is that stick welding is not the preferred method of welding thin sheet metals but if you have no other option then it can be done. The first thing you need to keep in mind is to select a thin electrode and work on a low amperage. Rods like the 6013 and 6011 are preferred depending on the situation.
Remember that you will have to practice a lot before trying a real-life project. Using stick welding for thin metals can be tricky and needs a lot of practice before you can start using it.