To the welding novice, knowing which filler metal to use can be completely daunting. There’s so much information out there and none of it seems to make any sense. There’s codes, and matches and equipment considerations. It’s enough to make you want to throw in the towel. So, let’s go back to basics. Here are the things you need to know to help you start narrowing down your options.
Your base metals and filler must be metallurgically compatible. This is to say, the weld metal shouldn’t possess any hazardous qualities that might lead to cracking under high heat or brittleness. That makes it sound like you need to be a qualified metalworker, but it’s far less complicated than that. Certain welding equipment distributors, like www.welding.com.au for instance, contain extensive lists of filler metals, their typical applications and even nearby outlets from which you can pick them up. There are also lots of guides and tables online that provide a reference for matching up filler metals with your job – many of them are rife with codes and technical jargon, though, so if you aren’t too sure what they’re talking about, it never hurts to ask an expert.
Hot and Cold
The welded joint should remain strong and tough regardless of temperature. The joint should hold up the same at room temperature as it would in the bitter cold or high heat depending on the specific job’s ultimate purpose. If the job will be going on a roof in an area that gets a lot of wind, look for a combination of metals that will remain strong in those conditions. How cold does the area get during winter? Is the job going to wind up indoors or out? If outdoors, will it be in constant, direct sunlight during summer or are there times when it will be in shade? There are so many variables to consider and they will all inform the type of filler metal that will be best for the job.
The welded joint should also be resistant to water or heat corrosion and should be geared toward the predicted environment the finished job will be living in. This will play a larger part in selecting your filler metal, especially for outdoor jobs. These are a whole other set of variables all together. Is the area prone to frost or snow during winter? Is it humid? Rainy? Dry? Do your research – the more you know about the area’s meteorological tendencies, the better.
As you can see, there is so much to consider when picking out a filler metal. Preparation is half the battle here, so know what you’re aiming to do long before you get there. If you aren’t sure, ask lots of questions, get online and do your research and don’t proceed without being absolutely sure you’ve got the filler for the job. Got any tips and tricks? Ever gotten it wrong and had a horror story on your hands? Leave your answers in the comments below.