What To Look For When Hiring a Mobile WelderCentral Mobile Welding
It is often difficult to hire a tradesperson qualified in a skill that you are both untrained in and unknowledgeable of. The intent of this article is to facilitate your choice of a qualified mobile welding professional in Ontario, with regards to their certifications, equipment, and pricing. It should also be noted that the aim of this article is for the layman and thus takes a broad focus on the mobile welding industry without getting into the nuances of the specific needs of every mobile welding job. Fortunately, it so happens that generally, the more specialized and qualified the skill needed by the customer is, the more knowledgeable of the welding trade the customer is as well.
Type of Work You Need to be Done
The best-related topic to first address would be the type of work you need to be done as this will affect all three criteria mentioned above for hiring a mobile welder. First off, how much weight will the welds be subject to holding and will this weight be static (staying in one place like on a shelf) or dynamic (moving like vehicles on a bridge)? Properly made steel welds are usually rated for sixty to ninety thousand pounds per square inch, and this strength is what certifications prove that a welder can attain with his or her welds. What this means is that welds holding enormous loads should be executed by certified welders, while welds holding small loads can often be done by any tradesperson so long as the weld passes a basic visual inspection by the customer. We’ll briefly discuss the parameters of a visual inspection later in this article. The question is then a matter of what constitutes a small load. There is no hard and fast rule of at what exact mass of load you should opt for certified welds, but as a general rule of thumb it would be safe to say that welds holding over a thousand pounds should usually be certified.curring!
Static loads are invariably much more forgiving of poor or mediocre welds than dynamic loads generally are. Any object to be welded that doesn’t experience a load that is either moving or exceeds one thousand pounds, usually need not be welded by a certified welder. This can apply to projects like step bumpers on the back of trucks, lamp posts, fences and pretty much anything responsible for holding only its own weight.
Again, the previous text-only applies to static loads as the dynamic variety is a whole other ball game. Let’s say you need a swing set welded together. The weight would be far less than one thousand pounds, especially if only children are to be using it. Even still, the top beam that actually holds the weight as the chains swing back and forth is susceptible to fractures or even breaking at the welds when the load pulls the beam in a direction that it is not properly reinforced. For this reason, it is never advisable to hire an uncertified welder for projects subject to dynamic loads.
Certifications and Pricing
Now we have mentioned that there are instances when it is forgivable to hire a mobile welder that does not have any certifications. There is only one valid motivation for this, which is to save on cost. This route is much more advisable to clients that have a general knowledge of what a sound welds look like. Some uncertified welders are very capable skill-wise but have just not bothered to get certified as it is not necessary for Ontario, especially if they are generally only doing small jobs. These welders will often work for less than what a certified welder demands and they are worth searching for if you have an eye for a sound weld. As for clients new to the world of mobile welding in Toronto, there are many drawbacks to choosing an uncertified welder. Even if the weld is for something under minimal stress and with low liability, such as a fence repair, it should be noted that an inexperienced welder can easily leave you with a weld that will need to be replaced within a few years, or even months. A client who can evaluate a sound weld from a defective one can easily put a stop to the job early or at least avoid rehiring a less than an ideal welder. A client who hasn’t a clue of what they’re looking at, however, should always opt for a certified welder.
Type of Certifications
Now that we’ve gone over the importance of certifications, it’s important to know what certifications you require. The vast majority of all mobile work will require stick welding (a.k.a. shielded metal arc welding). This is because it is one of the few types of welding that can be operated outdoors even in windy conditions. Almost all other types of welding use a shielding gas that can easily be blown away, which is why they are often strictly used indoors only. For this reason, nine times out of ten you need your welder to be certified in stick welding. Acceptable certifications are either from the CWB or TSSA.
The Fundamentals of a Visual Inspection
As for a basic visual inspection, there are a few simple qualities to look out for in a weld that will give you a good idea of its integrity. Firstly, is there any porosity? This is the single biggest flaw in a weld as these tiny bubbles form a sweet spot for fracturing to occur once a heavy load is applied. Next, is the weld concave or at least slightly convex? Regardless of the joint, whether it be inside a corner or on top of two flat pieces being joined at the ends, concave welds should always be taken as a sign that the weld is thinner than the two pieces of metal it is joining and thus forms a weak spot. Always make sure that all your welds are convex (even a millimetre above flat is good enough). Another thing to watch out for is size. The general rule of thumb is for the weld to be the combined thickness of both metals it is joining. So if you’re welding two 1/16th” pieces together, make sure the weld is at least 1/8th” thick. The last thing to mention would be undercutting. This can occur along the edges of the weld as slim grooves that run parallel to it and it usually occurs due to too much heat. When it is visible, this implies a weak spot in the metal where fractures or breaking can occur.
What Equipment to Expect for a Mobile Welder
The final topic to be discussed is the equipment that should be expected for a given welding job. Usually, for sheet metal (metal less than one eighth of an inch thick) the type of machine on site is irrelevant. This is because thin metal needs very little heat to be welded effectively. For thicker metals, however, you will need a welder with a machine that runs off at least 220 volts. The outlets commonly found in residential housing are rated for 110 volts while in industrial buildings it is more likely to find outlets rated for 220 volts or higher. If you have an outlet rated for 220 volts then it is possible that a welder can plug a 220-volt machine into it, but not guaranteed. This is because there are many different plug styles for 220 volts, and they must match the corresponding outlet. For this reason, it is advisable to always first ask a mobile welder if they have a generator before hiring them over the phone. Sticking to mobile welders that have generators will ensure that there is never an issue with them not being able to power their welding machine when they show up at your location, and also that they will have enough power to weld your project correctly.
To Summarize, Factors You Should Bear in Mind for Hiring a Mobile Welder:
- Do you need certifications for the type of work you require? If so, is the mobile welder certified in stick welding with either the CBW or TSSA?
- Does the welder have a welding generator?
- After you have seen some of their work, is there any porosity or undercut? Are the welds thick enough and convex?
That pretty much sums it up! Always do a little bit of research before hiring a tradesperson and you’ll be sure to save some money or even prevent a large setback from occurring!
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