Toolweld, Inc Blog

I purchased my laser welding machine in October 2005.

At the time, it was considered the new technology, and I thought long and hard about purchasing one. I had read about laser welding a few years before and I found some things: although it produces impossibly small welds, I was stymied by the cost and the time it takes to produce such a small weld. Would our customers want it? Would it be a waste of money? In certain parameters it’s at least 5 to 6 times longer than micro-tig welding; most of my customers would never go for something that could take a hours to do. I asked some customers about laser welding and they told me they would have no use for it.

My questions of necessity was answered by the summer of 2005 some competitors bought a laser welding machine and our sales started to drift south. Apparently, there as a need for it and I had to upon it, thus my life in laser welding begin. After some phone calls, detailed questions and a lease agreement from the bank, my machine was delivered. I got 3 days of “training” from a technical representative, and I was off. Frankly, I had to learn most things on my own. What I learned from the training was that laser welding could take longer than I even imagined. The techniques shown to me had some initial uses but I found them to be impractical in the long term. In order to achieve no undercuts on an edge,  I was instructed to lay a “.015  to “.020 rod on the side of an edge and just use pulse to seam both pieces together; the next step was to add rod on the seam for the build up. Yes, the procedure works, but the problem is that it’s rare to have the room to even do this it — I found this out after the first day. The tolerances were too tight to use it on a constant basis. I had other problems in the impracticality of techniques and I needed a solution.

After a few weeks, I determined that I needed a new game plan. I decided that I needed to approach laser welding as a tool-welder and the first thing on my list was to find a way do a bead on the a edge without putting rod on it. It took a week of practice in order to accomplish and feat — and my results were quite less that I hoped for. However, I kept at it, out of necessity since the jobs I had coming in weren’t getting any easier. My results were slow going but my welding speed increased over the next few years. Looking back from 2005 to now, I surmise that my welding speed increased about 50% as I got more confident and experienced.

Unfortunately, there was hiccups along the way — one of them being inherent nature of “pitting” in laser welding which I fought a battle with. “Pitting” in laser welding is a fact, although most don’t want to admit it. When something has “pitting,” it means there is porosity in between the weld beads, meaning air gaps. In most forms of welding, this doesn’t matter; however in mold welding it’s unacceptable. The problem lies in the fact that the laser gives a certain amount of small power, and the optimum rod is “.010. Trouble begins when I have large buildups with impatient customers: then I “cheat” by using .015 to .020 to order to complete the job. The majority of my “pitting” was with .015 to .020 rod. I know what you want to say now: Do use thicker rod?! I completely agree with you, until the moment a customer comes in and “needs” to wait for a job with a large buildup. A conundrum. I done a lot of reading and experimenting in order to fight “pitting” and I’ve come up with some solutions. One solution is to turn my machine power up to least 15-20% higher than I normally would; in addition, I increased the timing of the laser pulse and use back-passes on pulse only when I finish a bead. I also use some other tricks in angling. Using these procedures I can greatly reduce “pitting.”

To have a laser welding machine is a great benefit for a tool-welding shop; but like everything else, it takes time to learn to properly.

 

Differences Between Micro-tig and Laser Welding

Yes, I started a blog. This will explain things from tool welder’s prospective. The topics will be varied, of course; much like the jobs we do everyday. The tool-welding shop is often treated like an emergency room: meaning you crash something and we fix it. It seems simple on the surface, unfortunately there are pitfalls. When a plastic injection mold is not running, the molder is losing money; when a mold shop makes a mistake, they can’t go on until it’s fixed; when an engineering change  needs to be made, the concept of time is throw out the window. These are the jobs that end up at the tool welder for repair.

Here at Toolweld, we do micro-tig and laser welding. Both procedures give you the same result; however, both are vastly different in it’s approach from a tool-welder’s prospective. Before the laser, micro-tig welding was the only way to produce tiny welds. Micro-tig welding makes for low sink, and less machining time; it’s still the option for most repairs. Recently, laser welding took form, which provides for even smaller welds and less sink. Noticeably, mold and inserts are getting smaller and smaller, so it makes sense to have equipment that can effectively go smaller. However, there are some major differences between micro-tig and laser welding: laser welding is a slower process. The beam is in fixed position for laser welding, so one has to position the part and filler rod to the area you work on; it’s not flexible like a welding torch. In addition to being a slow process, laser welding some materials such as powered metals are not recommended for laser welding according to the manufacturer. So course, one tend to break these rules when servicing the customer, but it still stands as a general rule.
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