I am amazed however at the lynch mob forming over this. Two and a half months isn't a long time to obtain resolution. Everyone seemed to agree about the need for quality, wouldn't you agree also that a thorough investigation is important to identify the causes needing change as well as to ultimately give customer support?
People tend to like the idea of a second opinion in medicine, wanting to be assured what the problem is- before accepting the quickest remedy. But obviously, a number of people are involved who need to review all of the information available and perhaps obtain more info before a decision may be made.
Who knows what the true underlying problem is. A guy I know (a welder) said to me once "The difference between an ugly looking weld and a good looking weld is an angle grinder. The only way to tell a structurally sound weld is by x-ray".
besides, how many of us who complain about quality, are just as diligent about ensuring our "end product" is flawless when we work?
I agree on the root cause investigation, but also remember many folks here have been told many things over past products that failed to live up to quality over the years, and never got any resolution. They where lead down many roads only to be back where they began. The web has change many things now, as more viewers are now aware of the individuals plight. He continued to keep us updated and informed so that we the end user could ascertain how the company was addressing his quality concerns. I am sure this did not go un-noticed in Kubota head quarters. I do wonder how quick it would have been resolved with a letter and no public notice though.
Oh and as far as the only way to tell the quality of a good weld requires more than radiography (Xray) as we also have been examining welds since the late 60's with ultra sound at various angles to actually see inside the weld. Many times with Xray because its one dimensional, you have a potential of masking more serious flaws, such as a mid wall slag inclusion which could mask lack of penetration at the root, as the two indications on a piece of film would be stacked on top of each other, so the likely hood of seeing the LOP would be overlooked, and in many codes, some amounts of slag is permissible. This is why ultrasound is now so widely used throughout many industrys that have a high level of public trust and safety. Furthermore you can accurately measure the length of the indication within thousands.
It would be great if we could rely on only one test to determine the quality of a weld, but all critical welds must pass a series of testing to ensure integrity. The first inline is a visual examination, where one looks for spatter, crater cracks, excessive reinforcement, undercut, and a few more detrimental defects, these must be corrected before the next test begins, which would be a surface examination. Many of you that may be familiar with modified engine building also use these techniques in their projects. These surface exams consist of two vary different techniques, but the results are almost always the same. The first is liquid dye penetrant examination mostly used on stainless steel or finished welds, and the other is magnetic particle testing. Both are very mobile and can be performed in the field. The dye test can pick up hairline cracks which may not be visible to the eye, and its based on contrast to make these indication visible to the viewer, magnetic particle can also detect subsurface indications, but it must be very shallow ( we are talking wave lengths) Any indication detected by these two methods must be corrected, and those areas must once again be visually tested, and re-examined with the method that detected the original indication before it can proceed to the volumetric exam, which as you stated would be xray, or ultrasound, as these methods can see inside the weld. Xray is mostly used as a base line exam, because you will always have a piece of film as a record for the life of the weld, but as technology continues to evolve, we now can save ultrasonic data as well to an optical disc.
Think of a heart monitor and the ekg image, this is the sound wave that is produced within a weld, but as the sound bounces off the root, or counterbore, it creates somewhat of a pattern in the sound wave image. And as the sound increases in height on the screen, we can now apply a color to that height which is known as signal amplitude, the width of the screen is time or depth. So anytime a crack appears within a weld, you receive a signal that basically paints in a pretty color and is not consistent with the rest of the image. There is a little more to it, but thats a simple way to explain it.
Ultrasound is used in many industries because its also very mobile and quick to perform, one industry that uses it on almost all its products it the tire industry, they check for steel belt placement and voids in the rubber, they also use it measure fat content on farm animals going to market.
But it DOES require more than one test to determine and acceptable weld depending on its use. Oh and in my industry, its my job to ensure your welds are FLAWLESS, as the public depends on my work (And yours). I am very diligent at my job for what I see and do could affect millions of people for a very long time, We look for folks that take shortcuts in their work, and deal with them accordingly. This industry pays people generously that take their jobs seriously, and can maintain a high level of professionalism and integrity. There is a very good chance I have worked close to your home, and your saftey depended on my diligence in doing my job.
I will leave it at that and let you figure out where to look to see what it is I do. But I would perfer if you where to think about it before you looked, and see if you can figure out what my job is. I would suggest diligence in everything you do, it will not go unnoticed if you do your job to the best of your abilty all the time and you will always sleep better at night knowing you did your best.
