I just picked up an old hastings hand held magnafluxer and i need some filings, i could go around the shop with a broom, but i'd rather get the right stuff BTW, any advice on learning to use it?
Right here http://www.goodson.com/store/template/display_by_search.php?SID=73d7065130185c1cd317d1a89d3b364e
Couldn't a guy make his own low budget version for testing the valve pockets of a flathead (or other localized areas) with a few strong rare earth magnets, a handle and some of that powder?
Sorry Kevin, but I'm afraid not. A magnafluxer, or magnaflux machine if you will, doesn't use the magnetic properties of the magnets within the tool to highlight cracks. It uses elecrticity to generate magnetic fields that actually "energize" the piece being tested... To put it another way, the magic isn't really in the tool, but the magic happens when the tool uses electricity to do create magnetic fields in ferrous metals in proximity to it. Now if your asking if you could construct a magnaflux machine using a couple rare earth magnets..... Well, sure... Hypothetically, I guess you could. But it isn't really nessecary to use exotic parts to construct one. It's basically just a regular magnet with copper wire wraped around it and electricity flowing thru it.
What you speak of exists I use mine around flatheads all the time.Had it for 15 years or so serves me well. Use their powder also.Brake lathe shavings etc. are all too coarse the powder is fine like flower.Hope this helps. http://www.silver-seal.com/product/10100/Magnetest-Crack-Detection-Kit---10100 Just my 2¢ Tig
Do you find cracks, or indications? Can you tell the difference? Is it surface, or subsurface? How do you tell the difference. Are all indications defects? That should start your thinking.
Go to NDTsupply.com. Today we use iron powder in various colors. As an alternative, and my preference, go for the liquid suspension in aresol. Remember mag particle is directional so you need to check in several directions, 90, 180, etc. Magnuflux is a brand, the terminology is magnetic particle inspection, also known in NDE circles as MT. Should also mention that mag particle only detects surface breaking indications. It will do very little if there is a subsurface crack. And another link for some light reading: http://www.ndt-ed.org/EducationResources/CommunityCollege/MagParticle/cc_mpi_index.htm
goose-em Are you speaking of the use of AC current only when you say surface defects only? Or is that a blanket statement of all MT inspection methods.
This may or may not help but go to your local office machine repair place and explain to them what you are doing. See if they will save some old developer for you. It get routinely changed and is basically fine powdered iron with a toner mixed in with it. It usually just gets thrown away so I am sure they would probably just give it to you.
Magnaflux or mag particle inspection selection is sort of like welding. For welding you need to know the material you’re welding to, current type etc. Mag- particle inspection you need to know if the material is ferro-magnetic. Put a magnet on it. You need to know what you are looking for i.e. cracks, forging laps, pinholes etc. How sensitive do you want the test to be? A very sensitive test will find all sort of non -relevant indications on a cast iron part. Precleaning the part is also very important. <O Magnaflux unit ? What type? AC Yoke , stationary system ,magnets ?Remember if you are going to magnetize something you are most likely going to have to demagnetize it. You wouldn't want your crankshaft or rods to start picking up iron particles . <O</O AC induced magnetization - great for tight surface defects- need to keep the current on (continuous method) for both wet and dry particle applications.<O</O DC induce magnetization- great for deep, wide defects both surface and slightly below surface. DC magnetization does not decay quickly - Demag required . For checking residual mag field use a gauss gage. <O</O You can perform a mag- particle inspection with an AC DC welder . If you are thinking about it , you'll need to calculate the amount of current needed to magnetize the part. Too much current you'll burn up your part or your welder.<O</O <O</O Iron particles-There are all sorts . There are different colors like red , white , orange, black, fluorescent green,fluorescent orange <O</O You have dry particles and wet particles. Wet particles can be suspended in liquids such as mineral spirits or water.<O</O Wet fluorescent is the most sensitive mag particle inspection. It does require a UV black light for viewing.<O</O And there is black and white -wet black particle with white contrast. <O</O 30 years in the inspection business and still going.
Nice thought ... not a good idea. They are changing out the wet bath for a reason. It could be low on iron particles, or it could be contaminated. The bath is usually oderless mineral spirits. They use a centrifuge tube to assure the proper particle concentration. Developer is for dye penetrant testing. If your are inquiring about copier toner thats not recommended . That stuff is extremely hazardous for your respiratory system. Bad for da lungs man!
The magnet we had in the school shop was pretty simple with a handle that you used to help release it from the head or block. It worked good under a sheet of glass or other non magnetic material to show the kids the effects of magnetic fields by sprinkling grindings from the brake lathe on the glass. In another shop we had what amounted to a big horseshoe magnet that we used to mag heads. It was more of a C rather than a horseshoe but it was simple and worked. A guy might play with one of those HF retriever magnets http://www.harborfreight.com/retrieving-magnet-100-lb-pull-36903.html they come in several sizes and weld a piece of square bar stock to each end to make a C out of it. I'm not sure if the magnetism would be affected by welding though. I might have to pick one up and play with it a bit. That and the proper powder and a guy might be set to go.
Rare earth magnets can be used on parts that do not have a lot of geometry. Remember if to magnetize , you need to demagnetize.
Jogyver Glad to know I'm not the only old guy that's been in this business. My dad worked for Magnaflux Corp. starting in the early '50s so I received an introduction to MT, PT, at an early age. I even had the chance to learn to use the Stress Coat method, no longer used thanks (and I do mean thanks) to FEA software. Later learned to use UT when the equiptment was the size of a steamer trunk, with a 6" round screen and transducers the size of a pop can. ET equiptment was also big and bulky. Today the equiptment for these systems can be held in the palm of your hand and does more than was ever dreamed of back then. Thats progress for you. The whole business of NDT has under gone a lot of changes from the time I got into it. The ASNT-TC-1A Cert. Program brought on a lot of changes. The early testing methods lacked a little in that if you could read the tests were not too hard, and were pretty general. The price was not that bad either. As time went on the tests became more industry specific and the test locations scattered out across the world. When I got to the point that I no longer wanted or needed the Certs., it was getting pricey to maintain them. I did hold level 111 in; MT, UT, and PT. as well as level 11 in ET and X-Ray for a number of years. I have worked on ever thing from rockets to submarines, and hypodermic needles to skyscrapers, and ever thing in between. I learned a lot and saw a lot and wouldn't trade it for any thing. I have had the chance to meet and work with some great people and work on some projects that many will only dream about. Well so much for my rambling for now. Jr. Clark "CrkInsp"
Thanks Crkinsp. I've been around the block in the NDT industry . Played in the aerospace, nuclear and fossil fuel power plants, and petrochemical industries. Now with a major oil company playing with smart pigs(UT & MFL) for pipeline inspection . Yes , I have many times carried a M90 UT scope that weighed 70 lbs up a 60 ft tower in my early days. The MT & PT methods haven't changed much. The UT , RT , and ET testing has reallly evolved. I do need to go to the next ASNT conference to see the lastest toys the NDT industy has developed lately. Future plans - Retire in 7 years , buy a big pole barn , build hot rods. Did your Dad work out of Chicago?
Jogyver Dad started with them in Wichita, Kansas, later moved to Tulsa, Okla. as Lab Manager. After Magnaflux Corp. was sold to General Mills, yes the cereal and food co., he left them and went out on his own. He did make many trips to Chicago and other co. locations.
I guess that I should have been more clear. In any dual component photocopier, they use what some call developer, others call it starter...It is a "creatively shaped" powdered iron filings. Toner in the copy process is not magnetic so they use the developer as a carrier for it. Over time, it loses it's ability to control the toner so it is a time replacement item. Most is black but in a color copier it comes in cyan, magenta, and yellow although the pigment is just the toner color that is added to it. I work with this stuff every day.
Greg thanks for the clarrification . I never knew this. I have seen it at work though. It's a very very fine powder . It would be great to use with a wet bath liquid ie water or mineral spirts. Wet bath particle size is < 0.5 to 10 micrometers. For dry applications particle size should be 5 to 170 micrometers. One concern - An accumulation of theses fine iron particles could cause some major issues in a motor if not removed properly. It is recommended to demag the part after inspecting and to thoroughly clean it .
I don't know anything about the magnaflux process. I know copiers. Others will help you with the magnaflux part. Thanks.
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