|
DIY Magnafluxing
Quote from one of the tech mailling lists I'm on.
> Last night at a meeting of my metalworking club: > > http://www.upstatenymachinist.com/ > > I got to see magnafluxing done for the first time. It was very cool. > > The guy ordered dry magnaflux powder from the local NAPA but it took a > long time to come in because no one does their own magnafluxing. He demoed > it on a cast iron Model T cylinder. You sprinkle some powder where you > think a crack is, then apply a heavy magnet on either side. He had two big > u-shaped magnets, and another one he made out of iron, wire, and a diode > that you could plug in (the diode makes the AC become DC). When the > magnetism is applied the "flux" gets disturbed right where the crack is. > It's very cool. Too bad it won't work on aluminum. > > The other neat thing is one guy repairs copiers so he went to his car and > got out black toner powder and guess what, that has iron in it so it > worked just as well. So if you see and old laser printer in someones trash > or at the dump, and the toner cartrige has anything left, you can get some > free magnaflux powder that way. > > A very nice thing to know about when you think you have a crack in cast > iron. > > Cranky Frankie > "In heaven all the interesting people are missing." > - Friedrich Nietzsche |
Re: DIY Magnafluxing
Originally Posted by Joseph Davis
Quote from one of the tech mailling lists I'm on.
Too bad it won't work on aluminum. |
Re: DIY Magnafluxing
Neato, never knew how it was done. So basically some iron ferrite powder and a strong magnet will reveal cracks. |
Re: DIY Magnafluxing
If the powder is magnetic, and the magnets were strong enough, couldn't this work on aluminum... I'm guessing you couldn't get a strong enough magnet to do it?
|
Re: DIY Magnafluxing
Originally Posted by slo_crx1
:P
>> metallurgist at Dowty's - BI, they made air sprung forks for Velocette >> and Panther - and one of my first jobs was crack detection on aircraft >> undercarriage parts. We used the Magnaflux® process on ferrous >> components and Ardrox® on non ferrous. >> There were two Ardrox systems, one used a red dye which was >> sprayed on, allowed to soak and washed off. The part was then >> sprayed with a solution of french chalk in a quick drying solvent >> which absorbed dye from any crack and showed up as a red line. >> The other process worked in the same way but used a flourescent >> dye which showed up bright green in UV light. >> I frightened myself by using Ardrox on my Dominator valve covers >> which came up bright red all over but painting the inside with Araldite >> epoxy resin sealed them and stopped the oil leaks. My Commando >> which was made 20 years later had the same problem, all part of >> the Norton "character", so I knew how to deal with it. >> >> You can do this at home using coloured kerosene as the penetrant >> and Dr. Scholls® foot spray in lieu of the chalk spray. >> >> Regards, >> Gerry Bristow© >> >> "There's a fine line between a hobby and mental illness". Dave Barry Don't try me, slo... I have teh interwebs at my fingertips. |
Re: DIY Magnafluxing
Originally Posted by Joseph Davis
>> In the days when men were bold I had just started my training as a
>> metallurgist at Dowty's - BI, they made air sprung forks for Velocette >> and Panther - and one of my first jobs was crack detection on aircraft >> undercarriage parts. We used the Magnaflux® process on ferrous >> components and Ardrox® on non ferrous. >> There were two Ardrox systems, one used a red dye which was >> sprayed on, allowed to soak and washed off. The part was then >> sprayed with a solution of french chalk in a quick drying solvent >> which absorbed dye from any crack and showed up as a red line. >> The other process worked in the same way but used a flourescent >> dye which showed up bright green in UV light. >> I frightened myself by using Ardrox on my Dominator valve covers >> which came up bright red all over but painting the inside with Araldite >> epoxy resin sealed them and stopped the oil leaks. My Commando >> which was made 20 years later had the same problem, all part of >> the Norton "character", so I knew how to deal with it. >> >> You can do this at home using coloured kerosene as the penetrant >> and Dr. Scholls® foot spray in lieu of the chalk spray. >> >> Regards, >> Gerry Bristow© >> >> "There's a fine line between a hobby and mental illness". Dave Barry Don't try me, slo... I have teh interwebs at my fingertips. |
Originally Posted by danronian
(Post 929238)
If the powder is magnetic, and the magnets were strong enough, couldn't this work on aluminum... I'm guessing you couldn't get a strong enough magnet to do it?
The strength of the magnet will make no difference because the aluminum won't be affected. You think this because you do not know how magnafluxing works. The magnet puts magnetic currents in the iron head or block you are testing. The fine metal powder aligns with magnetic fields. Cracks disrupt or cause their own magnetic disturbances in an otherwise unbroken piece of iron. When the powder aligns with the crack it makes the crack visible. Well actually the powder is visible along the edge of the crack. Because aluminum is not magnetic it will not affect the magnetic powder at all. |
| All times are GMT -5. The time now is 08:23 PM. |
© 2024 MH Sub I, LLC dba Internet Brands