Magnaflux? Anyone have any good information on the process?

[Wayne 962]

An internet search has revealed limited knowledge, especially from the company Magnaflux.

I'm looking for a FAQ or some more information (from a reputable source), but I can't really seem to find any...

Can anyone point me in the right direction? Google doesn't seem to be helping me on this one...

-Wayne

[911nut]

The way the process works is that you pass a current through a ferromagnetic part (like a crankshaft or connecting rod) or place a part to be inspected inside of a magnetic coil. When current passes through a conductor, a magnetic field is induced around the conductor, or vise versa. If there is a crack in the conductor, a leakage flux (field), or distortion in the magnetic field, occurs. Iron filings are sprinkled (either wet or dry filings, dependant on the nature of the part being inspected. Sometimes fluorescent wet filings are used) along the conductor and line up along the leakage field that is present due to a crack.

See the "Non-Destructive Testing Handbook" for information on the process.

[sweater914]

i haven't heard of anyone using magnaflux on auto engine and components, but i know that it's used quite often in the aviation world, any general aviation engine overhaul shop has the parts fluxed to get "yellow tagged" as a reusable part

[Wayne 962]

It's somewhat standard procedure to 'magnaflux' your crankshaft and inspect it for cracks...

-Wayne

[RLJ]

In the early 70's I was lucky to have my best buddy start working in a machine shop building oval track racing engines for APBA (boats),NASCAR and a few sprinters and midgets. After hanging around long enough I was put to work part time doin' grunt stuff, like checking parts for cracks. At that time we had a spray can of hot pink colored very very thin dye STUFF (thirty years ago OK) that was applied like spray paint. If the part that was being tested had a crack there was no question went the dye was sprayed on, oh yea we used a black light as well with the lights out. Spooky but way cool whey your 22 years old. Taking the motors to the dyno was my favorite time. Then it was cool, today with the computer in the middle it is outstanding.

Thirty years of tech the process should be simple by now.

Then some circle track cars required "Papers" for all front ends. If it was crashed it need to be checked and new "Papers" were issued. There was a USAC station in Portland Oreagon when I was a kid.

How do you get "Papers" for carbon fiber? X- Ray?

Randy Jones
1971 911

[82SC]

Wayne...

i know next to nothing about this but I will let you know what I have found in the past couple months when buying a crank

I did it at EMS on the recommendation of Tom Gould...Great group of guys...I am sure they can answer more stuff...

Plus I was looking at a hot rod book in borders...all america big/small block stuff...but they had about 3-4 pages devoted to explaining the process and had some great pictures

From what I got they add a current and drench the piece in the magnaflux liquid...and with the charge the exciteable ions get pulled into every crevice and crack...

then they pass a specila UV light over it and look for any cracks where the magnaflux has soaked into the cracks...

they also X-ray the crank from many angles since the magnaflux would light up the film when excited by radiation

Also the old school way is to hang it so that it is dangling in the air and striking it with a hammer...supposedly because the metal is a solid piece any crack or inconsistency would mess up the tone...and even when setting down my crank...I can hear a clear ring when it hits (softly) the ground....

That is my layman's 2cents...

If I am in borders again...maybe I'll take notes on what is in that book for ya


MJ

[911nut]

Originally posted by 82SC
Wayne...
they also X-ray the crank from many angles since the magnaflux would light up the film when excited by radiation
MJ

MJ,
When you get an x-ray do they magnaflux you first too?

[82SC]

well Mr. nut....

Being it that I am a medical student....not in my experience....

but if you thought it through, you know that x-rays are stopped by dense materials such as metal...where as bone and tissue does allow some rays to pass through since it is not as dense...thus I have no need to be bathed in magnaflux liquid

since a crankshaft would appear as one gigantomous white blob, I think that they reduce the strength of radiation and allow the excited ions to make the image on the film...

that is also how we do tests for certain DNA's and RNA...we label with radioactive isotopes and take an xray and see where the ions were excited by the radiation and left a mark on the film...

But I think that not all machine shops do it since film and x-ray machines are expensive...probably most rely on the UV light

MJ

[J P Stein]

I was a certified Mag inspector for Boeing (no longer current.....NPI)....
Penetrant, also.
I have working knowledge of Eddy Current, X-ray and Ultrasonic.
Whatcha wanna know?

[TimT]

Magnaflux is one of a few methods available to check metal objects for flaws (cracks porosity, etc)

basically an object is magnatized, and iron powder is sprinkled on the part. the powder migrates to where there is a change in magnetic poles (i.e. a crack)

If you want to check some non-critical pieces for cracks, you can get a dye penetrant kit from almost any welding shop.

[Doug Zielke]

Originally posted by RLJ
At that time we had a spray can of hot pink colored very very thin dye STUFF (thirty years ago OK) that was applied like spray paint. If the part that was being tested had a crack there was no question went the dye was sprayed on, oh yea we used a black light as well with the lights out.

Randy is refering to the ZYGLO system here.
It differs from Magniflux in that it is (as he says) based on a dye that penetrates cracks and is then visible under shortwave UV light.
I had a local engine rebuilder Zyglo a crank from my '70 Triumph 750 Bonneville for peace of mind before I put it back together.

In any large city, there should be several firms that perform non-destructive testing. They can tell you everything you want to know about the different methods.

[Joeaksa]

Wayne,

Any licensed aircraft mechanic was trained at magnaflux, as well as the other NDI (non-destructive inspection) methods.

I was an instructor as well for A&P's years ago with the military and may just have some books on the subject lying around if it would help. Still have several friends who are instructors as well as inspectors in the field and can look for current info as well, but the process has changed little in the last 50 years.

Pls let me know if you need a book or contact in the area...

Joe

[911nut]

Originally posted by 82SC
well Mr. nut....

since a crankshaft would appear as one gigantomous white blob, I think that they reduce the strength of radiation and allow the excited ions to make the image on the film...

Dr. MJ,
Cracks and other flaws in metals can be detected as long as the x-ray angle of incidence isn't parallel with the flaw and the x-ray wavelength and power level is correctly chosen for the type of specimen being tested. There's lots of other factor that I'm not mentioning that affect detection. The skill of the person interpeting the film is critical. That's why radiaography is not the preferred method for testing for small flaws like a crack in a crankshaft. Higher power is used as compared to x-raying biological stuff. Magnetic particle inspection prior to x-ray inspection has no effect on the x-ray image, however.

You are correct in saying that most machine shops aren't equipped to x-ray stuff. It's expensive and potentially dangerous work best left to trained professionals. Magnetic particle inspection (Magnaflux is a trade name for the process) is cheaper and safer and can be easily handled by an engine machine shop.

[HawgRyder]

Another method of testing is Dye-Penetrent....
It consists of two spray fluids....the first is the penetrating fluid...and after that has been applied and allowed to do it's job...the second "developer" fluid is sprayed on.
The result is a colour on the surface with a line of other colour where the crack is.
But...I still "ring" my cranks...every time...old habits die hard...LOL
Bob

[911pcars]

Wayne,
Just wanted to chime in here to clarify the excellent responses to your question.

Magnaflux for ferrous parts
Zyglo for non-ferrous (non-magnetic) parts

Both are trade names.

Sherwood Lee

[stormcrow]

Wayne,

Look in the Phone Book Yellow Pages under Non Destructive Testing. There are companies out there who do X-Ray, Magniflux and Pt testing.

I used to be ASME certified working on nuclear plants. We used to do magnaflux and PT testing on welds. Magniflux is good for finding surface cracks and so is PT Testing.

However, if you want to see what's going on inside the area of a weld, for example, X-Ray would be the way to go.

There are lots of companies out ther who do it, so you shouldn't have any problem finding one. If you can't find one, or are having a problem locating one, call the local Union Hall

(Pipefitters/Welders/Plumbers/Instrumentation/Steamfitters/Sprinklerfitters) Union and they will put you in the right direction.

If you still have a prblem locating one, let me know.


Steve

[stormcrow]

Wayne,

check out this site

http://www.asnt.org/publications/publications.htm

Steve