Is it possible to build a home made magnaflux machine ? As I understand it, you need an electromagnet and some magnetic yellow powder. Any plan ? Thanks in advance.

There is that dye that comes 2 parts in aerosol cans, works just as well. Works on aluminum parts as well where magnaflux won't work. Can't remember the name of the stuff, maybe someone will jump in with that info.

Steve,

I assume you are talking about a dye penetrant examination method. The test materials consist of 2 components. A dye, usually red, that is sprayed across an area, allowed to penetrate and then wiped off. The second step is a dry white powder type material that is sprayed over the area. This powder leaches out any dye that has been absorbed in to deformations in the metal and give a very clear view of any cracks or surface deformations that might lead to cracks. I have performed this type of testign in power plants where large weld areas were inspected. It is very quick and very telling. However a magnaflux test might be a little more sensitive to internal mettalurgical issues that have not given a strong surface indication yet.

The dye penetrant test is a good and cheap first look at a piece for any obvious issues.

I am not sure where you might get dye penetrant supplies, possibly at a welding supply store or on the internet.

Out of curiousity, I just looked at a welding supply site on the internet and they have the Dye, Cleaner and Developer. Looks like about 9 dollars a can or 27 for the kit.

Here is where I found it.

http://store.weldingdepot.com/cgi/weldingdepot/search.html?id=LXUPdAvn

I am sure if you have a local welding supply store they will have it as well

Try a machine tool supplier, some machine shops use the penetrant to check dies and other work rather than magnaflux. Possibly McMaster-Car or Enco stocks it. I purchased a three step system from a local supplier a while back to check a crank shaft, which is still on the list of things to do

Here's an interesting kit that uses a black (UV) light and a 3-step process. A bit more dough then the other products described above, but probably still a lot less then a magnaflux setup.

UV Crack Detection

I purchased a Dynaflux 3 part system from Linweld. It consists of a cleaner, dye penetrant and developer. Works well but be sure to have latex gloves handy when using the dye penetrant. Also use in a well ventilated area.

McMaster carr sells this in kits or by individual pieces.