It's rumered that NDT (Non Destructive Testing)was first thought of in the 1800's when man noticed water vibrating out of cracks on railroad tracks when they moved or hit them.Then they realized they can have a better contrast if they mixed kerosene with dirty engine oil and hit it with a hammer.So heres a way to check some scrap or whatever you want before you put hours into a piece to later break a piece off.First you want somehting with low viscosity like wd40 and mix it with something to give it contrast like red food coloring then you need either dry talc or even a thin layer of spray deoderant will work.First clean the part with solvent remover,letdry for 5 min.nextapply penetrant,let sit for 20 min,wipe off with dry rag."If its cast you might want to spray a little cleaner on a rag and give it a quick wipe",then litely apply a thin coat of talc and wait 10 min. If there is a crack youll see it plain as day.Its best to test it on a piece you know is cracked to see the results . I hope I saved one of you from stess later.:)

Hmm that is a neat idea! low vicosity oil with color contrast? Red in color?
Would'nt that be the marvel mystery oil I have on the workbench all the time anyway?

Amost anything solid steel will ring if you hold it up and tap it with a ;piece of steel it will sound dull if cracked,,,but the railrod tracks are a bit hard to hold up ...thanks

Ya ,that would work.I didnt think of marval.You could use wd on its own.But the red on white contrast takes out the guess work. You can also pick up a real kit from magna flux.I think around $25.00.

The other day I stumbled across this method. I had some steel wool that my wife used in the Kitchen that had a little bleach on it. (I wasn't aware of the bleach at first) I was aging an axe that I had fabricated for a friend. It was basically done and I just needed to go over the last layer of controlled "spit" rust before I soaked it in tongue oil. I rubbed it for about 30 secs and did something else for about 5 min. I came back and noticed all of the lines mocking me as if to say "you can't hide me." The lines were on tig welds that I would consider near perfect. I couldn't believe it. So I took a cap of bleach and put it on a couple old axes I hadn't messed with yet and sure enough. The stress cracks stuck out like a sore thumb. It has to be the most effective and cheapest way to find cracks and past welds. Very good way to talk someone down on the price of an old antique hunk of metal. I wouldn't recommend doing this in an unventilated space as I'm sure it sets off some sort of fume thats not good for ya.

Wow...home made dye penetrant testing. Sounds good.

And I don't even have to keep up any NDT cert. paperwork anymore since I retired.

Steve

tiny Im gonna try that