Pt developer

By Lawrence (*****)

Date 12-09-2011 14:10

It really depends on what your written procedures say and the type of developer your using.

Are you doing an inspection or a check?

My Magnaflux developer says right on the can, that be used with both "spot check" and "Zyglo"

By Superflux (****)

Date 12-09-2011 14:53

LAWRENCE,
I had Top Brass doing the buzzard stare down on me all morning and saying that the he wanted Visible for photographic purposes. All I have is a Zyglo kit. Managed a successful commando raid on another department and "borrowed" a can of red visible penetrant. Then Lady Luck came through for me, after removing all the interior components, it was discovered that the crack went completely through and the plate was separated by a 1/4". That purdy much nullified the necessity for the PT examination.
Finally had some breathing time, checked my posting and you came through for me. After reading your response, I scrutinized the directions on ZYGLO ZP-9F developer, and lo and behold, it too is rated for both penetrants.
Shop 4man hid my UV PT kit, DoD QA running me around like a ferret on meth...
Been a rough couple of days. Now to write the report on a situation that is messier than a soup sandwich.
Thanks for the help.
John

Would a I&TP have to specify that the dual purpose developer is acceptable?

By Lawrence (*****)

Date 12-09-2011 16:21

I'm not sure about your last question.

I would think if you are obediant to the manufacturers written instructions, there shouldn't be an issue.

However I have seen in-house doccuments for some players that do high level FPI (post emulisified water wash) that had some very specific procedures. They called it level IV and the entire FPI process was timed and moved on a robotic line, with an enclosed dust shaker for developer, rather than aerosol...

Alot depends on the level of sensitivity required when you are putting together developer application procedures.... Usually it's a simple manufacturers admonition to make sure you don't "put it on too thick"

By scrappywelds (***)

Date 12-09-2011 21:58

It is funny that the thickness of the developer can really change the dwell time that much.

By Lawrence (*****)

Date 12-09-2011 23:59

Scrappy,

It's not that the thickness has that big an effect on the dwell time (at least that's not what I was thinking about) :)

It's more that a very light covering of developer, one that falls naturally, rather than painted on with an aerosol can, will help the more sensitive inspections draw out and show small or tight surface flaws.

If a thick coating of developer is applied (especially with FPI) there can be very small defects that are covered or will not bleed out sufficiently to be seen, even with a black light.) If the indication is small enough, all the dwell time in the world won't make it appear if the developer is misapplied.

Now dwell time is important, don't get me wrong... Thats why people smarter than me develop those procedures, with dwell time depending on the amount of sensitivity required, with an eye toward the size of discontinuity that can be accepted... For example; if the inspection criteria calls for a minimum size of 1/8" for defects, it makes little sense to create a procedure sensitive enough to find much smaller indications..

By Superflux (****)

Date 12-10-2011 02:52

LAWRENCE,

I rather doubt those people that develop the procedures are any smarter than you. They just have a lot more time invested in the R&D of the product.
I know I have learned volumes from your posts... actually responses would be more accurate... don't seem to recall you posting too many inquiries.
Anyway, thanks again for the help concerning my particular issue, and all the other info.

Didn't think to take 20 seconds and READ THE CAN!!!!DUHhhhh....

By Lawrence (*****)

Date 12-10-2011 14:48

Thanks for the nice words Superfulx.

Most of the trouble shooting help I give here is born of epic failures on my part. :)

When I started my current job in 2003, I walked into a shop with about 35 power supplies that were at least 15 years old and had about a week to master them all. I milked the forum. I also milked my local Miller rep, Who on SEVERAL occations came a long distance to walk in and flip a swich or push a button, turn around and leave. :)

It happens.

By Shane Feder (****)

Date 12-12-2011 02:10

Hi Superflux,
On the ITP or I&TP you would not need to note it.
What you would need to note is the applicable code and the applicable procedure.
If it is in compliance with the relevant code and the acceptability of your dual purpose developer is noted in your procedure you are good to go.
Regards,
Shane

By Superflux (****)

Date 12-14-2011 08:29

Hi Shane,

Thank you.
The I&TP did not address dual purpose developer specifically. Since it was recommended by the manufacturer on the individual cans, I went for it.
Not prohibited, then it is allowed. Heck, I have used flat white Krylon for developer in an "Information Only" application.