The title says it. Like split rims, babbitt thrust washers, and clinchers, this is one of those terms that's used a lot but not everybody has experienced first hand. So who's going to tell what it is and how it's used?
Gosh Steve, I thought everyone knew what it is for. It's for blueing in bearings, or anything else you want to check the fit on. It comes in a tube, and is made by Permatex.
It is a very thick ink.. It is used for tight fitting of parts. Machinists use it often. It will sow where the parts are not touching by still being blue. If the parts touch together the ink will wipe away. In putting a gear set in you will see the contact patern on the mating gears.
Just blue oil paint, you have to have it in the shop. Messy and will blue your fingers for real!
Nice to use on 'Z' head chambers to see where the piston bumps the chamber top
Actually the most common use of Prussian blue is a pigment in painting:
http://en.wikipedia.org/wiki/Prussian_blue
In machine work:
Aids precision-fitting of machined surfaces. Locates high spots on bearings, valves, gears and other close-to-tolerance components. Nondrying. Easy clean-up.
Suggested Applications: Bearings, valves, gears, other close tolerance or machined assemblies
http://en.wikipedia.org/wiki/Engineer%27s_blue
Babbitt scraping:
http://www.smokstak.com/articles/babbitt.html
Jim
Another great use is to put a small dab on the hand crank handle of a lathe or milling machine.
The operator will get it on his hand then scratch his nose or ear....well you get the idea.
Has also been used on the door handle of a car or lunch box handle.
Great sport!
Bob I was just going to write that it was BANNED in our shop because of that same reason. One day our boss walked around the shop with a freshly blued hand from the handle on the lathe.. It was meant for someone else. :-)
I've seen grease on a car door handles and various hand tools, a glob of hand cleaner in the earpiece of the telephone. The worst and actually dangerous, was gun grease on windshield wiper blades. I'm glad we didn't have Prussian Blue in the shop. Boys will be boys.
Jerry...spoil sports!
Won't let ya have fun any more.
Not suprised, Bob one more reason not to trust you. you are trouble! bet you have been banned from having that stuff at your house too. Steve! I will blame you if all our club T's get blued by this prankster
Back in the day;;;;Almost every machine shop around here had a 4 Oz can of red lead for center hole lube. Worked good for bearing scraping.
Sincerely
Jim Weir
I've used it on heads & intake manifolds. Coat the mating surfaces. When dry mount the intake gasket and trace the openings in the gasket onto the head & manifold with an awl. Leaves a crisp outline in the metal for porting. Worked with a wielder that used to pull a similar prank but he used the carbon that formed on the gas torch head. A friendly pat on the cheek left you tiger striped.
Dapra sells a nice water based version that is easy to clean up, like off your hands, and comes in other colors, like RED.
http://www.dapra.com/biax/scrapers/accessories.htm
Don't forget the eyepieces on binoculars, microscopes, etc. headbands in hard hats, welding helmets. DO NOT let them see you doing it however.
It really is the best thing for finding fitment issues between metal parts. Also used to help inleting metal parts into wood such as gun stocks to see where wood needs to be removed.
I think a work / blueing party at Mikes house.
Ahhhh......good ole bearing blue......
I'm giggling as I type
I'm glad to see the USA machinist/pranksters are just like us Canadian machinists/pranksters
Lipstick works too better for gun stocks
Good point Don. Makes the wife mad I bet. Where do you find blue lipstick? Just kidding.
If your lips are blue you might be choking!
Herb
It may be easier to explain blue on your collar than lipstick <@^@>
Hey Mike...I have a tube of it!
I ran out one night and used a wide felt tip pen to color the bearing surface instead. It works just fine and is not as messy.
I use layout fluid. It doesn't smear. It just takes a minute or two to dry before you can use it.
Steve -- To answer your original question, the most common use for it in the Model T world is to fit babbitt bearings. Rub a very thin coat of the stuff on the crankshaft journals (one at a time) and test fit the main bearing or rod bearing to the journal. The blue spots on the babbitt will tell you where you need to scrape the bearings. Continue fitting and scraping the high spots until you have blue on most of the bearing.
If you can't find it at an auto parts store, Hobby Lobby has it as a painting supply, as alluded to by Jim Thode above.
Here is some being used to refit a lathe cross slide by scraping. It it is at all thick, it won't mark like this.
http://img.photobucket.com/albums/v337/johnoder/Monarch/DCP_0290.jpg
Make that first "it" an "IF"
Way back in the day before everybody became so litigious and OSHA started meddling in our lives horseplay sometimes got a little rambunctious. If a guy showed up at work on his wedding day he'd likely go home wearing a liberal coat of Prussian blue on his "honeymoon equipment." My wedding day was a Saturday, a day off, but just to be safe I called in sick on Friday. That stuff is real hard to wash off.
Steve,
it can also be used by "proper" panelbeaters or "bodyshop people" or whatever you call them in the US when identifing high spots when hand filing, finishing panelwork etc, obviously when RESTORING cars, not the modern replace or bog brigade.
Bede
OT, I've always thought of Prussian Blue as an East German, like a little kid, holding his breath a long time because he didn't get his way.
My great grandparents left Prussia in 1870. They came from the western part, near Cologne.
from wiki:
Prussia (blue), at its peak, the leading state of the German Empire
Coincidence, or a sense of humor?
Which is more difficult to keep off your fingers while using : Never-seeze or Prussian blue ?
Blue nitrile gloves at 8 cents each do it for me.