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Pigment Colors for Printing Your Surface

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Titanium
Joined
Aug 8, 2007
Location
Greendale,WI
Back in the day, well before my time lamp black and red lead were used. I will be honest I have no clue what, where you got this. I guess it was not the best for your health so it was banned by the govt. Then once companies ran out of their supply others things were turned to. This recipe was given to me from the ex Mattison guys who were still scraping. The paint pigment is a powder and you mix it with way oil until it is a very thick past.

You put black on your master and orange on the surface you will be scraping. If done correct with just the right amount it shows up great.

I just use a rag that is tied in a knot to apply. I mix the pigment in tin the size of like a car was tin.

This week we will be scraping my big mattison, I will post some pics then of how it looks.
 

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I use either paint thinner or dykem. but normally I go towards dykem due to its intoxicating scent.......

Some people cant stand the small or it on their hands.

But best to use the medical gloves to apply.
 
Around here it seems most scrapers mix their own from powdered prussian blue and oil or grease. I've done it too, but prefer ordering in dykem hispot. Hispot is great for spindle bearings but for flat stuff I use the Dapra pigments now, a little less intense in color but they actually wash off my hands.
 
Neither lamp black nor red lead pigment are "banned by the government".
You can still buy both of em
Lamp Black Pigment - Natural Pigments
Minium (Red Lead) - Natural Pigments

what is frowned upon by the government is exposing your employees to toxic materials- OSHA doesnt like that.
So if you were going to be regularly having your employees use red lead, you would probably need a pretty intense set of safety procedures.

But its perfectly legal to buy it, and use it.
Commercially disposing of it might be expensive, though.
 
The red pigment - iron oxide - is an abrasive used in glass shops to polish windshields. I don't reccommend it unless you're willing to frequently re-scape and calibrate your reference tooling. Rub out a film on the work and you'll see the red color soon gets muddy with abraded cast iron. Red iron oxide is a very effective lapping compound.

You can get red lead pigment from suppliers in sample amounts make a cake large enough to scrape in a Panama Canal lock gate. If you do use red oxide, spread it with an ink roller (caled a "breyer" in the printing trade for some reason).

A word about rollers Vs daubers. Daubers (rolled beltng, leather pads, fabric knots, stencil brushes, etc) are time wasters. Draw from your own experience and compare with this: I can ink a 3 ft x 4 ft surface plate from scrach in about 40 seconds (my students have seen me do it) and it leaves no crumbs, fuzz, or threads to screw up the print. And at the end of the day my wrists and finger joints don't ache with the swirling motion needed to produce a thin uniform film.

Breyers (ink rollers) are available from most any art supply store along with a wide selection of dry powder paint pigment and intaglio inks specially formulated to stay put in a humungous array of colors.

If you insist on old school. here's a seller of dry red lead pigment. They might offer samples.

Lead Powder,White Lead Powder Manufacturer,Red Lead Powder Suppliers from India

One reason why red lead was so popular is the stuiff is more of a solid lunricant. It also has a vivid color and spreads to very thin films. The grains are very soft and smoosh without abrading. It is toxic but it's also the best ever for a scraping contrast medium. Don't lick your fingers. Keep it off your sandwiches.

I always bought my pigments and breyers from Mister Art but a large local art supply will have what you need.

Here's a website for the rollers:

Speedball Rubber Brayer | MisterArt.com

I don't know what you have for black. If it's carbon or graphie, fine, but it's a bugger to mix. Chances are it's manganese dioxide and other stuff. Manganese dioxide is also abrasive but not as aggressive as iorn oxide.

Have you looked at the Canode line sold by Dapra Corp:

Power Scraping Accessories & Aids | DAPRA

Here's something I wrote a few years ago pertaining to spreading blue:

One can with care and a little math predetermine film thickness of scraping media by deliberate control of the blue to be spread:

Starting from a clean surface plate, use a hard rubber printer's roller (breyer) to spread the blue. Calculate the area of the surface plate and multiply by 20 millionths. For example: 18" x 24" = 432 sq inches x 0.000020" = 0.0086 cu inch. A nerdle (official term for a blob of any kind of paste or gel issued from a tube) of Prussian blue if stretched a bit as its squeezed from the tube is 1/8' dia. If your eye needs a little help, use a short length of 1/8 wire for visual comparison. 1/8" dia = 0.016 sq inch. 0.0086 cu inch / 0.016 sq inch = 0.54"

Therefore a 1/8" dia nerdle of Prussian blue a bit more then 1/2" long uniformly spread over an 18" x 24" plate will results in a 0.000020" thick film of blue (starting from a clean plate) and counting the area of the roller. When spreading the blue, roll briskly, lifting the breyer at the end of each stroke so it spins to randomize the blue spots it lays down.

This film thickness imparts a strong but transparent blue color. If you keep this color in mind, you can refresh the blue several times before the thickness starts to drift. BTW, 20 millionths thickness is best suited for finishing; it's too thin for initial scraping prints. Use 40 - 60 millionths for general rough scraping. .

Metricoids: there's about 40 millionths of an inch to a micron or 0.001 mm.

Do not use a dauber. It takes up varying amounts of blue making rough quantifying the film thickness almost impossible. Use a rubber printer's roller (NOT a foam one) as it is non-absorbent and its small area has little effect on the film thickness on the much larger plate area.

Do not use your fingers to spread blue, the vigorous rubbing necessary puts heat in the plate and the circular motion is hell on your finger joints.

I noticed discussion of alcohol as a "hazing" agent used with a clean (unblued) flatness reference. I don't recommend alcohol. or any cleaner with a high heat of evaporation. When it evaporates it carrys away significant heat contracting the face it wetted. While the haze it leaves behind is easily visualized and very thin, it comes at the price of having to wait a few hours for thermal equilibrium to wend its slow way through-out the mass of the scraped workpiece before a print can be taken. Instead I recommend a fast rub with the heel of your hand to leave a thin coat of skin grease. If done with a rapid wiping motion problems from heat input are reduced to nearly zero, and the haze seen in grazing light is as visible as the alcohol haze. Us older farts may have dry hands deficient in skin grease. If that's the case, use the inside of your forearm being careful of shedding arm hair.

When you look at the printed surface in grazing light you see the haze dulling the flash and sparkle of the scraped surface. Scattered in the haze are little bright pinpoints indicating the bearing points. Tracking down and scraping these points is a truly heroic task requiring immense patience and persistence; the process is called "pinpointing" (surprise). The result of pinpointing when carried to its logical conclusion with excruciating temperature control is a scraped surface in conformance to its master reference surface within small millionths.

I encourage any advanced scraping beginner to go through this pin-pointing ordeal at least once as a rite of passage. Having done it once, there is seldom a need to do it again unless you are re-scraping precision gaging equipment like the bed of a Pratt and Whitney Super Mike. Scraping references and high end machine tools are not improved in perceivable accuracy or longevity by such refinements and they represent a significant waste of time when employed on general purpose machine tools
 
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That red iron oxide is definitely a fine abrasive, it also known as polishing rouge and it's one of the best for polishing glass by hand, it's what the reddish brown bars of buffing compound are made from. Texereau's book "How to make a Telescope" has several pages on how to calcine it in a cast iron frypan over a gas flame and then sort and grade the particles in a bucket of water to get the finer grit for final polishing of glass surfaces.

Another good source of rubber rollers suitable for brayers is from dead photocopiers, they have many wide hard rubber rollers of various diameters and a larger diameter silicone based roller in the fuser unit. Usually the older larger non digital units have thick diameter rollers.
 
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Lots of good info here. Lots of what I know I have learned from others.

I never would have thought the red oxide would be abrasive. So far I have not seen and sign of this. And this involves pulling a 20,000 lb table along a bed to get a print.

For me if shows up very well to see where you need to scrap. Sometimes on the bed due to lighting it can be tough to pick out the high spots since you can position it at the angle you want to.

The black really shows up.

I will give some of the dapra stuff a shot.
 
I once talked with a doctor of chemistry about pigments. That's what his interest is, as he has a shop for pigments (Kremer Pigmente).
The iron oxide pigments are needle shaped and bigger (I forgot the number) than Prussian blue. Prussian blue pigments are about 1 µm in size and ball shaped.

Nick
 
Guys,

give Kremer Pigmente's website a look: the amount of pigments you'll find there is simply astonishing. They have a very nice blue (Milori) which is I believe the equivalent of true Prussian blue. They also have red lead, even if purchase of the latter is somewhat difficult due to safety regulations.
Has anybody got a name for Canode's shade of yellow?
 
Red Oxide.jpgBlack.jpgPrint.jpg

We can all debate what is the best pigment/color to use. Or if it is a bit abrasive.

But I think you will be hard pressed to find something that prints better than this.

The first photo is the black on the base. Then the second is the red oxide. Last shows how the black transfers.

This was just our first print after gluing a new strip of turcite on my back vee way. But it gives you an idea of how easy it is to see.

We pushed the table about 6" to get this print.
 
Yes-the bed is pretty much now done. We may do a bit more touch up but it may just be one pass scraping. Once we get the table straight we may use it as a straight edge to check the base.
 
For those who are interested in using lamp black as one of their contrast agents, it is commonly used as a coloring agent added to concrete. It is very inexpensive and usually stocked as a dry powder in about a one quart bag. Most concrete mixing plants will have it. In dry form it is messy stuff as it is so light weight it wants to puff out of the bag at the slightest provocation.

Any favorite recipes for mixing red lead---what grease or oil do people prefer? I can imagine mixing it until it is of a consistency similar to Hi-Spot. Or should it be thicker or thinner than that for best results? I have some coming in a few days----100gms for 18 dollars shipped.

Denis
 
I used to experiment with scraping pigments. I used a putty knife on a hard mineral surface like a ceramic tile and a puttly knife. For vehicle I used soft short fiber bearing grease about the consistancy of soft butter or hair gel.

I mixed pigment in a little at a time sliding, spreading, scraping up, and folding until I got a toothpase coinsistancy. Red lead is easy. Carbon black is a PITA. You'll get sore wrists by the time you mix up a smooth batch of soft paste black. Don't substitute oil if you want a gel or paste consistancy, It will smear like hell.

If you want a cake (maskara or shoe polish) consistancy, same deal: less grease (or oil) more pigment. It can be labor intensive.
 
Thanks for the info, Forrest. Of course, the first thing that came to mind is "Using a grease with fibers in it for a spotting agent?!" So, I tried to cure my ignorance and found this informative thread http://www.practicalmachinist.com/vb/general/fiber-based-grease-171568/

Now I know that the "fiber" really is just a descriptive term for the appearance of the grease which has no true fibers but just looks that way. Makes sense.

Denis
 








 
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