Black Granite vs Black Marble

[Scott Shepherd]

No worries Paul, it's all good It's easy to read the written word so many ways and not seeing that face saying those words, it's often difficult to catch the wink in the eye when it's said.

I've always said that if people were sitting across the table, enjoying a cup of coffee or cold beer, most of the huge disagreements on the internet wouldn't happen, because you'd see the grin on the face or you'd instantly know when you said something out of line and you'd make it right.

I'm sorry for your family situation. Having just lost several people dear to me, all in less than 8 weeks time, I feel for you. It's always a sad thing, but also a happy thing. Happy for them, sad for us. Living through that still sucks, and knowing they are better off, doesn't mean a lot when you just miss them and want them back. So take care of yourself, take care of them, and make sure they know how much you love them.

[Dan Hintz]

I've always said that if people were sitting across the table, enjoying a cup of coffee or cold beer, most of the huge disagreements on the internet wouldn't happen, because you'd see the grin on the face or you'd instantly know when you said something out of line and you'd make it right.

And sometimes there wouldn't be any coffee or beer for others... as I would have bashed the carafe or bottle across their head. Luckily there are few of those around, losing a beer like that approaches a party foul.

[Larry Bratton]

Sorry, hardly any pictures on this computer. The centaur is from a test we were doing with 3cm granite frames for painted 1 cm black veinless marble. This particular one was a tropic brown granite frame made for a 9" x 12" tile if I remember right. The centaur was only 8" x 10" so you can see under her skirt a bit, but it was what was laying around at the time. This particular version of her was a reject piece because of some horizontal banding so the color was added rather quickly just to evaluate whether to continue with the concept. Still, it gives a decent idea I hope.

The lighthouse was a 2' x 3' practice mural for a new person. That's why the pieces were just roughly pushed together for the picture. We did not go any further with this one. Had it been going out the door there would have been some cleanup and then highlighting done and the lines between pieces would have almost not been seen by the time it was set and framed.

Hopefully, with a little imagination, you can even see with small files of these 2 pieces that it is not terribly difficult with a bit of practice and some trial and error. I'm best at the error part.

I cannot for the life of me find any pictures of those revolver pieces on this drive but they really did come out well. Perfect canvases for 2nd amendment statements. You know, the "When guns are outlawed, only outlaws will have guns" with the revolver pointed right at you.

I did find an example of where we used less power on an image than on text so that we didn't blow out the image, but got the best contrast for the text. For whatever reason I can't seem to add it now to this post so I'll just do another post for that in a minute.

Paul :
What did you use for color? Lithichrome?

[Terry Swift]

Thanks all for continuing to share and fill in the many gaps I have when it comes to the Laser Engraving World.

Granite has been a cruel taskmaster for me; although it's the most work I do currently. After all of the trials and tribulations I've been thru trying to reach a good balance between cost of time / materials versus frustration and product results- I may not show granite as much. If the marble works out better; then it could be the new product of choice.

Everyone here has brought much to the table and I've tried many of the suggestions with differing results. I guess I may not have all the details involved in each process; which could be lengthy.

With all that said, here is where I've been and come to in engraving and color filling (metallic silver) granite:

1. Tried using spray enamels to color fill, as I thought this would be the fastest / easiest way to do it and provide an even color throughout.

Result: Enamel didn't dry and would smear. Did provide good coverage and evenness though.

2. Moved to acrylics. Used cheap and pro types.

Result: Acrylic did dry. Clean-up was a long process if no masking (paper type) was used. Lots of alcohol and Q-tips along with Exacto knife for fine lines / details where swabs not practical. Once paint was touched in engraved area - metallic became dull and uneven look.

3. Trying One Shot oil based now.

Result: So far better coloring and less dullness (but still enough there to make piece look off).

I am switching gears once again and going to try the marble to get a hopefully better finish and maybe not even need to color fill as some have posted. Also going to a vinyl mask to again - achieve a better resulting product with less effort to clean up.

I have seen / read about mediums for both acrylic and One Shot that may / may not be an answer to the metallic issue and dulling out. Any ideas on that from those who may have used them. Using non-metallics probably doesn't produce the dullness associated with the metallics; but customers prefer the shiny silver on the black granite / marble effect. Should I use some type of primer / coating on the granite / marble before color filling?

I've included a couple of pictures to show what kind of work I'm doing and the effects of dulling using different paints. Pic 1 is using One Shot. While smaller areas usually do okay - on the larger ones - shading is occuring. Pic 2 is using Liquitex Hard Body Pro Acrylic. Does fine until knicked or touched by alcohol swab.

If your response may be too long (what is that in my world of newbieness); please PM me. Frustration and stress are not a friend of laser engravers.

[Larry Bratton]

Terry,
Maybe this is an oversimplification for you, but I use Winton's Artist Oil paint Titanium White to fill with. Engrave, rub it in with your finger, let it dry (overnight if possible) buff off the excess with a microfiber cloth. You may want to seal with stone sealer. Some recommend sealing before engraving. Looks great and just makes the engraving pop off the rock.

[Terry Swift]

Titanium white is probably easier to use and work out - but my customers want the metallic silver. When I tried white before; it just didn't "pop" like the metallic does. I'm looking for any ideas like I said to make this as easy a process as possible. Especially for future jobs where I might not give them a color choice at all - it's engraved gray / white and that's it. If they pursue a color choice - then charge more as it's extra time on the clock. Sometimes $$$ make decisions for people... LOL

I bought some of the Rub~n~Buff to play with; but haven't had a chance as I had to get this order out and no time to play / test things very much. It's one of those Catch-22 scenarios.

[Larry Bratton]

yes, I understand. I was going to suggest Rub n Buff. I tried that product before but I don't think on stone. It may work fine on stone but best I recall I wasn't too impressed with it on wood.
I have not tried this before but Lithichrome makes a paste mask. It is removable with water. I was thinking you could apply the paste, laser away the design, then use Lithichrome stone paint for your color. They make a silver color but I don't know if it would suit your needs. Just a thought.

[Terry Swift]

Larry,

I've heard about the Lithichrome paint; but not sure about the paste. Lithichrome is hard to find - at least when I was looking for it. I think I found one supplier on the Internet.

[Larry Bratton]

Terry,
I bought some paint from these people. Had an excellent price, shipped it right out, got it like the next day. Your in Texas, probably take a couple of days for you.
http://www.granitesalesandsupply.com/
The paste is called Litho Masking Paste

[Paul Perkinson]

Terry - I did a fairly long post (I know...hard to believe) on lithichrome once before, but here is the gist of my opinion.

Best stuff available for harsh outdoor climates - including those rare, sunny, high-ultraviolet days we get in Florida as well as freeze/thaw conditions some of our customers in South Dakota, Idaho, etc experience.

Unless you are applying way too thickly at once, it dries almost immediately, but still needs to "cure" for about 24 hours to toughen up.

Once cured, we have just about caused heart attacks for fabricators and customers by scrubbing over it as hard as we can with a shop rag and stone cleaner. It isn't fazed (so long as it was applied properly to begin with).

We use a very expensive and hard to find (Harbor Freight - I think it was $9.99) sprayer for application. We really do have some artist quality air brushes, but the lithichrome almost seems to prefer the cheaper tool. The cheaper one holds lots more paint and it is far easier to clean. The air brush in first attached picture is NOT the cheapo we use now. Lithichrome isn't all that finicky about exact pressure or mixture settings which is good.

No special application methods - use like any spray paint. Comes in cans too, but WAY more expensive. One small difference I guess is that we apply 2 or 3 VERY light coats before continuing as normal. We sometimes (but rarely) thin those first coats way down too, which is what manufacturer recommends. You may be able to see how light the coat is on the photo showing the stone being painted. BTW - that painter (who happens to be my son) as well as everyone else does use a mask while painting. The air brush had gotten clogged and he had spent a while cleaning it out so he could continue (told you the expensive air brushes aren't as good for this!). We decided it would be a good time to get a "candid" photo and did without the mask only for the moment the picture was snapped and before any actual painting started up again. The very light initial coats dry in less than a minute and ensure we never have an issue removing the mask. Finished picture shows the gold lithichrome on Black Galaxy granite (nice combination) - two 3cm pieces laminated after the top one was beveled and both were edge-polished.

The small black letters on the next photo were a bit less than 3/8" tall. That is a real challenge. You must get a bit of depth into the stone with the laser for small items or the lithichrome may not permanently adhere to the stone in some places. It varies somewhat with intricacy of font and such, but we want to be at least in the ballpark of 0.03" (about 3/4 mm) for smaller stuff. Doesn't sound like much but some stone components act like the CO2's wavelength is just tickling them.

If the stone has small crystals (usually things such as mica, but sometimes even small, loosely-held pieces of quartz) that may become dislodged here and there, GOOD LUCK! We have tried sealers, clear paints, adhesives that dry clear, and a good number of other things to try to "lock" those pieces to the main portion of the stone. We've been lucky a few times and the pieces are still holding together, but the exact same processes and materials tried again later do not necessarily give the same results. Beginning any time after lasering the message/image, small crystals in the stone that the lithichrome becomes bonded to desert the mother ship, taking the lithichrome with them. In as little as a few hours to as long as a few months there will be very unsightly gaps in the lettering/logo/whatever. Hopefully the one attachment will show up enough that you can see that on some of the letters - maybe the "s" and "e" in Bullnose show it best?

The other pictures show a 20" x 40" x 2cm piece of white Thassos marble with black lithichrome before and after the bronze reliefs (sculptor shown in that photo) were added. We got to make that one twice because the first one didn't take too kindly to a university maintenance guy dropping it from about 4 feet. Point of this one is really just to show that marble does fine with it too. As a matter of fact, we just did another marble piece about 24" x 24" x 3cm last week if I can find a picture of it. Yep, it's added. Now I just don't know if I've exceeded an upload limit.

Summary: Dries fast - very good in ways, but no chance of blending colors. Wears better than iron. Limited (but adequate for us) number of colors available. Get the lithichrome solvent for thinning and final cleaning of tools. Can be used as a great selling tool against competition that uses other types of paint because this is specially formulated stone "stain". Even a decent knowledge of it raises your perceived expertise if you happen to be relatively new to the work. Like Larry, we purchase through Granite City Tools - don't know of another dealer, but may be one. They've always treated us right. Consider using clear lithichrome as a clear coat as recommended by manufacturer, but there are certain times we don't. It is a restricted substance as far as allowable delivery methods so allow a little extra time to get it.

This may not do you any good because we've never used the paste so I can't help you there, but hope this gives a bit of a feel for lithichrome in general. I did post pictures!!!

[Paul Perkinson]

Ok - I knew it! Overdid it again and the first 6 pictures didn't make it. That's ok. I'm patient. I'll keep tryin'.

[Larry Bratton]

Paul:
Correction - my vendor for Lithichrome is Granite Sales and Supply in Elberton, Ga.,not Granite City Tool. Their prices are much better than Granite City Tool. Plus, they are much closer to you.

[Paul Perkinson]

Hey, THANKS, Larry. Saw "granite" in the name you listed and the old steel trap mind filled in the rest as it saw fit. That's great. I really appreciate it!

[Larry Bratton]

Paul:
I have limited experience with them, but they were spot on with the paint I bought from them. I ordered it one day and had it the next day. I forget exact price for what I got, but it was a lot cheaper than GCT. You know Elberton Ga area is a big granite producing area, especially the grey Georgia granite used in monuments.

[Terry Swift]

Paul,

Thanks so much for the info. I've tried contacting Granite Sales and Supply for pricing, etc. - but have not heard back from them. They are located somewhat close to my original hometown outside of Atlanta; but far enough away to be in the boonies. Having to get via UPS Ground is okay, as that is how I get most of my stuff anyway. Can't afford 2 Day or Overnight usually; as it doubles and triples my shipping costs.

I bought my air brush and mini compressor from Harbor Freight of Northern - can't remember; but it's not some $100 or more pro model. Don't need that kind of painting yet.

I think GSS only had a paste type of mask; so not sure of what other product you may be using. I'll check out Granite City and see.

Not to slam the monument people; but those I've tried contacting - even those not within a few hundred miles of me - were not responsive to inquiries about lithichrome or doing larger pieces of granite - as I had a customer who was looking for a 36" circle to be engraved with a Police SWAT Logo. Unfortunately I have found some of the same resistance in our lasering community as well; but guess that's just people and signs of the times. You would think if I was offering the business in this economy and climate - they would be interested. Possibly they don't read their emails (why have it then posted on your website, etc.) and phone contact is the only way.

Many, many thanks and your work looks awesome.