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Hello. I want to sandblast wirh finw details polished marble/granite with laser cuttable sandblast mask. What matterial can i use for mask? The matterial must not produce toxic-corrosive fumes must peel off easily from marble-granite after sandblasting. Do you know something for this ?
Not quite enough info to give you a complete answer but I can give you some general info. Since marble and granite are very different in terms of hardness you won't get similar results with the same image/text with the same stencil material. Also - saying you want "fine details" is very ambiguous. You also need to consider the depth you want to engrave. The max depth you can engrave a nice "V" groove is approximately the same as the width of the opening in the stencil. eg. A 1/16" wide line will only engrave 1/16" deep. You can go deeper than that with thicker/wider lines but the results are difficult to keep consistent and you won't get a nice "V" shape. You also want different adhesion properties for different finishes on the substrate; highly polished granite or marble would require low tack and flame polished or matte finish would require high tack. I have used tons (literally!) of Anchor 113 on granite and could get as deep as I ever wanted to go with it. You won't get text smaller than about 12-14 points though, that's too small to cut and weed. For highly polished substrates I used Anchor 226 or 227. I have also used various laser tape materials and they get give better detail but can't stand up to much blasting time so you are limited to surface etching granite or very shallow marble - same with UV stencil. Lastly - your sandblast equipment will also dictate what you can use. If you are using a pressure pot then you can dial down the pressure and feed to be low enough to do fine work with thin stencil, if you have a siphon feed system then you lose most of the control and really can't expect to do fine quality work.
So to get better answers give some more detail - fonts, size, depth requirements, equipment, etc.
Quote:
Originally Posted by Alex Tzoulis
I want to sandblast polished (high deegre of polishing/10000 grit) marble & granite for letters about 10mm letter height a simple font like arial bold.
I don't want very high depth only a little just enough for color to stick good and make good contrast.
Something like this
https://www.youtube.com/watch?v=ZRCQ5XnhUYo
What is this tape material ?
I have big air compressor and i can get the required sandblast machines (they are cheap)
I always use Anchor 153, a medium tac rubber on clear backing, medium adhesive. It can stand up to granite and be laser cut. You would also need transfer tape to apply it smoothly.
Ikonics Imaging sells a laser cut sand carving mask.
If all you are doing is paint fill then you could use laser tape on the marble but not likely on the granite. That video is stencil material like the Anchor product I mentioned, definitely not tape. Having a large compressor is great but the sandblast equipment is where the "magic" happens. A good pressure pot and the right nozzle for the job will mean the difference between a bad result and a great result. I used Harbor Fright pressure pots but made a lot of modifications to them and NEVER used their nozzles (they are complete junk). I had a 20# for glass and fine work and a 110# for heavy duty blasting. Oh, and don't forget the proper media - 1. Never use silica sand! 2. Aluminum oxide works great and the static shocks will keep you awake.
Quote:
Originally Posted by Alex Tzoulis
I want consumables from europe.
It is difficult to buy from US due to customs..
is not the customs taxes but needs complicated paperwork at customs to import items and this paperwork costs much more than taxes.
What grit aluminum oxide to use for marble/granite for sandblasting letters ?Quote:
Originally Posted by Gary Hair
This machine will work https://www.bormanntools.com/portfolio-items/bwr5065/ ?
What nozzle must use ? 3mm ceramic is ok ? what modifications needs the previous machine ?
I used 80 grit for deep engraving and 120 or 180 for surface etching. That sandblaster looks a lot like the Harbor Freight one that I used so it should be fine. A ceramic nozzle will wear very quickly and you will be changing them very often, a boron carbide nozzle will last a long time. They are not cheap but they will save you money in the long run. The modifications are too detailed to list here, most of there were learned from a sandblasting forum that is no longer in existence. It would be best to start with a good nozzle and then as you work with it make any changes necessary to improve media flow, reduce clogs, etc. Get lots of practice pieces of granite, marble, stone, etc., and take your time to learn how to get the results you desire. There may be some videos on youtube that may help but I haven't looked for any in years.
Quote:
Originally Posted by Alex Tzoulis
Quote:
Originally Posted by Gary Hair
I got a machine like this 44liters capacity
https://www.directmarket.gr/ebossima...DF18888947.jpg
A standard chinese cheap sandblaster with ceramic nozzles..
What diameter boron carbide nozzles you suggest for granite sandblasting?
What sand/grit is better for granite? aluminum oxides or silicon carbide ?
How many liters/power air compressor this sandblaster needs ?
Can you suggest me some modification that improve the operation ?
The nozzle size will be determined by a few factors - grit size, detail of the engraving, and most importantly, the cfm your compress puts out - continuous free cfm, not "rated" cfm. The 5hp, 10cfm, 60 gal, compressors at places like Home Depot are really not adequate for anything besides very light etching of glass and small text and detail work on soft stone. For granite and most harder stone I used a 3/32 nozzle for small text and detail work and either a 5/32 or 3/16 for large work. I had a 40hp diesel powered rotary screw compressor that put out 125 cfm at 100 psi so I could very easily run the 3/16 with no loss in pressure. A rotary screw compressor typically puts out so much air that they don't have a holding tank. The minimum compressor to run even the 3/32 nozzle would be something that puts out 25 cfm and has a 90 gallon tank, but even that will run quite a bit to keep up. Quite often I used green diamond for granite, it isn't as hard as either AO or SC but it's cheap - $15 for a 90lb bag. If I was onsite blasting and couldn't contain the media for reuse then I would always use green diamond, that or the customer would have to pay for the media as an extra charge. AO works well but creates a lot of static electricity so either you ground yourself or it will shock you often! SC is better because as it breaks down it retains the sharp edges that do the cutting where the edges on AO round off as it breaks down - SC is more expensive initially but you can reuse it more because of this. Whatever you do, do NOT use silica sand, playground sand, it releases silica dust and you risk the very real possibility of silicosis - google that for more info.
As for upgrades - the hose and nozzle that come with them are junk and 99% unusable. The only time I used the deadman nozzles was on a couple of very large jobs where I needed 1/4" nozzles and didn't want to rebuild the one I normally used to take the larger nozzle. I have attached a picture of a nozzle similar to what I used. You'll have to go to a hydraulic supply shop and have them help you put together the various fittings, make sure you get a good quality hose, they will wear so keep an eye on it for soft spots indicating a wear point.
The other upgrade was fitting a piece of copper tubing in the media outlet of the pressure pot to make the media flow better. I attached a rough drawing so hopefully this will make sense. I cut a piece of 1/2" copper pipe to about 6" long and drilled a lot of 1/8" holes in it. I fit this into the top of the mixer that screws into the bottom of the pressure pot. This made it so that instead of the single hole in the mixer for media to flow from the pot, you now have dozens of holes - this reduces the potential to clog when media doesn't flow perfectly for some reason.
Quote:
Originally Posted by Alex Tzoulis
My sandblaster takes these type nozzles https://www.aliexpress.com/item/10000084079030.html
What shape boron carbide nozzle can i get ?
First - get rid of that deadman setup, it's garbage! Second - you won't find a boron nozzle for that setup, it is garbage.Quote:
Originally Posted by Alex Tzoulis