Granite sandblasting technique

[oneearthjc]

So, I tried sandblasting some letters into a piece of granite for the first time and it was a total fail. When I bought my new plotter I asked which vinyl I should use and the representative told me Oracle 951 would do the trick. When I started blasting the vinyl disintegrated. Is it the vinyl or my technique. I would appreciate any help. Maybe a "how-to" link? Thanks!

 

[VTSigns]

So, I tried sandblasting some letters into a piece of granite for the first time and it was a total fail. When I bought my new plotter I asked which vinyl I should use and the representative told me Oracle 951 would do the trick. When I started blasting the vinyl disintegrated. Is it the vinyl or my technique. I would appreciate any help. Maybe a "how-to" link? Thanks!

You are going to need to use a rubber sandblast material.

http://hartcoservice.com/sandmask/

 

[equippaint]

You should use sandblast mask

 

[oneearthjc]

thanks, will I need to use a filler? I've seen in used in some videos. What is the best abrasive to use? Most of my work will be done outdoors.

 

[Gino]

Using that vinyl is more for etching glass or mirrors. You need rubber mask for stone or wood, which generally needs a sprocket fed plotter. Some of the newer ones can do it, but I don't know which.

 

[equippaint]

thanks, will I need to use a filler? I've seen in used in some videos. What is the best abrasive to use? Most of my work will be done outdoors.

Depends on whats available in your area. Sand, garnet, starblast

 

[oneearthjc]

What is most most effective? What's the best "bang-for-your-buck?"

 

[James Burke]

Stone engraving is our only business, and we use Aluminum Oxide in our indoor blast cabinet, and Starblast (staurolite) in our outdoor booth. We do everything from paver bricks to boulders to granite monuments.

I don't fly by the "bang-for-your-buck" theory. Time costs a whole lot more than abrasive ever will, and you'd be absolutely amazed how much better (and faster) a high-quality abrasive works.

For onsite boulder jobs where abrasive recovery is nearly impossible, we use expendable flintshot silica. Silica isn't the sharpest abrasive, so we've had to modify our pressure pot to generate a higher velocity.

By now, I hope you've become educated with the dangers of using silica. Like any other hazardous material used in industry, it can be used in a safe, responsible manner if you take proper precautions.

JB

 

[Sandman]

I've been sandblasting for over 20 years. Rocks, wood, HDU, glass, & ceramics. Listen to what James Burke said. He's right on the money, and don't underestimate the dangers of silica. You absolutely have to blast with a fresh air supplied hood for silica and not be too close to any building either. As far as sandblast mask, there are three main companies. Some swear by Hartco but I never liked it. I've always had terrific results with Anchor and I've only owned Roland friction feed plotters so if that's what you have don't worry, it will work. Experiment with blade force Anchor makes a hich tack (good for stone and raw wood) and medium tack (pre-painted wood). I had great results at 240 grams of down force at 15 cm/s feed rate.

 

[decalman]

Good information. This isn't my area but enjoyed learning about this.

 

[rjssigns]

If it's not your main line of business do what I do. I cut the mask and bring it to the monument place down the street. They ask how deep, texture etc...next day I pick up the finished work. Best part is they get to deal with the specialized equipment and mess.

 

[oneearthjc]

Stone engraving is our only business, and we use Aluminum Oxide in our indoor blast cabinet, and Starblast (staurolite) in our outdoor booth. We do everything from paver bricks to boulders to granite monuments.

I don't fly by the "bang-for-your-buck" theory. Time costs a whole lot more than abrasive ever will, and you'd be absolutely amazed how much better (and faster) a high-quality abrasive works.

For onsite boulder jobs where abrasive recovery is nearly impossible, we use expendable flintshot silica. Silica isn't the sharpest abrasive, so we've had to modify our pressure pot to generate a higher velocity.

By now, I hope you've become educated with the dangers of using silica. Like any other hazardous material used in industry, it can be used in a safe, responsible manner if you take proper precautions.

JB

Thanks for the advice! JB, Sandman, and others.
When I said "bang-for-your-buck" I didn't mean cheapest. I meant most effective in regards to quality and time spent, so I will follow your advise.
Another question I have is what should my pressure be set at? The pressure pot I have has a max of 120psi.

 

[oneearthjc]

Also, do I need a special blade for cutting the Anchor sandblast mask, or can I use the one that came with my Graphtec CE6000-60 Plus?

 

[equippaint]

Thanks for the advice! JB, Sandman, and others.
When I said "bang-for-your-buck" I didn't mean cheapest. I meant most effective in regards to quality and time spent, so I will follow your advise.
Another question I have is what should my pressure be set at? The pressure pot I have has a max of 120psi.

You measure blast pressure at the tip and can guarantee that you are not getting 120psi unless you have a pencil tip. Volume is what you need and the tip needs to match the volume. Typically Id say 90-100psi would be blast pressure when its set right.
We run a #8 nozzle with a 375cfm and a #6 with a 200cfm, there are charts to determine this.

 

[oneearthjc]

If it's not your main line of business do what I do. I cut the mask and bring it to the monument place down the street. They ask how deep, texture etc...next day I pick up the finished work. Best part is they get to deal with the specialized equipment and mess.

Although I am new to all of this, the focus of my business will be sandblasting into stone. Originally I called 3 different monument companies and each told me 6-7 weeks before they could get to my project.

 

[JimmyG]

Also, do I need a special blade for cutting the Anchor sandblast mask, or can I use the one that came with my Graphtec CE6000-60 Plus?

I use the heavy duty blade holder red tipped (PHP33-CB15N-HS) with the thicker shaft 1.5mm 60 degree CB15U-K30 blade for small lettering and the 45 degree CB15U-K45 blade for large lettering with my CE3000 Graphtec.
I also set up stencil "feed tables" on both front and back of the plotter that are level to the plotter platen. This takes the weight load of the rubber stencil off of the plotter feed rollers and will cut the layout much easier without any drifting. I use near maximum down force and slow the speed to minimum... A sample run will give you your best settings quickly.
Do your research when buying the blades, some suppliers really over price them...

 

[James Burke]

We're using a Gerber GS plotter with a 60 degree blade for cutting our monument stencil. A tangential cutter is critical, especially for flourishes and fine-detail artwork

I started 13 years ago with zero stone engraving experience and learned by trial and error...mostly error. I had ten years of graphic design and nearly twenty years of tool and die experience, and that has been a major contributor to where we are today.

You'll find out real quickly that any technical help from monument companies will be non existent. Typically, any responses you do get will be borderline hostile if they do decide to talk to you. The barriers to entry are extremely high, with technical training and equipment costs being the two main factors.

Out east (Barre, VT) , and down south (Elberton, GA) are the stone "Meccas" of the USA, and plentiful opportunities exist there for a newbie. Some vocational schools even offer stone working classes.

You can either spend time, or you can spend money learning the trade, it's up to you. With the right assistance, you can literally save thousands of hours of making mistakes. Ron Clamp from Memorial Design offers a two-day monument sandblasting course in South Carolina. It would be helpful to consider this, but two days is hardly enough time to get all your questions ironed out. Ron specializes in training memorialists how to artistically sandblast shape-carve stone, but he also offers basic stone engraving education as well.

Here's his information: https://www.memorialdesign.com/monumental-sandblast-shape-carve-training

 

[d fleming]

I blast granite tiles for our local Am Legion Hall Memorial Wall. I use iron oxide (80 grit) and a cheap pin gun from harbor freight. I have a very old blast box. I use a double layer of cheap, old, calendered vinyl cut on my graphtec. Ocassionally for very special charity events I have produced some plaques of granite blasted, painted, then trimmed in wood and stained. The attached pic has a digital print as well at top. For these simple etching projects my set up works. Anything more involved than that I would send out.

 

[oneearthjc]

I use the heavy duty blade holder red tipped (PHP33-CB15N-HS) with the thicker shaft 1.5mm 60 degree CB15U-K30 blade for small lettering and the 45 degree CB15U-K45 blade for large lettering with my CE3000 Graphtec.
I also set up stencil "feed tables" on both front and back of the plotter that are level to the plotter platen. This takes the weight load of the rubber stencil off of the plotter feed rollers and will cut the layout much easier without any drifting. I use near maximum down force and slow the speed to minimum... A sample run will give you your best settings quickly.
Do your research when buying the blades, some suppliers really over price them...

Thanks for the advice JimmyG! Good info.

 

[Pitzu]

For sandblast mask you can also try Oramask 831 and 832 film from Orafol, that are specially designed for sandblasting.

Love these sandblasted & illuminated artwork