Anyone know how to engrave on a BRICK ?

[David Iannone]

I had one of my wholesale customers hand me this brick and ask me if I can do this. It is another sign shop in my area who needs this service.

I don't know anything about engraving bricks, but would it be possible on the Bot? Of course need the correct masonry bit? would it be scratch engrave, or rotary?

If not how do they do it? Mask it and sandblast it? Waterjet? Laser?

If its something I can't do, but someone else here on the forum has the equipment that can, I would would send him your info.

Thanks,
Dave

[maverickx50]

Yuppers I work part time at a granite monument company. We do bricks for vet memorials every week it seems. All are done by cutting a sticky back vinyl template and then sandblasting. After that the blast area is filled with a colored epoxy (usually white or black) right to the top to keep water from pooling and freezing. Only other option that might work is using a diamond dremmel.

[maverickx50]

PS: You need GOOD quality bricks. not the big-box store ones. Get them from a quarry that makes retaining wall block etc. Centers of your small letters like e will blast away if you use the cheap stuff.

[jerry_stanek]

I use a laser to etch bricks

[garyr6]

Jerry, what type of laser and how much power?

[David Iannone]

Thank you all for your info so far.

Jerry do you have a few pics of what the laser etch bricks you do look like?

So if we sandblast, I am thinking of a Joe Crumley technique for blasting. If I remember correctly he cuts 1/4" thick PVC to block the sand instead of rubber mask through the plotter. (I hate cutting sandblast mask through my vinyl plotter even know its rated for it)

I called my customer about 30 min ago after reading these answers and turns out he has a small blast cabinet. I told him PERFECT, I think. I told him pull that thing out of the corner, get a few good quality bricks like the sample he supplied me and here is the plan:

-I am gonna cut him a 4"x8" sample blast template tomorrow out of 1/8" PVC. What I am thinking is coat the back of the PVC with thin double sided banner tape. When I cut out the letters I need to leave an onion skin on bottom of the PVC. It comes off the table ready to peal and stick.

-He is to coat his brick as he needs to so a layer of gerber paint mask will stick to it securely. He then applies paint mask.

-My CNC template is then stuck to the brick covered entirely with paint mask.

-Now take the brick to the blast cabinet and have some fun? The sand should break the onion skin of the PVC and the vinyl paint mask layer I am guessing?

I have never sandblasted myself, have always sent it out, and never tried to blast anything with small details. With an onsrud .125 up-spiral bit and a good vac hold down I think I can cut any detail they may want in a brick.

I am gonna cut the PVC template tomorrow and he is to get the bricks and paint mask them. Will post results.

What would be the best abrasive to blast with on a brick?

Dave

[jerry_stanek]

The etching are not very deep but they change color I will have to see if I can find one that I have done.

[Alex Naumenko]

If you going to be doing more than dozen I would laser them.

[bleeth]

Those beautifully v-carved commemorative bricks that you see in many places are done with diamond tools on a cnc made for stone cutting that spray water while cutting. A shop-bot just isn't made for it.

[bleeth]

Too late to edit:
And many are done in molds.

[Brady Watson]

And many are done in molds.

Yup...You'd be hard pressed to tell the difference between a 'cold cast' concrete brick and a real one with the right dye and aggregate mix. An interchangeable plate with the inscription of your choice at the bottom of the mold can easily be changed.

After machining various stone/aggregate products early on and dealing with grit getting everywhere on my expensive robotic tool - I vowed not to do that again...No matter how good your 'dust' collection is, you just can't keep grit from getting into the gear racks and machine ways. It just isn't worth it - for me anyway. It's one of those, "We can...but should we? Is it really worth the mess and risk?". Something to consider...

-B

[Davo]

Brings up a good question

Best way to make a mold on a Shopbot?

And with what?

[mtylerfl]

Brings up a good question

Best way to make a mold on a Shopbot?

And with what?

I did a presentation on mould making and casting at the 2013 Vectric User Group. It was an example scenario of creating multiple hotel wall plaques using casting instead of carving a bunch (carved the one plaque using the ShopBot, made a mould, then did the castings).

I first carved the plaque in 15 lb green foam (I think it was Duna brand?...not sure). Then made a container (called a flask) to make a silicon mould (a negative of the plaque), then made castings with plaster, Durham's Rock Hard Putty, and a quick setting plastic from Smooth-On (the silicon and spray release was from Smooth-On also).

The plaster casting was too fragile for my liking...the Durham casting had tons of air bubbles (which could be fine for a brick!)...the plastic casting was my favorite - strong, fast to set and easy to apply finish.

I just saved the PPT presentation to a PDF to get the file size down for the forum to accept the upload. Not much in the word descriptions on the slides, I'm afraid...I covered most of the details "live" during my presentation. But, I thought it might give you an idea how easy this is to do.

[Davo]

I wonder if it's more cost effective and time saving to cast things instead of remachine - loses the quality of being made from wood but neat to make it in other forms

[mtylerfl]

I wonder if it's more cost effective and time saving to cast things instead of remachine - loses the quality of being made from wood but neat to make it in other forms

It would depend upon the item. One would need to add up all the time/material costs for a particular project to see which method makes the most sense all-around.

[donclifton]

The best way is to cut a sand blast mask and sand blast it.
Don Clifton

[Davo]

i wonder if glass etching cream would be strong enough vs sand blasting - less clean up

[Brady Watson]

Brings up a good question

Best way to make a mold on a Shopbot?

And with what?

In this case using concrete etc, the easist way would be to make a clamp together melamine box. Machine your text in reverse and screw it/stick it down to the bottom. Pour in concrete, remove sides to demold. This eliminates the draft issue. There are plenty of mold box examples using melamine on the web. The only thing that you need the CNC for is engraving the text (prismatic letters etc) on your interchangeable plate if there are different names etc. When done put it on the shelf for the next time.


The best way is to cut a sand blast mask and sand blast it.
Don Clifton

There ya go...Easiest solution if you have access to a blaster setup.

I still would not recommend machining bricks on your good CNC machine...

-B

[mtylerfl]

I'm with Brady! Funny, I had to fight off the urge to just go out, make a mold with my surname and cast a brick today!

[RossMosh]

As mentioned above, laser or sandblast is the most common way. Sandblasting is more expensive than lasering. If you buy the right brick, as the laser hits the brick it turns a near black color which allows you to skip the color fill application. It's also easier to personalize as you don't have to make a new mask for each brick.