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I have been requested to bid on a job carving 3.5 X 8 inch brick pavers. The organization will sell memorial bricks to be placed on a concrete pathway.
The engraving will vary with each paver; something like “In loving memory of John Doe”.
They think they will have about 400 of the pavers to do!
Any ideas of what kind of bit to use, speed etc.?
Should I even bid on the job?
Don,
The only thing that comes to mind as I read your post was to machine the engraving as you want to see it in wood or prototyping wax and make a urethane mold from it. You could then pour concrete or whatever agregate you want into the mold and make the paver. You could just carve "In Memroy Of" etc... and then make a movable text block for each name. Of course the rubber mold would be useless after you made one paver...but I really doubt that you want to carve brick pavers on your Bot. For one, the mess is disgusting...and you will need to use a liquid coolant and probably a diamond tipped bit. It gets ugly quickly.
-Brady
The only way to do that many bricks would be to have them sandblasted - just like they do head stones. I have tried engraving patio stones and only succeeded in creating red hot glowing bits.
I have tried using carbide tipped drill bits (in the router) and also the tile cutting bit that RotoZip makes. I sprayed the bits with water while cutting and they still got way too hot.
Maybe the problem was the router speed. It could possibly be done with diamond router bits but it will probably cost you more for bits than you will make on the job.
Cut sandblast mask and sandblast them.
I was thinking of maybe a water tub and a diamond bit. One brick at a time. The one quote they have is $92 a brick. I think there will be more after the 1st 400.
If I was going to do this in wood I would use a 60 degree v-bit. Anybody know where I can get a diamond v-bit?
I will buy a cheap router at Harbor Freight and try it. If I can beat the $92 and make a few bucks I will be helping a local charity.
Don
The best way to do that is with a Laser Engraver. I would do it for $8.00 a brick plus the cost of the brick and shipping
Joe, I will keep your offer in mind. I will e-mail you with more information.
I don't think that a "surface-burnt" laser method will be as durable under foot as a "carved-in" routed method. This Google search could help.
Don,
it depends on the type of paver.
I've done slate and ceramic tile in low relief and engraved line drawings on the cheap pavers from HD to about 1/4" deep (1/4" carbide masonry bit). you will need to slow things down (both the router and the table) and use a coolant spray.
a good cheap spray can be made from the 'misty mates' personnal cooler (around $20 at WalMart). they're a plastic bottle that holds water and has an air pump to pressurize the bottle. the outlet is a flexible tube ending in a fine mist nozzle that can be clipped to your router near the bit. you may want to get 2 of them so you can re-fill one while the other is in use.
you may also want to wrap the edges of the paver in duct tape with about 1/2" sticking up. this'll make a 'dam' to help hold cooling water on the surface of the paver.
Check out the manufacturers of stone cutting CNC machines. They use diamond tooling, tons of coolant and move slow. If they could turn you on to someone running one in your area you could probably get lots of pointers
Eric
Don, our town did this in 1998, and the cost to the end customer was $30 per brick. Everyone made a lot of money off this project; the charity, the folks who installed the bricks, and the fellow who put the lettering on the bricks. It was done by cutting an adhesive backed stencil which was stuck to the brick and then the words were sandblasted.
. . . and then there are also CNC sandblasters . . . .
I have been lurking here for almost 2 years. I haven't asked a question or helped anyone else. I don't like to write, afraid I will make a mistake in my spelling or say something dumb.
However, After this experience, I think I will jump in when it looks like I can help. I sure appreciate all the help you have given me on this problem.
I am going to try the quarter inch masonry bit on one brick and see how it goes.
Thanks again. I will report back on my progress.
Don
PS I share my phone line with the computer. I try to get on line at least twice a day. I live out in the country, no DSL no cable modem.
Don, my limited experience of cutting bricks (with an angle-grinder), or drilling them, taught me that there are HUGE differences in the hardness or "cut-ability" of them. Therefore, you need to specify the hardness of the bricks if you ever win a bid. Alternatively, you could find a nice "soft" brick somewhere and then bid a price to include your own bricks.