How to get high contrast laser engraving

[Matthew Grant]

Hi,

I'm working on a game for the kids - it's based on tiles with varying pips on the sides. Put down a higher number of pips, you flip your opponent's tile.

It is laser engraved from 1/8" baltic birch, but I'm having trouble getting high contrast in the engraving after staining. Here's what I tried:

Stain and quickly wipe - not much contrast, essentially washed out.
Stain, wipe, overstain with thinned "mocha" stain. What you see below - a little better, but still low contrast.
Blue tape before engrave and stain - doesn't mask the stain at all.
Polyurethane before engrave and stain - Masks, but bleeds laterally, no good.
Sanding sealer before engrave and stain - less bleeding, but not great.
Sealer + poly... Same as sealer alone, some of those deep pores still bleed it out.
Sealer + poly + spraypaint & wipe. Too hard to wipe, need paint thinner to clean the surface which ends up bleeding.

And for any of these cases, if I sand afterwards I simply can't get the dust out of the thin engraving. So I'm hoping to do it without post-sanding, or maybe to find something that fills the engraving completely so it's easy to get the dust off afterwards.

I saw the stuff about toner. I don't know where to get it, and I don't want to re-laser, lest the air assist blow toner around onto the lenses. Maybe a hot air gun?

skystones.jpg

Last - there's 80 tiles. So it's gotta be somewhat batch-oriented, can't paint each by hand for several sets.

[Matthew Grant]

Thanks for the move!

[Joe Hillmann]

Mask it, engrave it then use a very very light coat of black spray paint. If you want it darker do multiple coats allowing it to dry between coats. If you spray it on too thick it will bleed into the grain of the wood around the engraving. Also colors other than black don't work as well because they require many more coats to show up.

[Matthew Grant]

Seems like a good method. What do you recommend for mask? My blue painters tape tends to peel off the small parts of the engraving, and I didn't get great results the one time I tried contact paper.

[Kev Williams]

...And for any of these cases, if I sand afterwards I simply can't get the dust out of the thin engraving.

Sure you can-- Do you have an air compressor and a toothbrush? They'll get the dust out--

I 'invented' this over 30 years ago for cleaning the burrs out of engraving. I have brushes attached to almost every air hose in the place! (pat. pend. )

[Matthew Grant]

Now that, my friend, is pure genius! I shall drill me a toothbrush in the morning.

Now how many beers is your licensing fee?

[Dan Hintz]

Blue tape before engrave and stain - doesn't mask the stain at all.
Polyurethane before engrave and stain - Masks, but bleeds laterally, no good.

Mask, engrave, then a couple of quick coats of clear to seal the grain. Once dry, hit it with a coat or two of your desired color... no bleeding.

[Mike Null]

First sand the entire sheet. Then seal it. Mask and engrave. Seal engraved area and color fill. Baltic birch and other light colored woods will not provide consistent contrast.

[Matthew Grant]

Thanks, fellas! So it seems like sealing after engraving is one big step I'm missing, that's good advice which I will try this evening.

So for my lunchtime Lowes run - what type of making material should I be looking for? My 3M blue tape seems to have a very light adhesive which tends to peel up during engraving. Did I get a bad batch, or is blue tape not the right mask at all?

[Ross Moshinsky]

Transfer tape is what most people use for masking. Green painters tape can work in a pinch.

[John Calhoun]

I'm new to transfer tape (and layering, generally).

Will any transfer tape work — the clear Contact Paper from the local hardware store? Or is there a better brand?

I'm picturing the stuff curling, peeling up, and generally not making for a good mask. But maybe I'm mistaken.

[Bill Stearns]

Hi All - Matthew -
Pretty obvious that your game project is requiring lots of trial 'n error, uh? (lots of good advice being offered.) You're right - blue tape doesn't seem to hold securely. I've found that green painter's tape (Home Depot) is especially designed to prevent bleeding; has helped me. 'Couple of thoughts: the suggestion to paint the pieces "black"? - kids like colors! - am I wrong? (but, that comment 'bout other colors requiring more coats, that's been my experience, too.) a pain! Wonder if the pieces, if engraved more intricately might be just as appealing to kids? (like using the 3D engraving function on Corel Draw. (under printing > advanced>) - so that the image "sticks out" from the piece. ??
'While back, I created a "game" for my young grandkids - all five of 'em. (just for fun.) - engraving pieces similar to yours - called the game: "Share". (They were always fighting over the IPad 'n other gizmos! Each time they shared it - they earned "Share Points" - game pieces. Once they reached their "point goals" - their parents treated 'em to something special. (anyway - the plain Baltic birch seemed to interest 'em just as much.) Lastly: I'll post 'picture of ornaments I did for one customer - her parent's photo engraved - used green tape to prevent the "burn" 'n cutting. Not my finest work - but, the customer liked 'em.
Good luck with your game - maybe, let the kids participate 'n the engraving process, uh? - might turn out to be even more fun for 'em.

Bill

[Jim West Jr]

I made a clipart image deep engraving on basswood that i had first given a couple of coats of lacquer. After the engraving I used walnut colored timbermate (an australian wood filler available from Woodcraft or ebay) to over fill the engraving. After dried for a few hours I sanded and applied another couple of coats of lacquer and it turned out beautiful.

[Matthew Grant]

Thanks Bill and Jim for your suggestions. Bill - nice work on that engraving there!

Since I last checked in, I've tried acrylic with no mask (fail without sanding) and green tape/clear/spraypaint and had just a little bit of bleeding. I like the color of acrylic, so next round will be
pre-finished wood
mask, engrave
squeegee acrylic and let dry before peeling mask.

If it masks properly, I'm done. Else it's getting sanded, air-toothbrushed ala Kev, and re-finished. I think the process will get easier over time, but the learning curve for teensy color fill seems to be steeper than I expected.

[Julian Ashcroft]

Another alternative would be paint in the cut out area. This is what I used on this clock. It was engraved rather than lasered, water based paint wiped on with a sponge and then just wiped off with a dry paper towel.clock.jpg