Two Tone Painting With Masking Tape

So I have a project that I want to paint two different colors. My main goal is to paint the carved areas black and the un-carved areas white. I saw a youtube video where someone painted the board white, applied blue masking tape to the entire board, ran the CNC on it to cut through the wood (and tape) and then painted the exposed areas black.

I think this might not work with Maslow because the sled slides on the surface and remnants of cut tape would start sticking to the sled. This might result in tearing of the tape or even worse, sticking of the sled. Also, not a big fan of the potential for mucking up a router bit with adhesive. However, I don’t know if this will be a problem or not. I’m thinking it might work with very low adhesive tape (green tape) might work because it doesn’t have much holding power, but am looking for opinions.

Alternatively, I was wondering if I could cut through two boards at the same time and make a painting mask that way… i.e., put a very thin sheet of wood over the work piece and cut through both and then use the thin sheet as a painting mask.

And even more alternatively, I could just cut out the painting mask and just paint a cut board that hasn’t been carved into (no depth… just an outline). I’m doing something for a kid so he may not really care… And I can then do many more for other kids that complain I didn’t make them one…

And even more more alternatively, I could use that painting mask as a guide for manually routing out the piece… So many options.

Just looking for comments

carve things out, paint it (without worrying about overspray), sand the paint
off of the top surface, and paint with a roller or similar that on’t put paint
down into the cut parts (light coats, low nap roller))

I did that for another project and it worked well, but it was a sign with carved lettering. In this project (guess I could have mentioned it), I will have some wide areas carved out and worry that I won’t be able to effectively roll over the uncarved areas. In some areas, the uncarved areas will be an outline of the carved areas. But I guess I could get a set of various width foam rollers and try that out. Thanks for the suggestion.

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Either should work, but both have worries:
If you’re cutting 2 at once, overspray and center of stencils falling out.
Tape - probably will work. I think there’s enough sawdust flying around to “lubricate” any exposed tape that comes up. At least you don’t have to worry about holes in your stencil. Also you have to worry more about chip-out (compression or down bit?)…

I’d try green tape or blue painters tape.

Just an idea but could you glue together 2 different woods to make a laminate. Or possibly glue a few layers a veneer to the front of the board to make it a few mm thick. Essentially making something like the laminated plastics used in sign making.
https://www.engraving-supplies.co.uk/?act_lno=6560&act_stno=2000
If you dont need it all to use wood you could glue black plastic to the back of whatever wood you want to use then cut through the wood to reveal the black. Or use vlack and white plastics?

Tape over the already cut project, could use newspaper over big uncut areas. Cut out the desired areas with an xacto knife (some careful rubbing will make them easier to see), spray. It’ll work for multi-color too.

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I went ahead and did the cut regular. I might try to @dlang suggestion and use some foam rollers to apply the white. This is what I have to paint.

I don’t think I can use the exacto knife method… too intricate.

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the key to doing this with a roller is to keep light pressure on the roller, and not have a thick nap on the roller. (both of which would push paint down into the gaps)

Also try not to have much paint on the roller at any time.

That is going to be very interesting to see how it comes out.

It’s already something for bar to put in the newsletter

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That’s why I was thinking a very small foam roller would work well. I’d roll it in the paint, then roll excess off on the tray, and then roll on the piece… multiple light passes. I might just try to apply it over the dry black paint rather than try to sand the black off.

That’s awesome! I look forward to seeing it painted. I am also envisioning some LED and/or EL lighting :slight_smile: Any chance you’d be willing to share the files? Also, feeds, speeds, and depth of cut?

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Sure… I’ll post it soon… it’s highly unoptimized and gcodemillopt fails to fix it. Took about 5 hours… mostly moving from onside of the piece to the other because it’s unoptimized. I ran the profile at 20 ipm at 0.08 inch depth with a 1/8 inch bit. I cut it out at 30 ipm, .15 depth step with a 1/4 inch bit. Used 1/2 inch birch ply. It’s a birthday present for a friend’s 6 year old kid so I’ll probably not go all out with the lights… but good idea :wink:

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What is your current CAM program, out of curiosity?

Makercam… have really found anything else that works well for me (or really haven’t put enough effort into learning something else). It does “well enough” for what I’m trying to do at the moment but I hope to try to do more and will likely need something else. In meantime, it suits me.

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Good to know. I played with MakerCam a little to see how it dealt with SVGs, but found that for intricate drawings, it was too difficult to select paths. I like that JSCut lets you group items by layer so that you can select a whole layer to perform an operation upon. And the zooming is much easier to use. I still haven’t done much with JSCut yet either, though. In grad school I used SprutCAM, but that is an expensive proposition that I don’t intend to pay. Giving some thought to CAMBAM, though.

I’ve been “testing” it in demo mode… There’s some things I want to figure out how to do on it before I commit to spending money on a program. Again, just haven’t put in the effort yet, but its a strong candidate… Learning Fusion 360 is also in the cards but that’s a big undertaking… Reward potential seems high though.

Found this… make sure your spindle is off and let Maslow cut the tape for you :slight_smile:

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that’s amazing.
what material are you using?

Just 1/2-inch Birch plywood from HD.

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Here’s pretty much the final product. Not thrilled with the silver paint as it was really hard to get even… I guess that’s what you get when you buy cheap paint and try to apply it over decent black spray paint. I probably should have sanded down the black paint off the raised areas so I wasn’t painting over it. Lessons learned.

I’ll upload the svg from makercam tomorrow. It has a single pocket toolpath for 1/8-inch bit (beware, makercam produces highly unoptimized code and gmillcodeopt didn’t work properly on the output) and a single profile for 1/4-inch bit to cut out the piece when done pocketing. It’s written for 1/2-inch stock, so you can adjust accordingly.

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I’ve made a few signs using Avery paint mask. It is a vinyl product with adhesive on the back side.
Works very well. I bought a roll of it on ebay.
I would first paint the blank material. After the paint dried, I would apply the mask.
Route the design. Then paint the exposed part. Peel off the mask.
Easy and not messy. The adhesive holds very well but releases when pulled up.