Painting the wood then CNC cut

[mmak2916]

I'm thinking about painting the surface of the wood then run the CNC cut so the parts that are cut shows the raw wood. Is there a certain paint I should use, is there anything I should look out for? Will the paint still be clean around the cut edges? Has anyone tried this method and had success?

Thanks for sharing!

[bleeth]

This is done all the time Margaret. Any good quality paint properly applied will do fine.
You can also apply a "paint mask" over the paint and then paint the carved part after cutting and then remove the mask. Do a forum search under paint mask and you will get lot's of info on that. Most of the good information about this and other paint and carve methods is in the signmaking section of the forum.

[scottp55]

Don't forget there is always "Burning" as an option too(Just in case you're feeling "Pyro" :)
http://www.talkshopbot.com/forum/showthread.php?t=20239&highlight=burned
Works particularly well on light woods like Maple and a very light touch can turn it black with no charcoal :)

[scottp55]

Margaret, Also quite a bit on the topic on Vectric Forum.
Here's one I liked on how to prevent bleeding .
http://forum.vectric.com/viewtopic.php?f=3&t=19389&p=150380&hilit=paint+bleeding#p150380

[mmak2916]

Thanks! Here's a photo of what I'm trying to do with the exception I want the windows to be carved in with the raw wood exposed. A lot of examples I've seen so far have the carved areas painted in and that's not what I want. I'm planning to paint the board first then carve out the areas. I haven't seen examples of something like this yet so I was wondering if the paint will peel/chip on the edges when it gets carved.

Not really looking for the burned wood look...thanks though!

[Kyle Stapleton]

It will work fine. Just make a few test parts first.
Vbits and down cut bits will be you best bet.

The picture is corian, blue was the base coat white is the corian.
The mask (orange) is the so we could paint the yellow.

[David Iannone]

Margaret,
Thanks for the pic of what you are trying to do. I would do some tests with the material you plan to cut. Peeling and chipping could occur depending on what bit you cut with, the speed at which you cut, and what wood you are cutting. Like Dave R. said, paint mask is a good idea after you paint the face, before you do your cutting. IMO even if you don't plan to paint the area you cut out, the paint mask will for sure help to hold the edges from chipping. Make sure when you prime and paint, give the paint the proper time to cure. Once cut, peel the mask off slowly.

What type of wood do you plan to cut?

Dave

[scottp55]

Margaret, Shopbot used to include projects in the QuickStart kit.
This was called "Optical Ball" and was the very first project I ever did. Material was scratched so just gave it 2 coats of this paint, and then cut an hour later.
It was under QuickStart Projects.
You should be fine, but may have to play with paints. Cut with starter set .125" Onsrud BN.
This is just the color of the plywood underneath, nothing touched.

[mmak2916]

@Dave - Thanks for the tips! Where can you buy paint mask or do you mean painter's blue tape or something like that?

@Scott - Thanks for the sample images! Definitely seems like I need to explore with different kinds of paints.

[scottp55]

Wups, Starter bit Onsrud 90degree VBit

[bleeth]

Paint mask is a specific product. It sold on line and in sign supply houses like Feller's. Two major brands are Gerber and Avery. Avery will send you a sample pack. (Or they used to). Different results happen with different products and cutting strategies, as well as the surface. For mask product to work your surface must be smooth and the paint must be fully cured (not just surface dry)

[bill.young]

If you can do it the way you originally thought...paint it and then cut through to expose bare wood...it is a lot easier and faster than using paint mask. I've done a lot of it using canned spray paint and it works well.

I've been making these for local elementary school teachers for years:

http://seaside5592.blogspot.com/2004/11/puzzle-letters.html

[David Iannone]

Bill,
Those look great.

[mmak2916]

Thanks Bill, those look awesome! Thanks for sharing, it makes me more confident in trying this method.

[scottp55]

Bill, I like the Vac Jig and Love the through-tenon wedge holding trays!!:)

[bill.young]

Thanks Scott. I use that same detail for the "Cabin Shelves" and lots of other projects and it's pretty sturdy. I've been 3d printing the wedges recently...it's one of the few things I use a 3d printer for.

I learned pretty quickly though that kids can remove the wedge no matter how tight it's tapped in! So for those trays I ended up having to put a small screw into the wedge through the plywood from the inside. It's not very visible and seems to solve the problem.

Bill

[scottp55]

Tricky Bill:)
off topic,
At least you made the tenon long enough not to split out(unlike my carpenters when they shortened my tenon and changed them from half round to square to "Stack" better). They also were house carpenters and not furniture makers, so they thought it made no difference if wedge was driven "Up" OR "Down" :( Made it interesting that first winter when the cat started "batting around" these little Ebony pieces that were on the floor:) Jeez, does wood shrink when humidity goes down in winter!!? :)

Off topic again, BUT using your flat Dovetail like my MakerCrate(which I love).
If you jigged the wood at an angle could it do a acute joint like the last pic in this thread?
http://forum.vectric.com/viewtopic.php?f=2&t=21629

Have fun Margaret!
scott

[bill.young]

hey Scott,

Don't want to divert the thread too much, but I don't think that either system would allow you to tilt the workpiece and still cut dovetails that fit correctly. The issue is that the ramped cuts would have to progressively rise at the same angle as the tilt of the piece. Currently they only cut in the XY plane

Not that it wouldn't be possible to modify the routines, but I don't think it would be quick (for me at least!)

[Michael Breedlove]

Easy to do, spray it on, let it dry for a few days, you can sand it off for a distressed look.

[MogulTx]

Mike Breedlove

that sign on the left..... somewhere in my dark and sordid past, I seem to recall some of those... aren't they the different expressions of Ohm's Law?

[Michael Breedlove]

This is a sign that hangs in my office. You may recall this from a physics class.

Ohm's Law states the relationship between current, voltage and resistance. Watt's Law states the relationships of power to current, voltage and resistance.

[MogulTx]

Ah. Of course. Nicely done. I like your work!


Monty

[David Iannone]

Yes, I agree. Great looking work by all.

A good question asked and well answered by this forum. Spray paint has come a long ways......:rolleyes:

Dave