Laser Engraving, Masking and Painting Help

[David Fierstien]

Hi everyone, I'm new to this site, but my google searches keep sending me here, so here's my question for you experience laser engravers/woodworkers.

I've been laser engraving for many years, love it, keep super busy with it. Recently, I've started engraving and painting. Currently, I'm using 1/2" birch plywood.

My process is, I sand the plywood nice and smooth using 220, then I paint it. I'm using a paint and primer combination paint from Home Depot and paints the wood red or blue or whatever other color I paint it. And then apply paper application tape over the top of the wood. I then engrave the design on my universal laser engraver which has air assist and outside ventilation. During the process a lot of times the tape comes up off of the wood, which i'm trying to figure out how to prevent. Generally once I am done engraving I use a sprayer and spray a layer of polyurethane over the top of it, let it dry for two hours and then throw another coat of polyurethane over the top of it and let it dry for another two hours. Then I can paing the project, let it dry and remove the paper application tape. Many times there's a little bit of bleeding, I personally think that's coming from the paper application tape coming off during the engraving process.

My question for you experienced woodworkers is what am I doing wrong? Is there a better way to keep the paper application tape applied to the wood during the engraving process, should I be putting a layer of polyurethane over the wood before I paint the wood? I'm just trying to refine my process so it looks beautiful when I am done and i've run into a stop where I don't want to keep going until I figure out what I need to change. Should I be using a different type of wood, different process, etc. My templates are 32x18 and 24x12 on my laser.

Any help or suggestions would be great. Thanks so much for any suggestions.

David

[Kev Williams]

1st- IF A layer of poly paint first won't affect the project much if at all, then YES! The poly will give the tape something much better to stick to than wood, and any lingering byproducts from the lasering shouldn't be too tough to remove from the poly coat. And all this is especially true if you're going to apply more poly afterward. It'll take more laser power to get thru the initial poly coat but that's nothing compared to the extra time & effort you're going thru now!

2nd- paper tape comes in several brands, and several levels of 'tacky'-- If you're not using the most tacky at the moment, an upgrade in tack may help. But try this AFTER a poly-first trial, what you're using may work just fine :)

[John Lifer]

Stop using air assist when engraving.... the paper tape might flare just a bit, but you should be able to engrave without air. NOT cut, but engrave. Helps keep the paper on the material.

[Mike Null]

David
Welcome to SMC. After 25 years of engraving, I am not a fan of engraving unfinished wood. I agree with Kev and John's suggestions. I always use a finish coat of some type before engraving. After engraving I apply a clear finish to the engraved area prior to paint filling in order to prevent bleeding.

The type of wood makes a difference and plywood, even if it's birch, is susceptible to bleeding. It will require more care and probably more clear coats to prep it for color filling.

[David Fierstien]

David
Welcome to SMC. After 25 years of engraving, I am not a fan of engraving unfinished wood. I agree with Kev and John's suggestions. I always use a finish coat of some type before engraving. After engraving I apply a clear finish to the engraved area prior to paint filling in order to prevent bleeding.

The type of wood makes a difference and plywood, even if it's birch, is susceptible to bleeding. It will require more care and probably more clear coats to prep it for color filling.


Thanks, what type of wood do you recommend? I'm having a hard time finding a better piece of wood in the sizes I require. Usually 12x24 or 32x18 and then I can cut what I need, what might you suggest?

David

[Mike Null]

David

Your selection is very limited in those sizes. If you have a good architectural millwork store near you they'll have hardwood veneer plywood. (cherry, mahogany, walnut.) I've had good luck with cherry and mahogany.