How do I make "laser ready" boards?

[Linda Creatore]

Hi All,

If someone can help me out, I'd really appreciate it!

I have been trying to figure out how to make my own "laser ready" wood to keep the costs down and also make larger pieces to use. You know, the kind that has a finish already on it that is easy to simply wipe off the residue you get after lasering. Anyone out there with some suggestions?

I've tried poly, but it cracks and the residue then gets under the poly. Don't really want to do lacquer as it is nasty stuff and I'm not set up to do anything like that anyway. I know that Colorado Heirloom uses two coats of CAB acrylic lacquer on their boards, and suspect that Laserbits does the same and others, too.

I'm looking for some way that's less toxic and more human friendly, but that after lasering, the residue can just be wiped away with a damp cloth or one with a little furniture polish or something on it.

Thanks,
Linda

[Dave Laird in NM]

We make all our own "laser ready" material.

We have found that the easiest for us is laquor. There is some water bases laquor out ther and if you are using that make sure you get one that has a "burn-in".

The person taht we bought our first laser from used a water based poly with very good success.

Good luck in getting your material "laser ready".

[Mike Null]

Linda

Unless you need a custom size or a special wood it is far cheaper to buy plaques already made. May not make sense but it's true.

Sometimes you need a size, shape or wood species you can't readily find. In those cases I almost always use sanding sealer (shellac) as my base coat prior to lasering then finish with clear acrylic or lacquer. Although I'd love to use polyurethane I don't because of the slow drying time.

Look at JDS prices for plaques.

[Linda Creatore]

Hi,
Thanks for the info.

David, what is meant by "burn in?"

Also, if I use a sealer, can I just wipe off the burn residue or do I have to sand it off?

The time sanding is the problem. I make lots of ornaments and other things that I cut from 1/8" baltic birch (24" x 12" sheets) and there is a lot of residue left on the pieces after lasering. I wouldn't mind sanding first (after sealing) but I don't want to have to sand again -- sometimes hundreds of pieces for an order -- to get the residue off before putting on the final finish.

Mike, what kind of acrylic are you talking about? Got a brand name for me, maybe?

I found the poly cracked at the edges and the residue got underneath. That was an oil based poly, though -- maybe a water based would work better.

Bottom line is, I have some boards from Laserbits and Colorado Heirloom. When I laser etch/cut them all I have to do is wipe the boards to get rid of the residue. I want to figure a way to make my own wood act the same way.

Thanks!
Linda

[Keith Outten]

Linda,

Try Deft spray lacquer in a rattle can. You can by it at Walmart, Lowes, Home Depot or almost any hardware store. The spray cans are inexpensive and convenient for small jobs, the lacquer dries fast and you can wipe the smoke damage off your plaque after engraving with a damp rag.

.

[Harlan Kilbourn]

Linda,

On baltic birch the Minwax Polycrylic water based finish works well. But it generally requires 3 coats with sanding after the first coat. It drys fairly fast and I do the back side after about 30 minutes then wait 2 hours between coats. It fairly inexpensive and readily available and goes on ok with a good brush. I have not tried spraying it. I will do 10 to 15 sheets at a time and then go do something else while it is drying. I need to built a rack to allow me to do more pieces at the same time.

After coating a damp rag is all that is needed to wipe off the residue.
I stain a lot of the wood to get different colors and then clear coat them.

Harlan

[Mike Null]

Linda

Like all wood you should sand it before applying a finish. The acrylic is available under several brands but all say clear acrylic.

I have Krylon on acrylic and Minwax on lacquer. You won't have to sand after lasering if you use either of these first.

The lacquer I described is what Keith is talking about.

[Dave Laird in NM]

Linda, "burn-in" is what a finish does when the second coat melts the layer below it so that you get a great adhesion of the coats. Most poly finishes do not have any burn-in and require that you sand the finish before you put another coat on, and even then you can get minimun adhesion.

[Philip Sheridan]

My 2 cents. I do wood working professionally and have used most finishes out there. The best, in my opinion, are the water based poly-acrylic finishes. For a quality finish, stay away from the minwax and other Home Depot brands (deft included) they are too soft and scratch/damage easily. The best are Target's USL (ultimate spray lacquer) and the Crystalac products. They are both water based and non toxic when cured. You should spray them both for the best coats. Re-coat time is less than 1 hour unassisted. They are probable not available in your area so you will have to order them. I have used them both for lasering and they work great; there is easy cleanup plus there are no issues with different species (such as polyurethane with cocobolo rosewood). You should also coat both sides evenly to avoid warping and should use 3+ coats as grain raising can be an issue with water based finishes. Good luck!

[Rodne Gold]

The easiest way to get a perfect finish on wood when lasering is to apply paper based sign application tape , this is a low tack sort of "masking" tape , real cheap.
Laser thru this and then remove (very easy to remove) and you will have no residue at all. You can even apply a darkener before removing or spray paint etc as the paper acts like a mask.
When cutting , the way to lessen residues is to use the lowest PPI (might be called frequency) you can. Basically the laser treppans when cutting , IE drills a series of holes. Ideally you do not want the holes overlapping too much as the heat affected zone just gets worse when doing this , if the holes are optimally spaced , you get the minimum heat affected zone and a nice cut. The "drier" the wood , the better the cut (IE less resins)
We have a different way of doing things , we cannot get large thin pieces of solid wood , so what we do is laminate veneers either one or 2 sided on low density Fibreboard (LDF- like MDF). We then have sheets of whatever size and thickness we desire , that are totally uniform. The laser slices thru the LDF easily with far less residue than solid when cutting.
We also have another "cheat" , we use wood grained formicas and engrave and cut em and mount the formica on any substrate (pex , other woods etc). Thew formicas are almost indestructible and can easily be paint filled etc . Great for stuff outdoors.

[Paul Anthony]

Linda, Being a professional shop , we spray all our work with lacquer. I find that to work best for lasering also.We do hundreds upon hundreds of wooden book covers that way. Many of our laser customers buy their wood already finished and seem to save time in the end . One reminder . If you are coloring the engraving , be sure to seal it first with something like zinzer seal coat to prevent bleeding under the finished surface.

[Stephen Beckham]

Linda - head spinning yet?

Mine is and I understand most of what was said...

Not sure if it's an option for you, but you may find it easier to get a local woodworker to run a couple boards/panels of baltic birch through their finishing room as you need it. It won't be as cheep as you doing it yourself, but if it saves you a couple hours but cost you a couple bucks - your time is more valuable...

You can make more money, you can't make more time... My $.02...

Steve

[Mike Null]

I think Steve an I are usually in agreement but here I would recommend buying a random orbit sander it you don't already have one along with three grits of paper, finishing with 220.

Clear off all the dust and spray with one of the finishes previously mentioned .

Two or three coats is preferable. Use 0000 steel wool and engrave. Clean with diluted orange cleaner, wax and package.

Phillips suggestion is good but usually we don't have the option of mail ordering our finishes.

[Linda Creatore]

Wow, now that IS making my head spin...

Thank you all for your comments. I think I will try one of the water based polys or lacquers...should I seal before sanding? What kind of sealer?

So far, I have been using various Watco Danish Oils to finish after sanding, and sanding, and sanding off all the residue.... . If I want to continue using some Danish along with a clear finish (as has been suggested, so that I can just wipe off residue), should I use a sealer before the oil and if so what kind?

BTW...I REALLY APPRECIATE all the help and patience with all my questions.

Now, I am going to print this thread and reread...AFTER my head stops spinning!!!

Thanks again...
Linda