Best engraving filler & technique

[ramaroodle]

Just looking for some general results that people have gotten without me doing 25 different tests. I am going to burn and fill an insignia and initials into a very hard, wood pen. What filler are folks using that gives crisp lines when it's sanded down? What power laser are you using and at what power. I keep thinking that the best way to do it is to first apply a thick layer of CA so the filler (paint, powder, etc.) has a space to fill. Without the CA it seems like the wood gets burned and you lose the ability to get a crisp burn. I have the stock NEJE laser head and the 3500.

My issue is that when engraving darker woods if you want it to stand out then you need more contrast so you actually don't want or need it to burn the wood as you are covering the black. I've tried various fillers and techniques with varying results. Almost seems like I should add a LOT of CA and only burn down to the wood?

I have tried just about everything known to man as a filler with varying results both good and bad. Last night I used Rub n Buff again. I tried something new after applying a few coats of the CA I use (Glu-Boost) . Before burning I put a piece of scotch tape over the location of the burn. Then, after the burn I basically have a stencil of the burn to apply the RnB over/into which when it dries, gives me a clean fill that is proud of the blank by the thickness of the tape as the tape pretty much vaporizes when the laser hits it. It is then a simple job to peel the tape off and lightly sand the inlaid RnB down. Then I'm just applying more CA as I always do.

 

[Pierre---]

I would say the problem comes from the burning - which is always irregular - rather than from the filler itself. The powder should only be thinner than the thinnest groove, but you have to make thin or steady, even and regular grooves up to the end.
This one does not seem bad because of the crisp engraving. The filler is a finely ground malachite powder, from Arizona Silhouette if I recall correctly, but could have been many others:

 

[MRDucks2]

Keep in mind that a laser fires through a clear substance. It then burns the non-clear surface with the energy. More CA runs the risk of creating a worse surface/burn from bubbling/over heating the CA itself.

You were getting close with the scotch tape. The energy of the laser was then etching the surface of the CA and not the wood underneath.

Try a blue painters tape and see if the surface etches better. I have used black sharpie and found that difference colors of spray paint will actually yield different colors of etch. HOWEVER, I use an X-Carve with dual J-Tech Lasers and precision lenses. As such, your results may vary.

 

[Rick_G]

I generally go with 2 layers of thin CA, burn, clean the burned area off with a toothbrush and alcohol. Use acrylic paint to fill and immediatly wipe off excess, give it time to dry then sand any leftover off with 600 grit then complete my CA finish. I only have a 1 Watt NEJE box unit but for pens and small wood medalions I put in the bottom of bowls that I make it works well. Sample shown is using a piece of blood wood I had.