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Bob Davis - Sturgis SD
07-02-2015, 10:40 AM
We've been engraving barnwood for a few weeks, and I am by no means an expert. Now I have a couple questions for other wood burners here:

First we sand one side of the barnwood, then coat with 3 coats of water based poly clear, then mask, then engrave, then Laser Dark.

First question: Sometimes we get a sticky, oily residue where we've engraved on the wood. Is that the resin in the wood? Or maybe too much poly clear? I think most of the old barnwood around here is pine, so I suppose it has a lot of sap and oil?

Second question: We've been using cans of Laser Dark. Is there something about Laser Dark that makes it Extra Special? Won't any rattle can paint do? Or maybe acrylic airbrush paint, I've got loads of that. I know Laser Dark dries fast, but so does airbrush paint.

Thanks for any suggestions,

Bob

Keith Winter
07-02-2015, 10:55 AM
Hi Bob,

Your residue does it eventually dry or stay sticky after a few hours?

As to the laser dark Steve/Scott had an excellent post talking with Bert about making wood darker less than a week ago using airbrushes, might check that out.

As to the Poly, 3 coats does that engrave ok? Or does it take you bumping up the power significantly (10% or more) to cut through?

I see you're running a Trotec, you could also play with the ppi/hz to increase or decrease heat, might help with the issues.


We've been engraving barnwood for a few weeks, and I am by no means an expert. Now I have a couple questions for other wood burners here:

First we sand one side of the barnwood, then coat with 3 coats of water based poly clear, then mask, then engrave, then Laser Dark.

First question: Sometimes we get a sticky, oily residue where we've engraved on the wood. Is that the resin in the wood? Or maybe too much poly clear? I think most of the old barnwood around here is pine, so I suppose it has a lot of sap and oil?

Second question: We've been using cans of Laser Dark. Is there something about Laser Dark that makes it Extra Special? Won't any rattle can paint do? Or maybe acrylic airbrush paint, I've got loads of that. I know Laser Dark dries fast, but so does airbrush paint.

Thanks for any suggestions,

Bob

Mike Null
07-02-2015, 11:10 AM
Bob

I think 3 coats of poly might be overkill but you'd have a better feel than I. Try using mineral spirits to clean the residue. I haven't tried LaserDark in that application so I don't know how it works but I generally use acrylic paint either brushed on or air brushed. The plaque was a homemade one by a customer with lacquer. I masked it, engraved it and colorfilled with brush on acrylic.



316635

Joe Hillmann
07-02-2015, 11:36 AM
What are you masking with? There are several brands of masking tape that cause a sticky residue to be left behind even if you engrave through it deeply into the wood. Up until a couple months ago Duck brand was the brand of masking tape I found to work the best. But the most recent batch I got of it was leaving residue. They must have changed the glue they use on their tape.

Bob Davis - Sturgis SD
07-02-2015, 11:36 AM
Hi Bob,

Your residue does it eventually dry or stay sticky after a few hours?

I don't think it will ever dry.

As to the laser dark Steve/Scott had an excellent post talking with Bert about making wood darker less than a week ago using airbrushes, might check that out.

Yes, I've been looking that over. Seems like airbrush paint will work just fine, I'm going to give it a try.

As to the Poly, 3 coats does that engrave ok? Or does it take you bumping up the power significantly (10% or more) to cut through?

100 power and 45 speed seems to work well. I might run a little test with uncoated vs coated wood to see how much of a barrier the poly is.

I see you're running a Trotec, you could also play with the ppi/hz to increase or decrease heat, might help with the issues.

The problem is, I can take two pieces of wood that look the same, have been treated the same, and one will be oily and the next one is OK. I'm a little mystified.

Thanks for the suggestions,

Bob

Bob Davis - Sturgis SD
07-02-2015, 11:38 AM
Bob

I think 3 coats of poly might be overkill but you'd have a better feel than I. Try using mineral spirits to clean the residue. I haven't tried LaserDark in that application so I don't know how it works but I generally use acrylic paint either brushed on or air brushed. The plaque was a homemade one by a customer with lacquer. I masked it, engraved it and colorfilled with brush on acrylic.



316635

Thanks Mike, I will try mineral spirits. I've also got one board out in the hot summer sun to see if it will ever dry.

Bob

Bob Davis - Sturgis SD
07-02-2015, 11:49 AM
What are you masking with? There are several brands of masking tape that cause a sticky residue to be left behind even if you engrave through it deeply into the wood. Up until a couple months ago Duck brand was the brand of masking tape I found to work the best. But the most recent batch I got of it was leaving residue. They must have changed the glue they use on their tape.

Thanks Joe,

Thats very interesting. I'm using masking tape from JDS. I've got a few other kinds of mask here, I will have to experiment. I wonder if there's any chance I can skip the mask. Since the wood has 3 coats of clear and smooth as glass, maybe I can airbrush and wipe off? Probably not, but I might try it.

Bob

Dan Hintz
07-02-2015, 2:11 PM
316635

That backwards US is freaking me out...

Mike Null
07-02-2015, 2:27 PM
Me too. That's a logo for a clothing store.

Julian Ashcroft
07-02-2015, 6:02 PM
I engraved a piece of varnished oak the other day, I didn't mask it. I also got a slight sticky residue. I use cheap white vinegar and a soft cloth to wipe it off. To darken the burn, I use a dark varnish stain which is applied over the whole surface and is then wiped off, due to the varnished finish it wipes off easily but remains in the burnt areas.

Bert Kemp
07-02-2015, 6:40 PM
Excellent way to do it:)
I think an ebony stain would work for most woods. Just dab on and wipe of then clear coat , awesome Julian. just seal the engraving first to avoid the bleeding prob

I engraved a piece of varnished oak the other day, I didn't mask it. I also got a slight sticky residue. I use cheap white vinegar and a soft cloth to wipe it off. To darken the burn, I use a dark varnish stain which is applied over the whole surface and is then wiped off, due to the varnished finish it wipes off easily but remains in the burnt areas.

Roy Sanders
07-02-2015, 7:15 PM
that is comical; the east and west are in the correct position to the graphic though.

Braden Todd
07-27-2015, 11:26 PM
When I bought my first laser I had an issue that may be close to what youre seeing. I lasered some wood and had a mask on it, after lasering there was a strange residue left behind in my work. I ended up using a different masking and it went away, now I will only use transfer tape as a mask because it has very little glue and will not hurt touchy surfaces.

As for the laser dark consumption, I have had great luck with a rattle can approach. Most important step to remember is that you have to seal your engraving and then paint. If you do not seal the engraving the paint will wick and make the lasering look fuzzy/blurry. Also, make sure your sealer and paint are compatible to one another to prevent the paint from blistering off down the road.

Good luck and hope you enjoy the rally, I may even get to make it up for a few days!