Best masking options for lasering wood.

[Keith Downing]

I've done several searches on this topic but I can't find anything really helpful from the last 4 or 5 years. Most threads seem to end in someone saying "you don't really need to mask". Anyways...

I do a lot of wood pieces that need masking, usually pre-finished wood, sometimes raw wood.

I had been using traditional masking tape in the beginning and it worked reasonably well, but the rolls aren't wide enough to avoid repeated overlap on most of the larger pieces I'm starting to do more often now. And I have definitely noticed that the overlap caused some very unwelcome lines in my last larger piece where the laser didn't raster fully where the tape was thicker.

So, what does everyone recommend in this scenario? I'm looking for something at least 6" wide. Other than that I'm wide open.

I had several people recommend high tack transfer tape. But both brands I've tried so far didn't have anywhere near enough holding power; not sure if they're too thick or weak glue. I can't even remember the first, but the second was RTape Clear Choice A75. Just horrible.

Did I just luck into two bad brands for lasering? Or is there a better solution?

Cost effective would be great, but at this point I'd settle for something pricey if it works well.

[Mike Null]

I use transfer paper on finished wood--it won't stick well on unfinished. I roll it with a wallpaper seam roller before and after engraving. Even high tack transfer paper is not a stickly as masking tape so don't expect too much there.

I also use it for clear acrylic to avoid scratches.

[Bob Davis - Sturgis SD]

You can buy transfer tape in any width you need. We engrave barnwood, sanded then 3 coats of poly clear. We mask it because we usually paint the engraved part. Masking raw wood, that doesn't usually work. We've had customers bring us pieces of wood they want us to engrave, sentimental wood like from the family homestead, but they don't want us to sand and clear it. That also doesn't work, lol. That's a job for a Cnc router.

[Brian Lamb]

If I need it to stick, like for painting afterwards, I use 3M Blue painter's tape and be careful about not overlapping the strips, you can get it up to about 3" wide without too much trouble. I bought a roll of the 6" wide transfer tape from Laserbits and it's pretty much worthless, I can't get it to stick long enough to cut anything.... the draft from the exhaust system will lift edges and cause it to flutter off the piece being engraved. If I lay steel rulers along all four sides I have a 50/50 chance of getting it to stay down well enough to keep the smoke from depositing onto the part.

[Gary Hair]

but the second was RTape Clear Choice A75. Just horrible.

I've never had much luck with the clear tapes, they just don't stick as well. Try some that isn't clear and see if that makes any difference.

[Ross Moshinsky]

You want the paper high tack transfer tape.

Not saying to buy from here but this is basically what you want: http://www.uscutter.com/RTape-Conform-Series-4076-RLA-High-Tack-Application-Tape-with-RLA-100yd

[John Blazy]

I would think that permanent adhesive tapes would work like a dream on wood. Standard clear 3M packaging tape sticks well, and removes well - might pull a few fibers up a bit though. I use clear packing tape for glueing miters together in birch plywood, and removal is fairly decent when pulled at the right speed. I burnish the tape down with a hard roller though, and sometimes it looks like I laquered the surface. I also have a 60" wide PSA laminator, and a roll of permanent adhesive 2 mil vinyl. this thread gave me the idea to use that vinyl for fully masking plywood sheets, as my medium tack masking roll wont stick to it.

[Gary Hair]

this thread gave me the idea to use that vinyl for fully masking plywood sheets

It's been said countless times DON'T LASER VINYL!

[Bill George]

What I have done in some cases, I run the board through my 12 inch wide sander. Engrave, paint let dry and then run the board again, usually comes out pretty nice. Yes, I realize that a lot of your work would not fit in my Grizzly sander but for the work that does it cuts down on a lot on work time.

[David Somers]

Keith,

I have been using a product called "conform low tack application tape with RLS." It is a low tack transfer tape that I found at a Seattle Sign supply company. I have not had it come off while lasering even with a blower and air assist going hard. It will start to release if I leave it on too long. For example. I put some on one day and then my wife sucked me into a project and I didnt touch it for close to a week. It had started to lift at that point. But if I use it in a reasonable time period I dont have issues with it. It picks OK, but any picking is annoying in my mind so I am biased that way. I can buy it in any width I want. The shop will cut rolls to size. And one roll of whatever width you want is a lot of length. Holy cow. I will be into my 12th reincarnation when I use up my current roll and it was pretty inexpensive, especially when you look at it by the foot.

Having said that. I usually try NOT to use a mask and usually dont need it. With wood I will typically use an HVLP sprayer to spray it with clear lacquer. Very fast drying and doesnt interfere with any other clear finish later on. Though obviously it would interfere with stains. I dont use stain though so that is not an issue for me so far. With the lacquer on any soot from the lasering wipes off easily with water, or Denatured alcohol (often abbreviated as DNA in case you werent familiar with the abbreviation) Depending on the wood I can often just wipe off unfinished wood as well. Deep grained woods like Oak dont work well for this. But smooth grain woods like maple and cherry do well.

The name of the Seattle sign company is Sun Supply and I believe they have shops all over the country so there may be one near you. You could probably get a hunk of the tapes they carry to try before buying a roll.

For a masking tape, I prefer a good blue painters tape. I will also use Harbor Freight's masking tape which comes in a number of widths. It is a higher paper content than many tapes and is a moderate tack. Works well for lasering, at least for me.

Hope that is useful to you.




Dave

[Keith Downing]

You want the paper high tack transfer tape.

Not saying to buy from here but this is basically what you want: http://www.uscutter.com/RTape-Conform-Series-4076-RLA-High-Tack-Application-Tape-with-RLA-100yd


This is what I was starting to think. The one's that are clear (and subsequently seem to have the highest ratings for actual transfering) don't seem to stick well at all, especially with air assist on. I think what I really want would be more like 6" or 12" masking tape. Hopefully the paper transfer type will work better.

[Mike Null]

Keith

As has been mentioned, your local wholesale sign supplier will have this paper. Typically it comes in a 54" log and for an extra $5.00 they will cut to sizes you want. I usually get 4", 8", 12", 24" etc.

[John Bion]

I am using this chlorine free “Vinyl” for masking, I have no connection to the company: www.grafityp.co.uk/Eco%20Friendly%20Sign%20Making%20Films.html

[Mark Taylor2]

I've been using this when I need it... https://www.amazon.com/Application-Transfer-GreenStar-Classic-Adhesive/dp/B00C131Y04?ie=UTF8&ref_=cm_rdp_product Seems work pretty good, IMO.

[Keith Downing]

Keith

As has been mentioned, your local wholesale sign supplier will have this paper. Typically it comes in a 54" log and for an extra $5.00 they will cut to sizes you want. I usually get 4", 8", 12", 24" etc.

What exactly is it called though Mike? Transfer paper? Masking tape?

[Michael Hunter]

I only use transfer tape on unfinished wood.

For finished wood, I clean off the smoke marks with spray-on furniture polish.
The polish helps get rid of the bonfire smell too.

[Tony Lenkic]

What exactly is it called though Mike? Transfer paper? Masking tape?


I sign industry it's called "Application Tape".

[David Somers]

Keith,

In the store I mentioned I only saw it listed and heard it sold as paper transfer tape/application tape. It is a paper back and came in 3 tacks; Low, medium, and High tack. The low was recommended for use on plastics and finished wood. The medium for use on unfinished wood. The high tack was for situations where the sign maker was using a paint or fluid that had a very thin consistency and had a higher chance of running under the low or medium tack tape's edge. They said the high tack could be difficult to pull off, and if you were trying to do something that had tiny pieces it could make the process of picking it off very time consuming. They said it works well when needed but had limited use overall. Remember this was a sign shop and not a laser shop that sells this.

If you can, I would be tempted to find a sign supply shop and see if they can sell you a small amount of low and medium tack tape and play with it and see what might meet your needs. Better yet, if you can manage to do your work without use of the tape you will keep your cost down by not having to use a tape (not that it is especially expensive) and my not having to take the time to apply it before every job and remove it after the job. If you have lots of tiny areas to pick this can be time consuming and a significant cost if your time is $$ for you.

Some ideas....is most of your problem on the upper surface of the wood or the bottom surface? Or both? If the bottom is the issue can you make use of a pin table to raise the piece and provide better airflow to remove the soot before it settles on the wood?
It sounds like it is the top surface that is causing you the most problem as you mentioned engraving on "pre-finished" or raw wood. By pre-finished do you mean it has a sanding sealer on it? Are you putting the sanding sealer on or is it coming that way? Any value in spraying another coat on? Or have you attempted to remove the soot from this "pre-finish" with something like Denatured Alcohol (DNA)? For the raw wood can you apply a sealer or clear lacquer before lasering? Lacquer dries wicked fast and doesnt affect the color of the wood in my experience. And you can get it in varying levels of gloss. I use an inexpensive HVLP sprayer that I got at Rockler during a sale. I think I have seen it since at either $69 or $99 on sale. I have seen the same unit at Harbor Freight for similar prices. It works well, easily cleaned, especially with sanding sealers or lacquer or clear shellac, and it sprays evenly and controllably.

Or, can you play with your air assist to help eliminate the soot? For example, I think most of our air assist systems blow through the lens tube, largely to help keep "stuff" from coming back up the tube and affecting the lens, and partly to clear the kerf and stop flaming on cuts of certain materials. Can you add another "air assist" line that is aimed obliquely across the piece to keep the soot from settling on the surface?

Just brainstorming for you. Hope we are giving you some good ideas.

Dave



Dave

[Keith Downing]

Keith,

In the store I mentioned I only saw it listed and heard it sold as paper transfer tape/application tape. It is a paper back and came in 3 tacks; Low, medium, and High tack. The low was recommended for use on plastics and finished wood. The medium for use on unfinished wood. The high tack was for situations where the sign maker was using a paint or fluid that had a very thin consistency and had a higher chance of running under the low or medium tack tape's edge. They said the high tack could be difficult to pull off, and if you were trying to do something that had tiny pieces it could make the process of picking it off very time consuming. They said it works well when needed but had limited use overall. Remember this was a sign shop and not a laser shop that sells this.

If you can, I would be tempted to find a sign supply shop and see if they can sell you a small amount of low and medium tack tape and play with it and see what might meet your needs. Better yet, if you can manage to do your work without use of the tape you will keep your cost down by not having to use a tape (not that it is especially expensive) and my not having to take the time to apply it before every job and remove it after the job. If you have lots of tiny areas to pick this can be time consuming and a significant cost if your time is $$ for you.

Some ideas....is most of your problem on the upper surface of the wood or the bottom surface? Or both? If the bottom is the issue can you make use of a pin table to raise the piece and provide better airflow to remove the soot before it settles on the wood?
It sounds like it is the top surface that is causing you the most problem as you mentioned engraving on "pre-finished" or raw wood. By pre-finished do you mean it has a sanding sealer on it? Are you putting the sanding sealer on or is it coming that way? Any value in spraying another coat on? Or have you attempted to remove the soot from this "pre-finish" with something like Denatured Alcohol (DNA)? For the raw wood can you apply a sealer or clear lacquer before lasering? Lacquer dries wicked fast and doesnt affect the color of the wood in my experience. And you can get it in varying levels of gloss. I use an inexpensive HVLP sprayer that I got at Rockler during a sale. I think I have seen it since at either $69 or $99 on sale. I have seen the same unit at Harbor Freight for similar prices. It works well, easily cleaned, especially with sanding sealers or lacquer or clear shellac, and it sprays evenly and controllably.

Or, can you play with your air assist to help eliminate the soot? For example, I think most of our air assist systems blow through the lens tube, largely to help keep "stuff" from coming back up the tube and affecting the lens, and partly to clear the kerf and stop flaming on cuts of certain materials. Can you add another "air assist" line that is aimed obliquely across the piece to keep the soot from settling on the surface?

Just brainstorming for you. Hope we are giving you some good ideas.

Dave



Dave

Thanks for all the thought Dave. Mostly I just like to do some painting or staining in the masked areas after they have been lasered. So it helps tremendously if I do a mild finish first (like a polycrylic, 2-3 coats), then mask, laser, and fill as needed. Sometimes it's colored paint, other times just a little extra stain or finish to darken the color of the engraved area to my liking.

I do occasionally use the mask on the back side of the piece to avoid burn marks from the honeycomb table. But I had also planned to build a second platform for those wood pieces that need protection from burning on the bottom. So I'm not overly concerned about that right now.

I think after reading through everyone's comments I was just using the wrong type of material to mask. I will try a couple different brands of the paper application tape, in medium and high tack, and see if I don't get results closer to what I was expecting.

Thanks again guys.

[David Somers]

Ahhhhh. I got it. I didnt realize you were masking for painting after engraving rather than to eliminate cleanup. Let us know how it goes.

[Dan Schiaffo]

Hi Dave - two questions for you - when you are using the lacquer, are you still able to paint the final piece (as opposed to a simple clear finish)? Secondly, you said "Depending on the wood I can often just wipe off unfinished wood as well..." - does that mean that there are times when you don't even use lacquer on unfinished wood but are still able to use water or DNA to wipe off the soot? If correct, when would you do this? If you were working with the types of wood you specified?

Thanks - Dan

[Greg Rodie]

Thank all of you for this super helpful info!