Best method to prevent burn marks on wood?

[Dan Kozakewycz]

I have just ordered in some strips of various types of wood to set the wife up for making Christmas craft gifts for the local craft fairs starting next month.

i have only cut plywood so far, but I really want to try and avoid burn marks on the wood as best possible. Is there some kind of solution or film that can be applied prior to cutting, or would masking tape suffice?

[Dan Kozakewycz]

Just found self adhesive graphic paper in large rolls, that looks to be ideal?

[Joe Pelonio]

I use paper transfer tape, and for thicker wood (1/4") will mist it with water after applying the transfer tape and right before cutting.

[John Frazee]

Normally if I laser unfinished wood I just run a sander over it and use air to blow all the dust out of engraved areas. If I laser finished wood like plaques, I use Pledge furniture polish before I laser and then spray a little on a rag to use for cleaning up. Putting a coat of the wax really helps in cleanup time. If you laser small details I don't think a tape would help much but will on larger jobs. The cleanup could take quite a while picking out all the centers. As Joe suggested about application tape, if you buy any, try to buy from a sign shop. I buy 48 inch rolls for just over $100 and have them slit it to different sizes. They will also sell by the inch and will be much cheaper than buying from a laser supply supplier.

[Dan Kozakewycz]

Cheers chaps, great advice thank you! :)

[Mitchell Tutty]

A little more time consuming, but best quality results in my opinion.

1. Clear coat
2. Engrave/Cut
3. Sand

[Ed Maloney]

I have just ordered in some strips of various types of wood to set the wife up for making Christmas craft gifts for the local craft fairs starting next month.

i have only cut plywood so far, but I really want to try and avoid burn marks on the wood as best possible. Is there some kind of solution or film that can be applied prior to cutting, or would masking tape suffice?

I apply a thin coat of floor wax and after cutting clean it up with a cheap general purpose cleaner. If the bottom of the item won't be seen you are good to go.

[Kevin Gregerson]

The easiest no mess, cleaning or otherwise method would be to run a inert gas through the air assist like Nitrogen.

[Ross Moshinsky]

There was a relatively thorough discussion of this within the last month. Link: http://www.sawmillcreek.org/showthread.php?221031-Something-better-than-masking-tape-from-HD

The general opinion was to either apply transfer tape or seal the wood before engraving.

[John Noell]

The easiest no mess, cleaning or otherwise method would be to run a inert gas through the air assist like Nitrogen. Not to mention being the most expensive of all methods!!!

[Kevin Gregerson]

Not to mention being the most expensive of all methods!!!

Nitrogen gas is pretty cheap. 304 cf runs around 8 bucks on the refill. Get a larger tank at 3500 cf and it's about 35 bucks to refill it.

Reality is that you almost never need 100 percent NIT. Remember that air is already 70 percent nitrogen, so just adding a little to the mix will reduce your burn by a significant amount increasing the life of your tank a bit. But, it really depends on what material you are working with.

[Dave Sheldrake]

Nitrogen through a standard nozzle is going to make little or no difference, you need to be running 1.5mm nozzles on adaptive optics with no more than a 1mm standoff over the work . The gas will need to run at 120 - 180 psi to get results.

cheers

Dave

[Kevin Gregerson]

Nitrogen through a standard nozzle is going to make little or no difference, you need to be running 1.5mm nozzles on adaptive optics with no more than a 1mm standoff over the work . The gas will need to run at 120 - 180 psi to get results.

cheers

Dave

Hasn't been our experience of that much being needed. We've had really good luck with much much less nitrogen than that. Most of the time the difference between flame and no flame is just a 10 percent difference in the gas mix.

[Dave Sheldrake]

Nitrogen is used to prevent oxidation not to suppress flames Kev, to knock out flame ups it takes about 6 psi of simple air, Nitrogen in laser cutting is used for an entirely different purpose. It's used on industrial lasers to prevent round oxidation on stuff like stainless steel (removes the blue hammon line and provides a clean edge) to use it to reduce flare ups is an expensive waste of time when air will do the same. Most of the staining on wood is re-deposition of liberated detritus and not from the surface actually scorching, higher powered extraction or point of cut extraction works far better.

Most of the issues with small format machines scorching or giving a mucky cut is the bad design of the nozzles, it's too far from the job to assist in the cut , the exit holes are too big to get anything like laminar flow and the air tends to be piped in at the side so pretty much ruining any chance of a good flow centre.

All that aside using Nobels on machines not rated for it can lead to asphyxiation in confined spaces.

cheers

Dave

Using Nobel gasses on small format lasers is a gimmik, if people really must them CO2 will work just as well (although CO2 can tend to scatter IR radiation)

[Martin Boekers]

Consider getting sheets from someplace like Colorado Heirloom, they have a great selection of woods, sizes and color.
Coated on both sides easy clean up with Endust and a Magic Eraser. If you search "Ornaments" here at SMC there are
hundreds of nice vector files... ;)

[Kev Williams]

My BIL spends every evening deep (3/16"+) engraving cedar boxes in a 30w LS800. Been doing it every night for over 5 years. He's tried everything listed above (except nitrogen) and then some, and his preferred method is 'hard-stick' transfer tape. NO AIR during engraving. The only issue is dealing with weeding the tiny spots in high detail areas. But when the weeding's done, the boxes are done and perfect.

[Martin Boekers]

Have him try plastic razors, I love them, at least on finished wood the work great!