Ambient Temperature

[Adrian Hill]

Its been quite cold in our city for the last couple of days. I find that the laser (70w) struggles to cut through 3mm MDF. Could this because of the humidity & low ambient temperature?

[Dan Hintz]

Define "cold"... define "high humidity"...

MDF is notorious for being random in its ability to stifle a laser's ability to cut (though I would think 70W could cut through even the nastiest of glues).

[Adrian Hill]

My chiller normally runs at about 27 degrees c but it's been running at about 16 degrees. I realigned the laser, cleaned the mirros and cleaned the lens. The laser seems happy with other material. I live at the coast and it gets very humid. My cars live outside and they are totally wet in the morning. I wonder whether the MDF absorbs the moisture. I just got an idea, I'm going to stick the a piece of MDF in the oven in the morning and cook it for a bit to see if the moisture makes a difference.

[Neil Pabia]

I just got an idea, I'm going to stick the a piece of MDF in the oven in the morning and cook it for a bit to see if the moisture makes a difference.
I would be careful doing that without proper ventilation, formaldahyde and other chemicals in there could be a problem in a closed room.

[Mike Null]

MDF will definitely absorb moisture.

[Kay Bengtson]

I live at the coast in California and we often have foggy mornings with so much fog that it soaks everything. I have found that when it is like that, I won't be able to cut 1/16" Baltic birch plywood as well as in the afternoon when the sun comes out and humidity drops down. At that point, the air gets so dry that wet laundry can dry in an hour outside. Then I can cut the ply with much less effort. I also set the my supply of ply out in the sun every so often to dry out then store it in plastic garbage bags to keep the wood as dry as possible.

Kay

P.S. Sometimes, I take a hair dryer and heat up the ply before cutting if it is raining. That seems to help too.

[Adrian Hill]

Its a bit warmer today and the machine seems to be a tiny bit happier. I did some tests and I found that the lastest purchase of MDF seems to be different. The new lot seems to be more coarse and the laser really chars the surface and doesn't burn through. I think Dan is right about the latest purchase, the laser really doesn't like the glue in the material.

Thanks Kay, looks like we have similar problems.