Laser Engraving vs. Acrylic Mirror: Scattershot

The improved Holly Mirror Coaster looks pretty good:

Holly Coaster - overview
Holly Coaster – overview

Until you realize some of those specks aren’t surface dust and take a closer look:

Holly Coaster - mirror speckles 1
Holly Coaster – mirror speckles 1

The surface scratches are doubled by their reflection in the bottom mirror. The little dots that aren’t doubled reveal marks in the mirror surface itself.

An even closer look:

Holly Coaster - mirror speckles detail
Holly Coaster – mirror speckles detail

As nearly as I can tell, those are random speckles caused by the laser tube firing when it shouldn’t, due to the chaotic nature of the gas discharge going on inside.

In this case, they cause defects in the mirror coating allowing alcohol from the fat-tip permanent markers coloring the engraved areas to hit the acrylic. The starbursts come from stress cracks around the punctures.

Peering even closer shows similar cracks along the edges of the colored areas:

Holly Coaster - mirror speckles tight detail
Holly Coaster – mirror speckles tight detail

Not much to do about the random speckles, but it’s obvious I must up my coloring game.

Which would be significantly easier if rattlecan spray paint sprayed at winter temperatures …

One thought on “Laser Engraving vs. Acrylic Mirror: Scattershot

  1. Winter temperatures. Oh dear.

    I tried using latex spray foam to seal some gaps in the siding late last fall. The instructions said to use at a minimum of 45F, but it was a lot closer to freezing. Too cold, and the “foam” turned into latex beads.

    When you can get the proper temps, latex foam is good stuff. OTOH, apparently the urethane foams don’t do well in the cold, either. On the gripping hand, that’s what patch panels are good for. Sigh.

Spam comments get trashed, so don't bother. Comment moderation may cause a delay.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s