Many might say "I haven't got a laser"... hell, many people can't speak English, but do we stop writing English articles because of them? I can lead a horse to water, but be buggered if I'm gonna give out free floaties.
For anyone that may be interested, here is my experience with laser engraving using my Trotec Speedy 100 with a 30W lens.
I'm no mechanical techo and refuse to be, but as a layman I can try to pass on my experience to anyone interested.
I am about to succumbed to my typical "digression", into what people couldn't give a stuff about... but, it's my blog!
13 years ago I was a systems programmer and in all "proud humility", one of the better ones in my field (it's a limited field). My forte was assembler programming for the IBM mainframe (and the dodgy Fujitsu), that is no longer being taught openly at any institution 'cept the Arkham Assylum... Yo bfatman, I sent out an APB asking if anyone wanted to understudy me... I only got 1 reply... which was a simple NO! ⏰,13 years later, I am getting 📧📧📧📧📧emails asking if I want a job as there are NO/Very-FEW competent ASSEMBLER programmers still available. The $300 per hour I have been offered (only one, not all, most cheapskates were offering only around $200-$250ph) would not entice me... though most with unlimited overtime at 1.5x ph to boot.
So don't be too proud to take my advice as in 13 years time you can all go and .....
I set up my laser to engrave to approx. (a maj measurement - long story) 1mm to 1.5mm depending on media using a standard 2 pass engrave (no level/height change). Depending on the media, I can make many passes with up to 5mm height change between all the passes.
This usually guarantees me with sufficient depth to be able to fill the engrave void with my choice of Timbermate (or any other wood filler) without bottoming out when sanded, which could become aggressive 120G/150G, though my preference is 240G.
This engrave is about 6 passes (and maybe some depth change... too long ago to remember details), with all the circled (and many not circled) grain that protrudes just below the top level. If I filled the void and sanded, some of those ridges may poke through, though I may/hope to have about 1-1.5mm lee way for sanding. Any less passes and that gets worse.
In this case I found that filling was probably not an improvement, and the oops below, is an indication of why you don't move the object if re-engraving (educated daughter spelling... DOH!),
In MDF and pine , I usually make 2 passes to get my 1mm-1.5mm depth, however, if the area is large, I may take 2 more passes to ensure sufficient depth to allow for "concavety" when sanding the larger area without bottoming out. the see through in the above MDF is quite obvious, unless you're a perv.
You need to watch out for inconsistencies in MDF/timber, that objects to the laser, ... the corner of the head had some tough material to cut through.
After the engraving, I immediately Timbermatefill, sand and re-fill voids blemishes and then re-sand,
I've been asked about pre-finish... I normally don't use it so I'm no way an authority on it (any feedback would be appreciated), however, I see no reason why tung oil may not be used. Not having experimented, the words oil and woodfiller (water based) do not compute. My thought would be more along the line of sanding sealer... yazall know about 1:10 shellac and metho mix, don't you?
One thing I would recommend is, depending on the timber used, is to sand to a good level 240G at least to cover up the pores so that the woodfiller used would not fill them and contaminate the area.
Lets go through a gallery of me using Timbermate on my engraving, pine, more pine,
same pine, same camera,
the "MIlwaukee" red was food colouring on natural wood filler.
Ebony Timbermate on MDF,
Find the elipipolante (yeah... my childhood)...
White Timbermate on ??? pen blank (Sierra pen, wolf engrave) Ebony Timbermate on Faux Ivory pen blank... garn the Woods!...
White Timbermate on pen box and below silver bling and ebony Timbermate on sample dowel (love me wedding present),
The Pen box (white Timbermate)
I love Old English font...
Testing various food colourings on neutral Timbermate,
With the laser on various projects... some of the samples available... Ebony,
Legible ebony and clip art,
Jarrah wood filler,
White filler (check out the pores filled in the background... may not be desirable),
Cryptic box name (ebony Timbermate),
One thing I did find... I couldn't for the life of me engrave over Timbermate... On "concrete" setting, it couldn't even cast a shadow.
And I can tackle cats,
This gives the impression of grain vs laser. (made out of LOSR).
If your first cut is too short... Take the second cut from the longer end... LBD