I’m often asked if we can engrave recycled wood. Here’s an example of a project where we did just that.
We laser engraved two of these signs made from reclaimed pine for Old School Fabrications (OSF). They were for an exhibition for the National Library of Scotland in Edinburgh.
When the wood arrived for engraving, it was covered with nasty old green paint and looked awful! OSF had cut the boards to size as they were too thick for us. We just had to engrave them.
Engraving through to the good wood
We made a good, deep engrave to give a significant 3D element to the signs. This was particularly important as OSF wanted to sand the signs after engraving to get back to the good wood under the layers of paint. A pine is a softwood, this was easier to achieve than if oak had been used. Engraving using the same power and speed settings on the laser machine will always deliver a deeper engraving if a less dense wood like pine or larch is used rather than on a more dense wood like oak.
Old School Fabrications then took the engraved wood for finishing and treatment for outdoor use. As you can see, the transformation was incredible, and all the knots and imperfections in the wood added to the beauty of the signs. This picture shows one of them mounted in Edinburgh’s St Andrews Square by the pond, where OSF put a model crocodile to complete the African vibe!
We were lucky enough to get our hands on one of the signs the exhibition was finished. They were no longer required, so ours is in pride of place on the workshop wall. It’s a great example to show customers when they visit of how they can expect engraved wood to look. And it also shows just how well reclaimed wood can scrub up.
LaserFlair makes fun and funky acrylic jewellery for Jaggedy Thistle in Dunkeld. We laser cut their reindeer brooches in the run up to Christmas along with highland cows and Scottie dogs. This is how it all happens.
We need vector artwork to create items like this. Jaggedy Thistle provide the artwork for their bespoke products, and the acrylic in the colours they require.
Vector cutting detailed shapes
Vector artwork is very simple. It consists of hairline shape outlines, and the laser follows the lines in the artwork to cut out each shape. There is a vector line for each outline cut on a piece. In the case of the reindeer in the picture, we cut the eye shape first. When the body is cut, the whole reindeer can drop out of the acrylic sheet and is then in the wrong position to cut out internal detail. This is why we set the machine’s cutting order so that internal details are cut before outline shapes. We minimise waste by using our laser cutting software to tile shapes which maximises yield from the acrylic available.
Protecting the pieces
Acrylic has a protective film on each side to prevent the surfaces from scratching. We leave it on during production to protect the acrylic surface from the heat of the laser which causes discolouration near the cut edges. After manufacture, it protects the pieces during shipping, keeping each shape in perfect condition as acrylic is easily scratched.
When Jaggedy Thistle receive their delivery, they remove the protective film from each brooch. Then they add the red noses and brooch pins, and mount them on cards for sale. Aren’t they cute!
You’d assume that 3mm plywood is 3mm thick, wouldn’t you?
Wrong! With plywood, thicknesses are nominal, not actual. This is because plywood is made up of different layers glued together. 3mm usually has 3 layers, and the result is an actual thickness of 3.2-3.3mm. 4mm ply has another layer, and is usually 3.8mm thick.
Potential design disasters
This can create a whole worlds of pain for designers and manufacturers if they want to create products made up of pieces that slot into each other and require a good fit.
If you assume a thickness of 3mm and you design 3mm slots in artwork and then try to fit 3.3mm thick wood in the slot, it’s not going to happen. Or if 4mm ply were used, 3.8mm parts would be too loose.
Imagine making 300 reindeer kits for Christmas, sending the artwork to a maker, and getting back parts that don’t fit?
This could have happened to one of our earliest customers, but we made a prototype, realised the problem and fed it back to the customer. They tweaked the artwork before we performed the production run. This simple check saved our customer – and us too – a lot of time, money and heartache.
Always check that your designer and maker are speaking to each other to avoid disasters like this.
I love these wooden rings! But when Waiata Bespoke Jewellery (nga waiata as they were then) first got in touch and asked if I could engrave the backs of their chunky wooden rings with their logo, I wasn’t sure if I could do it.
Engraving on a curve
First of all, rings are cylindrical. Lasers need a flat surface to engrave. This is to maintain the right focal length for the laser beam for best results.
Secondly, the rings have such knobbly stones on them and nga waiata wanted to supply them made up rather than without the stones. How could we support them securely in the laser so they wouldn’t wobble or fall over during engraving? Any of these scenarios would be disastrous for engraving quality.
It’s amazing what you can do with Blu Tac! I use it all the time to support jobs on the machine. A nice big blob on the engraving bed floor held each ring securely, even although the stones are all different shapes.
My secret weapon
Now for the engraving. The text was small and fine and was to be centred in the middle of each ring back. I used my longest focal length lens which helps maintain focus better over curved surfaces. I also slowed the engraving speed down to maximise precision and minimise any wobble from the machine. This ensured crisply engraved letters, with a nice depth of engraving to give good visual impact in the chunky wood.
We’ve been branding stainless steel cocktail keys for Panch Drinks recently. They’re made in three sections for measuring fixed amounts of sweet, sour and strong ingredients, allowing cocktail recipes from mojitos to Moscow mules to be mixed to perfection every time.
These measures are made from stainless steel. Our laser can engrave some types of metal, and stainless steel usually gives good results. We had to use Thermark metal marking paste as the laser can’t engrave the metal directly.
The circular bases of the cocktail keys are only 50mm in diameter, which means that logos must be small to fit the space. As a rule, the smaller the logo is made, the harder it is to reproduce the fine detail when engraving it. Thick lines become thin, and fine detail that would look great on a large scale becomes almost indiscernible when scaled down to a few centimetres wide. In this case, we had to remove all the detail apart from the text, and even then I had to engrave some samples to make sure I could get good engraving results.
How does Thermark work?
Thermark is a mixture of pigment and glass particles. When the laser engraves it, it melts the glass and traps the pigment onto the metal surface, forming an enamel finish for a durable, weatherproof mark. Perfect for using in bars!
Yesterday, a customer asked me if I can make laser cut wood edges as black as possible as it would enhance her products. She wanted this even if it caused some charring on the surface which could be sanded off. No other customers had asked for this before. They just accepted that the edges would look as they came, and I would prepare them for what to expect.
The colour of a laser cut wooden edge is more to do with the colour of the wood used. A pale wood like birch or sycamore will have a lighter cut edge. Oak will be darker and mahogany darkest of all.
Best machine settings for laser cutting wood
The golden rule of laser cutting is to cut through cleanly in one pass as quickly as possible with a maximum of 90% power. This should minimise damage to the material and maximise product quality. If you cut more slowly than you need to, you don’t get a darker edge. You just get charring and flaming on the back of the wood. And it’s possible that the flaming could ignite the wood and cause a fire in the laser machine.
In this case, all the woods from plum to sycamore had quite dark laser cut edges. Kirsty makes wooden jewellery from the tiny shapes and sometimes paints them. You can find her as Hamespuns on Instagram.