Relatively new to the entire world of multi-filament printing. We use our machine (P1S) to print out or patterned conchos that we put onto our coats as their hardware.
These have current raised designs on them, and the owner of the company was wondering if there was some way to add a top “solid” layer of clear filament to make it into a smooth surface with the design still appearing 3d underneath.
The comparison given was make it look like a snowglobe.
Currently printing our conchos in PET-G. Designs are solid, and do not have a danger of collapsing as is.
Just wanted to get input from those more experienced in the realm of 3d printing and various filaments.
I did some similar work a few years ago where a perfectly smooth, clear and shiny surface was required.
For some parts I could have sanded it smooth, give it a flame treatment and apply a clear coat.
The majority however had raised features…
I got some 2k casting silicone.
Picked a small plastic ball to provide the required roundness for the clear top.
Actually I had three balls in three sizes but never mind…
Some modelling clay was used to make a basic mold to hold the cut part of the ball.
This was then filled with the casting silicone in order to create the mold for the resin.
Goes a bit like this:
Place the model face down into the mold and make sure the bottom is level - I used a tiny bubble spirit level.
Mark the flat bottom level of the model with a few dots using a permanent marker.
This makes is much easier to align the model in the mold
IF your model has vertical walls from the bottom you can either fill this void using modelling clay to prevent the resin from filling it or cover the entire model in resin.
Up to you.
Now for the fun part, the casting…
If you don’t have a vacuum pump get a cheap hand operated one for sealer bags or a more universal one for a sex toy supply store…
They are quite cheap.
For the first try prefer a resin with a long enough pot life.
You might need a few more minutes until getting used to it.
Degas the resin after mixing by applying a vacuum.
I have a big glass jar that once had pickles in it that I use for this.
A glued in hose connector in the lid and a hole to vent it covered by sticky tape.
For the models I abuse a small cooking pot and use a wooden lid (sealed with clear coat) and a silicone ring made from the same casting silicone to seal it.
Pour the resin into the mold and try to let it run over the model you hold with your other had - it has raised features.
This helps to create a resin film on the model and won’t trap as much air.
Put the model into the resin and tilt it a bit back and forth if you know there will be air trapped.
Once properly aligned place in the pot to apply a strong vacuum several times.
Most models are not water tight, so they won’t be air tight either and the trapped air will escape.
If in doubt repeat this process a lot of times if the surface of the model allows for lots of air to become trapped.
Assuming the resin has a pot life of 15 minutes try to stop messing with cast after 10 to 12 minutes.
Assuming it has a curing time of 8 hours allow for at least 10 hours…
Once you tried it and worked out what mold shape works best for your needs you will have already worked out a routine that works for you and get good results.
Just be prepared to ‘waste’ a few models before getting it right.
Might be worth to print them as cheap as possible to use the real ones once you worked out the casting kinks.
