unequally from the part , which means that the dimensional accuracy of the part can be affected . Wearing a mask is also highly recommended for sanding .
Then there is the question of DIY or contract out the paint finish ? The application and the required outcome will be the determining factor here . For example , for an art installation versus an architectural model .
For DIY painting finishes , paint selection is important , specifically choosing a highquality acrylic paint , which can be used with a choice of brush , airbrush or spray paint . There are lots of Youtube videos out there for beginners .
Alternatively , there are a range of professional services that utilise highly skilled model makers , of which there are a good number that are familiar with the specific finishing requirements for 3D printed parts . For this , you generally need to build in extra time for delivery .
HYDROGRAPHICS
Also called hydro dipping or immersion printing , as its name suggests , this is a water-based surface printing technique for 3D objects that has been developed over centuries . It can be applied to 3D printed parts to produce stunning customised finishes on parts and models . It ’ s a bit messy
As bespoke finishes go , painting a 3D printed part can provide a very accurate , almost “ photorealistic ” finish .
and difficult to achieve standardized finishes on multiple models , but hydrographics is not really about standardisation .
Any 3D printed part will need to go through the same post processing stages as for painting as outlined above to achieve the smoothest surface finish possible , plus primer . As with painting , the quality of the surface finish will determine the quality of the hydrographics , so a great deal of sanding and / or smoothing by other means is required to eliminate any supports , layer lines or rough surface . Subsequently the part is dipped in a tank of water that contains the hydrographic design using speciality inks , controlled water temperature and the application of an “ activator ” chemical .
The results can be stunning , but again there is a time and mess trade-off .
TEXTURING
This is a bit of a weird one — whereby textures * can * be added to 3D printed parts as a post process . But the question must be asked does it need to be done this way or can you design the required texture into the part and print it ? One of the greatest advantages of 3D printing is that you can design this sort of complex detail into a part with little to no economic difference in the cost of the part .
This is particularly relevant for functional textures of parts that are required for added strength , or grip , or traction etc . If the rationale is the aesthetic , again , is it possible to include in the design . For fine details and tolerances , however , sometimes the best outcome can be to apply it post build via etching , routing , or grinding methods , but these processes do add time and cost .
CNC MILLING / MACHINING
This is generally a post process used for metal parts ( note it can also be an alternative production method for metal parts ). However , it is also possible to utilise it as a post process for polymer parts to achieve specific goals . It is not a particularly cost-effective method for finishing high volumes of parts , but can be useful for critical applications that require precise accuracy .
Issue 59 PECM 35