As the basic principle of FDM technology is to grow products by layer-by-layer application of material to a substrate, a perfectly smooth surface cannot be achieved. The lines of the layers are visible in the finished objects. To bring a product, such as an Obsidian mind helmet, to the right parameters, it is subjected to post-processing. There are various ways of post-processing. The most commonly used ones are shown below.
Removal of shims
This is an obligatory processing step which does not improve the final appearance of the product. It is not difficult to remove the stump, and we recommend using a brush, brush, or Makeraser to get to hard-to-reach places.
Removal of soluble sticks
You will need to prepare a solvent-resistant container and the solvent solution itself (in some cases, water is sufficient). An ultrasonic cleaner, if available, may also be helpful. If HIPS with ABS was used as a prop material, the solvent should contain D-Limonene and isopropyl alcohol in equal parts. To dissolve PVA and PLA backstops, ordinary water will suffice.
Sanding
Once the prop has been removed and dissolved, it is advisable to start sanding the object. Use sandpaper of different grit sizes, a cloth for wiping, a brush, a soap solution and a face mask. Throughout the sanding procedure, the item should be kept moist. This helps reduce friction and eliminates the risk of damage. Start sanding with abrasive paper with grit size P100-150, gradually move to a finer grit (P5000).
Cold welding
If a large product is grown using a 3D printer, it is printed in parts. These are then bonded together to form a given object. When using PLA and other similar plastics as material, dichloromethane or a special adhesive is used for assembly. ABS parts are bonded with acetone. To join the elements, their mating parts are wetted with the desired solution and pressed together firmly until it has evaporated. This is how chemical bonds are formed.
Filling of voids
Voids may appear after the removal of shoring or sanding. To fill them, you can use epoxy (if the void is small), automotive putty (to fill big ones), ABS laminate with acetone (for small voids in ABS objects).
Polishing
After you have cleaned the object, you should start polishing it. To do so, it is worth preparing a polishing solution, P2000 abrasive paper, a cloth for wiping, a brush and a polishing disc (microfibre cloth). The object that has been sanded with sandpaper is washed under water using a brush. Once this is completely dry, the polishing compound is applied and the polishing process is then started on the polishing wheel or cloth.
There are also other post-treatment methods: vapour or solvent baths, metallisation, epoxy coating. After completing all of the above processes, the product is primed, painted and coated with a finishing compound. In this case, it is important that the materials are compatible so that all efforts are not in vain.