There’s just something so satisfying about a perfect 3d print. But upon closer inspection, we still see tiny little layer lines that just isn’t good enough for us makers. To the common non 3d printing person, they wouldn’t really see the small layer lines that we see. To them all they see is the magnificence and marvel of a 3d printed object, no matter what it is.
But we’re just not satisfied with that. We need to have perfection. We need to have that beautiful glass surface finish that we can really show off to people.
So lets get to that. Here are 5 ways to smooth your 3d prints so you can quell that OCD nature of ours.
The first method is XTC 3d. This product is sort of an epoxy. It’s a PRICY product but it’s priced fairly once you see how well it performs. It’s a 2 part mixture that fully cures after a few hours. It has a fairly thick viscosity that allows for an even application to the surface of the print. The best part about this product is that it self levels. Which means you don’t need to keep brushing it over and over. As a matter of fact, it’s not a good idea to.
All you have to do is mix a 2:1 ratio of A to B. Then mix it thoroughly. PLEASE MAKE SURE YOU’RE IN A WELL VEINTILATED AREA. And if you have a face mask, please use it. The fumes aren’t that bad, but just do it as a precaution. A little xtc 3d goes a long way. So it’s better to mix this in small batches. Remember, all you’re trying to do is fill in the small micro trenches between layers(layer lines) to have a smooth print. After you mix the 2 parts together, apply with a brush. Make sure you use a disposable brush as the epoxy will ruin the brush unusable after the initial use.
Another great thing about this product is that it’s 100% sandable. If you feel like the surface of your print still isn’t satisfactory, you can take a sander and sand the XTC 3d to the desired level of smoothness. As always, start with a rougher grit sand paper such as a 120 then work your way up to 220 and 400.
One warning though, this stuff can get pretty messy, so if you can lay down some old news papers or a mat so you don’t ruin your table.
ALSO, XTC 3d can get into the details of your print. So if you have etch lines or other small details in your print that you want to show off, the epoxy might cover it up and you’ll lose that detail. So think about that before applying it.
This method is another common way to smooth your surfaces, especially if you’re building Iron Man Suits or other cosplay armor. You can do it of two ways, with a power sander or just straight elbow grease. I suggest the power tool.
Using an orbital sander with a low grit sand paper like 80 or 120 start sanding the surface of your print. BE CAREFUL not to stay at one place too long as the friction might start to melt the plastic and we don’t want that. After you get a hazy colored surface, move up to a higher grit sand paper and repeat.
One thing to note that some materials sand better than others. PETG is far easier to sand than PLA.
If you’re still printing in ABS you can use acetone to smooth your prints. I’ve personally never done this, but from my understanding, all you do is put a print in a container with acetone and the vapors of the acetone will create a chemical reaction to the print that smooths it out. Only a small amount of acetone is needed to smooth the 3d print.
I’ve even seen 3d prints put in to a mason jar with acetone and just shake it so the print is evenly covered. Then take out the print to air out.
Again, this isn’t something I’ve personally done, so if you know more about this, please feel free to email me and we can fix this article.
Wood filler/Spackling/Glaze and Spot Putty
What I love about these products is their ease of sanding. I don’t need to spend hours with an orbital sander or mess around with stinky chemicals. I just open these up, apply, wait for it to dry, sand, and done. These all work about the same, although they differ in chemical make up.
For these all you have to do is apply these with a scraper. You can also buy these at any hardware store or Amazon. Or if you have a rigid but flexible flat applicator. Think of something like a credit card. Then take a little bit of the product around a tablespoon size amount and then apply to the desired surface you want to smooth out. After you’ve applied the wood filler or spackling, wait for it to dry. They normally start off pink then turn brown once it’s dried. Depending on the time of year, it could take an hour to a few hours for the stuff to dry. After that, sand like you normally would.
Glaze and spot putty is slightly different. I don’t use this one for large surface areas, but mainly for spot fills for my prints. So small divets or small crevices are what this is best for. Just like the wood filler and spackling apply and wait for it to dry then sand.
Much like XTC 3d fiberglass resin coats the surface of the print with a thick viscous material that hardens after it dries. It dries in UV light so the winter time isn’t the best time for this.
Read the instructions for mixing the fiberglass resin. When you buy this it normally comes with the fiberglass resin and an activator. WARNING: this stuff is super potent. YOU NEED TO USE THIS IN A WELL VENTILATED AREA AND USE A MASK WHILE HANDLING THIS CHEMICAL. You also might want to use gloves.
Application for this is just like XTC 3d. Mix the activator and main component together, apply with a disposable brush, wait for it to dry, then sand.
Again, if you’re going to use something like this, ensure that you’re ok with some of your details going away because this stuff is super thick and will cover those up. XTC 3d and fiberglass resin is best for flat surfaces that don’t have much detail.
Lastly but definitely not the least filler primer combines all the good things we want from the previous examples. Filler primer comes in two ways, a spray can or a regular can. It can be applied via spraying the print with it or using a brush to apply it. Spraying allows for a more even coat on the surface but the bigger regular can is SO MUCH cheaper.
When applying the filler primer with the spray can, spray it with a smooth sweeping motion from side to side to ensure proper application. When using a brush also try to thoroughly mix the contents as the filler particles may have fallen to the bottom. After applying, let it dry. It should dry in about 30 minutes.
After drying you can directly sand the surface with 400 grit sand paper, although I suggest wet sanding it. Wet sanding is basically sanding the print with a wet sand paper. This helps the sand paper not build up gunk on it. To wet sand the print, just dip the sand paper in water and sand the surface of the print. Continually dip the sandpaper in the water while doing this.
Filler primer performs best if your machines are perfectly calibrated and is printing perfectly.
So there you go, lots of ways to smooth your 3d prints. There’s no wrong way of doing things. I would take this knowledge use apply each method for the given situation. For armor, I would do the sanding and wood filler method. For helmets, I would use the XTC 3d, and filler primer for your all around prints.