ON TO THE PROGRESS! The initial phases of the finishing process have begun. First, I had to join the pieces of the helmet together. For PLA plastic parts, this is really quite easy. The helmet is printed in 2 pieces, and the thickness of the pieces ranges from 2mm to 4mm. Normally, I'd superglue the pieces together. However, the pieces are quite thin, so the superglue doesn't have enough surface area to create a strong bond and can easily be snapped apart. Instead, I used a soldering iron to "weld" the PLA together.
**How to "Weld" 3D Printed PLA Parts: This is accomplished by slowly applying a small soldering tip to the back of the pieces, while the pieces are held together. You'll want to drag the tip along the joined edges softly and in quick strokes, so that you don't melt through to the other side of the part. If there are any places with a very large gap, you can use PLA filament as solder, and feed it into the gap while softly dragging the soldering iron over it. This will melt the filament into the gap, which will eliminate any large holes while joining the two pieces. Once you're done soldering, you'll notice there's a visible seam on the outside/visible side of the part-- that's ok! We'll cover that in the next update.**
After joining all pieces, you'll want to fill any other gaps and make the surface even by filling and sanding. My filler of choice for large defects/holes/seams is spackle. Yes, the stuff you use on drywall. You can purchase it at any home supply store (Home Depot, Lowes, etc). It's cheap and dries quickly. I only use this on large defects, holes and seams, not to smooth visible layer height (I find spackle is too messy and soft to get the final desired surface). Once the spackle has dried, I'll sand it smooth and make sure the defects/holes/seams are smooth to the touch. They don't have to be perfect, but the better they feel at this point, the less work you'll have to do later.
The next step is to use Filler Primer to get a perfectly smooth surface-- but for now, here's photos of my progress so far. Also, a bonus photo of the weapon so far. I still have about 3 more parts to print!