Epoxy Coating Your Print

So the other day I printed what I think is a pretty cool bracelet. The only problem was that because it was in PLA, it felt a little too flexible/weak to me (the thinnest parts are only 1.2mm thick) so I decided to see if an epoxy coat would add some strength and thought I would write a little how to for the forum here.

Here is the print (no structure, what a PITA. It was like magic watching it finally come out):


It's a pretty simple process if you haven't ever done it before, simply mix the epoxy and the hardener together in the right proportions and "paint" it on to your object.

You really only need:
1. A two part epoxy kit $12
2. Small disposable brushes $2
3. Latex gloves (this stuff gets stiiiiiicky)
4. A cup or disposable surface to mix it on

I ended up using an epoxy from my hardware store with a 5 minute work time, which sucked. If the product work time is too short, it will start to harden before you are done applying all of your batch to your object. Good epoxies have about a 1 hour work time. In the end, I mixed about 5 small batches on my disposable work surface instead of the usual 1 large batch.

A rather useful tip if you're going to epoxy your object is to figure out a way to hang it so it doesn't stick to anything while it's drying. I looped some fishing line through before I started to epoxy it and hung it from my balcony roof overhang when I was done .

Overall, I feel the epoxy didn't add much strength, even though the box says "1500 psi" on it. I have used it in the past and gotten much stronger results. I think that perhaps another layer will add the needed thickness for it to be really strong. One nice thing though is that the bracelet is now gloss coated looks and very shiny, which is hard to get a PLA print to do. I'd like to print some trusses and do some strength tests to test the actual benefits of doing this.

 

how thick per layer does the epoxy add?

I would like to get my prints with a smooth, glossy surface but still need to be within prototyping specs.

 

It is all in how much you brush on. Obviously, you will need to put on enough to fill in the rounded gaps between the layers, but you don't need much more than that and you can always sand it afterwards. It would be pretty difficult to be that precise though, much easier to just print in ABS and acetone vape it.