Hey guys! I was hanging around the Siraya Tech group on Facebook and someone from Siraya Tech mentioned using fermentation belts to keep resin warm in the vat so I decided to check it out. Here are my findings.
What is a Fermentation Belt?
For those who don't know, fermentation belts are basically a heating element wrapped in silicone with a plug on it. They’re simple devices, you plug them in and they get warm or hot (depending on your definition of hot). They're primarily used to make beer, kombachi, kimchi, etc. You can use fermentation at a relatively steady temperature. So you might be wondering, why you need to do this?
Why Do You Need One?
There's two main reasons why you might need a fermentation belt to heat your resin. Number one is if you're working in a non-conditioned space (no A/C or heat), you have relatively wild temperature swings or it simply gets too cold for your resin to work properly. All resins have temperature ranges that they're designed to work in. If you set up your resin 3D printer, run some test prints and get an exposure time, then the temperature drops that exposure time will be longer. If it gets warmer, then the exposure time potentially gets shorter. If you're in an unconditioned space and you start printing at one temperature, then the temperature drops significantly, the exposure time is going to change and your print's going to fail.
The second reason is some resins are specifically designed to work best at higher temperatures. The resins I primarily use are Siraya Tech Sculpt and Siraya Tech Build. According to Siraya Tech, both work best above 25 degrees Celsius. You might have seen my other video where I built an enclosure, put a thermostatically controlled outlet on it and a cheap amazon heater. That worked great and it's still a completely viable build and it works especially well if you want to enclose some of the fumes that could be produced while 3D printing.
The fermentation belt is not only good, but it’s fast and it's cheap which is kind of a miracle of engineering. I strapped one onto my Epax E10 and about an hour later the resin was up to 25 Celsius. Within about two hours, it stabilized at right around 30 Celsius. This is perfect as resin needs to be above 25 and 30 Celsius as well within a normal range. The belt fits perfectly on the Epax E10. On my smaller Creality LD2, I had to put a support. You can use materials such as a rubber band or a Velcro strap to hold the fermentation belt close to the vat. If you have a printer with a metal vat, such as a Saturn or the Mars, its going to heat up quicker since they're more heat conductive.
Heating Resin Outside of the Vat
There's one area where this doesn't perform as well as my heated enclosure and that is if you need to add resin in the middle of a print which I often have to do when I’m printing large molds. So for that you need another fermentation belt, or in this case I got a Kombucha heater. You can also get large pad heaters if you want to do multiple prints. These pad heaters work really well since you can put multiple resin containers inside and keep them heated. It still comes out much cheaper than the enclosure and the thermostatic control outlet and the space heater. You're looking at under sixty dollars for the fermentation belt set up and it works great.
Links to the different fermentation belts I’ve used are in the description below. if you're using any engineering resin that needs to be warm, this is a great way to do it. It absolutely works flawlessly.
Hey welcome to Gulfstream Outdoors where I help you get the lure out of your head and onto your line. In part three of this series we're going to actually shoot some molds I 3D printed and we're going to see how they turn out. Let’s go!
Processing the Molds
So to post process these molds after you've done printing them, we're going to do a two-part wash in acetone. The first wash is what I call the “dirty wash”- I don't change the acetone that much it's just really to knock off a bulk of the uncured resin off the mold. Once I get done with that I rub it down pretty good, maybe dunk it again and then I move it over to my wash-and-cure station. Here and I dunk it one more time in cleaner acetone and give it a spin, about 30 seconds. With the resin I use you can't really have it soaking in acetone or IPA or anything for too long or it starts to break down so I give it a quick spin for 30 seconds dry it off and look over it real quick to make sure I have all the resin off. Then, I pop it back and I cure it for 25 minutes. So for some resins that's an insanely long time, but for psoriatech scope that I use that is the recommended cure time. Interesting fact, when you don't switch modes on the washing cure you get a wild ride. Elephant’s foot is caused by overexposure of the resin and we do that when we print it flat against the build plate. Those first layers are overexposed and it spreads out the resin or actually the exposure of the resin and it gives you a lip (or they call it elephant's foot). It's really easy to take care of, I just knock it down with some sandpaper give it a few strokes there and we're all good and we're nice and flat.
Shooting the Molds
So today we're going to shoot a few different molds, going to heat up plastisol. We have my multi-cavity worm mold we have this weird, I don't know, headless salamander I guess I would call it. We have the mold I made in part two of this video a little Ned kind of ball tail. The reason I’m shooting multiple molds is they all have kind of different venting characteristics. The last Ned mold I have only has a back vent, the other Ned ball mold I have has the side vents that we did in the video. The headless salamander mold has side vents in part, but not all throughout, the body. The earthworm mold has only very large back hole vents, you'll see what trouble that causes. As always when you're shooting plastisol, proper ventilation and a mask is critical. So you'll see here how I use the M5 bolts and the M5 rivet nuts to get this thing all squared up in place and cinch down. Now you'll see on a few of these molds I don't actually put M5 bolts throughout the whole mold because I’m going to use my bench vises to clamp them down into place. I find it's just a little bit easier to deal with you have less screws and bolts to remove at the end and it holds pretty tight and it's secured in place very, very nicely. I’m actually going to do a two part injection, I’m going to first inject them all with chartreuse then I’m going to go back and clip some tails off and we're going to come back and shoot this kind of purplish galaxy kind of color. This will show that we can actually get two parts of the plastisol to fuse together in these molds and there's nothing weird.
Let's check out the results! These are very interesting to me because I’ve never actually done these types of molds with different venting back-to-back. The molds that had the side venting that I put on in part two, they certainly worked. There's no air bubbles to really speak of, it seemed to vent quite well and I actually got a decent amount of flashing right there, no major air bubbles or anything. But I get a lot of flashing and that's, I think, the vents are too big. The interesting thing here is if you look at this Ned ball mold that I did without any venting other than a single vent in the back, it has a little bit of flashing as well but obviously not as much flashing as the other ones. Then you look at the earthworm mold and it has an oversized vent in the back and it has no flashing and no real air bubbles, although I do have one where I did the laminate that got an air bubble stuck in it in one part but even all the other worms around it came out fine.
Resin vs. Aluminum
This leads me to an interesting theory, I think that the resin molds are nowhere near as precise as aluminum molds. Any aluminum CNC machine, you're going to get a production quality aluminum mold from it. It’s going to have tolerances at least in the thousands of an inch that's .0001 inches which ends up being like .002 millimeters. My 3D resin printer is pretty darn good by default, it does .05 millimeters and I can get it down to .01 millimeters but I can't get it down to .002 millimeters so I think any venting that I have that I can actually render the detail on is going to be too big and cause flashing now and on top of that. 3D resin printers are not very precise, the edges are not perfectly flat like you'll get with a CNC aluminum mold. They have variations, the resin I’m using has a three percent plus or minus shrinkage. Once you cure it so all that adds up to what appears to be a flat surface but it actually is a relatively uneven surface. I think that plays to our advantage here and those uneven surfaces actually are uneven enough to allow the air to escape so you don't need like this super complex venting system that you would need with an aluminum mold because it's just not as precise that makes our design a lot easier. I got air pockets but I got the air pockets in places that I couldn't really add venting anyways, they were up on the top part of the mold not on the side of the mold where my vents were. I think that might be due to not applying enough pressure on the chute, not shooting cold enough or hot enough. If you have any suggestions on what you want me to try to fix, please leave a comment below and I’ll give it a try in another video. Really there's no better way to produce a prototype mold or a mold that you're going to shoot for yourself than 3D resin printing compared to CNC aluminum.
Printers and Prices
I have two printers, the Elegoo Saturn and the Epax E10 both mid-sized resin printers. The Saturn will run you about $500 before taxes the Epax E10 will run you about high $600 before taxes. I also have the Creality ld002h that runs about $250. Any of those printers will produce molds for you so you're getting into a machine for between $250 and $700 and you'll have some resin costs. Let's just call it right around another $100 for resin and other stuff, then you add a little free software fusion 360 blender and you can be producing molds. The molds are going to cost you each in materials about two to five dollars depending on how they are. I can confidently say for under a thousand bucks you can produce probably hundreds of molds and that's incredible compared to even a desktop CNC machine which is going to run you a few thousand dollars. You got probably $10-$20 in materials and frankly I think it's a lot more complicated because now I need to learn, in addition to CAD I have, to learn CAM to run my CNC machine. At the end of the day aluminum is far superior to resin, it gives you far better results. Less flashing and less hassle but adding a resin 3D printer to your design step makes sure that you have a viable lure that swims exactly how you want it to before you send it off to a CNC machine.
Hey guys I hope you learned a ton from this series. Hit that subscribe button, I have a ton more lure videos coming up some really exciting projects that I’m happy to see. I’m super close to a thousand subscribers and as soon as I get to a thousand I’m going to be doing a really, really cool giveaway that I think you will all enjoy. Take care- tight lines. Get the lure out of your head and onto your line.