I noticed a post asking about the resin wash solution, and thought this would be a good point to add in regarding cleaning.
Several months ago we were working with the guys at Formlabs (prior to the resin wash solution coming out), and they were kind enough to provide a Wash II for us to use in testing. I should publicly apologize to them for not getting back sooner (i had my reasons - see below).
We had been (Q2 of this year) working with ultrasonic quite a bit, but in addition using SimpleGreen (concentrated). I’ll outline a handful of the paths we ran in our testing, and give some feedback as well
Due to being a victim of a pretty bad car wreck, my own writeup of our testing got terribly sidelined for the fall, and I’ve been well enough to have picked it up again around a few weeks ago.
Now, we’ve only run ~ 25 liters of resin thru our Form4 this year, so I wouldn’t claim to be an expert on it by any stretch… This has been across: Black, Grey, various Silicons, and Tough2k.
This testing has been over the course of producing somewhere around 2200-2500 various prototype and production components… approx 20% of these parts have been smaller than 1 cubic inch, about 60% have been the range of .5" x 1"x 2",and the remainder have been a bit larger - say 2"x2"x3 ish… So a good smattering of options. 80% + of the units have logos, lettering, or other high-visibility surface engravement on/in the surface, which makes for excellent test subjects…
So… We had several goals in this process:
- Get away from any brushing or cleaning work. With the exception of one or two above, we never actually brush or clean any production parts post-print. We simply move them into the next container and let the tools do the cleaning. No brushing, no scraping, etc… in fact, the only real handling we do is breaking parts off of the build supports… And we’ve gone to miniscule support brackets (.15-.25 mm), so there is virtually no cleanup of parts post cure (obviously your mileage may vary, considering product dimensions and material strength)…
- Cut down on waste of IPA. yes, it’s cheap/cheaper, but there is a non-zero ecological impact, and we really wanted to cut this down… It really adds up when you start doing small runs of prototyping. We found that the general IPA life was too short, and the eco foot print was larger than we liked.
- Consumables loss. We wanted an intermediate solution which could be recaptured, and cut down both ecological and logistics…
- Time savings.
So…
Our testing paths:
Control path:
- hand clean/wipe resin off
- wash in IPA Wash 1 (10 minutes)
- cure
Alternate test paths
1. Simple Soak
- soak in Simple Green (10-20 minutes)
- wash in IPA (10 minutes)
- cure
2 Long SimpleSoak
- soak overnight in Simple Green (8-12hrs)
- wash in IPA (10 minutes)
- cure
3 Simple Wash 1
- wash in Simple Green (in FormWash version 1) - (30-40 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA (10 minutes) in Wash 1
- cure
4 Soak & Wash 1
- soak in Simple Green 10 minutes)
- wash in Simple Green (in FormWash version 2) - (20 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA in Wash 1 (10 minutes)
- cure
5 Soak & Hot Ultra SimpleWash
- Ultrasonic/heated to 40C in Simple Green 10 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA Wash 2 (10 minutes)
- cure
6 Soak & Warm Ultra SimpleWash
- Ultrasonic/heated to 30C in Simple Green 10 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA Wash 2 (10 minutes)
- cure
7 Soak & cold Ultra SimpleWash
- Ultrasonic/no heat in Simple Green 10 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA Wash 2 (10 minutes)
- cure
8 Soak & Wash 2
- soak in Simple Green 5-10 minutes)
- wash in Simple Green (in FormWash version 1) - (20 minutes)
- splash thru IPA bath to remove SimpleGreen
- wash in IPA Wash 2 (10 minutes)
- cure
SO, results.
First, the control path is the most simple. It has all the negatives and few of the positives.
Now in their defense, this wash process was with a Wash 1, which is significantly lower performant than a Wash 2. I know - we have Wash 1 and Wash 2 side-by-side, and the difference is visibly obvious, due to the waves and intensive motion induced in the Wash2.
However, using a Wash2 alone would not solve for any of the various other goals.
On Ultrasonic. - - - Hot Ultrasonic (#5 above).
40C is too hot. the product comes out soft. too soft. we figured out that we’ve likely been causing changes to the plastic at that temp… So while the product came out clean, the product was likely altered (not visibly, but likely altered to be weaker).
#6 (Ultrasonic and wash)… 30C is ok, though we really didn’t see any significant cleaning difference from the room temp SimpleGreen Wash (#8). In fact, the heat doesn’t seem to help remove/loosen the resin in any noticeable level from our testing.
Conclusions:
- The Wash 2 rocks. It really IS JUST THAT GOOD. Quite a significant improvement over the 1. quicherbitchin and go buy one. or, I’d say buy 2 (see below)…
- Ultrasonic isn’t really useful, if you are running the Wash2. The real need is to have good agitation… the ultrasonic action is an acceptable displacement engine, but the wash is long-term more effective in my opinion.
- We have only ONE of the Wash2, but if we had a second, I think we would have 100% perfect products, nearly every single time. In fact, as it currently stands, using paths #4, 7, or 8, we’ve lost fewer than 5 production/prototype units due to incomplete cleaning in the post-production processes. So that’s greater than 99% effective cleaning for acceptable outcomes… I’m not displeased…
- SimpleGreen is your friend. 2.5gallons Concentrate is $22 at Lowes… and it cleans up easily… Now, I’ve not tried the resin wash solution, but I’m going to step out on a limb and say there’s no way it can match SimpleGreen for cost and usable life. SimpleGreen (SG) is nearly permanent… in fact, we bought 5 gallons, over 7 months and 2000 parts ago, and are still using it… and likely have over 4.5gallons of it left…
Our steps with SG is simple: The resin tends to fall to the bottom,and if left dormant, will separate to the bottom… We let it settle over the weekend, then pour it thru a metal sieve to capture the majority of the resin out of it, and pour it back in the wash tank… Then every 2-3 months, we pour it back into the original SG 2.5 gallon containers, let it settle again overnight, then set it on the dock for a day… This causes further separation, and the resin hardens into a sludge at the bottom, for easy separation.
I’m not saying SG has eternal life…but well, it’s well past several DOZEN liters worth of resin in production at this point, and is super effective. and it’s $10/gallon…
Finally, we also bought a $120 whiskey still off of Amazon, and we use it to recover 90%+ of our IPA… We never toss IPA, and because of our use of SG, we only have to clean and recycle the IPA every 3-4 months. It has quite a significant impact on the life/longevity of the IPA.
The distillation of the IPA is pretty simple - though it takes about 4 hours to run… So you really do need to either have enough IPA to have a run batch and a batch to clean, or you need to have shut down production for a day or so while running the distillation process…
SO…
Which path is most effective?
#8 and #4 above. These are the 2 most effective and least complicated (both in time and hassle)… And they happen to be the less expensive as well…
If I had my way, we’d have TWO of the Wash2 units, no ultrasonic tank, and a couple of the Form4 Finish Kit buckets for ‘splashing’ thru…
Our process is usually most effective when we ‘splash’ the initial units thru a bucket of SG, which gets ~50% of the resin off (thereby doing the most concentrated initial cleaning, THEN the SG Wash2, THEN a splash thru an IPA bucket (to get most of the SG off the product, THEN the IPA wash in a Wash2.
Would love to get some feedback or questions…