Differences between Clear V2 and Clear V4

Can anyone explain what the improvements were between V2 and V4?

I have been supplied a V2 cartridge by the local dealer (reseller) They are listed by FormLabs as a reseller.

What is the best way to clean up the resin after printing - I used IPA but the print went from clear to cloudy opaque very quickly.??

It will always be cloudy/opaque.
This has nothing to do with IPA, but its (print’s) surface finish.

You can’t get an optically clear print straight out of the printer.

The reason it appears completely transparent after printing is because the surface irregularities are filled in with uncured resin. Once you rinse that off, you get the real surface texture, which isn’t perfect, and so can’t be completely transparent either.

In order to get a transparent print, you’ll need to clear-coat your print (easy), or sand it and polish it to a high gloss (hard).

I understand what you are saying, but if I print the same part using a third party resin and another printer (rather than using FormLabs and a Form2) it is crystal clear after clean up and does not require further polishing or sealing.

The other resin was used in a printer costing a tenth of the price of the FormLabs printer - so why should the print from that be crystal clear after cleanup and the one from the Formlabs is cloudy.

I will now try that resin in the Formlabs.

I think only something like a Carbon 3D printer could possibly print something optically clear, and that’s because it prints continuously, and it’s much more expensive than a Formlabs printer. It has nothing to do with the resin, it’s all about how the object is printed in layers.

Also, I don’t think Clear V2 has been in production for more than a year, so if a seller has that available then it should be long expired by now.

I would disagree, I believe that the 3Dresyns clear is very close to optical clarity - and it does not require polishing after printing to see its clarity (Unlike the FormLabs clear).

100% guaranteed if you use it in the Formlabs printer it will not be perfectly smooth and clear once you rinse it off with the IPA, it’s all how the printer makes the object and has nothing to do with the resin. I don’t think that there’s any printer that can do that either, the only printers I know that will do that will make the object clear by polishing and processing the print afterwards.

The only case where you can get some optical transparency is if you’re printing an upright cylinder or cube or anything with exactly straight vertical walls, on a DLP printer (not SLA).

That is the only case that will (possibly!) produce no layering artifacts, and thus, optical clarity (under perfect conditions).

The clarity that I was seeking is glass like transparency after printing- rather than the misty white translucency of the Formlabs resin

As @Ante_Vukorepa mentioned, optical clarity is mostly a function of surface topology rather than innate material properties. This is why mechanically polishing Clear Resin will yield a fully transparent result. Taulman has a neat explanation of the effect on a more pronounced scale with FDM printing.

Clear Resin shouldn’t have a milky finish after printing. Can you upload some photos of the results you’re seeing?

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Just to be totally accurate - the print was printed and washed off in FRESH IPA. Its printed at 100um layer thickness using the correct setting for V2 CLEAR. TypicalLid3 wall thickness is approx 2mm

The way to tell if the milkiness comes from the surface finish is to put the piece into water. If it is clear in the water it’s the surface, if not it’s the resin.

I have put the print in water - it looks exactly the same as in the photograph

That looks like typical results, you’re not going to get it more smooth and clear without processing it.

Also, if you want it perfectly circular you need to add more segments on the curve, you can see the facet edges on there pretty clearly.

Thanks for the observation with regards the facet edges - That is exactly as drawn - (for grip)

If I print the same product using a third party resin it comes out clear - WITHOUT “processing it”

My original questions was asking the differences between V2 and V4 - any ideas? Is V4 clearer?

That’s a fair bit more clouded than I’d typically expect. In my experience, parts out of the printer will be near perfectly clear when given some sort of surface coating whether that be resin, oil, or water. You mentioned that water didn’t improve the clarity of this? That would point to some sort of coating on the surface causing the opacity you’re seeing. What’s your process for cleaning and UV curing?

Hi

I normally follow the FormLabs instructions from here: https://support.formlabs.com/hc/en-us/articles/115000024524-Form-2-Basic-Finishing-Steps

I have also tried cleaning with an airbrush and Ultrasonic cleaner - all have similar results (as per the pictures) with this material (V2)

I have also tried putting the printed part straight into liquid paraffin (mineral oil) and then leaving overnight before exposing to UV 395nm (at 30mw/cm2) for two hours (still in the liquid paraffin). It gives the same result as soon as exposed to air for a day or so.

I have tried post curing in air with UV - all gives me the same result.

Have I got faulty resin?

When dipped in mineral oil does the part become transparent ?

The resin is transparent at that stage - but even after post curing it becomes cloudy within 24 hours of exposure to air.

I understand that not only is the oil an oxygen inhibitor but it’s also a solvent of uncured resin. In much the same way as a glycol. Liquid paraffin is just a very slow solvent compared to IPA

I haven’t tried using mineral oil as a cleaning solvent. Does that seem to remove uncured resin from the print effectively?

The film you’re seeing sounds a bit like what some people observe after curing a part in water to inhibit oxygen exposure. Have you tried following a standard IPA cleaning process, allowing the part to dry, and then UV curing?

The standard IPA cleaning process was what I did very first - had that worked I would not have done anything else.

Mineral oil is a slow solvent - it takes approximately 5 times longer than IPA but normally with no discolouration of the surface.

What do you suggest I do next - The clear I purchased is certainly not as described ITS NOT CLEAR… Going back to my previous question, is this a faulty batch / cartridge of resin? If so how should I deal with that?