Sunlu water Washable Resins WARNING!!!

[philipy]

I was getting major grief from SWMBO about the smell, not of the resin, but the IPA wash! As a result, some while ago I switched to water washable resin, which although more expensive than standard resin means there is no expensive IPA to buy, so overall there isn't a great deal in it AND I don't get my ears bent!
The Phrozen resin recommended for my printer is hellishly expensive at over £70/Kg so I tried the supposedley next best option which is the Elegoo WaterWashable. I am currently half way down my 2nd bottle and I haven't yet managed to get a satisfactory print from it - the usual story, prints fall off the plate and/or won't come off the FEP.
However a month or so back I decided to try Sunlu WaterWashable resin on the basis that it is half the price of the Elegoo stuff. Somewhat to my surprise it prints perfectly! Then a couple of weeks back Trevor said what good results he gets from Sunlu ABSLike resin. I went to look what was being said about it in reviews and came across what appeared to be the best of all worlds: Sunlu WaterWashable ABSLike resin! Although it is £31.99 at fullprice, on Amazon it is currently on offer at £25.59 ( https://www.amazon.co.uk/gp/product/B0C ... =UTF8&th=1 ) which is still expensive but I have not had a single printing failure with it and have just finished the first bottle.

This shows a ladder I've just printed with it, flat on the bed, which is 220mm long and the sides are 2mmx1mm with 1.1mm diam rungs.

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[Peter Butler]

That's a 'step' in the right direction!

[Trevor Thompson]

I haven't tried printing things flat on the bed without a raft - but something like a ladder seems like a good subject to try it out on.

Trevor

[philipy]

The problem is of course the dreaded elephants foot.
I've done a lot of digging around and found most of the answer to be the rest time for the first few layers. It slows down the whole print tremendously but having a bottom layer count of 3-5 and Rest after Retract of around 40-50 seconds allows the resin to flow and settle down so that it doesn't get squished out as it cures, which is what causes the problem. It doesn't eliminate it completely but only creates a small lip which is fairly easy to remove.

I'll have a dig for the blog that I found it on and post it here asap.

[philipy]

As promised, this is the link to the blog about printing on the bed, etc:
https://blog.honzamrazek.cz/2022/02/a-s ... d-printer/

He several times refers to a piece of software from Github called UV Tools, which I have downloaded from the links. The problem is that they are Czech and Romainan or something and my poor brain can't really follow the slightly tortured English instructions and I've not got things as good as they suggest, but its certainly better than just using conventional settings, although it slows down print times massivly and only viable for thin items, imo. The other thing is that he seems to have done it all on Elegoo printers and possibly not translatable to all other makes.

[philipy]

I've been really positive about the Sunlu Water Washable ABS-like resin, because it gave me superb results.

HOWEVER..... After I finished the Water Tower, I moved on to some winter maintenance of other buildings, one of which is the little signal cabin from Bench Junction. Having been outside for about 6 years 24/7/365, it needed a few bits sticking back on, etc. The barge boards at one end had dropped off and disappeared so I thought I'd print one V-shaped replacement, rather than messing about cutting styrene sheet. That worked easily and a couple of drops of superglue and some paint and job done.

Running out of space to keep them I took them down to the shed, which is cold and damp but watertight, and put them on a shelf out of the way.

That was three weeks ago.
Yesterday I went down to get something else, and to my horror this is what I found:

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I think that even when cured and painted, this resin is extremely hygroscopic and has absorbed lots of water with the result that everything swells.
It is very obvious on thin items, but in fact the tower and tank sides are no longer flat either.

Just to complete the sorry tale, I did say in one of the conversations at the time with Trevor, that I would put a dummy building outside over winter to see how it stood up... this is the result:

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Again, it has absorbed water but because it is constrained at the corners, the 4 sides have all bowed inwards!

So the lesson is: Don't use this stuff for anything that might get damp.

I'll find somewhere warm and dry to put them now and see if they shrink back, although I'm not optimistic.

[-steves-]

I've been really positive about the Sunlu Water Washable ABS-like resin, because it gave me superb results.

Do you know if the standard resin does the same or is it just the water washable resin?

Really sorry to see your buildings in that condition, but alas I am with you, I don't hold much hope of them shrinking back

[philipy]

I've been really positive about the Sunlu Water Washable ABS-like resin, because it gave me superb results.

Do you know if the standard resin does the same or is it just the water washable resin?

No, I don't know for sure, because I haven't got anything else in resin that has been left outside.

However, I don't know if you remember that I was working on a DeWinton with a one piece resin printed body? I left it on a window cill just supported at both ends on its end plates and forgot about it over last summer. I've found that it has sagged significantly in the middle. That was printed using Elegoo water washable standard resin. So it looks as the W/W resins are not very robust.

[Trevor Thompson]

That is a bit of a blow.

I will keep an eye on my creations using their isopropyl washed resin. So far there has been no serious distortion that I can see. I have a wagon, a locomotive, some sheep and some buildings created for others sitting in the workshop. Some are unpainted. The temperature changes significantly - warm when I have the wood burner lit, but cold and damp overnight. So it aught be a good test.

It is a timely warning as I was thinking about buying some of the water washable. That was driven by the isopropyl in the wash tank turning itself into a jelly again and before I would have expected to have to filter it. The cost of 5 litres of isopropyl every 2 months is significant, and of corse there is the issue of disposing of the jelly!

Trevor