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Geert Keteleer's Salt Water build-plate adhesion...amazing!

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I decided to try Geert's salt-water method today and was blown away. A thin, hardly visible layer of salt on the glass plate created trouble-free adhesion. When cool, the prints simply pop off with light pressure.

No fuss, no mess. I could not believe it until I had printed 3 of Geert's "snake" clamps for the UM2+ feeder tube and wiring loom. No pressure on the feeder tube, just support.

Thank you Geert :)

If you're interested you can get details here. Grab the info while you can.

Edited by Guest

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I'm interested, I've read Geert's original post, but I have questions?

(The link you provided doesn't work for me)

How do you actually lay down the layer of salt?

Do you dip the glass bed in a bucket of salt water?

Do you dip a cloth in the salt water and dampen the glass bed?

Or is there another way?

Thanks

Peter

P.S. I find glue stick generally works for me, but not always, so I would like to try this method if possible.

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I am glad the salt method works for you too.

@prb4: try this link: https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

First thoroughly clean the glass, and then clean again with plain warm tap water only (no soaps, no window cleaners). This outside of the printer, of course.

Then I just put a few drops of salt water on a paper tissue, and gently wipe the glass plate. Gently keep wiping while the water evaporates. So it leaves a thin mist of salt stuck to the glass, nice and equally distributed, but almost invisible. It looks like the glass is just a bit dusty.

On the second application, I just redo the wiping in the printer, without prior cleaning, and without taking the glass out.

The disadvantage: you have to wait until the models cool down, to get them off. And it requires a heated build plate.

For me this works very well for Ultimaker and colorFabb PLA, and a bit less but still okay for ICE PLA. But it does not work at all for ABS. For PET it works a little bit, but less than dilluted white wood glue (gr5's receipt: ca. 1 part glue in 10 parts water).

If you try other materials, let us know the results (or the lack of).

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Thanks for the extra information.

I've followed the link (thanks) to your website and downloaded the very detailed explanation. I'll give this a go and report back. I use almost exclusively Faberdashery PLA so hopefully this will work well for me.

I also noticed your gentle atomic pull method and have downloaded a copy of that too. I will give this a try next time I do a clean as I have always been concerned about the force exerted during an atomic pull and consequently don't do them until it is absolutely necessary.

One comment I do have is, have you tried going to 240 C during the clean even for PLA?

Your instructions suggest that 210 C is enough to melt the PLA which is of course true but I have always understood that it was a good idea to do an atomic clean from 240 C to melt higher temperature plastic debris (even if I only print with PLA).

Thanks again

Peter

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I never go over 210 to maximum 220°C for PLA. This would cause the PLA to get burned, thus worsening the amount of burned material inside. If you have printed with PET or ABS before, and you do the cleaning with PLA, you might try higher temps indeed to melt their residu, but only for a very short time. If you use nylon to do the atomic pulls, you will need a higher temp. It depends on the materials.

The brute force of the traditional atomic pulls is indeed why I developed this more gently method. I did displace the nozzle and teflon coupler a few times, and I worried about bending the rods, or doing other damage. There is no such risk with the gentle method.

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Hi

I'm reporting back my findings.

I've tried the salt method for sticking to the bed for a few days on a number of different prints.

It did work to a degree but I didn't find it better than the glue stick so I have decided to return to the glue stick.

I am prepared to admit I could be doing something wrong, or perhaps this method doesn't work so well with Faberdashery PLA.

Thanks anyway

Peter

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Thanks for the feedback, I appreciate it.

I have never used Faberdashery PLA, so I can not comment on that. But it is entirely possible indeed that some PLA-brands are more sticky than others. If they stick reasonable to an untreated glass (no glue, no salt, nothing), then they are likely to stick better with the salt method too, in my experience. And vice-versa.

Concerning the glue stick: it seems that different brands give different results. For my difficult models, I had poor results with the default glue stick in the beginning: corners did lift, but fragile models got damaged when removing them.

That is why I searched for an alternative method and came up with the salt method, which (for me) did not have both problems.

But that was before I read that you could spread the glue out with a wet tissue, and it may have been a different brand of stick. And it was long before I read about neotko's method of using window-cleaner to remove models.

So I think there is no "best method" that suits for everyone, every filament, and every model. But there are lots of very good and usable methods for different circumstances. So you should try a few and then use the one that suits your models, your environment (moisture, temp, etc.), and your filament best. And important: choose one that you like. :)

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Hi Geert,

Your previous help via this forum and your tutorial site were extremely useful. I wanted to let you know what a relief it is to have your saltwater method as a tool. It hasn't let me down yet.

I've moved on to slightly more ambitious prints and that fine salt haze on the glass makes PLA adhesion rock-steady. Thank you again and I hope life is going well for you.

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After learning of the salt method I have been experimenting with it and PETG.

 

PETG adheres well to plain glass (reportedly) and sometimes even breaks it during cooling (reportedly). I had been using the glue method: whilst can be reliable has been a hassle and eventually messy and I wanted to find something cleaner and quicker.

 

Whilst I can't say that the dozen or so prints so far constitute extensive testing, the salt seems to do enough to allow the print to cool uncouple without breaking the glass, but still adhere very well when warm. It's also much more reliable than the glue that with PETG is sensitive to the tack level right before the first layer is laid, as well as usually being an uneven surface that disturbs the first layer.

 

A risk though is that one day a print might be started forgetting that the salt has not been re-laid, and may result in damage to the glass.

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Thanks for the feedback.

 

When using dilluted wood glue for PET, indeed I have had chips being taken out of the glass. I already heard weird loud cracking sounds while it was still cooling down, before removing. So I think that was the moment the glass chipped. Mostly I print PET on bare glass, without salt. But in both cases (salt or bare glass) I have to use as little cooling as possible, otherwise large models tend to warp, so for PET bonding is not as good as for PLA. But results may differ a lot from brand to brand.

 

For PLA, since 2 years I always use the salt method with success, although here too there are differences in bonding from brand to brand. The biggest advantage for me is its simplicity. But I still don't really know *why* the salt method works, on a chemical or physical level. I guess it has to do with surface tension: soap and oils reduce surface tension and reduce bonding. Salt on the other hand increases surface tension, and by observation increases bonding (of PLA, not for some other materials), so it might have to do with surface tension too? Or would mechanical grip around the salt crystals, on a microscopic level, also play a role?

 

So if there would be any chemists around here, feel free to add your viewpoint. Educated guessing is also okay for me, as long as you tell so.

 

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