Why NOT use saltwater?

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gmoneyphx
Posts: 49
Joined: Wed Jan 29, 2014 8:57 am

Why NOT use saltwater?

Postby gmoneyphx » Sat Nov 15, 2014 8:52 am

From what I can tell here the consensus is top down with resin floating on saltwater works well. My primary concern was pigment loss from the resin into the water which does not seem to really be happening in the real world.

So the question is - if you are using a top down machine why would you NOT use the floating resin solution?

Phife
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Joined: Fri Jan 17, 2014 5:24 pm

Re: Why NOT use saltwater?

Postby Phife » Sat Nov 15, 2014 4:10 pm

While I dont have a top down machine, I did do some testing of resins floating on salt water.

I didnt have a problem with the dyes I use separating after sitting for 2 full weeks. Im sure pigment would settle though, so you'll have to remove the resin from the saltwater, or vice versa, if the printer will be sitting for a while.

The resin also seemed to want to move more when sitting on water, any bump of the table the printer was on caused waves that seemed to last longer than waves on just resin.. Not sure how this would affect printing though.

I guess the main reason everyones not doing it is it would require a more complicated vat to be able to separate the resin and saltwater, Also I dont think there are a lot of top down printers out there..

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PomeroyB
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Re: Why NOT use saltwater?

Postby PomeroyB » Sun Nov 16, 2014 5:45 am

I've got a top-down, and I haven't really looked into salt water. For one thing, my build area is small enough that I can just barely fill it with 1 liter of resin (~50$). purchasing another liter to top it off is not that big of an investment.

It also seems like it would make it more complicated to clean out the tank. Obviously, if you leave your resin in the tank for weeks at a time, that becomes a smaller issue, but I empty and clean my resin as soon as I finish printing (I print in a public workshop, so I can't leave the printer there).

kakapoopie
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Re: Why NOT use saltwater?

Postby kakapoopie » Wed Nov 19, 2014 2:25 pm

I have a top down, been using resin over saltwater.

Do it. It works. I've left it sitting for months now with no problems. No need to clean out the vat. Water is still clear after all this time. You can stir the resin if it needs and the liquids will still separate after if you wait.

Hugues
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Joined: Thu Oct 02, 2014 3:20 pm

Re: Why NOT use saltwater?

Postby Hugues » Wed Nov 19, 2014 2:54 pm

sorry but, i'm always confused between top-down and bottom-up. Do we speak about the direction of the light ? or the direction of the build ?

Is the Titan 1 for example top-down ?
http://www.kudo3d.com/

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PomeroyB
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Re: Why NOT use saltwater?

Postby PomeroyB » Wed Nov 19, 2014 8:30 pm

Hugues: Titan 1 is bottom up. It's projector/laser is on the bottom, and when it builds, the platform moves upward.

Machines like the Sedgwick3D or the Uncia are top down -- the projector is above the resin tank, pointing at the surface of the resin. The build platform slowly descends into the tank of resin.

kakapoopie wrote:I have a top down, been using resin over saltwater.

Do it. It works. I've left it sitting for months now with no problems. No need to clean out the vat. Water is still clear after all this time. You can stir the resin if it needs and the liquids will still separate after if you wait.


Interesting. What resin do you use? Sounds like it could be quite convenient if your printer stays in one spot most of the time.

maxman
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Joined: Wed Dec 18, 2013 11:34 am

Re: Why NOT use saltwater?

Postby maxman » Thu Nov 20, 2014 6:15 am

Hello everybody,

i've tested a lot and in my opinion saltwater is not the best choice. There are a lot of problems if you use it everyday.

And also the cleaning of the vat with a pump makes problems with saltwater.

That's the reason why i've developed my own resin replacement. With that you can use different vats for different resin colours or you can use a pump for suck of the resin replacement.
Even heating of the vat for lowering the viscosity is no problem.

In the next few days i will show you my resin replacement kit including 2L of resin replacement and a suction kit.

FR3Dprint
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Joined: Tue Dec 16, 2014 4:20 pm

Re: Why NOT use saltwater?

Postby FR3Dprint » Tue Dec 16, 2014 4:34 pm

Hi all,

I'm using this method for 1 year and very happy about the results. also very impatient to see how you proceed because you may have found a better solution.

CaptElmo2165
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Joined: Thu Mar 19, 2015 7:26 am

Re: Why NOT use saltwater?

Postby CaptElmo2165 » Sat Mar 21, 2015 2:41 pm

I'm wondering why saltwater bottom-up method hasn't been tested... My theory is that although there's bound to be some issues with light reflecting off the interface between the two liquids, having a liquid / liquid interface would completely eliminate the peeling force - effectively giving you the benefits of Carbon3D's new CLIP method without the expense of Teflon AF or the issues with creating good flex vats. Surely those are benefits worth testing this out for?

I have a Titan 1 and tried this but my vat isn't deep enough; without sufficient water in the bottom when I dropped the resin in, it dipped below the surface and grabbed hold of the bottom of the vat preventing it from floating again. I'd love to make a deeper vat and test this out though.

Hugues
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Joined: Thu Oct 02, 2014 3:20 pm

Re: Why NOT use saltwater?

Postby Hugues » Sat Mar 21, 2015 5:00 pm

I have a Titan 1 also,

Seems it was tested, please read this post with some links,
viewtopic.php?f=13&t=2767

Maybe you should try with glycerin

If we can crack this problem, it would be so great ,