Salt baked 3D printed parts

[John78]

This popped up in my YT feed a few days ago...  Its quite interesting for 3D printing things in general but especially stuff that goes outside on cold damp days.

I haven't tried it yet, still getting my new printer running right before I switch over to PETG - but it seems like a good way to make strong brackets without making them super thick and also waterproof electronics boxes, all sky cameras etc....

 

 

[Mognet]

I'm a bit curious about this too. I was watching Stefan of CNC Kitchen do similar with plaster of Paris. His method is a lot more involved though and needs a few items of kit that we wouldn't normally have around

https://www.youtube.com/watch?v=bG8dlxTX3AI

[markse68]

interesting idea- wouldn’t the salt stick to it though if it really re-melted? I guess you could always wash it off and it might give a pleasing texture 🤷‍♂️

[Dr_Ju_ju]

Personally, before I went down the hassle of the annealing route, I'd rather get it right in the first place i.e. properly slice & print the parts, e.g. 0.5mm layer height & 80-100% infill.

Strength wise I doubt you would see much difference, maybe not as pretty, and with salt filling in the threads, as pointed out in the video, meaning more cleaning up to do....   

[vlaiv]

48 minutes ago, Dr_Ju_ju said:

Personally, before I went down the hassle of the annealing route, I'd rather get it right in the first place i.e. properly slice & print the parts, e.g. 0.5mm layer height & 80-100% infill.

Strength wise I doubt you would see much difference, maybe not as pretty, and with salt filling in the threads, as pointed out in the video, meaning more cleaning up to do....   

I was thinking the same thing.

How much print speed influences all of this? My reasoning is that one can lower fan speed if printing slowly and let layers bond better together.

Time spent on slower printing would be the same as above preparation and annealing (at least for small parts).

[Mognet]

Apparently print speed and temperature do also affect the strength of prints though I'm not sure I'd use PLA or PETG for anything that would need to be reasonably strong, even if it was annealed. ABS might be better suited

[PeterW]

There are epoxy based coati by a you can apply if you want smooth and water proof. The only time I heated a part of up in an over it melted and left a small puddle! How have people got on with leaving prints outdoors, how long does PLA take to get damaged? I print solid PVDF for pretty much everything proof parts, not the cheapest though. 
With printing non-PLA do watch out for fumes.

Peter

[JamesF]

I printed a PLA mounting for the anemometer and wind vane of my weather station that has been outside since December and it's still looking fine.  It is a bit "over-engineered" perhaps, but I really wasn't sure how strong it needed to be.  It's not solid: 30% infill, as far as I recall.

James

[Mognet]

Stefan of CNC Kitchen has now done an analysis of the salt baking technique https://youtu.be/DyAKtS1b3SQ

[Chriske]

On 21/10/2020 at 23:12, JamesF said:

I printed a PLA mounting for the anemometer and wind vane of my weather station that has been outside since December and it's still looking fine.  It is a bit "over-engineered" perhaps, but I really wasn't sure how strong it needed to be.  It's not solid: 30% infill, as far as I recall.

James

As long as you print in white colour there's nothing that will happen with these parts, even in PLA. Sunrays are reflected and do not warm up the parts at all.
Good job..!

[Chriske]

Printingspeed does not affect layer-bonding at all -- as long as you're raising print temp. together with speed. + partscooling. For partscooling I use a 50mm radial fan. In the near future I'll even use a 70mm radial partscooling fan to be used when printing with even larger nozzles then 1.5mm.
I do print at 100+mm/s using print temp of 245 and even 255°C(PLA). To do this I use a Volcano hotend. With short 'standard' hotends this would not be possible at all.
Using a 1.5mm nozzle I need to lower the speed to about 50-60mm/s.  And I can assure you, my parts have all perfect layer bonds.