Are 3D prints water tight?

i print soap dispensers, 1.2mm thick single wall vase mode, .6 nozzle. and 5 base layers. ive been using 1 of my prints for a good 2 months now for hand soap in the bathroom and its still watertight. ive used over 15 different types of colors/filaments and i dont have any leak at all. its 70g in filament and a few hours of printing for each one. EDIT: forgot to mention, the default infill overlap is 25%, i set it to 50% in order to make the bottom layers overlap the wall slightly more, completely sealing the bottom so that there is no leak in the transition of complicated geometry

Another thing to take into consideration is the material you print with. PLA is porous and it was recommended to me not to use it for watertight objects. PETG is very similar to PET, the same material used in plastic water bottles. Not that you couldn't use PLA without success, but some materials will work better than others.

It's hard to make assumptions about whether the complexity of the object influences water tightness when you yourself say that pressure is greater in your larger vessels. You need a single wall thickness "cup" with the same volume as your larger, more complex walled designs. THEN if the large cup performs better wrt. water tightness, you can make a claim about surface complexity and layer adhesion affecting water fastness.

I've been 3d printing surfboard handles that have to be water tight. Using 100% infill and ASA, what's nice about ASA is i can use acetone to smooth the surface finish so the layer lines all merge together as an extra but of insurance.

Unfortunately you didn't mention your nozzle size, what material settings or band and most importantly your slicer settings.

for me i dont have problems with the walls, i have problems with the bottom. Just need to up the flow rate in my experience. Another way to make sure the walls are good is to make it print the outer walls first, then the inner wall with a higher flow rate so it fills any gaps between the two outers.

I have been able to make some prints water tight by increasing the Extrusion Multiplier in Prusa Slicer to 1.5 (150%). It even works on some simple vase mode prints

Thanks this was very helpful ...Can you please do fastening load test on filaments? or whats the best filament for say metal fastener strength inch pounds etc ..?

Got a file for that watering can? Looks pretty cool

the key ive found to watertight prints is increased extrusion multiplier. 4-5 perimeters with anywhere from 110% to 125% extrusion rate

i 3d printed a little watering can out of PLA+ and left water in it for over a month with no sign of leakage. I was impressed, this was before i knew it wasn't common for 3d prints to be water tight.

Holy poop, fusion finally made a dark mode?! That’s awesome!

I want to say thanks for making these videos. To say that they are helpful is an understatement. As a new, rookie 3d printer user,I have no idea about how to make my own designs. BUT I do want to learn. I have subscribed to your channel and will be taking ur masterclass to learn how to use fusion 360. But I have a question regarding 3d printed cups. Are they safe or have any of the filaments been tested to be safe to drink ANY liquids from whether they be hot or cold if u were to use the right filament for either hot or cold liquids? I ask because one of the goals after taking your masterclass is to 3D print my gf a coffee cup if its safe to do so.

What microcenter filaments did you use gor these two containers?

Is it possible the first one just leaked at the seam lines on the outside?

Is it possible to make airtight prints as well? I need a specific pneumatic valve, I'm I able to just print hem?

be carefull with your bambu lab jerk settings, your cilinder suffers from hight jerk, thats what I think, and nice video!!!

Lead in nozzle problem, any good solution?

Need a bigger nozzle with thicker line width

If the prices for a purchase and a print are very similar, you should add the electricity costs. That's not to be neglected!