Concret Vessel sink casting mold

01/03/2026 Update: I modified the mold at the base of the floor drain (trainer recess). When I first created this vessel sink, I machined this part by hand (which was quite a delicate process, I must say).

I took the measurements based on a standard French floor drain I have here. However, if you have the specific dimensions of your own drain, please feel free to send them over, I can then edit the corresponding version for you.

 To complement my bathroom vanity, I created this custom concrete vessel sink because nothing on the market was a perfect fit. Sharing this here in case it inspires someone else!

print settings:

I use PLA, but PETG or ABS will be more solid. Printed on my MK2.

Height 0.2 mm

Always orient the inside of the mold up for a nice surface. Use organics supports (look the exemple in the photo section)

My concret recipe

50% white cement

30% sand 

20% white marble 3 - 4 mm

Optionally a handful of zeolite or dye.

Add water to obtain a creamy texture.

Mold assembly:

Use screws and bolts to assemble the bottom and the top separately before you assemble them to make the main mold.

Be careful to ensure there is no gap or misalignment between to section.

Mold filling:

Return the mold and fill it carefully. Tap tap tap gently all over the mold to ensure the best filling in the corners. 

Post process 

you must patient 30 day for a proper curing of the concrete

After you can remove very carefully the mold. In my case impossible to keep the mold intact. I must use a heat gun to remove it. Maybe with mineral oil or mold release wax you can conserve it.

After that, use a  Flexible Diamond Hand Pads (200-400) to remove the layers lines and have a good surface finish. 

I’ve had it installed for two years now and it does the job perfectly. My wife is also satisfied with it. Regarding care, stay away from acidic cleaners and prioritize soap. I occasionally use a little bleach.