hi
I need a way or/and a substance to make my printed items watertight throughout the wall thickness, not only on the surface?
Why don’t you try to coat couple of times using spray rocker that is used by hobbyist?
spray rocker is only a surface treatment. I need a way to make it waterproof all the way through the material. Something thin as water and non turpentine based.
And further, it must be able to withstand a temperature of 80-100 Celsius
ABS with a heavy acetone wash?
Maybe you can make the cavity hollow and use spray foam or resin to fill it?
Whatcha makin?
@Jon_Gordon Not a bad idea. I can fill it with silicone.
I just edited to say resin too, at least with the resin it would get in the internal cracks easily.
@Matt_Harrington It a complex cooling tower in a mold. With a of Cost of 3500 $ a apiece i can make a considerable saving by 3d printing the tower. But it has to be watertight the first time without any doubt. and the only way to test i have til assembly the mold with the tower, and that alone its a 2 day process for 2 men. If its fails its another 2 days.
Can you vacuum mold the tank? Or am I way off?
@Jon_Gordon I’m not quite sure I know where you’re going with your question. But Vacuum molding is not an option, unless it is a step to make a 3D printed cooling tower waterproof. 
I was just thinking about vacuum molding the bulk of the tank because I have a project that’s similar (water tank) is all and there’s no question if it water tight or not.
Just saying you don’t have to 3d print everything if you don’t have to.
If you were so inclined, you could over fill the layers. Basically make the slicer think the filament is 20% smaller than it is. That should leave smaller air gaps.
@Mikkel_Bohme , awesome. our big cooling water tower at work leaks all the time so I can appreciate your concerns.