Least hydrophillic resin

In my business we are always using and testing prototypes of products in wet and humid environments. A certain degree of resistance to water can be obtained by lacquering, but they always eventually absorb the water like traditional SLAs do, swell and lost their integrity.

Could one of the formlabs chemists (@Frew?) , or a user with a lot of experience of similar please advise me? Which resins are the most resistant to this?
I am wondering if for example the dental resin stops this because it is formulated to be biocompatible?


I may have regarded myself as somewhat of a chemist while doing questionable experiments in my parent’s garage, but those days have passed…

Each of our materials are densely cross-linked and highly resistant to most solvents including water. What level of resistance are you looking for? The water absorption of Standard Resin is well under 1% by weight and each of our other materials will be comparable. The absorption tests were conducted over a 24 hour period so you might want to run your own for longer depending on the application.

Thanks for the quick reply. This particular application at the moment is a float in a hot water humidification device. It will be in water at around 60degrees C for up to a week.

I was just wondering if some resins were better than others, so I have the best chance of the prototypes surviving.

Most Resins are comparable in terms of solvent compatibilty and based on that application, I’d go with the Standard or High Temperature Resin. The HDT of Standard Resin is 58.4C @ 264PSI which sounds like it’s at the boundary of what you need so High Temperature Resin might be a better option.

I’ll give that a go, thanks.