Full infill is not 100% !?

I wish the "Full" infill was truly full also.  My guess is they don't offer it because it requires knowledge to know when that will cause a print to warp badly or not.  Zortrax seems to have made "ease of use" one of their primary targets.  IMO, that's may be worth it in terms of how much happier the general user will be for not being able to cause their prints to fail.

However, I suppose Zortrax could just add a disclaimer dialog box like they do when you don't use supports to warn that "full infill" is not a recommended setting.  It is useful to have parts that can be machined, drilled and tapped and to not worry about them getting crushed or over stressed, which is easier to achieve with truly full infill.

Something I have noticed in almost all FDM 3D  printers that I have worked on is that they do not support true 100% infill. The open source printers tend to be able to do true 100% infill however some problems begin to occur. As Rafal put it "...the print will be strongly deformed, further due to lack of cooling prints can be "swollen"." what I have also  noticed is that some square parts want to shrink in all directions mid print, leading to highly deformed walls or surfaces.

Another problem is going to be that as accurate as the Zortrax may be, it will always have over or under extrusion when laying down each layer due mainly to consistency in diameter of the filament. I am not saying the material is inconsistent I am just saying that even with a +/-.05mm tolerance there is a factor the printer or software cannot account for. Another thing to consider is the bed level, we are operating with a fairly large build area that is not perfectly flat, when you lay down a layer over a high spot, where is the excess filament going to go? Well it will have to spread out or overlap with another line, this only compounds the effect.

On using taps and screwing parts together I have used PolyMax on a few prints that I was going to screw together or tap the hinges and It worked surprisingly well even with M5 and M6 sizes. I think what Zortrax needs is a setting to increase the amount of inner walls a surface can have, starting at 2 up to maybe 5. This would give people more options when wanting to sand, drill, and tap. There is a "Shell" setting that allows for an input of wall amounts, just add in support with the setting and BANG you got a new setting people will love.

As for WKirk's question about infill settings being different, I did some test print's yesterday and did not find any differences between them. I was writing you a followup email then saw this so I figured id leave it here. 

-Michael

Yes, post processing the part with acetone (I dipped it once in acetone and let it dry) totally solved the problem.

Good idea!  

Its easy to leak tight FFF prints.  Vapor polish, a self leveling epoxy coat or even paint in some cases (depends on part geometry and strength and whether you are sealing liquid or air and at what pressure).  To the point of the original OP... you could make a leak tight part with more geometries without post processing if full infill were allowed.