As I just 3d printed a set of sunroof drains for a member here I thought about improvements. As I understand it the weakest point is the drain tube, as it turns out you can add a brass insert for 3.00 CDN / 2.50 US.

If you setup one of the brass inserts and test fit it, you can then put epoxy on the tube and around the flange. When the epoxy dries you should have a solid brass insert. Running a rubber hose all the way up with some RTV against the body of the drain should give you a pretty solid connection that will not crack.

6.00 CDN for this it contains 2 brass pipes




The pipes ,note one edge has to cut or bent


Rough bend with a pair of pliers for testing



Fully inserted



Going in.

 

I saw something similar way back, but this is a great idea.

 

I have routinely screwed in brass fittings when the factory tubes broke off. A little thin wall but they hold. If you are printing replacements you could print them with enough meat to use threaded fittings, plastic or brass. Fun fact, the intake manifold fitting we remove to install the PCV valve is the same exact size.

 

@Extinct interesting thought I may try reworking it for that

 

Very similar to someone earlier, hat tip.....
I got really tired of constantly chasing leaks only to have issues with drains not allowing water to pass because of how tilted I had to park in some situations. I decided to weld in some 10mm stainless steel tube in all four corners of my sunroof trays - eight total. Then I added 3-way T's on all eight locations so that water can drain to either the front or back of the car from any catch tray corner. This also has the added benefit of reducing vacuum/suction issues for draining. Last I changed as much of the hose as I could to 10mm, since mine were 8mm and I wanted to improve water flow. So far... cross fingers... I have not had any leaks. I drilled holes right next to the plastic drain connectors and filled in the previous ones. Let's hope it finally does the trick!