Question on join three trimmed surfaces then mesh

I’m trying to mesh two 90degree pipe with a stiffener at the 45degree interface, tried Join and Boolean Union, I can only join two out of the three surfaces; then tried join edge, it successfully joined three surfaces now but when I try to mesh with QuadRemesh, it can only mesh two of out of the initial three surface together, did I miss any Rhino basics here?
Monotube.3dm (294.9 KB)

Thank you

Hello- you can do that with NonManifoldMerge but the object will not be ‘real’ since the surfaces have no thickness - are you trying to make a physically accurate part or something for analysis only?
MonotubeMeshed.3dm (452.5 KB)



Thank you for helping out, good to learn the nonmanifold edge.

Answer to your question, I’m trying to create quad mesh of the three surfaces then export for analysis. And a follow up question regarding this goal, I want to create quad mesh with joins that are shared by all three surfaces, now after using Nonmanifoldmerge then QuadRemesh, I saw the joint is no long shared by the surfaces unlike I tried on two out of the three surfaces previously. Is this because of the reason mentioned in the help manual below?

Any suggestion on the meshing technique and/or help material? For example, is there a way that I can control the location/point of division on each surface when I do quad mesh as I don’t really need to combine the surfaces if I can control the division point at the open and nonmanifold edge, such as something like below:

Thank you,