I say railing, but I don't know the real word for it.

Here is the issue

Now, Source brushes are constructed in a way that they can't be concave/convex without being split, without carving it into an arch etc.

well, with a basic cube, you can't make stair railing very well. or stair borders. regardless, it is not fun.
The borders are as sharp as a knife near the bottom, yet smooth at the top. this is because of the nature of source, where you can't have differing angles between the higher and lower parts of the railing, or else a "lump" or "crease" would be made in the brush, and I am not sure, but that isn't stable to my knowledge. like trying to make a brush concave. it'll auto-delete itself next startup. This is why there is a little triangle at the bottom, to transform the angle from a slant to a straight line.

I know, the more experienced mapper would say this is a horrible idea, and it needs to be a model. but, I lack a modeller, and I really want just a basic border for it. has anyone got any ideas or tips for alternate methods?

All I can recommend is arches, and vertex editing. Start with an arch with a lot of sides, like 16 or something, for smoothest looks. Here's something I have had sitting on my hard drive since two halloweens ago:

I basically just took arches and cylinders and shoved them together in different ways. What you have there looks kinda messy, I'd recommend trashing it and starting over.

p0rtalplayer wrote:
All I can recommend is arches, and vertex editing. Start with an arch with a lot of sides, like 16 or something, for smoothest looks. Here's something I have had sitting on my hard drive since two halloweens ago:

I basically just took arches and cylinders and shoved them together in different ways. What you have there looks kinda messy, I'd recommend trashing it and starting over.

The issue is, I'm recreating this:

so the side isn't exactly railings, it's a solid wood. but to do that, the angles are all messed up.

You can split the top/bottom face by selecting two verts and pressing Ctrl+F. This will make the brush be convex, and therefore valid.

Idolon wrote:
You can split the top/bottom face by selecting two verts and pressing Ctrl+F. This will make the brush be convex, and therefore valid.

I have tried this, but it seems when saving/reloading, the shape, while not corrupted, has a large chunk taken out of it. no basic shapes have worked at all without reverting to a smaller shape. the "devolution" of the block seems totally random.

if just basic shapes aren't working, I don't think it'll work for a sweeping staircase. :S

Idolon wrote:
You can split the top/bottom face by selecting two verts and pressing Ctrl+F. This will make the brush be convex, and therefore valid.

I have since retried this on the stairs themselves, and it seems to be stable.
However, still unstable for true convex brushes. But, that wasnt really the goal.
Thanks for the help! ^^