is it possible to make an "L" shaped brush using only one brush
for example maybe using cut, but i havent gotten able to shape like an L,
but keep the L perpendicular

It's quite impossible. You cannot make a brush that curves outwards, only inwards. If you place an imaginary line inside a brush connecting two random spatial coordinates, it must all the time stay inside the brush - it cannot ever leave the brush and then come back inside.

But don't let these cruel words dishearten your adventurer's heart on your quest for a perfect brush :)

you got it muddled up, it must be convex, not concave

Oh yeah. "Curve" was a wrong word, and definitely not the one I should have used.

Well, "convex" and "concave" weren't included in my English vocabulary before this... :)

i dont thinik he is talking about making a curve, or a convex or a concave. i think he is asking how to make "an L shaped brush" with 90 degree angles at all corners. i too have been wondering how to do this and have found so far that the best thing to do is make 2 brushes and place them beside eachother to make an L or cut an L shap out of one giant brush. in the end, no matter how many brushes it took u to make your L shape, it will not effect game play and should affect the compiling proces much.

i kno, i was just correcting what he said

(remember that concave goes inwards because of the cave part)

Just to clear it up you CANNOT make an L shape with just once brush, you can make it out of 1 patch mesh but it's a lot of trouble and the lighting on it will be all smooth and unfitting.