I want two 90s tight together. Will the joint still draw solder? If I can't see the pipe nipple between?

Well, ideally you would have at least a minimal gap, even just enough to slide a piece of paper in. However, even with the fittings tight up to each other, as long as the fittings and pipe are properly cleaned and fluxed and you distribute the heat with the torch correctly, the solder will find its way into both fittings and you won't have anything to worry about. The heat and flux will draw the solder into the fittings. Ive done it many, many times with absolutely no problems. As long as you are proficient at soldering, you don't have a thing to worry about.

Good luck and take care.

Lee.

Yes, they will seal... Also, consider using Regular 90 and Street 90 together... Back to you... Milo