How to solder this?

[SilverBouillon]

I need to solder a dome into frame. What is the best way: sweat soldering or to solder frame and dome together from the "wrong side"? The frame thickness is about 2mm where it contacts with the dome.
Here:

[medusa]

I'm really rubbish at soldering anything more complicated than really basic stuff, but it looks to me like there are gaps between your frame and dome. You will get much better advice from others, but if it were me, I'd solder it the right side up (on basis of gravity helps) and I'd try to find some way of making it a tighter or better fit to improve contact between the two surfaces. not sure if binding wire would help, but those soldering clips James makes probably would.

[SilverBouillon]

medusa, I'm working on gaps to eliminate them completely. The picture was taken before the final shaping.
Originally it should be just a dome ring with the pearl inside, but the dome looked too thin alone.

[Dennis]

1. Check that both are perfectly round. If not:

The dome needs to be re-annealed and when re-inserted in the doming block, punched around the sides as well as the base, using a slightly undersized doming punch. (I tend to use wooden punches in a brass block to avoid unwanted marks)

The ring, or frame is rounded on a triblet, also called a mandrel, using a soft mallet.

2. If the frame is too large, cut through the solder joint with a heavy saw blade, re- join and re-solder. Then gently tap it on a triblet to round it again.
The ring will be reduced in size. Do this repeatedly, if necessary, until the dome can be pushed in to fit snugly.

Once the two fit by friction, turn upside down and rub on flat abrasive paper, to ensure a flat surface. Then it will be safe to solder upside-down. Dennis.

[SilverBouillon]

Thanks, Dennis.
I figured out the shaping pretty much as you told, spent so much time (but educational!), made good fit, then decided to change to easy round frame with 14gauge round wire because I plan round shank as well. I stopped on that point now thinking what frame is actually better, and so far I like them both. and playing with aluminum wire.
It also supposed to be my first etching attempt. It will be easy since I don't need to learn that on my own, I have professional circuit board maker at home

[SilverBouillon]

Well, I messed up with that ring as usual.
The shank moved during soldering, I used the saw to cut it off, put the dome aside, then recently decided to make something out of it. Lesson learned: it takes too much time to re-do the work.
I decided to play with the dome as with waste shaping it different ways. As the result I made the ring named Pearl in the hot tub (more like a bucket )
Pictures are coming soon.