I know how to solder. I was helping someone else and they wanted to use the compression fittings in a concrete wall. They got this Moen valve in the states but no fittings. I had to show them you can't do it and compression is more for soft copper. I used the compression fitting and the fit was good enough to sweat so we did that. There are no 90's we could find here in Costa Rica. Here is what they end up with. I don't like the hole set up too many joints, but it is not mine. All you can do is try and show them.
I may go home hungry, but not tired and hungry.