@72bluNblu " soft enough to work into the seam but not so soft that it runs off the car." That there is a fine line too. I was working with 2 propane torches, so not exactly a pinpoint spot of heat. I ran a bunch off on the floor before I got the hang of it.
I like the liquid state so I know there aren't air pockets, so I ended up using my rotisserie to make the work area as level as possible, making a dam with the solder in "putty" state, then creating a liquid lake behind the dam til I was built up enough, then melted the dam down. An old time body guy came by my house at one point and said I did some fantastic lead work.