Very simple work holding with a sacrificial nut and bolt. When silver soldering you don’t want your best engineers clamps in the path of a blow torch. Also, you don’t want the thermal mass of a large clamp.
I often have this problem and resort to a piece of wire that wraps around and is twisted tight. Or I try to balance a fire brick on top to hold it all together. The other option is to use a mechanical joint as well such as a rivet. However, sometimes these are not great options for other reasons.

Here you can see that I’ve clamped the edges of the joint between two washers on the nut and bolt. I used quite thick washers for this so they didn’t just deform.
Two fixings like this were enough to hold this joint together.
You can also see here the silver solder paste. This is low temperature Easyflo paste from Cookson Gold.


The Sacrificial Nut and Bolt held very well during the high temperature, around 650°C, silver soldering event. Both bolts were quite easy to undo with a screwdriver and spanner.
One of the washers was slightly stuck to the brass. However, a small amount of wriggling and it came free.
OK, this is not an earth shattering approach to a problem, but I think worth sharing these ideas. Hopefully in the longer term we can turn this into a place to share lots of maker ideas, tips and projects. So, I encourage you to comment, send me articles or even request a login so that you can post makes to the internet.