When I build double barrel rifle barrels and attach the bottom and top ribs, I use a tinning paste that auto body shop workers use. It can be purchased in lead/tin as well as 100% tin. After you apply it you MUST clean it absolutely clean to remove the acid and then you additionally wash it with backing soda several times.

https://www.amazon.com/Eastwood-Tinning-Butter-Jar/dp/B003745IW6

Regards;
Stephen Howell

Last edited by bushveld; 05/22/21 11:14 AM.