There will always be a time when you need to combine to bits of metal. Something in your house may well have broken and it’s needing to be fixed. Other materials such as wood and paper are easy to bond together but metal is an altogether much harder prospect. What stops metal from being easy to stick? We now have excellent adhesives from CT1 to do this job. They are the experts in Metal bonding adhesives.
The simple fact is that metal, being heavier exerts more pressure and pulling force on the substance holding it together way more than the wood and paper does. This means that the glue has to have some incredibly strong polymers to make the bond last.
The only way that we could make metal bond together in the past was to wield it. This was fine as long as the substances that you were wielding at the time were not flammable or near another flammable substance. The process was to use another melted metal to be added between the two parts. When this cools it forms a hard bond but it is usually not a smooth joint and is susceptible to rust.
The other way was to literally heat up both pieces of metal and then jam them together and wait for them to cool. This would then set and join them.
Obviously this took ages and required lots of energy. This is one of the reasons why the need for adhesives in the first place.