Garrett44

I’m looking for advice in joining small metal components, similar to the nut and bolt sculptures you see online (https://www.google.com/search?q=sculptures%20with%20nuts%20and%20bolts&ie=utf-8&oe=utf-8&client=firefox-b-m), but I’m using some slightly larger components e.g. hinges, brackets etc. The components are steel (not stainless), aluminium and brass. Some are old and corroded, others are brand new. Cost is starting to be an issue as I’ve had a number of failed tries. So far I’m limited to using a soldering iron and a butane blow torch, what I had available and what was low cost, have tried soldering (does not adhere), tried brazing (cannot get a high enough temperature. Not sure if I should try silver solder, this is what tutorials for nut and bolt sculptures advise but given soldering had zero success I’m doubting this. What will work? What is suitable? Do I need to go to welding? Is there some welding solution that is reasonable cost, small scale and can be used indoors (no access to a workshop or outdoor space)?