Hello , really the only way to go is a tote-a-torch oxy-acetylene set up because it's plenty hot (6300deg fahr) to melt the 15% silver solder sticks and is easily portable . The only draw back is the oxygen bottle is 20cu. ft. and they charge about $15 to fill where-as if You had say a 125cu. ft. oxygen bottle they charge about $25 to fill those , so if it's possible to have a larger tank 125 or 225 cu. oxygen and fill You're tote-a-torch oxygen bottle Yourself would be alot cheaper but I have not checked into a fitting to do so yet . And a good idea to probably have at least 1 dual fuel (propane/mapp) gas torch as a back up , really in colder weather it takes 2 plumbers torches depending on what You're heating ,,,,,some systems have some brass components that require more heat than copper tubing .