the only trouble with sil-fos(silver phosphorous) is it is hard to buy just a little/ also it comes in different silver content/more silver the more it cost but the stronger the joint/ almost any good welding shop or appliance parts store or ref. supply house will sell it to you but you need to figure out what you are going to use the othe 27 1/2 sticks for/ a lot of compressors that I installed came with a 5-6 inch piece/so I have a box of 2 in pieces left over//I know i never had to buy less than 2 lbs in 30 years of ref, repair//a little goes a long way /if you can find a ref, tech around he might be willing to part with a short piece// I hold it in needle nose pliers when it gets to hot to hold/but it sure makes a strong repair/but I still prefere silver when I have it.it makes a copper to steel repair that will never leak//but it is a lot harder to use.. sid