I have used most all of the torch tips from my torch to melt gold; any will work if used properly, and somewhat dependent on the size of your melt.
I suggest you try this, pick the medium size brazing tip (this will give you all the heat you need and a flame that will be easier to control, light the torch with gas and add oxygen, adjust the flame using knobs, large blue flame with a small bright blue cone, yellow tips to the large blue flame, this is the flame you want, use a small version of this flame for heating (keeping torch back from your work using the end of the large flame, for melting we will readjust this flame size to a larger version of this flame and use the hot small cone in the center to melt with.
Prepare your dish, I would preheat the dish and sprinkle on a little borax to coat the dish (you do not need more than a coating that seems to wet the dish, heat dish slowly till hot at first only letting the flame tip lap at the dish this drives off moisture, heating the dish too fast will crack it, also use the flame on the outside of dish to heat the dish evenly.
Once dish is hot I add my dry gold, the gold can be added first if it is easier for you, or you can allow dish to cool and add it.
If you are afraid of blowing away, your gold you can put it in tissue paper, and spray it with a mist of alcohol in cool dish this is not necessary once you get the hang of using your torch.
The hard part is not blowing the fine gold out of your dish, a smaller flame and using the outer flame torch far back slowly bring the yellow tip of your flam up to the dish and to the gold in the dish, try concentrating on heating your dish and not the gold at first, playing the yellow portion of the larger flame on the outer of the dish, the rim of the dish and let flame barely lap at the gold powder, it will take a little while to fuse the gold, when gold is fusing you can bring flame in closer, still concentrating on heating the dish, work the gold powder into one glob, when fused well you can bring in more heat and your torch in on the gold and dish, bring the torch in closer slowly while heating until you can heat with heat the hottest part of your torch, the small inner blue cone, when gold begins to melt, readjust the torch for a larger flame and blue cone, use this blue cone to chase the gold around in your dish pushing small balls of gold into one melted liquid glob of molten gold, this gold being pushed around the dish with the small blue cone of your torch flame, if you are going to lift the dish and pour out the gold be sure to heat your pliers before grabbing the dish, if pouring keep the dish and gold hot with your torch, when finished it is best to back off on heat with your torch slowly, so the dish does not cool so fast that it cracks.
Now we need to teach you welding with your torch, torch tips are chosen by thickness of your iron, take two pieces of iron clean the metal where you wish to weld them together, butt them together, using the blue inner cone heat both pieces of iron (begin at one end of weld), in this one spot, use this blue cone of flame to make both pieces red hot then cherry hot then melting in a small circular motion push around this small molten spot with your torch until the two molten sides melt to one spot, in small circular motion slowly move this molten spot down the length of the weld where the two metals join, melting and mixing these two molten metals, doing this without a filler rod is a good way to learn to weld, after you can do this without a welding rod , adding a welding rod will be easier, now get a coat hanger for a welding rod and try this again this time weld the two pieces of metal together adding the metal from your coat hanger (welding rod to melt the three metals together). If welding a larger thick metal to a thinner piece of iron focusing most of the heat on the larger piece, so they melt about the same time.
Be careful with your torch learn to use that tool safely, they are a great tool to have, but if not treated properly or learning a few things about them they can also be dangerous, but can be very safe to use if you learn how, and treat it properly.
