The original
Portasol Technic is a very nice dedicated gas iron. Its bits have an integral catalyst, and are securely swaged to the stem tube which is retained in the iron's body by a screw collet, so unlike most multifunction gas tools, they don't suffer from bit wobble, its only about 45mm from the end of the body to the tip of the bit, and the slimline body (approx 17mm dia) is well balanced in the hand, so is excellent for precision work. The gas flow control valve is easy to adjust to vary the power output, and is separate from the shutoff valve so you don't have to readjust whenever you use the iron. The flint wheel striker in the cap lights it easily, and the cap makes it pocket safe immediately after use. Although its not intended for the purpose, it shrinks heatshrink tuning easily if you hold it about half a cm above the exhaust ports in the tip and turn up the gas flow.
I've had one for over 20 years and it still works perfectly, is in very good condition, and doesn't leak gas in storage.
Although its intended that you should replace the whole bit and catalyst assembly (
spare Technic bits) when the tip is worn out, you can refurbish them: Mask off the catalyst with tape to protect it against contamination when cutting and drilling. Cut off the knackered tip, leaving an approximately 5mm stub (longer if possible) , then drill the end (take care not to break through into the combustion chamber when drilling the tip - don't drill deeper than where it flares out to the O.D. of the chamber), to take approx 15mm length of heavy solid copper wire (2mm or 2.5mm dia is good). It should be as tight a fit as you can still manage to insert. Sand down the end of the wire slightly if is too tight. Swage it in place by nipping the sides of the stub of the tip, then dress the end to your desired tip profile. Of course unplated copper wire tips don't last as well as proper iron plated tips, but as long as you allow the sides to oxidise and only tin the face, they are easy to keep dressed to a good shape and tinned, and when too worn down, its easy to work the stub of wire out of the hole in the bit using heavy pliers, lightly ream the hole by hand with the original drill bit in a pin vise and swage in a new length of wire.