Jim Davey
R H Davey Welding Supplies Ltd
- Messages
- 5,736
- Location
- Southampton
If the torch was water cooled you could in all probably negate the brass neck liner altogether and run a plastic liner all the way to the tip, however the temperatures inside the neck of an air/gas cooled torch can melt the liner, hence the need to run a brass neck for the final part.
Due to the fact that aluminium easily galls when run metal on metal (even with brass) I make the brass neck as short as I possibly can to minimise the amount of metal on metal contact. You wouldn’t think it would make much difference but the resistance to feeding with the wire negotiating the bend with a long brass neck liner can be significantly higher than when it’s shorter, ideally the plastic liner makes its way round most of not all of the bend in the neck and the brass part just supports the wire in the straight section between neck bend, tip adaptor and tip.
Due to the fact that aluminium easily galls when run metal on metal (even with brass) I make the brass neck as short as I possibly can to minimise the amount of metal on metal contact. You wouldn’t think it would make much difference but the resistance to feeding with the wire negotiating the bend with a long brass neck liner can be significantly higher than when it’s shorter, ideally the plastic liner makes its way round most of not all of the bend in the neck and the brass part just supports the wire in the straight section between neck bend, tip adaptor and tip.