grade 1-4 is okay to weld together, as there all none alloyed i think..

grade 5 and above is okay aswell to weld to eachother (they are alloyed)..

it is possible to weld 2 to 5 etc together though.

its somthing todo with some types of titanium being alpha and some being a beta type.

Kenny if you want ill pop down to my sponsors on friday before you come to the coopers and ask which are the best rods to use to weld them together and pick up a few while im there. I think its about £1 a rod.