Magnesium Frame Repair

Unknown
edited December 1969 in MTB workshop & tech
A pal of mine has a merida magnesium frame which has a crack just below the seatpost clamp on the seat tube. Is magnesium repairable, if so can you recommend a frame-builder who will tackle it? He lives in Wantage, near Oxford. Before you all shout "Warranty!", he bought it 2nd-hand off Fleabay about a year ago, and Merida said cos he's not the original owner, the warranty doesn't apply.

Many thanks in advance for any help.