Me and my friend are working on a very rare espresso machine and while disassembling the boiler we noticed the holes for the group head flange assembly have cracks. That explains why it was leaking with the correct gasket + sealant... The boiler is made of stainless steel which is 3mm thick. I'm wondering if the cracks are possible to TIG weld with argon or we should fabricate an entirely new boiler. The boiler needs to hold max 15 bars of pressure and the bolts / nuts that go against these holes have a torque spec of 16Nm. Thank you for your help!