What the general pushback is because when you weld on the cylinder it distorts the barrel and potentially causing more damage as the rod moves in and out and the clearance is not there anymore for the piston and valves. In the shop the barrel is honed after the welds have been applied.
That said, We do weld on our cylinders on the machines knowing that we will have to pull it apart at a later date and do it right, it buys us some time and sometimes there’s only enough time for a bandaid. You have to make sure the fluid level is below the weld line and make sure the packing and valves are also below the the weld line. The crack will come back with the bandaid fix, it’s just a matter of time.
