Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Congratulations on your new #20, a fine plant.
A few drops leaking around the piston rod & leaking out the end of the crosshead is completely normal.
I use paper currency (one-dollar bills) is an excellent gasket material, & yes, there should be gaskets on each end, the rear cap makes a fine template. my suggestion to get a good centering of the crosshead (the snout end) is have the connecting rod disconnected from the crank pin, & once you get the gaskets in place on both ends, before you completely tighten the crosshead end...hyperextend the piston as far out against the crosshead as it can go & then tighten up the 4 crosshead bolts, this ensures the greatest concentricity as possible & should make a smooth running piston in the bore. the butt end isn't as important, just make sure its centered good. good luck.