Reply To: Stanley No 4 Gap Between Frog And Plane

Either the frog is sitting high on the side with the gap or the frog is sitting skewed in the plane body. On all of my Stanley planes I line up the bed of the frog with the rear of the mouth to form a continuous ramp for the iron all the way through to the sole. You can use a small steel ruler to check for straight alignment. I would check the mouth to make sure it is square to the sides of the plane. I’ve seen several that aren’t. If needed you can square up the mouth with some light filing.

Next clean off all of the oil from the frog and plane body. Use a Sharpy to color the mating surfaces on the frog and body then seat the frog in the plane and slide the frog back and forth. This will rub off the Sharpy ink and show you whether or not the frog is fully seated on both sides. It may be that you have to use a metal scraper to slightly lower the mounting platform on the side where the ink rubs off until the frog sits evenly from side to side. Just take it slow and constantly check alignment until everything seats and properly lines up.