You are correct, I searched and called around and they actually do not even make a bulkhead anywhere that has a 1 inch O.D. Several places told me that, I found it hard to believe but it makes sense. That would make the I.D. very small for a bulkhead.
First post on Tinboats, glad to be apart of this useful group!
I have a 14ft Alumcraft aluminum semi-V. I recently removed the live well and need to plug two 1 inch holes in the transom down by the garboard. Its just alum, no wood. I have searched up and down the internet for a 1 inch plug...