In this tutorial, you will learn to create an affordable boat drain tube with a Thru-Hull boat plug that could be used on tenders.
You can create the drain tube by installing a PVC pipe that allows a standard 1” marine plug. All-purpose cement for PVC is used to secure the inner pipe as well as automotive goop to seal the fitting from the outside water. This method clearly works but is, however not as safe, as a store-bought fittings, and is probably more suitable for smaller boats- tenders etc. When it comes to thru-hull boat fittings bronze, brass, stainless steel, and Marelon plastic are more favourable materials. They are also stronger and more durable to the marine environment.
A notable alternative is a boat bung which can be purchased fairly cheap online. These are often used on small dinghies and tenders and fairly easy to install. If available use stainless steel screws to prolong the life of the fitting.
Full credits – OldGuy DIY