this is the tool for forming the lips on the drain tube in the transom. the tubes are usually brass with one end already rolled. for this little demo i used a piece of 1"od copper pipe.
looking at the tool, the large flange is 1.25 in. in diameter and .15 in thick. it reduces down to .91 in.in diameter with approximately a 1/8 in radius. the piece is .62 in.long. the hole in the center is .5 in.in diameter. both sides of the center hole are chamfered as is the edge of the end that goes into the tube. a three inch bolt will give you about 2 in. of reach and i would recommend using a fine thread bolt rather than a coarse thread one. this tool has two washers at each end,one steel and one brass. have fun
for this demo i am using a piece of 2x4. i cut it in half and then reattached it before the hole was drilled. more on this later
the edges of the hole need to be rounded. i use a round rasp to do this
some of the other things needed are,epoxy,an acid brush,and the tube. the tube is cut so that approximately 1/8 of an inch protruds from the transom. if your are using a preformed tube this would be only on the unformed end. since we are using an unformed one here,it should protrud on both sides of the transom. after mixing some epoxy liberally coat the inside of the hole with epoxy. use plenty of epoxy to be sure all the wood in the transom is coated.
here we see the tube ready to be crimped into place. you can see the tube protruding from both sides of the wood.
here,the mandrel has been tightened and the lips of the tube are crimped into the wood
this our finished installation. all excess epoxy should be cleaned from the surfaces of the transom and the tool with acetone
here is why i cut the 2x4. this hole was drilled in a drill press and if you look closely along the lower edge of the tube,you will see a gap between it and the wood. the chance of this is greater when the hole is drilled with a hand held drill. this is why it is important to be sure the inner surface of the hole is completely coated with epoxy. otherwise,this is where rot is going to start in your new transom.
i hope you found this helpful.