OKay redear FM and Others.The description will come first pictures later.
First figure out where you want the hook to sit. That is the most important part of the whole process. It might not seem that way but it is. I like mine near the top of the mold if you are going to use that dimension of Aluminium stock. Next part is to have the to blocks of Aluminium square this might require some filing to make them the same. Be sure to use a 90 degree square and check often. When they are square chuck them up in a machinist vice flat side down and drill two holes in opposite sides of the blocks. Go all the way thur one and 3/8 inch into the other. This is for the locator pins so you will want to find some brass rods I like to use 1/4 inch welding or brazing rods for this. I chuck these rods into my lathe and give them a slight taper and round the ends. If you do not have a lathe them use a electric drill and a piece of heavy grit sand paper to do this part of the operation.
With the block still in the vice drive the pins in place and make sure that they stick out at least 3/16 inch out of the one side that you are driving them in into the other. These pins will be driven in and out several times while you are pressing the blank so have a tight fit but not a super tight fit.
The Hook is then put in between the two blocks of Aluminium and pressed with a 2 ton Hydraulic jack with the blocks still in the vice. Do not have the vice tight but have the block so there is no side movement This will take very little pressure and you will be able to feel when the hook is pressed in as the jack will be hard to pump. When you take the jack off of the vice and the blocks off then you can see the hook impression and at the bend of the 90 degrees is the most important place at the moment.
A bit about the blank it can be made out of most any steel material I like to work in tool steel because I know it well and can put a good temper and polish on it. In the old days the old boys that taught me used Marine Brass and steel.The Marine Brass takes a good shine and is ease to work in to the Blank that you want to make a mold from. I like to have a very good polish to my blank as when I pressed it in to the Aluminium it required no polishing only to take the burrs off the face of the mold.
Now back to the mold at the 90 degree bend take a punch and rap it lightly to make a started hole for the drill hole that you will be drilling. Do it on both sides. Next measure your blank and figure out it's depth and width divied them by 4 and that is the depth that you will need to drill down. Example the width of your blank is 1/4 inch the depth is 3/16 inch you will drill in the the 90 degree 1/16 of a inch in this case I would use a 3/16 inch drill. The Maximum I would drill would be 1/8 inch deep.
Now you can do your first pressing of the mold with the blank in the blocks. Still keeping the block in the vice with the blank sitting it the holes that you drilled do a light press so that you see the block start to move down but not far just start to move. release the jack and check that it is starting to press in the right place. If you are happy where it is pressing put the blank back in and press a little further.
After you have done your second press take the blocks out of the vice remove the blank and tap the locator pins out of the one side and have a sheet of 180 grit sand paper the kind that is black for wet or dry. put it on a glass surface and work the blocks in a straight back and forth way to face the mold do it on both parts when it is smooth on both parts drive the locator pins back in and repress the hook if need be and then put the blank back in the mold and repress as before going deeper until both side meet up flush. This might take a few times but you will want to keep your faces flush as possible and lap them a few times as you go along in this process.
After you have your cavity made you will need to make a fill hole or sprue. I make mine 1/2 the diameter of the blank.I take a drill bit and press it in to the middle of the cavity so that I can see were to drill and know how deep to cut. Chuck the mold in to the vice and drill your spure hole and then contersink this hole bigger so you can pour it easier.
Next get a set of hinges from the hardware store that will fit your mold Think I used 1/2 inch and attach them with self tapping screws.Mark you holes drill and screw them down. Do this on the opposite end of the mold were the hook is located. Get two 20 penny spikes cut off the heads and drill two holes at a smaller diameter than the spikes. do this on the end of the mold where the hook is located opposite the hinges. Then get a old piece of gas line from a out board motor and put this on the spikes and you have a insulated handle.
Mold is done ready to pour if done correctly there will be no flash you could have trouble with the hook and this can be taken care of with a dremel tool and some careful cutting . I use a Jewelers graver as it is my tool of chose. But thats how I do it and this is how one of mine turned out. This mold has been modified to take sickle hooks it first started out taking Aberdeens.It has pour thousands and thousands of jig over the years and is now about 40 years old.
Redman
