mold questions for redman

redear

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Redman,
I am wanting to try and make a few single pour home made molds. I have some 6061 aluminum that is 3/4"x1 1/2". I am guessing that the slug needs to be made from hardened steel like a grade 8 bolt or one of those black hardened bolts. what I am really trying to figure out is how to press the slug between the aluminum mold blocks. A four pound hammer comes to mind, or maybe make a heavy steel frame and use a car jack to do the pressing. how much force does it take to press a little 1/32 head in 6061 alum. ? thanks for any light that you could shed on this subject. kip
 

redman

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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.

100_2205.jpg

Redman
 

redear

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Redman,
thank you so much for sharing that information, I will forever be in debt to you. I have the tools I need, just needed redmans kind guidance to get my head wrapped around it. I coulda messed up alot of material without him. I bought the aluminum online at a place called metalsonline I think. could have got any dimension. now for the blank work, and maybe an iron framework to hold the jack and vice in place. It's gonna be fun. thanks again redman! kip
 

redman

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Redear Any help that I can give you just ask. Too old to not past down some of this info. Yes a Iron frame is what you will need for the jack to fit on. To be really truthful I build my stand using two pieced of scrap u iron and four 15 inch threaded rods. the rods were 3/8 inch threaded to in each corner and the u iron was big enough to get the jack and the vice on side ways comfortably. Just make sure that it is the same height in all corners and use lock washers on the top and bottom sides to keep from having it move on you. I put the jack on top of the vice to do the pressing. Hopes that part helps you out. Still not at 100% so will PM you if I feel that I have left any thing out.

Adam I wish that I was in better shape and younger and you would have one of my molds. I have used this method that you linked to for casting just to let you know that regular plaster of Paris is not the thing to use. Should you feel the urge to do this get some casting investment made with silica sand. Then this method will work much better but you will want to be careful you could get burned. Also a piece of saran wrap between the two parts is a must. They may have said it in the info and may have missed it. I did graduate with a degree in jewelry manufacturing so have done about every part of casting that was state of the art from the 1969 to 2008. The interesting part of this is the same basic casting was done in Egypt at the time the great pyramids were built.

Fatman Glad that you enjoyed this post it was a long one. took me almost three hours to remember every thing I wanted to say and the I edited it several more times before posting. Us older guys have got to past our knowledge on to this young ones they are our future.

Redman
 

redear

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thanks again redman, for saving me alot of time and frustration. It might be a little while before all the things I need are all lined up proper but I'm excited about it and love making stuff. I have a custom made mold and about six do it molds, but what I want to make is a balanced jighead that hangs horizontal on a loop knot. probably make several sizes and styles. I tie alot of kip tail jigs and would also like to try making a flat sided head that is balanced, a mississippi style hair jig. the flat sides will make it easier to paint eyes on. thanks again redman for putting the process in print. kip
 

redear

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I will do that fatman, with me being so simple when it comes to computers and posting pics, I may have to get my wife to help me. maybe I could take them with my phone and get her to help me send them to one of you alls email, and ya could post them for me. right now I am thinking about the iron frame design, and need to go buy the iron. I have a welder and a chop saw too. also I want to order some tool steel to make the blanks from. victor machinery in new york has the round drill rod in o-1 tool steel and also the flat stock for the flat sided head. this will add another dimension of creativity to our hobby thanks to redman.
 

redman

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redear must admit that I did most of my blank work on the lathe. If you have one then its no problem. Don't over look Marine Brass ether. Another hint is that I did my polishing on the lathe worked the blank with sandpaper then used rouge to give it the final polish. If you are going to do a flat blank I would do it in Marine Brass. Just my opinion.

Redman
 

redman

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Boy I am glad I am back too. The hand and arm still hurt but the mind is still clear ;well some what any way.

Redman
 

redear

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redman, glad to hear you are healing and feeling a lil better. I do have a metal lathe with a milling attachment on top of it. It's a chinese made grizzly brand so nothing fancy but it will do what this requires. also have a big drill press, and a 6x89 belt sander I built years ago, side grinders large and small for the iron work. questions, what do you do to the tool steel to temper it? and that marine brass must be harder than regular brass, I'll look for a source on the net. thanks redman
 

redear

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bought some iron for the press framework the other day. A 20 inch peice of 3"x3" box tubing with a wall thickness of 3/8", for the horizontal top and bottom peice, so I cut it in half with the chop saw. ten inches across the top and bottom. using anglr iron for the upright supports 1"angle with a 1/4" thickness. the box tubing had a slight cupped surface on the flats so I had to shave it a little on the belt sander, now it's perfect. bought a 4 ton bottle jack too, but with the 1/32 heads I'm wanting to mess with, sure coulda used a smaller one. thought about doing some welding on it today but it was so pretty out that I went fishing.
 

redman

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redear as long as the vice fits in there you have nothing to worry about. The jack will work the two ton would have been better but what you bought will work just fine. Just don't get too heavy handed with the jack. Firm and tight don't try to force the Blank in all at once do a couple of presses to get the blank to press in the Aluminium.'

Redman
 

redear

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redman, I'll be sure to take it easy with the jack. probably work on the frame today a little bit after work, laid all the peices of the frame out yesterday and put the jack in there with a few peices of 1" thick steel to replicate the aluminum thickness, frame looked a little too tall so will cut about an inch off the upright supports dress them up and weld them. taking it slow being the first time at this. thanks for the advice, I probably woulda gotten a little heavy on the jack without it. I know you said that you put the aluminum on the bottom and the jack on top. I know my jack wont work upside down, so you musta been pressing with the bottom of the jack. just thinking, I can see how a guy could need four hands to hold all this stuff in place while he operates the jack handle. lol thinking bout rigging my jack at the bottom with something to hold it in place, then I'll have one hand to hold the mold peices on top of the jack, and the other to operate the handle. I have a few chunks of thick iron that I can use to protect the aluminum from the jack ram.
 

redman

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I use the bottom of the jack to do the work. That way you only have to use one hand to do the work on the jack. Put the vice in the frame then the aluminium then the jack on top. The Aluminium is like a sandwich that the jack will press. The Aluminium goes in the vice. I hope that this will make it plainer. Wish that I had taken pictures of the process when I was doing it way back then.

Redman
 

Redboy

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Wow after reading all of this, I have come to the conclusion that my uncle is a beast at doing them jigs. Hahahaha cant wait to learn how to do them myself!
 
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