Fabricating, casting, and shaping a knife handle

Hey all.

Been working on a series of project I call : "Why the hell not?" My next step in casting was trying to make a symmetrical form by shaping on single half, then casting it to make a double. This was great a great learning experience!

This little project is the first that I'm trying to actually get an end product from (which will probably end up in the learning pile!). There are definitely things I would NOT do again (Like using super glue on foam, which apparently melts it), and some things I think i'll carry with me (ways to pack the petrobond for odd shapes).



Anyways, here's a bit more for my "Extremely unpractical in combat situations" knife project.

Nice !
I dropped a metal ruler across the bottom 1/2 of a mold once by accident & was quite amused later on to find the indentations of the measurements were very vivid even with it being a average sand grain size.

And the first thing I thought when you said about casting a handle was 'use deer antler as a mold.

Thanks for a great Video & the insight into your work.

Originally Posted by WhiteSquirrel

You know what, the thought of casting a deer antler for a handle hadn't even crossed my mind! My hamster is spinning on the wheel now - If I could cast the shape of some antlers in aluminium bronze, and use it as a cap for my hatchet handles (sliding it over the haft)...

You just added another one to the "why the hell not" pile, thanks!

After watching your videos it's apparent your more of a sculpture than a metal caster.

I've noticed several things your doing wrong, the pattern is usually fixed to a board which is indexed to the cope and drag, the pattern board is placed on the work bench, the drag placed over then filled with sand. The drag is then turned over.

You don't just reach in with your fingers to remove the pattern, should have threaded holes that you can screw a rod into, you gently tap on the rod to loosen the pattern before removing.

With petro bond why are you using two pour holes, one is all that is needed, if your pattern is not filling you need to extend the height of your cope. The added weight of the molten metal in the extended sprue will fill the mold cavity.

The extended sprue serves another purpose, as the metal in the mold cavity cools it shrinks, the extra molten metal in the extended sprue will feed the shrinkage.

I've mentioned this on your tube comments but you seem to thrive in repeating your mistakes.

Originally Posted by alloy2

After watching your videos it's apparent your more of a sculpture than a metal caster.

I've noticed several things your doing wrong, the pattern is usually fixed to a board which is indexed to the cope and drag, the pattern board is placed on the work bench, the drag placed over then filled with sand. The drag is then turned over.

You don't just reach in with your fingers to remove the pattern, should have threaded holes that you can screw a rod into, you gently tap on the rod to loosen the pattern before removing.

With petro bond why are you using two pour holes, one is all that is needed, if your pattern is not filling you need to extend the height of your cope. The added weight of the molten metal in the extended sprue will fill the mold cavity.

The extended sprue serves another purpose, as the metal in the mold cavity cools it shrinks, the extra molten metal in the extended sprue will feed the shrinkage.

I've mentioned this on your tube comments but you seem to thrive in repeating your mistakes.

A comment like that definitely requires a little more clarification from your side. If I get the results I was expecting, how is that a mistake? A more efficient process available? Definitely! The only one that hasn't worked so far is the cup - and I havn't had a chance to retry this with the advice give to me from different sources. My advice from three small casting companies is that the cup walls are too thin to cast with aluminium, which I will challenge using some of the suggestions provided. So let's explore this a little more.

-For the cope and drag being flipped over, how do you do that with a odd shape like this one? If I would have done it the flat 2 part master way, then the end piece on the pommel would have been buried, or the rounded handle part would have been recessed (I tried this method first, and it did not work with this shape). So seeing the result of the second casting that was identical to the first (and my previous rail road spike castings using this method)- what was the mistake I repeated? Was it just that this method is not as efficient as another?

-I do agree that pulling a shape out without touching the sand is the best theoretical approach. How would you have pulled this particular shape out without damaging the finish of the face? What how did my approach on this particular piece removal adversely affect the finished product? I do have some dirty edges to clean up normally - does pulling pieces out with a method like this generally help with cleaner edges?

-For the second sprue, you have mentioned filling both at the same time to reduce material shrinkage affecting the final casting. Smelko, who sold me the petrobond, recommended an entry and exit hole when casting. Chance for heightened efficiency? I'm all ears. Having said that, the half inch holes I use for aluminium doesn't seem to be able to let enough air out and has caused a few air locks and failed castings without a second hole. Adversely, anything copper based (with more mass) has no problem at all. My cope is already at six inches, so if I open up the hole to 3/4" instead of 1/2" maybe it'll give the results with a single hole? Single hole casts i've been seeing in videos are done vertically - do they work as well horizontally?
I just poured the final hilt over the steel frame. After hardening the blade, I didn't want to heat it and anneal it, so the blade was relatively cold. I put three fill holes since I was worried the molten aluminium bronze would solidify before it finished the form. Would a single sprue hole work with a horizontal pour like this? i didn't want to test it out with this and risk ruining the entire project.

Bring up some more details or comments, let's talk about it, and see if the next casting project will work out more like a caster made it than a sculptor.

Watch the myfordboy youtube series on metal casting. this boy surpasses my expertise ten fold.

Petrobond only requires one entry hole, i use a pneumatic tamper to pack the sand in around the pattern. Sand packs hard as a brick.

I use a tapered coffee table leg which is positioned before tamping, use a knife to cut in a runner, spoon to scoop out a funnel at the top of the sprue hole, makes pouring the molten metal easier.

Metal being poured into the cope enters a pocket carved into the sand which resides nearby the mold cavity, a runner is cut from this pocket to allow metal to enter the mold cavity.

The pocket serves two purposes, feeds metal into the mold cavity then feeds shrinkage, any junk ( dross ) floats to the top on this pocket so only clean metal reaches the mold cavity.

Use a plastic straw to gently blow out any loose sand that enters the mold cavity.

On a side note we would not be good neighbours, you make much too much noise.

This is some of the stuff i was casting from my home foundry, down rigger and scuba weight molds from aluminum, some Old Abe fence finials.

Authentic Old Abe's were made from cast iron all others like the one below are fake copies, just like the aluminum one's that i made.

If a hick like me is able to cast the hinges used on this type of down rigger mold, why are you finding so difficult to cast the pommel.

I had similar handles made from the longer sprues turned in my metal lathe, then used a knurling tool to make them easy to grip, used recycled threaded studs from aluminum intake manifolds threaded into both the handles and the mold.