Toor

On 4/5/2024 at 9:58 AM, swedefiddle said:

Good Morning Toor,

Canada is a big place, can you be slightly more specific. If you put your area in your avatar, people will then know how to help.  I live in Victoria BC. There are a lot of other association's across Canada, I was asking to help point you to someone closer to you, than on the interweb.

Neil

I'm in Alberta. I haven't used it yet. I'm not really using it for smelting as much as I am using it just as a solder pot on a electric laboratory hot plate so coming apart under temperature isn't really much of a concern. For my purposes, the concerns is more that carbon residue might contaminate the solder.

On 4/4/2024 at 2:46 PM, Nobody Special said:

Silicon carbide (carborundum) contains well, silica and carbon, and is usually sintered together from powder or pressed to shape, so, I wouldn't be overly surprised if it had black powder on it. The carbide itself will usually be black or kinda dark brownish when rubbed depending on the composition when they made it. Silicon carbide is also about half again as heavy as graphite, but if you don't have a graphite crucible to compare it to, that doesn't help much.

Of course, the real problem you have is that many silicon carbide crucibles contain graphite, just as many graphite clay crucibles contain silicon carbide. I dunno, if you use it and it starts coming apart too early, I would lean towards a possible counterfeit...or user error. Or rough handling during shipping. Or the stars are misaligned....

Hmmmm. I was wondering how they were able to form a refractory material like silicon carbide so cheaply but if it's just pressed together with graphite that would explain it.

Canada, but this was ordered off Amazon.

I received what is supposedly a silicon carbide crucible and it's leaves a dark black residue when wiped. Similar to what I would expect from a carbon crucible or piece of lead. Is this also expected of silicon carbide? Or is this a fake?

On 1/7/2022 at 7:28 AM, JHCC said:

Precisely. Then put a handle on it.

I don't want a handle. I want a palm drop mallet.

On 1/6/2022 at 6:49 AM, JHCC said:

My own soft hammer is a 3lb drilling hammer I picked up at a flea market and annealed. It was already unhandled, so I heated it to critical and put it in the hot box to cool slowly overnight. Works great.

I see. So just find a big hammer, remove the handle and anneal the head.

Business situation but only two or three people. But I also have a home shop so sometimes it's nice to have one there too.

Tools are purchased or made, depending on the need.

DId I type "lighter handle with a hammer for control"? That doesn't make sense. What I meant was "works better for me than a lighter hammer with a handle", as a heavier handless hammer which is slower works better for me than swinging a faster, lighter hammer. We're talking something like a 2.5kg/5lbs block. There's usually a $5k electronic sensor an inch to either side of the pin so I'd rather swing fast and miss.

It's mainly pins and center punches. So cold punching I guess.

In my case, I care more about the punches than the hammer, especially if the hammer is just a block of metal. It'd be different it was a nice hammer with a handle, but in my case the punches tend to be nicer than whatever I'm hitting them with.

We do have a torch the old toolmaker asked me to get at work just for that purpose but he never did show me how to do it. Is it pretty idiot proof? Sit it on a brick and blast it with the torch until it's red hot and just let it sit there overnight (or a couple days) to air cool? We would be talking something like a rod 2" in diameter and 6" long.

I suppose Rockwell C20. I wasn't sure about mild steels in general since they seem to be around that hardness when annealed. It's just I never know how annealed a piece of cold rolled steel is when I get it.

Hi everyone,

For driving center punches, pin punches and starter punches I have found a really heavy, drop hammer works better for me than a lighter handle with a hammer for control. I want to protect the punches from mushrooming and don't really care about protecting the hammer.

The tool maker who used to work here had this huge block of brass the size of a block of butter he would sometime used as a hammer. But brass is so expensive now that I can't justify spending hundreda of dollar's on a brass or copper block.

But I ran into ductile iron and it seems like it might be soft enough (Rockwell C20 from what I found). It also sounds like (at least some tempers of ductile iron) might not work harden like brass. I also seems like it would not chip or shatter but online resources are spotty and unreliable since it's a type of cast iron which is typically known for brittleness so I cannot be sure. Is ductile iron safe for this use? Is it soft enough to mushroom itself instead of punches? I am looking for something cheaper than brass, softer than your typical steel but doesn't need to be as soft, and something that resists work hardening.