Why do I make so many tools from Aluminum alloy, instead of steel? Surely it would be better to make it for the long term? Well its a bit of a sore point, but I'm glad you asked!

In my part of the world (a far flung corner of Australia) good quality steel is virtually unheard of. There is an abundance of that gummy hot rolled stuff. Local industry use it, and there are plenty of off-cuts if desired, but they want a pretty penny for scraps. And it's just awful to work with.

Ask for cold rolled steel, and you can expect a good natured shrug. Ask for anything more exotic like 12L14, or the wonderful (UK) EN8M, and there will definitely be furrowed brows. It just doesn't get used by our local manufacturers, so they never see it.  Gauge plate is unobtainium, although drill rod is still available from Blackwoods.

Basically we just don't have a steel industry in our country that even remotely equates to the UK or US. If we need the good stuff, we model engineer types have to really pay through the nose, by ordering  from specialist suppliers, mostly overseas/online.

Aluminum alloy on the other hand, is as common in my part of the world as water. All dimensions, grades, you name it. And I have a couple of local fabricators nearby that use a lot of it, so off-cuts are thick on the ground. (off topic - is there any better way to spend an afternoon, than by browsing the local off-cut rack, scoring some really choice cuts of aluminum for the next project? I think not!)

So when it comes to a substantial tool, my first thought is: "Can I get away with aluminum or maybe even brass?". Because I know steel is going to really hurt the wallet.

Usually its a question of wear and rigidity. For extra rigidity, I usually increase any critical dimension to account for the increased flex. For example, I think it was borderline making my Vise Sub Table from aluminum. But I stiffened it up by adding a bracing section underneath, and it sits like a rock in the vise. I don't have a need to push it too hard, and thus far it has served really well.

Regarding wear, the Aluminum certainly bruises very easily, and if it is part of an assembly that has relative movement, it also wears rapidly. But most of the tools I am making will have low cycles, so it's usually not an issue. I treat the critical stuff (mating surfaces, threads etc) with kid gloves, and thank my lucky stars that I didn't have to fork out a fortune for the steel.

If the worst happens, and it becomes clear that the aluminum is not up to the task long term, well at least I have a finished prototype that has been in the field for a while, to use as the living blue-print for re-making it in steel.

The other bonus from Aluminium of course is that its an absolute pleasure to machine; No excuses for a poor surface finish!

Thanks for stopping by,
Chris.

I made a chapter ring today. The pics above show the brass after being filled with wax.

After the silvering process, the numerals are left with a rough surface; a remnant from the last stage of sanding. So typically one of the last steps after silvering, is to gently heat the wax to melting point, to make the surface of the numerals shiny.

I have tended to do this by heating the underside of the dial with a butane torch, but it can be a little tricky if you care about the surface finish on the other side. 

Apply too much heat, and it will leave a mark. It is possible to avoid it, but its also very easy to make a mistake, and leave an unsightly burn mark.

If this side is to be polished, no problem. But if it is to be left silvered, the work is pretty much ruined.

So today I thought I'd try the kitchen oven, instead of the butane torch. It can heat up to 250°C which is more than enough to melt the wax, and it should be a uniform heat right? No scorch marks from an electric oven. What could possibly go wrong...

I finished the dial, and then applied a single coat of thin lacquer as usual. I decided to do this mainly because I was concerned about the silvered surface oxidising/discoloring in the oven. Of course, there was then the possibility that the lacquer might do something unpleasant while heated, but it had to be one or the other.

Well it worked a treat. In less than 5 minutes, there was a beautiful sheen on the wax, and I think the lacquer even benefited a little too. It looked to be a little smoother than before it went in.

Masterchef, here I come...

Thanks for stopping by,
Chris.

It seems to be a constant of life.

The moment you become attached to a product that really pleases you, its only a matter of time before it disappears off the shelves for good, never to be seen again. You then spend a large portion of your waking hours scouring Ebay for the last remnants of your forbidden treasure. If you stumble across a source, the only rational response is to buy as much of it as you can afford. Maybe even a lifetime supply. Who knows when you'll ever see it again, right?

Just as Smeagol becomes Gollum, the shift from mild mannered citizen, to obsessed hoarder is inevitable.

Such is the case for grinding and polishing pastes commonly used in horology.

The literature commonly refers to using Oilstone powder (powdered arkansas stone) for steel preparation, prior to final polishing with Diamantine (finely ground aluminium oxide powder). I have also found that using a medium grade Carborundum is a very effective first stage preparation,  prior to the Oilstone powder.

The problem is, a few years ago, Oilstone powder became almost impossible to find. I purchased a 30g jar from German materials dealer Ernst Westphal in 2011, but it appears to have been one of the last jars in existence. If only I had known, I would have bought up big, cornered the market, and built an Oilstone powder empire!

Instead, I only purchased the one jar, and remain an Oilstone pauper. Desperately watching my pitiful supply slowly dwindle to nothing, trying to stretch it out as much as possible.

Since then, I have not seen it for sale from any of the common retailers. Occasionally old stock pops up on Ebay; small quantities left over from what appear to be retired professionals selling the contents of their workshops (or perhaps estate sales?). I recently had a crack at an auction, and missed out. Given that my precious little jar is nearly empty, I really needed a break.

And just like that, good fortune came to the rescue: Oilstone powder is back for sale at Ernst Westphal. 

The order is in, and I patiently await my lifetime supply... My Precious...

Thanks for stopping by,
Chris.

Well here it is, my first effort for Youtube, so we're off and running.

I had a lot of fun making it, and spent a surprisingly large amount of time getting it into shape!

All going well, you will see reasonably regular video's from me; at this stage I am aiming for one every two weeks. You'll be able to follow my progress, as I make a skeleton clock from scratch, using raw stock.

I will also be making other machining video's related to tool making and the like. If you're interested in home shop machining, working with metal, and making things, you're in the right place.

Please like, share and subscribe via the Clickspring Youtube channel, and if you feel really motivated, please leave me a comment. Extra bonus points if you leave questions, or some ideas for future video's you'd like to see.

Thanks for stopping by,
Chris.