5 Aluminum discs on the Espresso Maker Base?

[Uncle Gizmo]

This is driving me nuts!

I’ve got a stovetop espresso maker (by Kirkton House) with 5 lighter aluminum discs on the base. Any idea what these are for? Could they be a safety feature or part of the construction process?

I have been around the houses interrogating ChatGPT, trying to get it to come up with a sensible answer but it has no idea, just like me!

So if you lot here can answer this question, then that means we have a collective intelligence greater than ChatGPT!

#EspressoMaker #CoffeeLovers #Kitchenware

 

[AccessBlaster]

Could they be a heat sink?

 

[Uncle Gizmo]

Could they be a heat sink?

I ruled that out because the whole thing is made of aluminium. Or should I say aluminum !

So I can't see any benefit from adding an extra piece of aluminum to conduct the heat?

 

[Uncle Gizmo]

Is it the same concept as a double boiler?

It's a single skin piece.

 

[Uncle Gizmo]

Both the inside and outside of that surface have been lathed flat as can be seen from the lathe cutting tool marks... (Possibly not visible in the picture)

 

[Darrell]

I think these are first sand cast, so they are probably the sprue marks remaining after then machine flat in a lathe.

 

[The_Doc_Man]

I like Darrell's answer but there COULD be another facet of this. Strictly hypothetical, but it IS based on how ebullition works.

If those little disks are in fact slightly different alloys than the rest of pot, then they are boiling surfaces built into the pot so that steam bubbles will form on those disks first. Aluminum has among the highest heat conductivities of all elemental metals. If the rest of the pot is aluminum but of a different thickness OR a different alloy composiition, that difference COULD be just so that boiling occurs at those points.

It would be a relatively easy test to just put water in the pot and leave the lid off. You might have to wait a while (watched pots never biol, remember...) but you should be able to see bubbles forming on those disks first. There is ALSO the possibility that they are NOT aluminum, but another alloy entirely, one with iron in it, and they have those disks for times when they are on an induction surface cook top.

 

[AccessBlaster]

I would think a casting that small would have only one sprue, but maybe commercial pours might be different.

 

[Uncle Gizmo]

I did a Google search for "how it's made - stove top espresso maker"

And found this YouTube video,...

Although a very interesting video, it does not discuss the disks. In fact in the video one clip shows the bottom of this original version of the coffee maker and it doesn't appear to have the aluminium discs in the bottom. See time index 4 minutes 20 seconds...

 

[Uncle Gizmo]

New information:-

 

[Uncle Gizmo]

I have seen lots of these coffee pots at car boot sales and none have the arrangement of 5 discs....

The video relates to what happened to my coffee pot when I put it in the dishwasher >>> it destroyed it!!!

 

[Jon]

Could be manufacturing process where it provides grip to rotate it into the base, if there is some screw thread. Or just aesthetic design.

 

[Uncle Gizmo]

Could be manufacturing process where it provides grip to rotate it into the base, if there is some screw thread. Or just aesthetic design.

I did a four-year apprenticeship with one of the best apprenticeships available at the time at AWRE.... I am well versed in the machining and manufacturing processes and this just does not make sense!

To drill 5 holes in something to fix it to a lathe or some other equipment?

It's a vessel for holding liquid, it is heated constantly, meaning a regular change in temperature which can weaken any fixings over time.

The only thing that would make sense is that they are designed to release pressure if the coffee pot malfunctioned...

But still that doesn't really make sense to me?

My interest in this puzzle is because it's puzzles like this that leads you to things you did not know, and can increase your understanding..

It might be time to ask the LLM's again! I understand many of them are being upgraded to university professor level of intelligence!

 

[Jon]

I did a quick search on Google and this came up, if it helps. Someone else with the same problem.

 

[Uncle Gizmo]

The Dates wrong !

 

[amorosik]

I have several Bialetti moka pots, of different sizes (1 cup, 2 cup, 4cup, 8cup..), and none of them have these inserts on the bottom
For safety against excessive pressure, there's always a special safety valve on the side of the lower tank
It's usually made of brass/bronze and has a yellow color
Have you tried checking with a magnet to see if the inserts are ferromagnetic?
They could be for use on induction cooktops
Who exactly is the manufacturer? Try contacting the manufacturer and asking for information
It seems like an important point to clarify .

Regarding the Bialetti moka pot, it's a highly valuable piece
It's studied in design schools and is one of the Italian style reference
The manufacturer has often attempted to offer more modern versions, both in form and functionality, in stainless steel instead of aluminum. However, the original moka pot has always stood the test of time and is a firm favorite, both because it was one of the first home coffee makers and because it's a very practical device to use and clean
It is so popular that its average price is about two or three times the price of a well-made coffee maker from another brand
Plus, you can always find replacement gaskets, handles, and safety valves. In short, you buy it once and it lasts a lifetime

Regarding the video of the girl saying the moka pot can't be washed, that's a common belief, they say that washing it would lose the aroma of the coffee it releases if it is cleaned without detergent
But many others (including me) wash it like other dishes, I don't see any logical reason to not wash it.

 

[BlueSpruce]

Those discs could just be cosmetic to enhance its marketability. I had one of those moka stove top espresso makers and it didn't last long. The aluminum alloy was so thin and light that it felt like it was made of plastic or pewter. So I bought an Imusa made of 72% stainless steel, 18% chrome, 10% nickel alloy and have been using it for 7+ years.

 

[BlueSpruce]

I will run your question through my neighbor who owns a machine shop. Among many things, he builds mini dragsters with 30hp engines for 8-12 year old children. I recently used his water jet shear to make a part.

 

[The_Doc_Man]

Thinking about this question when I am more awake, I have follow-up questions. Can you tell whether those five spots on the bottom are ALSO aluminum? When you look at the inside of the pot, do you see the five spots?

The idea of that being a different metal for induction heaters doesn't seem to be right. My wife has a solid aluminum "Dutch oven" that she uses to cook the holiday-season turkeys on an induction stove top. It has no spots on it and works just fine with induction heating. It is pyrex that doesn't work on induction stoves. If you have two different types of metal, you would run into differences in the two metals' coefficient of thermal expansion. That would make an alternate metal plug expand and contract differently than its surroundings - which means the plugs would pop out at some point and probably show some evidence of a seam after only a few uses. Are the five metal circles radically different in texture from the rest of the base? Like, rougher?

I could easily imagine that if it was molded like it appears to have been, those could be the remnants of the pour-holes, i.e. the sprues, after they have been smoothed to a flatter surface.

 

[BlueSpruce]

Thinking about this question when I am more awake, I have follow-up questions. Can you tell whether those five spots on the bottom are ALSO aluminum? When you look at the inside of the pot, do you see the five spots?

The idea of that being a different metal for induction heaters doesn't seem to be right. My wife has a solid aluminum "Dutch oven" that she uses to cook the holiday-season turkeys on an induction stove top. It has no spots on it and works just fine with induction heating. It is pyrex that doesn't work on induction stoves. If you have two different types of metal, you would run into differences in the two metals' coefficient of thermal expansion. That would make an alternate metal plug expand and contract differently than its surroundings - which means the plugs would pop out at some point and probably show some evidence of a seam after only a few uses. Are the five metal circles radically different in texture from the rest of the base? Like, rougher?

I could easily imagine that if it was molded like it appears to have been, those could be the remnants of the pour-holes, i.e. the sprues, after they have been smoothed to a flatter surface.

If those five discs have a coarse texture maybe their function is to keep it from sliding on hot glass stoves tops when water is boiling?