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Made of glass or stainless steel water reservoir?

6K views 24 replies 11 participants last post by  mrpinkdonttip 
#1 Ā·
Hello everyone,

Has anyone worked on such project?

Lots of tanked machines have cheap plastic water tanks, the idea is to replace the stock reservoir with a water tank made of glass or stainless steel. I am starting to experiment with Gaggia Classic and basically won't be difficult to cut 5 glass plates and glue them together with silicone or something that is non toxic.

Any ideas on the topic are welcome.

BR
 
#5 Ā·
I am at the stage of researching for now. 4mm glass would be enough, there are aquarium specific silicone based adhesives. I can't weld but like the idea of ss. Maybe someone could help with more info.
 
#7 Ā·
What is the problem with the cheap plastic water tanks?

A solution using Lexan or some generic polycarbonate might be worth considering....rigidity and clarity, plus easy use weld cements. Acrylic might be a little brittle. I think the Mini Vivalidi used acrylic for their slide out tank (might still use it) and it looked very nice. These type of plastics can also come tinted in different colours and a light tint of blue red, green amber etc.. can look quite attractive, some colours even prevent algae growth if the tank is exposed to light.
 
#8 Ā·
I don't like plastic things
:)
, probably that is the reason I got hooked into classical coffee machines and I believe plastic tanks react with water and with chemicals when you wash them, thus you drink plastic. This won't happen if you have a reservoir made of glass for instance.
 
#9 Ā·
L&R said:
I don't like plastic things
:)
, probably that is the reason I got hooked into classical coffee machines and I believe plastic tanks react with water and with chemicals when you wash them, thus you drink plastic. This won't happen if you have a reservoir made of glass for instance.
Then I think a custom solution is all you have....as they all seem to be plastic. I am not so sure about glass as a material, or how well it will glue together. I suppose the sealant seems to work in fish tanks and perhaps you can build a nice little business making glass tanks. Although someone did point out some of the difficulties of manufacture and cutting toughened glass might be a little more difficult than 2mm agricultural glass for instance.

A cheaper solution might be a plastic overtank with suitable fitting lab glassware inside it... of for square shapes what they call a glass museum jar....these come in various sizes, some examples below.

https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=glass+museum+jar
 
#10 Ā· (Edited by Moderator)
Aquariums glue together rather well using silicone rubber - the correct type for that use. There's no need to grind edges etc. No idea if the silicone is food safe. A rather large aquarium can be built using 6mm plate. I made one just over 1m long x 40cm wide for a similar depth of water. Imperial so the glass would be 6.4mm thick. Much bigger ones often use laminated 12mm - 2 sheets of 6mm. Stronger as it can flex more than a singe thickness of 12mm. Once filled at sizes where that is used support becomes a bit of a problem due to total weight.

TIG welding is usually used on stainless - tricky on thin stuff. It can also be silver soldered, there probably are food safe grades of that.

https://www.bssa.org.uk/topics.php?article=150

Plastic water tanks - read some of these reviews. Strange taste rumoured to be due to chlorine reacting with the plastic. Ours is filled several times a day and the taste problem seemed to be down to needing a severe descale from new but the chlorine aspect might be correct. They probably use the same plastic as all do on all sorts of things.

https://www.amazon.co.uk/Morphy-Richards-Dispenser-131004-Redefine/dp/B00XMK2KIA/ref=sr_1_7?ie=UTF8&qid=1533478991&sr=8-7&keywords=hot+water+dispenser

John

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#11 Ā· (Edited by Moderator)
I went on with my crazy idea and made a prototype of glass. I would say coffee machine water tanks will never be the same
:)
. Started with Rancilio Silvia 'coz I had one with a broken water tank. Definitely an amateur work but I like the result. Probably some glass factory company could easily produce it cast from one piece.

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#14 Ā·
I had to do some tricky silicone sealing recently. Not happy about the price but they really do work and leave a neat finish. The excess silicone can just be wiped off them with a kitchen towel.

https://www.toolstation.com/shop/p46602

The other trick once your sure the fillet or what ever is really down is to spray window cleaner on - it prevents the stuff from sticking - even to your fingers. Picked up of youtube but it actually works. Somebody just finishing the sealing off with their finger showing it didn't stick to those. It's water, IPA and a wetting agent.
;)
The one I used was blue - some sort of dye as well.

John

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#15 Ā·
ajohn said:
I had to do some tricky silicone sealing recently. Not happy about the price but they really do work and leave a neat finish. The excess silicone can just be wiped off them with a kitchen towel.

https://www.toolstation.com/shop/p46602

The other trick once your sure the fillet or what ever is really down is to spray window cleaner on - it prevents the stuff from sticking - even to your fingers. Picked up of youtube but it actually works. Somebody just finishing the sealing off with their finger showing it didn't stick to those. It's water, IPA and a wetting agent.
;)
The one I used was blue - some sort of dye as well.

John

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Pros use soapy water and rounded scrapers.

The crucial bit is to evenly apply the right amount of silicone, in the first place. This is down to cutting the spout open. Then spray soapy water and pull scraper along tightly and steadily.

I've seen folk use their fingernails. However, a scraper can hold more excess material before it needs a clean wipe, thus you can get farther in one go.

Wouldn't recommend using your fingertips as they are too soft/unstable to produce consistent inner radiuses.
 
#16 Ā·
Thanks mate, this type of work is not my forte, I sent an inquiry to a local glass factory to give me an offer for Classic and Rancilio glass containers, probably they will ask for 100+
:)
 
#17 Ā· (Edited by Moderator)
I found the profiled scrapers worth buying despite the price which is obviously way over the top. I have used water in the past so think I will stick with the window cleaner. Some of the silicones work well with just water. The acetic ones can be trickier but last longer and are stickier.

I also spent a bit more than usual on a caulking gun

https://www.toolstation.com/shop/Adhesives+%26+Sealants/d180/Sealant+Tools/sd3177/Rotating+Sealant+Gun/p35102

;)
Rotating as I needed to work behind taps and in corners, should have been done before fitting the taps really. Much to my amazement the flow actually stops when the trigger is released.

The good thing about the profiled scrapers is that they remove silicone each side of the seal. In my case work surface to hand finished tiles with an uneven surface. No chance of scratching the tiles and they did get most of it off those as well. Finished with folded up kitchen tissues soaked in window cleaner. That also recessed the seal to match the grouting.
:secret:
both black in my case. It's easy to leave a very thin film of silicone each side of the seal - that usually sticks out like a sore thumb once some one notices it.

The window cleaner is also good for getting grubby finger marks off the DB. Who ever owned that before use a cloth with something on it, some sort of polish. Hopeless - the window cleaner got rid of that too.

John

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#19 Ā·
I love this idea I am not a fan of plastic myself, would love a machine that doesn't contain any, but problem is with alot of home espresso machines, its not just the tank that's the problem the tubing and water feed pipes are plastic on some, plus alot even have a form of plastic in the portafilter.

I seen a machine that I came across by accident on ebay "DECENT ESPRESSO" it has a nice ceramic water reservoir. looked good.

I wait with great anticipation for the day I can get a machine that has zero exterior or interior plastic, or anybody know if there is one available?
 
#21 Ā· (Edited by Moderator)
louiseb said:
I love this idea I am not a fan of plastic myself, would love a machine that doesn't contain any, but problem is with alot of home espresso machines, its not just the tank that's the problem the tubing and water feed pipes are plastic on some, plus alot even have a form of plastic in the portafilter.

I seen a machine that I came across by accident on ebay "DECENT ESPRESSO" it has a nice ceramic water reservoir. looked good.

I wait with great anticipation for the day I can get a machine that has zero exterior or interior plastic, or anybody know if there is one available?
If you mean no plastic....then you won't find one anywhere. or I don't believe you will. Happy to be educated on this.

If you mean no plastic (e.g. Nylon or polymer) in the water path for water that you end up drinking as part of espresso...then yeah, that can be very tricky for prosumer machines. You will have to accept Viton, rubber RTV, Silicon and PTFE as not being plastics per se and not harmful, if you cannot accept these materials at all, then no machine meets the requirement.

  • Rotary pumps have plastic in the balanced bypass, this bypass feeds back to the inlet
  • Vibe pumps have plastic inside in places (some more than others)
  • Plumbed in machines have plastic in the water lines, or the fittings/valves used (you might be able to avoid this in rare circumstances, I'm not sure how)
  • Internal water tanks are always plastic (I suppose you can make steel, glass or ceramic ones, or use substitutes)
  • Flowmeters all seem to have plastic impellers
  • Plastic Ys and tees can be substituted for brass where they lead to the tank.

The nearest you are likely to get to avoidance of plastic and also as much PTFE/Silicone as possible out of the water path would be a Vesuvius with stainless piping and substitute a metal or glass internal tank. The Gear pump used doesn't have plastics inside to the best of my knowledge (it's metal) and the rest of the drinking and brew water path will end up being almost all stainless steel apart from the Silicone input pipe in the water tank. So for me this was an interesting mental excercise thinking about just how much polymer of different types is used in machines, but no more than that. The other option might be a carefully selected lever with no pump.

This is because the real problem for people who don't like plastics is below:

All the plastics in the water system upstream of your house....the miles and miles of plastic pipe laid by utilities carrying our drinking water from source to home, in the processing plants etc..the tiny bit in your espresso machine or it's tank, isn't going to make any difference. I know, what about bottled water in glass bottles?....If you can find it in a glass bottle, that's OK for the (modified) machine and the factory bottling it has used no plastic in the water path (hugely unlikely), then perhaps just perhaps....although all bottle caps usually have plastic on the inside don't they?

P.S. It's a bit like people who worry about a nick in the heel (breaker zone) of their flat burrs and posting up macro shots of the odd little nick and wondering if they should get new burrs.....whilst completely ignoring the 3 dirty great screws and holes that are often much further in than the nicks they are worried about.
 
#22 Ā·
Yes, I also thought about the same project: it's absurd that in machines that cost thousands of euro are still used cheap materials like plastic, especially for an important component like the reservoir - more so considering that a totally safe and natural material like glass is a perfect match and absolutely suited for handling and preserving water, while being still very affordable.
 
#23 Ā·
P.B. said:
Yes, I also thought about the same project: it's absurd that in machines that cost thousands of euro are still used cheap materials like plastic, especially for an important component like the reservoir - more so considering that a totally safe and natural material like glass is a perfect match and absolutely suited for handling and preserving water, while being still very affordable.
Dave's post above yours has a few key facts listed [emoji106]
 
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