The boiler of my espresso machine is aluminum, and as I'm doing a number of other modifications (temperature PID control, pressure gauge &
regulator, preheating of incoming water), and I want to also plate it with copper (or brass). The pipes and connectors in the machine are made of
copper and brass, and some of teflon. I know I can copper plate with a copper sulfate solution, but I'm wondering about the safety issue, in
terms of plated copper flaking off and getting in the water and me drinking them. Is there any specific to how I plate to minimize this?
Brass would probably be better, but I've never tried that. They sell kits, but I can't import chemicals into Canada without paying huge
fees. Anyone know anything about brass plating?
Temperature can reach 140*C for steaming, and pressure 190 psi, so I don't think the ad-hoc plating method I've used for copper would make a
plating that will stick OK in these conditions.
What about other metals? I was thinking silver, as I have some fine silver, and I could make silver nitrate for plating. Or would that not stick as
well as copper or brass to the aluminum?
Do I need to pretreat the aluminum before plating?
[Edited on 16-6-2005 by Quince]
Metall plating
Lambda - 16-6-2005 at 02:43
Hello Quince, I have done quite a bit of metall plating. Preperation, preperation before plating is of essential importance.
What you have done, is just a simple redox reaction. It stops a soon as your aluminium has been plated by a microscopic layer of coper or silver. You
have to go a step further, you have to electro plate your components.
It is of essential importance, that if you want a durable metall coating, that you prepare your surface properly. This does not mean that you can
allways just start with your final metall layer. Often the final coating is preceeded by a different metal to enhance a better adhesion of this layer.
But this all depends on the procedure that you use. There is a shitload of secrecy in the industry as to what the trick component is that gives just
that extra shine, or better adhesion. These trace components are often code-named.
For this reason, I buy every single book I can lay my hands on, and I have been lucky with 25-30 books on trade recipies in four different languages.
A lot can be said here about metal plating, and my hardcopies have not all been scaned yet. These books have been written by the pro's, so why
waist space here, if I can just upload a few PDF-copies to you. When I find them, I will upload them to Rapid Share, and past the links here.
Please have patients, for I will have to go through a hell of a lot of files before I can find them.
Rem: I have a few good brass plating recipies for you, however, they are nearly all based on the cyanide procedure. Maybe flaking off copper
won't kill you afterall !.
Quote:
All good things come to those who have patients !
[Edited on 16-6-2005 by Lambda]Quince - 16-6-2005 at 03:27
No, I didn't mean I plated with the copper sulfate, I meant that I electroplated with a copper electrode and used copper sulfate to make the
electrolyte.Lambda - 16-6-2005 at 03:33
Ok, but you did it in water, and this can be a problem with aluminium. Oxide formation, this oxide shields it off from proper adhesion of the copper
layer. You won't get a durable adhesive coating in this way. You may have to work without water. Or an enviroment that prevents oxide formation,
thus pH-buffering may be required. Using copper as an electrode is a good idee, in this way a bath may automaticly replenish itself. Only small
amounts of addatives will be needed to compensate electrolyte loss. By turning your object arround or multidirectional electrode placement, you may
get a nice and evenly distributed copper coating.
[Edited on 16-6-2005 by Lambda]Oxydro - 16-6-2005 at 04:41
To plate aluminum you are first supposed to zincate it (preliminary zinc plating) before trying to apply copper or anything else. A outline of the
normal aluminum plating process is shown here: http://members.cox.net/oldies1955/electro/pagealumtour.htm
Unfortunately the pics don't work, but the captions get the message across.uber luminal - 16-6-2005 at 05:53
Quote:
No, I didn't mean I plated with the copper sulfate, I meant that I electroplated with a copper electrode and used copper sulfate to make the
electrolyte.
If you use copper sulfate as the electrolyte... then your plating with copper sulfate. While the copper electrode may oxidize in the process, copper
ions go into solution... as Copper sulfate. The Cu ions in solution is what gets reduced onto the anode.
So you did mean you plate with copper sulfate.Quince - 16-6-2005 at 15:02
On second thought, since my water isn't acidic I may just leave it as it is. The only real problem with aluminum is what descaling agent would
be safe to use. I don't think acid like citric or acetic is a good idea. Last time I used CLR, but I don't know if that attacks aluminum.
There was a CLR smell left on the aluminum that took quite a long rinse to get off.
I have to descale every few months as I artificially harden my water to about 150 ppm (makes better espresso).
[Edited on 16-6-2005 by Quince]
Citric acid or.....
Lambda - 16-6-2005 at 19:47
Citric acid can be used to pacify aluminium. It is also used in certain anodizing processes, where current is used. Anodized aluminium is very
resilliant to further surface attack. As a matter of fact, when you buy a new pressure cooker of aluminium, the guide book advises you to first pacify
it by cooking lemon juice with water. I have a "Prestige" pressure cooker.
This guy is making money on procedures discribed in one of my books on anodising and coloring aluminium. It's a hand typed book-bound company
manual with the text "geheim" meanig "secret", that I bought in a secondhand book store. This bookstore often buy's books
from people from who the rellative have passed away. I was not the one who had stolen it !.
Copper plating is non- toxic. Think about it, the potable water in your house runs through copper pipes. I would hope that its not toxic. By the way,
CLR is an evil fucking chemcial. It is totally useless, and if you use it on stuff you use to prepare food and bevarages you are going to be tasting
CLR forever. I've had first hand experience with a barbque, and just thinking about it makes me want to vommit. I hate CLR!!!!!!!!!!!!
[Edited on 17-6-2005 by tom haggen]The_Davster - 16-6-2005 at 20:55
I like CLR... Time ago when my lab was shared with my fathers workshop, acid fumes rusted all his tools and CLR kept me from having to replace them
all.
[Edited on 17-6-2005 by rogue chemist]Quince - 16-6-2005 at 22:12
Quote:
Originally posted by Lambda
Quote:
Move to Italy, the espresso is good there !
I'm in Vancouver, and the founder of Caffe Artigiano recently won second place in the international barista championship in Italy. So I think I
have a pretty good baseline right here.
Congratulations !
Lambda - 17-6-2005 at 06:17
Congratulations Quince !.
I suppose you guy's are getting better at it every day.
I envy you !
The finishing touch, just that little extra shine !
Lambda - 17-6-2005 at 07:55
Quince, you may now get into espresso machine competitions.
Here are two good books, to give your espresso machine that little extra shine you have allways craved:
My espresso machine, looks better than your espresso machine !
Quince - 17-6-2005 at 16:08
Thanks for the files!tom haggen - 17-6-2005 at 18:20
I tried removing a bunch of zinc oxide of of some galvanized sheet metal last summer at work with CLR, and all it did was smear the oxide everywhere.
But small amounts of iron oxides are probably one of the easiest rusts to remove. So thats why it probably worked so well for you rogue.
[Edited on 18-6-2005 by tom haggen]
THanks
chloric1 - 19-6-2005 at 09:44
I had a copy of that Caswell book but every chapter was a separate doc! Now I have it all in tidy organized format. Time for some spring cleaning in
my hard drive!
More books on metall plating soon
Lambda - 19-6-2005 at 10:34
Chloric1 and Quince, I have a few more books that might interest you. The Caswell book was largely based on kits, for Quince said that importing
chemicals into Canada can be very expensive, and kits were available. The Caswell book is however a good introductory book, that gives you a headstart
in a better way than I have seen in many other plating manuals.
I have a few more books with recipies for the do-it-your-self metall plater, which I will upload shortly.
It is pleasing for me to see that some of you enjoy these book uploads, for this will then motivate me to continue doing so.Archimede - 22-6-2005 at 20:27
Quote:
Quote:
I'm in Vancouver, and the founder of Caffe Artigiano recently won second place in the international barista championship in Italy. So I think I
have a pretty good baseline right here.
Congratz on that. I checked and I noticed that the competition was in Trieste Italy which is my home town. Who won the first place? Illy?Quince - 22-6-2005 at 22:31
http://www.worldbaristachampionship.com/
2004: 1st Tim Wendleboe (Norway), 2nd Sammy Piccolo (Canada), 3rd Klaus Thomsen (Denmark)
2005: 1st Toels Overdal Poulsen (Denmark), 2nd Hiroyuki Kadowaki (Japan), 3rd Sammy Piccolo (Canada)
Looks like the Caffe Artigiano guy made it in the top three both this and last year.
