Brasilia Century rebuild - need help, advice, ideas

[aeroplane]

Sorry in advance, this is cross posting to another site, but to avoid re-assembling that thread here, this is the link --

http://coffeegeek.com/forums/espresso/machines/245083

This is where I am now --

Seals and such should arrive an a day or two. Boiler will be reassembled and hooked up - everything was working fine before, so hopefully it will again. (famous last words!)

Assuming that everything needs adjustment -

I am at about 5700' (Denver) Unpressurised water boils at about 201F. What is a good starting point for brew water temp? Is there an easy way to measure or do I have to get an expensive thermocouple?

How and why do you adjust brew pressure, (generally) or should it be set to 9bar and left alone?

A brew water manometer can/should be tapped off the HX after the boiler before the head? Yes, no?

Where can one buy a good, small dual manometer. If not dual, how's about two small ones?
(the boiler pressure gauge currently is pretty useless, it's old and doesn't read well...)

Thanks!

--jim

[barry]

This is where I am now --

Seals and such should arrive an a day or two. Boiler will be reassembled and hooked up - everything was working fine before, so hopefully it will again. (famous last words!)

did you disassemble the boiler itself (ie, remove the endplates and dismantle the heat exchanger)?

I am at about 5700' (Denver) Unpressurised water boils at about 201F. What is a good starting point for brew water temp? Is there an easy way to measure or do I have to get an expensive thermocouple?

i hate to have to break the news to you, but these things are notorious for running cold. in your case, that might be a good thing, as you won't have to worry about the altitude issue.

How and why do you adjust brew pressure, (generally) or should it be set to 9bar and left alone?

you can tweak brew pressure at the pump. set it at 9bars to start with and then play with it after you have some experience on the machine.

Where can one buy a good, small dual manometer. If not dual, how's about two small ones?
(the boiler pressure gauge currently is pretty useless, it's old and doesn't read well...)

http://www.thegaugestore.com


or you can get a stock gauge from rosito-bisani in los angeles.


--barry

[Ken Fox]

Sorry in advance, this is cross posting to another site, but to avoid re-assembling that thread here, this is the link --

http://coffeegeek.com/forums/espresso/machines/245083

This is where I am now --

Seals and such should arrive an a day or two. Boiler will be reassembled and hooked up - everything was working fine before, so hopefully it will again. (famous last words!)

Assuming that everything needs adjustment -

I am at about 5700' (Denver) Unpressurised water boils at about 201F. What is a good starting point for brew water temp? Is there an easy way to measure or do I have to get an expensive thermocouple?

How and why do you adjust brew pressure, (generally) or should it be set to 9bar and left alone?

A brew water manometer can/should be tapped off the HX after the boiler before the head? Yes, no?

Where can one buy a good, small dual manometer. If not dual, how's about two small ones?
(the boiler pressure gauge currently is pretty useless, it's old and doesn't read well...)

Thanks!

--jim

Denver is at around 5300 ft., and I live at almost 5900 feet. Since espresso is brewed under pressure, you will not have any problem brewing at any reasonable temperature you choose. This *might* not be true at the 15,000 feet, but it is certainly true at your altitude. Using a Scace device I have been able to get water temps of well in excess of 210 degrees F, well above any temperature you would want to use to brew espresso. By the time the espresso exits the PF, it will be below the boiling point at your altitude. So, I suggest you brew exactly as you would brew were you at sea level and I doubt you will have any differences in the results.

One reads all sorts of things about brew pressure but I've yet to read of a single blinded taste experiment where someone established that there is a difference to be had in the cup within the brew pressure range one commonly sees, which for the sake of argument I'll define as 8 to 10 bar. Most people set their brew pressure or OPV to present about 9 bar to the puck, and I'd just set it and forget it once I was confident the setting would hold.

There IS interest in pressure profiling and some evidence of benefit of a slow pressure ramp up, as provided naturally by a vibe pump and by a rotary pump in some situations if setup that way. I converted my rotary machine to preinfuse at water mains pressure controlled by a pressure regulator (set at around 3 bar after experimentation) for 6 seconds, followed by the actuation of the rotary pump at full 9 bar. I would not claim that it improved shot quality, but I would affirm that it has markedly reduced "sink" shots.

Good luck.

ken

[aeroplane]

I received the boiler seals (o-rings) today!

Is there an oil/lubricant that I can use on the o-rings to help them seat? Similar to how you put a thin film on your oil filter when you change the oil in your car.

Wesson? Some higher temp cooking oil? Crisco?

Or just leave them dry?

--jim

[Ken Fox]

I received the boiler seals (o-rings) today!

Is there an oil/lubricant that I can use on the o-rings to help them seat? Similar to how you put a thin film on your oil filter when you change the oil in your car.

Wesson? Some higher temp cooking oil? Crisco?

Or just leave them dry?

--jim

Not the same machine but Cimbali techs advised me to use high temperature food safe grease on the boiler O-Rings that seal where the Heat Exchanger mates with the boiler. This is the same grease they sold me previously for the O-rings in the frother and water wand valves, and I believe it is more or less the same stuff I use in my roaster, containing Teflon, and which I've bought from McMaster Carr.

ken

[aeroplane]

Well, at this time the boiler is back together and it holds pressure and seems to work great!

Everything is operative on the machine, and seems to be in good working order, except the pump, which sprang a decent leak. However, I have a new one on order - $42 from ChrisCoffee, and it has a better housing than the original (Brass vs. plastic) and should be a fine replcement.

I re-sealed the steam wand valve, and it closes like a bank vault.

So, at this point, I am merely awaiting the new pump, and with that replaced, the re-build should be complete.

Then on to tuning... I have a digital meter with thermocouple as well as a naked portafilter on it's way. I just need to borrow a friend's portafilter pressure gauge, and with that I can set the machine to it's ideal, and then decide if I want to mod it... (more on that later)

--jim