La Marzocco GS3 - material of the brew group?

#1: Post by **omega1848** » March 17th, 2016, 11:47 am

Hi champs,
I need you help/ information: Anyone know what the material of the brew group is of the La Marzocco GS3 which is attached to the brew boiler.
As far as I know/ understood the brew boiler itself is made out of stainless steel.
But what about the brew group/ head (the "swan neck")?
In the pictures it looks like chrome plated brass? What about the inside? AFAU the inside is circulated by water from the brew boiler, but whats the material made? Is it brass in contact with the water? or is the "swan neck" made out of stainless steel as well?
Any info highly appreciated!
Thanks in advance
Oliver

#2: Post by **keno** » March 17th, 2016, 12:03 pm

Based on this GS3 parts catalog it appears to all be stainless steel.

#3: Post by **boost** » March 17th, 2016, 12:13 pm

All GS3 group head is stainless steel and welded to the boiler as far as I know.
The older La Marzocco with bolt on group head is chrome plated brass bolted to stainless boiler.

#4: Post by **VeniaCoffee** » March 17th, 2016, 12:16 pm

I can't speak to very early models, but every machine I have seen is stainless steel. Earlier Linea machines had the brew group bolted to the boiler in which case a different metal could have possibly been used. All current machines use a welded boiler/brew group that is all stainless steel.

#5: Post by **danetrainer** » March 17th, 2016, 12:21 pm

Here's a photo of a cut-away boiler/neck/group
that LM provided to show it's all made from stainless (I believe this is a GB-5, the GS3 is the same design). AFAIK there would be no way to weld brass to a stainless boiler.

What are your plans or the reason you suspect otherwise?

March 17th, 2016, 12:26 pm

Thanks guys! You rock!
Well, I only saw the old pictures which looked like brass, and here over in Germany was/ is a big debate about having brass components and the possibility of leaking "lead" from the brass into the water and hence into the coffee.
(please note this was a general discussion, not about La Marzocco in principal!!!)

#7: Post by **bluesman** » March 17th, 2016, 2:58 pm

danetrainer wrote:AFAIK there would be no way to weld brass to a stainless boiler.

You can't weld it, but you can join brass to SS by either soldering it with silver solder and acid flux or brazing it with the right rod (SF6? - it has about 50% silver and is coated with a pink acid flux).

#8: Post by **Viernes** » March 18th, 2016, 2:10 pm

omega1848 wrote:Thanks guys! You rock!
Well, I only saw the old pictures which looked like brass, and here over in Germany was/ is a big debate about having brass components and the possibility of leaking "lead" from the brass into the water and hence into the coffee.
(please note this was a general discussion, not about La Marzocco in principal!!!)

If you don't "eat" brass, you're going to eat molykote anyway, so pick your poison.

#9: Post by **Terranova** » March 18th, 2016, 5:13 pm

The older La Marzocco GS had plated brass groups.

March 23rd, 2016, 3:59 pm

May I ask one more question about the principles of the saturated group? If I understood correct, there is water flooding the "goose neck" up to the shower cap, correct? Hence saturated group. But I am struggling to understand how that works? Because if the boiler is not filled completely with water, how is it possible that the water from the brew boiler is travelling to the "goose neck" itself? Please note I am talking about the "saturated part", not the final water being pressed through the shower cap/ portafilter.
Or is the brew boiler always be filled 100% with water, but even then? Because the "goose neck" is higher from a physical location that the boiler...
Sorry I am confused!
Hope someone will be able to help!
Thanks!!!