Hey everybody,

My name's Émeric. I'm from belgium and I'm totally new in this very interesting forum.
English is not my first language but I'm gonna do my best to be understood!

I'm currently rebuilding an old Olympia Cremina. I've been replacing all the gaskets & seals and for now everything work just fine.

The only problem I have is a part of the group head that has been suffering from the intensive use of the lever.
Here is a picture of the group head:


The problem is a bit too technical to describe in my english but I guess every Cremina users know what I'm talking about.

I'm planning to reload (refill?) with a correct metal, using a TIG welding machine (I used to be a TIG welder).
Welding technique is not a problem but the question is which type of metal do I should use.
have anybody ever done this? Does anybody knows which type of brass should I use?
Is there an alternative?

Thank you for the answer.

Although I can't really help you, I just wanted to say thanks for that picture... reminded me to lube that area a lot more frequently.

This thread could be of help I supposed, but it's definitely not an easy fix.

Ouch! Busted Cremina grouphead

Oldest Olympia Cremina 67?
^^

orphanespresso wrote:I have figured out how to restore the rear lever bushing slot and it works out pretty good overall. I made a jig from a perfect slot for a pattern and add small stainless steel shims layered in JB weld. Then insert the jig covered with Dow 111 so the JB won't stick. When it sets up then remove the jig and the slot can be filed and formed carefully until it is exactly the shape as the original....this returns the smooth function of the lever and hopefully extends the life of the top of the group. The patch is about 75% steel and 25% epoxy. the repair is mostly hidden inside the fork so one does not even know it has been done but for the good feel of the lever.

Thank you for the answers.

I don't know yet wich solution I will try.

I'll give you news & pictures as soon as the work is done.

To update the patch repair from that previous thread...it did not hold up well over time and was not a great substitute for a complete metal repair. This led me to consider that a machined inox insert with smaller OD roller bearing could be a possible repair approach.
Your group has worn quite a lot and does look to be near breaking through.

There are a great many different types of brass/copper/bronze alloys out there, so it's difficult to say what was used originally in the group head. Some types of brass lend themselves to welding better than others also (and some more to machining, etc.). Some brass is not very weldable due to a high lead content.

You might check into using an alloy rod such as 655 or 903 or something and try a small test weld.

The other option would be if you could find another group head; then you could just take some of the metal and cut/hammer it into a welding rod. Then just TIG weld the area shut and file it back into shape, etc. Of course, if you find another group head...

Another option might be silver soldering/brazing. Get yourself some bronze, make an insert and then silver solder it into place. If done properly, it might end up looking nice and would provide some improved wear characteristics.

I had a similar problem on my La Pavoni lever and ended up installing bronze bushings.

Bronze bushings for worn La Pavoni lever - DIY

Keep in mind, if the group head is chrome plated, that's going to be an issue when welding also.

Ray