Has anyone successfully powder coated their La Pavoni base without removing the boiler? I'm rebuilding a Professional and would love to change the base color to either a white or red. The base is in great shape overall with no rust and only a few scuffs, but I just don't like the look of it. I read somewhere on this forum that the plastic ring is glued to the base? If that is true it seems like a pain in the rear end to remove the boiler? I'm just evaluating whether I need to remove it (I'm leaning towards yes).

By the way, it's an interesting machine. Tag says April 2001, but the group head is pre-millenium. Also, there didn't seem to be much scale in the boiler but there was weird white lumps on the dip tube. Anyone know what those are?

The dip tube spots are likely due to chloride contamination, Chloride contamination of water causes pits to form that fill in with copper compounds, I suspect that the water was also somewhat hard. My 1999 Europiccola was covered with deposits like this but far far more extensive. The underlying metal was corroded and rough. I soaked it in strong sodium bicarbonate solution, and sanded it until it was smooth to get rid of the pits on the surface. Then I went over it with steel wool. That was in 2010. It is still in perfect condition today with an absolutely even protective coating of copper oxide. Chloride contamination can even corrode stainless steel! Do you see pitting and spots like this on the boiler walls? On mine the boiler was just a lime stone mine, but there was no corrosion there. On mine there was some corrosion on the group walls, I managed to polish it smooth without having to remove so much metal as to require an oversize piston. Chloride in water is an extreme evil. It is compounded when the water is hard. Having customers who use ultra hard water and chloride rich water are good for business should one be in business selling repair parts or even full espresso machines.

Thanks rpavlis, I'll take a better look in the boiler but I didn't see anything like what I saw on the siphon tube. There is also some green (I'm assuming copper corrosion) where the group head connects to the boiler. Can I sand that off, or is there a better way to clean up that corrosion?

They will media blast the base to remove the current paint and then the powder coat amounts to a high temp baking process, so you pretty much have to remove everything.

Does anyone know if the flange is glued to the base? If so, can you spin the boiler off without ungluing the flange?

Yes you can leave the flange on. its glued.
You can just unscrew the boiler after you remove the heating element.

I would contact the powder coater to see what temps the material has to be able to withstand. I've had some powder coaters refuse items made of pot metal because they were concerned they would melt or at least seriously deform, so I'm not so sure about how that plastic ring would hold up.