Post By samuellaw178
Post By rrm
Post By buzzramsey
Post By Gustopher
Boiler repair on a Brugnetti Aurora Lever
Just wondering if I could get some thoughts on whom I should get some help from.
I have a great Brugnetti Aurora that I am doing a refurb on. Its in pretty good nic....apart from the boiler bolts. There seems to be some electrolysis occurring because the bolts have rusted badly. 1 rusted completely, 1 snapped (or crumbled).
I am based in Canberra and cannot find anyone willing to put in some new bolts. The last guy I took it too said that the bolts would have to be sealed (welded) to to the boiler and to do this it might break the welds and they did not want to try. Canberra being Canberra there is not a lot around in terms of metal workers.
Does anyone know where I could source the bolts with the round head? Also does anyone have any suggestions on anyone in either Canberra or Sydney who might be able to assist with installing new bolts?
Not really keen to send it in the mail, its costly and dangerous.
I have attached a couple of pics for any who are interested. Its the strait through HX type which is interesting.
Here is a pic of the boiler and some links to a couple more...
Thanks for the advice
Hopefully someone will be able to give some recommendation to your question.
To fix the bolts, you do not have to involve welding (I imagine more expensive and riskier). What you need to do instead is to saw off the existing bolts (without damaging the sealing surface) and retap a threaded hole to accommodate stainless studs. This should be a more permanent solution. Here's what the other forum has posted. Aurora Brugnetti HX hevelmachine... - Koffiepraat.nl forum over koffie, espresso, filterkoffie, horeca en technieken
p/s: These are worth restoring and so worth persisting! There're only so few of these around. The group head is similar to the Faema Velox's grouphead - so the seals for the group are Faema's and shots are amazing. Plus, it uses higher line-pressure for preinfusion which is extremely rare for a lever (as far as I know only on the higher end Londinium 1-P and Victoria Athena). So simple on the inside!
Last edited by samuellaw178; 22nd September 2016 at 09:07 AM.
Find a decent fitter and turner, ie look for a smaller machine shop.
Originally Posted by buzzramsey
The "bolts" in the boiler flange are most likely Studs. Ie a section of rod with threads both ends. The flange is more than likely tapped and the the studs screw in.
I see two possible repair methods.
1) Cut off the corroded studs flush with the flange surface and drill and tap the boiler flange again. This can be problematic, because it is nigh impossible to find the dead centre of the existing studs. And therefore it's difficult to drill them out completely. And successful
re-tapping is impossible with slivers of stud remaining.
2) My preference, would be to cut off the existing studs flush with the flange face and then carefully drill the old stud out with a clearance drill, say 0.25 mm oversize to the stud. This will leave a through hole without any thread in the flange.
Then you can replace the studs with Stainless steel socket head cap screws and stainless washers. A bonus is the problem will never happen again.
Either way it's a job for engineering shop with an accurate drill press, a machinist with a good eye to judge centre of the bolt , and some sharp drills.
If it were me, I'd also have the flange on boiler and the cover plate surfaces trued up on the milling machine at the same time.
It be should no big deal: the operations involved are done every day in the auto cylinder head reconditioning or steam reticulation industry.
If you are in Melbourne I could suggest a machine shop (in Moorabbin).
EDIT : Just noticed you are in Canberra : I could ask around for a recommendation on the car forum which I'm involved with.
Here's roughly how it looks like. If you drill and tap just the right depth, there's enough 'meat' in the original bolt head to hold onto the new stud (here's another one that does the same thing - 4th picture https://www.kaffee-netz.de/threads/r...ugnetti.20634/).
Because it's welded on the inside, that also means you'd have to drill out the head (even bigger hole on the flange) rather than just the bolt/stud/body.
I might be wrong, but doesn't drilling a through hole mean you'd have to use a sealing gasket(or weld) on the inside of the screw? Will stainless washer suffice?
Anyway, if it is easy enough I might want to do the same modification as well (keep us/me updated ). The corrosion/rust only happens when the boiler gasket is old and start leaking over a long term.
Last edited by samuellaw178; 22nd September 2016 at 12:24 PM.
Ok, so the boiler is stepped and covers the bolt heads. It's now obvious.
Originally Posted by samuellaw178
So option 1 seems the only way to go.
No worries - thanks for the info. I thought a retap might be easiest. It's is tricky so I will find someone to do it.
Originally Posted by rrm
i will let you know how I go. Will definetly post some photos/info was also planning on machining the flange and the boiler cap.
Hey mate, I'm in canberra and am currently completing my own refurb of an Aurora. I've had to do the bolts on mine recently. Happy to have a look at yours.
Thanks - I will PM you.
Originally Posted by Gustopher