rusty-pie One more question: there was a considerable amount of surface rust and scale both on the outside of the bottom plate and inside of the cover plate where the two mate, most of it fell off or was easy to scrape away with my nails, but some of it is more stubborn: any suggestions on the safest way to remove this?
If it’s the bottom of the plate, the part that mates to the machine a non stick scouring pad should remove it. It’s all stainless so the rust will be from something else that wasn’t stainless which contaminated the water reaching it.
I don’t for sure know the thread pitches or dimensions of the plugs used….send maria at photo and she can check as to the dimensions…and thread pitch, most important to know is if it is a tapered or straight thread.
I “believe” the plugs are nickel coated brass not stainless steel (I might be wrong), when put in with thread sealant they are fine…but if water gets in there, especially water with salts in it an electrolytic reaction can take place which slowly weakens the threads. These can then strip on removal
If you put in brass replacements…then ensure you, put a bit of Molycote 111 on the thread (a thin smear), wrap well with a number of turns of PTFE in the correct directions it feels tight all the way in and then there’s no need to really torque them down as the PTFE is doing the stealing. This will ensure minimal contact and no electrolytic corrosion can occur. Of course if you can find the same thread pitch and plug type in stainless, use that and the procedure with PTFE is the same except you don’t need Molycote.
Feed back on the issue of the thread stripping off as well!
P.S. I think the boilers are plugged at manufacture and this use of Nickel Plated brass plugs is fairly standard across the industry (and all manufacturers) something I would like to see change. Steel needs the PTFE, as they can gall and become very hard to remove.
