Unexplained problem removing tap cover

[hippo49]

Hello. I wonder if anyone can help please. This is my first post.

I am trying to replace a washer on the hot tap (simple pillar type) in my bathroom basin. The basin is an 80 year old basin in Art Deco style original to the house and so I am keen not to break it or the pipe joints below. The tap is original as well I suspect. I have replaced washers before in comparable taps without significant difficulty.

I can't even get started because I cannot get the cover (bonnet?) off despite it having thin flats (actually octagonal) at the bottom which I can get a spanner on to. Because of being ultra cautious I made a mock up of a tool I have seen advertised for loosening the tap-head nut, just to remove the cover. The cover perhaps turned a little although hardly enough to notice. I took off the home made contraption to regroup and then found two surprising things. First the drip had stopped despite the fact that I had not turned off the water at this stage (crazy I know but remember I was only trying to get the cover off). Second, the tap spindle had jammed beyond hand tight despite being completely free before.

So my first thought was that I had somehow screwed the jumper plate into the washer seating. But how could that have happened? I'd imagined that the cover has essentially no connection to the "works" inside the cover.

I don't seem to be able to reverse the process to free up the spindle.

So my questions are:

1) Does anyone have an explanation for the above?
2) Could there be reverse threads involved such that anticlockwise turning has tightened something up?
3) Should I have fully opened the tap before I started as my ancient Home DIY book suggests and why would that make any difference? (I consulted it after all the above!)
4) How much can I apply force either to go forwards or backwards?

I am not keen to do anything until I understand what has gone on inside that tap!

Thanks for any help anyone can give me.

 

[rpm]

A photo of one tap from around 3-4ft away would help here. A tap of that age should be a simple design however it has been there awhile so may put up a fight to start with.

 

[hippo49]

Thanks for your interest. Here are three photos I had already. Nothing special about the tap I don't think.

 

[Stigster]

It's possible that the hole in the shroud you just about moved is not perfectly centred and after moving it a little bit it is binding against the spindle. Please do as rpm suggests and provide us with a photo if at all possible. It might be a simple job but a picture often speaks a thousand words as I am sure you understand.

 

[hippo49]

It's possible that the hole in the shroud you just about moved is not perfectly centred and after moving it a little bit it is binding against the spindle. Please do as rpm suggests and provide us with a photo if at all possible. It might be a simple job but a picture often speaks a thousand words as I am sure you understand.

Hi Stigster. I posted three photos last night. I hope they are visible to everyone?

 

[Stigster]

I don't think your post had gone through the moderator queue when I asked for pictures. Yes, they are visible now.

Yes, that shroud should just unscrew but it's very common to have these seized in place after many years of use and obviously yours has too.

If they are truly immovable then the only way I have had consistent success in removing them is with good blast from my blowtorch. Getting it nice and hot will almost certainly make it possible to unscrew. They do unscrew anti-clockwise looking from the top so you have been trying the right direction but as you know, it's well seized on.

That's the only surefire way I know to get it loose.

 

[hippo49]

I don't think your post had gone through the moderator queue when I asked for pictures. Yes, they are visible now.

Yes, that shroud should just unscrew but it's very common to have these seized in place after many years of use and obviously yours has too.

If they are truly immovable then the only way I have had consistent success in removing them is with good blast from my blowtorch. Getting it nice and hot will almost certainly make it possible to unscrew. They do unscrew anti-clockwise looking from the top so you have been trying the right direction but as you know, it's well seized on.

That's the only surefire way I know to get it loose.

Thanks. Yes, I've read about using a blow torch. Also boiling water. As a halfway house I have an electric hot air gun.

I'd still like to understand why the spindle has got so seized, given that I hardly was aware of turning the cover at all and yet the spindle has gone from completely ok to hand-seized. That's what made me wonder, and fear, that I've somehow screwed the washer seat into the jumper disc. I just can't think of a mechanism to explain the results. I'd rather understand what's going on before I try again to turn the cover one way or the other. I don't want to do more damage.

Do you think there's any significance in the fact that I didn't open the tap before starting on the cover?

If it was your off-centre hole theory, surely it would give at least some hint of moving by hand.