Assistance needed with bathroom conundrum

[beech1948]

My bath has a rotating knob of 4" diameter on the side and behind this is the overflow.

Access to the knobs fastening is through a 3/8" hole in the side of the knob. Looking in with a focussed torch light I can see what appears to be the threads for a grub screw. I have tried poking a screwdriver in there including a slotted one, a phillips one and a PZ one. The slotted one seems to get a grip but then slips.

I do not know if the grub screw is rounded over by the installer, if the screwdriver is failing to get a grip or what. I am unable to see to the bottom of the grub screw threads.

I have considered that the grub screw may not be there but I doubt that.

I have tried some penetrating oil but it does'nt seem to help

Parts are I think brass.

Anyone got any ideas

 

[thick_mike]

Try taking a photo on your phone with a flash?

Have you tried an Allen key?

 

[mbartlett99]

Have you tried an allen key - a lot of grubscrews are.

 

[AES]

Have you tried an allen key - a lot of grubscrews are.

Just what I was going to say. If you have a NICE set with the "rounded off" ball ends at one end try wiggling about with that first (at a GUESS it'll most probably 3 or 4 or 5 mm - or Imperial if you're unlucky - not so many Allen key sets around with the "modern ball ends I think).

 

[beech1948]

Many thanks too AES,mbartlett99 and anyone else who suggested an allen key end...good call. I have only ever found grub screws with slotted ends and then only about 4 -5 so I never considered allen keys.

It took me 3 hrs this am to find out that there is an allen key end on this.

I tried 5.5 mm only to find that it was a bit small. 6mm was too big. I tried 3/16ths but too small. I tried7/32 only for it to be just a smidgen too large.

Am I missing any sizes here ?

 

[Marineboy]

The obvious size you need is therefore 13/64ths. If such a size is available!

 

[thick_mike]

You’ll probably find the hex socket in the grub screw is corroded a bit, or full of gunk. Maybe try cleaning with something acidic (vinegar?), or a standard bathroom cleaner and retry the 6mm allen key.

As a last resort, you can always fit the key to the socket using a bit of wet and dry to carefully shrink the key.

 

[Distinterior]

It's very unlikely to be an Imperial Allen key size, coz Bath pop up wastes of the type you describe are all likely to be metric due to their lack of age.

 

[Lons]

If you can't get a std one to work, buy a very cheap set and carefully file one down until it fits, needs to be a cheap one as they are quite soft. Simple but it works.

 

[sunnybob]

Just to make your day complete... if its fairly modern it could be a TORX head

 

[AES]

OR ................ the other dodge that MAY work is to find an Allen key that's just a tiny bit too small (if it's not a Torx head !!!!!! - unusual but not impossible in my experience), get a small strip of ali cooking/oven foil and wind a strip (just a couple of turns) tightly around the end of the key. Secure it with a band of sticky tape (ABOVE the business end, but still holding the ali in place) AFTER you feel it "catch" nicely in the socket. More than a bit fiddly, but that trick has got me out of the manure a couple of times.

Try this AFTER you've tried cleaning any gunk out of the socket with bathroom cleaner, cleaning vinegar, etc, as suggested above, plus use a toothbrush (preferably a used one!) and/or a tooth pick, cotton ear bud, etc, etc. You may even find nail varnish cleaner helps if it's got acetone in it (not all of them have).

Good luck mate, I do NOT envy you, but bet that you do it - FINALLY!

 

[beech1948]

Thank you all for your comments.

I have wasted about 7.5 hrs on this so far and am going to ignore it for a day or so just to let the frustration recede.

I guess its back to basics so clean it first through 8mm access hole. I don't like the idea that its a Torx headed allen key. I will check but I'm fairly certain its a hexagonal shape.

It does appear to be an imperial size and the idea of slowly grinding down the allen key to fit appeals. I just bought a cheap Screwfix sub £4 allen key set to waste doing this. I thought I would use an old coarse oil stone I've had unused for years to do this.

But it will have to wait now until Thursday as I'm so fed up with this that I can't tackle it tonight.

Cheers
Al

 

[AES]

I can very well understand your frustration mate. Good idea to "take a rest" & think about it (or something else!) for a while! Lack of access cannot help - bit like working on UK-built aeroplanes, they NEVER gave the maintenance people a thought.

I am definitely NOT saying my idea is "the best" or anything like that, but you MAY find that adding a bit to the hex end of a slightly smaller Allen key with the ali foil may (rept. MAY) be a bit easier than grinding a slightly too big one down (even if the donor key is made of Chinese cheese).

"Sleep on it" as my old Mum always used to say. Anything worth watching on the box???

Edit for a P.S. I've never tried it, but I don't think the ali foil idea would work very well on a ball end Allen key - suggest you use a plain hex end one if trying this.

 

[Eric The Viking]

My twopence:

90% chance that it's metric. A huge amount of that sort of stuff is made in Italy.

I would try the filing down technique (due deference to AES) as it may need some torque to release, and you dont want it to slip. I agree that it is probably corrosion. If/when you reassemble I would use Loctite threadlock (the non-permanent type), so you don't need to get it impossibly tight, and a dab of nail varnish on top to seal it from water a bit.

I very much doubt it is Torx, but you really need to look rather than just try a driver - Torx drivers in hex sockets appear to work until the point when you strip the splines off and make a right mess of both. DAMHIKT!

I would also try an impact driver, if possible. Cut the right angle off a cheap hex key, and chuck-up the long straight bit. You really do need a clean and snug fit in the grub screw though, or one or both will be chewed. But the shock of the impact driver really helps in my experience. Having just the shaft also lets you apply a socket set to t'other end, and a rachet is really useful in a tight space - you can concentrate on keeping the shaft in line.

Also, if you slightly taper the flats, you might be able to gently tap the coreect size into place snugly, with a small hammer. I've done that too, with success, especially with tiny grub screws on equipment knobs (not much force there!).

 

[Lons]

I'd agree with Eric except to say almost 100% that it will be metric, would have to be a very old bath, or from the USA to be anything but.
I've fitted many bathrooms over the years and never come across a torx fitting, always either screw or allen type.
I wouldn't use an impact driver as the components are usually flimsy and also be careful not to spill acetone as it will damage plastic fittings - and your bath!

Just to add to your problems, the stud unless very good quality is likely to be steel not brass and the "nut" bit is usually a threaded steel insert press fitted in the moulded plastic component which accepts the overflow pipe so your assumption it's corroded it probably right. I'd squirt WD4 or releasing oil in over a few days and keep trying, carefully as if you break it you're in trouble.

It's a stupid design as though easy to fit during installation it's a nightmare when it comes to maintenance. I have one but made sure it was at the tap end of the bath so if if fails I can break it off and replace it.

I don't envy you, good luck and remember softly softly approach if you can.
Bob

 

[novocaine]

are you sure the knob comes off? I've seen these that are captured from the rear, you fit the overflow, pass the shaft through and lock it a the back then attach the rod that does all the hard work. if it's a factory fitted knob then it will be thread locked in and your unlikely to get it out.

3/8" is just shy of 10mm, thats a big grub screw, I'd have thought m10 which would is typically an 8 or 5mm hex unless it's a bespoke screw, which is unlikely. if 5.5 was to small and 6 was to big then it's most likely gummed up with crud the like and is actually an 8mm. use a pick to clean out the head and try again.

 

[AES]

Fair enough comments to both the above posters. I'd only add that whichever method you choose (too small key bigger, or too big key smaller) after cleaning out the gunk, the first attempt should be to GENTLY tighten the grub screw -just a bit, as this can often break the "bond" between the screw and its surround.

Good luck anyway, sounds like lots of us are rooting for you (I think everyone's has had such a pesky job at one time or another)

Edit for P.S. - all three above posters

 

[novocaine]

Good luck anyway, sounds like lots of us are rooting for you (I think everyone's has had such a pesky job at one time or another)

Edit for P.S. - all three above posters

normally rectified with a bigger persuader or a drill. mwah ha ha ha.

if it can't be fixed with a hammer it's an electrical problem

 

[beech1948]

I'm overwhelmed by the ideas and generosity of your knowledge. I will get back to this on thursday and let you all know how it turns out.

Al

 

[cammy9r]

Did you sort it?
Was it metric?