Lid on raw water separator is stuck.

[NormanS]

Thanks NormanS... obviously, you don't know me to assume as you did.

No, of course I don't know you, and don't see any relevance in that. I am not aware of having made any assumptions about you. I did make some suggestions as to what may be causing your apparent difficulty. I may not be correct, but I do know how to unscrew the top of my water strainer.

 

[ghostlymoron]

Is it this one? I would think a strap wrench would shift it. Must be done up too tight or perhaps a bit of grit on the threads. When you do shift it, thoroughly clean the threads and apply a bit of lubricant. http://www.marinepartseurope.com/uk/en/volvo-penta-explodedview-7745910-90-20487.aspx

 

[Rivers & creeks]

No, of course I don't know you, and don't see any relevance in that. I am not aware of having made any assumptions about you. I did make some suggestions as to what may be causing your apparent difficulty. I may not be correct, but I do know how to unscrew the top of my water strainer.

I have one the same design as the OP, I can categorically state that I have never cross threaded it and that yet once stuck nothing humanly possible on board will shift it. I understand your disbelief but honestly there is something of the darkness about their ability to be stuck. I bought an oversized gaitor when I should have written off the £100 it cost for the strainer and bought one that's easy to undo.

 

[Mistroma]

I have one the same design as the OP, I can categorically state that I have never cross threaded it and that yet once stuck nothing humanly possible on board will shift it. I understand your disbelief but honestly there is something of the darkness about their ability to be stuck. I bought an oversized gaitor when I should have written off the £100 it cost for the strainer and bought one that's easy to undo.

Yes, I've found the same thing. I mentioned in an earlier post that it was difficult to remove after a few weeks. I only smear with silicone grease and tighten lightly. Trying to undo immediately is fine and not any more effort needed that that used to tighten. However, a few weeks later it is much harder to remove. I only use just enough effort to seal.

I remember talking to someone who had a friend in the marine spares business with contacts in China. He told me that he'd sourced some identical units for about £17 instead of £100+. He sailed across to USA soon afterwards so I wasn't able to order one as a spare.

The OP said that the problem with strap units is they apply great pressure on a single point and he'd prefer a tool pressing on the raised fins. It might not be that clear cut. The fins have a length of less than 2 x Diameter and circumference is probably about 1.8 times longer than the fins (less the solid center X). So the strap might be contacting an area close to twice that of a plywood tool of similar thickness. Fins are fairly thin and raised but are a U section whereas lid is fairly solid at top. I can't prove which tool would be best but my feeling is that a strap wrench might actually be kinder. Best option would be to use both at the same time. But I imagine the body would need to be held to avoid the mounting lugs breaking. Simple enough if you have 3-4 pairs of hands.

 

[NormanS]

I have one the same design as the OP, I can categorically state that I have never cross threaded it and that yet once stuck nothing humanly possible on board will shift it. I understand your disbelief but honestly there is something of the darkness about their ability to be stuck. I bought an oversized gaitor when I should have written off the £100 it cost for the strainer and bought one that's easy to undo.

My plywood "spanner" cost nothing, and works fine. I honestly find it hard to believe that grown men are defeated by something like a big coffee jar lid.

 

[RichardS]

My Vetus filter unscrews provided it is well-greased with silicone grease before closing. However, if the Volvo version tightens up over time such that it cannot be undone by hand then I would try stretching a piece of kitchen cling film right over the top and over the screw threads before screwing the lid on as well as greasing the threads.

Richard

 

[Monique]

Is it this one? I would think a strap wrench would shift it. Must be done up too tight or perhaps a bit of grit on the threads. When you do shift it, thoroughly clean the threads and apply a bit of lubricant. http://www.marinepartseurope.com/uk/en/volvo-penta-explodedview-7745910-90-20487.aspx

Exactly. It was not overtightened ... it is my second such unit and I know how to deaal with them... all your suggestions were applied when I last closed it. Thank you for your thoughts.

 

[Monique]

I have one the same design as the OP, I can categorically state that I have never cross threaded it and that yet once stuck nothing humanly possible on board will shift it. I understand your disbelief but honestly there is something of the darkness about their ability to be stuck. I bought an oversized gaitor when I should have written off the £100 it cost for the strainer and bought one that's easy to undo.

HI CW, I can double on your comments. I have decided to throw out the %£%*(@! thing and install a proper brass unit. I ordered one in Majorca today and they will ship to the boat. VETUS units would be more price conscious but the brass one looks the dogs...

 

[Monique]

Yes, I've found the same thing. I mentioned in an earlier post that it was difficult to remove after a few weeks. I only smear with silicone grease and tighten lightly. Trying to undo immediately is fine and not any more effort needed that that used to tighten. However, a few weeks later it is much harder to remove. I only use just enough effort to seal.

I remember talking to someone who had a friend in the marine spares business with contacts in China. He told me that he'd sourced some identical units for about £17 instead of £100+. He sailed across to USA soon afterwards so I wasn't able to order one as a spare.

The OP said that the problem with strap units is they apply great pressure on a single point and he'd prefer a tool pressing on the raised fins. It might not be that clear cut. The fins have a length of less than 2 x Diameter and circumference is probably about 1.8 times longer than the fins (less the solid center X). So the strap might be contacting an area close to twice that of a plywood tool of similar thickness. Fins are fairly thin and raised but are a U section whereas lid is fairly solid at top. I can't prove which tool would be best but my feeling is that a strap wrench might actually be kinder. Best option would be to use both at the same time. But I imagine the body would need to be held to avoid the mounting lugs breaking. Simple enough if you have 3-4 pairs of hands.

I will cut the top off with my Dremel tomorrow... the suction cover will take care of things until I get my new one. As you say, it is incomprehensible why these darn things can become seized... they are some kind of plastic.

 

[VicS]

HI CW, I can double on your comments. I have decided to throw out the %£%*(@! thing and install a proper brass unit. I ordered one in Majorca today and they will ship to the boat. VETUS units would be more price conscious but the brass one looks the dogs...

I hope DZR not ordinary brass

 

[sarabande]

one possible reason for the lid refusing to unscrew may be the old engineering issue of 'galling'.


If there is the slightest roughness from tiny bits of grit or dust on the internal or external threads, then localised welding will take place. For a plastic unit this is easier to achieve than in a metal one.


Meticulous cleaning, then an appropriate coat of grease, and SCREW THE LID ON SLOWLY so as to sense a problem before the weld takes place.

 

[Plum]

I will cut the top off with my Dremel tomorrow... the suction cover will take care of things until I get my new one. As you say, it is incomprehensible why these darn things can become seized... they are some kind of plastic.

I have the same VP water strainer but my problem was difficulty in getting a good seal which resulted in poor water flow and an engine getting hot. Maybe I should have tightened the lid a bit more, but then maybe it would have got stuck like yours. I dispensed with the lid and the inner sealing disc and made up a flat clear perspex lid with a rubber seal which seals perfectly and I can check it without removing the lid.

Www.solocoastalsailing.co.uk

 

[Mistroma]

one possible reason for the lid refusing to unscrew may be the old engineering issue of 'galling'.

If there is the slightest roughness from tiny bits of grit or dust on the internal or external threads, then localised welding will take place. For a plastic unit this is easier to achieve than in a metal one.

Meticulous cleaning, then an appropriate coat of grease, and SCREW THE LID ON SLOWLY so as to sense a problem before the weld takes place.

Mine is clean with no grit or dust and is cleaned before reassembly. It always goes on smoothly with not a hint of binding and I can remove it just as easily. I tighten just enough to avoid a leak (it's fairly easy to see the O-ring sealing). However, it is a lot harder to remove after several weeks.

It almost broke when I first removed it in 2009. I used Vaseline on the O-ring and found it almost impossible to remove at the end of the season. I have had problems on other kit with an O-ring swelling up due to reaction with grease. I only ever used a very thin silicone grease afterwards but that didn't solve the problem completely. The only solution I've found it to barely tighten the top. I can always unscrew it now with a moderate amount of pressure, but at least there's no danger of it breaking.