Sealing fresh water tank lid (1 Viewer)

joggerman

Free Member
Jul 21, 2009
139
6
Lancashire
Funster No
7,592
MH
Just Looking
Exp
Since 2004
The large access lid to my watertank has a O ring to seal it.
In addition it seems to have a type of white grease on the ring.
The lid obviously needs to be a tight seal to avoid water seeping out the lid.

What type of grease do you think I would need to use?
 

scotjimland

LIFE MEMBER
Jul 25, 2007
2,246
9,759
Funster No
15
MH
A Woosh bang
There is proprietary food grade 'O' ring grease on the market but not commonly sold in high street stores..

I use petroleum jelly on tank 'O' rings and seals .. 'Vaseline'
 
Last edited:

JeanLuc

Free Member
Nov 17, 2008
3,304
2,199
Warwickshire
Funster No
4,952
MH
Hymer B630 Star-Line
Exp
Since 2007
If the O-ring is in good condition, I would not have thought you would need any grease. Ours certainly has none and it is opened / closed frequently. I open it after every trip to remove the drain plug, then leave it propped across the screw collar to allow air-flow until closing it before the next trip.

Philip

Subscribers  do not see these advertisements

 
OP
OP
J

joggerman

Free Member
Jul 21, 2009
139
6
Lancashire
Funster No
7,592
MH
Just Looking
Exp
Since 2004
If the O-ring is in good condition, I would not have thought you would need any grease. Ours certainly has none and it is opened / closed frequently. I open it after every trip to remove the drain plug, then leave it propped across the screw collar to allow air-flow until closing it before the next trip.

Philip

I presume the grease is to seal it well, but also to make it easier to turn and prevent wear to the O-ring?
 

hilldweller

LIFE MEMBER
Dec 5, 2008
605
36,109
Macclesfield
Funster No
5,089
MH
Zilch Mk1
Exp
From Aug 2007
make it easier to turn and prevent wear to the O-ring?

Gets my vote.

I'd use silicon grease. I believe petroleum based grease does nasty things to rubber. It might not be rubber.

But there is a negative - depending on the contours, grease can make it too slippy and the pressure squeezes the ring out. I've made that mistake with a flat rubber washer.

Our tank seal is dry but it is hard to turn, I might grease it.
 

scotjimland

LIFE MEMBER
Jul 25, 2007
2,246
9,759
Funster No
15
MH
A Woosh bang
Gets my vote.

I'd use silicon grease. I believe petroleum based grease does nasty things to rubber. It might not be rubber.

But there is a negative - depending on the contours, grease can make it too slippy and the pressure squeezes the ring out. I've made that mistake with a flat rubber washer.

Our tank seal is dry but it is hard to turn, I might grease it.


Unless you know what the ring is made of it's hard to say what is best..

Petroleum jelly can affect some types of materials and silicone grease will swell silicone O rings ..

Personally I've never has a problem using Vasaline on tank cap O rings, but if it were a critical O ring in a fuel or brake system I would use as recommended by the makers ..

but heh, this is a tank cap, better it lubricated than left dry, and if the ring was affected by the grease it's no big deal.. cheap as chips to replace..

Subscribers  do not see these advertisements

 

steles

Free Member
Sep 2, 2007
240
61
Kent
Funster No
210
MH
Panel Van Conversion
Exp
Since 2005
The only grease to use is Silicone, available from plumbers merchants, on line or RS .
The seal is probably EPDM. so be careful if using any thing else.
Steles.
 
Dec 23, 2007
4,077
6,547
Wirral
Funster No
1,064
MH
Hobby Van Kenobi
Exp
started when I was 11 with my parents-forgot to stop!been real one since 1980!
Lard or olive oil
 
OP
OP
J

joggerman

Free Member
Jul 21, 2009
139
6
Lancashire
Funster No
7,592
MH
Just Looking
Exp
Since 2004
Thanks for all the suggestions..........

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top