Modify an O-ring ???

[stragenmitsuko]

Sorry about the odd topic title , don't really know how to describe it .
I need to call on this lists wisdom . Can't seem to figure it out on my own .

Picture shows an odd shaped gasket from a 26 yo pressure washer .
Offcourse it is no longer available .

The gasket is basicly an o-ring , but it's not round . It's pre formed and
fit's in a groove and seals the high pressure chamber .The cross section is round .
A little oval now from being compressed all these years , but it was round once .

So I need to take a std o-ring of thesame lenght , and modify it to more or less this shape .
I need to modify it because otherwise it won't stay in its groove and I
won't be able to put both halves together .
Once it sits between the two halves , it'll seal and won't be able to move . The trick is getting it there .

I could make 6 rounds of the right radius , bolt them down on a piece of metal
and put the o-ring around it . That ought to shape it , but if I take it off it'll spring back to round .
Could heat be the answer ?

Another possible way would be to cyano- acrylate glue the o-ring in it's place , then put both halves together .
Don't know if that 'll work and if it'll seal as it should .


Tips tricks suggestions .... fire away .

Pat

 

[Cogsy]

Can you put something like a couple of dabs of grease or petroleum jelly in the groove so it holds the o-ring in place long enough to get the two halves together? Something like grease shouldn't affect the seal at all (which I'd be concerned about as well if you glued it with CA).

 

[kiwi2]

Hi Pat,
Can you put the O ring in one of the straight slot sections while it is sitting horizontally and then let the flat half sit on the top of the O ring. It may then be possible, using a piece of wire, to push it into the slot starting from the bit already in place. You may need a small hook on the wire as in some parts you'll need to pull the ring outwards instead of pushing it inwards. I'd also follow Cogsy's suggestion and grease the slot and the ring.
Regards,
Alan

 

[Longboy]

.....Super glue. One side. On the part that is removed from the main piece so when taken apart again.... it is in hand, at hand to scrape off and replace......again sometime. Probably only need a slight drop at every curve apex. Your job....finding the correct diameter o-ring that is neither too short or long that will fit in the distorted groove correctly. I will say magic words and burn incense that this happens right for you!

 

[Mike1]

Can you use "O" ring cord and make your own custom ring, see here. https://www.bearingboys.co.uk/Oring-Cord-1051-c UK address.

Mike1

 

[BaronJ]

Hi Pat,

I would go with the "O" ring cord ! At least that way you will get exactly the right diameter and length without having to worry about the shape.

 

[goldstar31]

Hi Pat,

I would go with the "O" ring cord ! At least that way you will get exactly the right diameter and length without having to worry about the shape.

I'm having a daft thought or three! I seem to recall that readily available 'plumbers' silicone sealing stuff in tube form will withstand heat, oils and water. Yes, I do know that proprietary things such as from George Angus in Wallsend, Tyne and Wear still make oil seals. I have a silver cigarette case in my safe from somebody who was part of the firm- but this repair suggests that it came from a throwaway garden pressure washer- and worth- not a lot.

 

[Peter Twissell]

I have done this kind of thing on many occasions, mostly motorcycle engine rocker boxes.
Stick the o ring in with silicone!

 

[Asm109]

Nothing you can do to an already cured oring will result in permanent corner radii.

Consider this a second vote for tacking the corners with Silcone RTV.

 

[stragenmitsuko]

Here's what I did .
I took a length of copper wire , pushed it in the groove and carefully formed it
to the desired shape .
Then I straightend it to measure it's length .
A little math gave me the desired length of o-ring .
To my surprise I had one in my o-ring box .

Then I applied a coat of sticky grease , and decided to do a trial fit .
What do you know , both halves kinda snapped together at the first attempt .
So I quickly bolted it down , and that's that .
The machine works as it should and doesn't leak .
25 Year old karcher , they don't make em like that anymore nowadays .

I'm sorry I didn't take pictures , I wasn't counting on succes at the first attempt , and opening it again just to take a picture seemed pushing my luck .

Thanks again for all the helpfull suggestions .

Pat