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Petrol resistant sealant?
nitram38 - 2/3/09 at 08:14 AM

I had my boubts when an engineer made me a flange for my fuel pump, that the "O" ring groove was too deep.
Well it leaks (very slowly), so I want to know what sealant I could use that will stop it bearing in mind that it is in the bottom of the tank.
I was thinking along the lines of Blue Hylomar?


skippad - 2/3/09 at 08:17 AM

I used Red Hermitite with no problems.


nitram38 - 2/3/09 at 08:19 AM

The trouble with red is that it doesn't like petrol and will harden and leak.


westf27 - 2/3/09 at 08:25 AM

could you pack up the seal from the bottom of the groove,with say ptfe tape.


westf27 - 2/3/09 at 08:26 AM

just had another thought,machine the flange face down,thus reducing the groove depth.


russbost - 2/3/09 at 08:53 AM

petro patch? which is basically a fibreglass type resin, or simply fibreglass resin???
Will obviously harden but assuming you're not taking the pump out every 5 mins does it matter?


tegwin - 2/3/09 at 09:32 AM

Can you not source a deeper ring?


nitram38 - 2/3/09 at 09:49 AM

quote:
Originally posted by westf27
just had another thought,machine the flange face down,thus reducing the groove depth.


The tank is in the car and even if I got it out, I'm not sure if they can bolt it in a mill.

I am going to try blue hylomar as it says that it is not effected by petrol.

Cheers for the replies


Description
Description


[Edited on 2/3/2009 by nitram38]


Cousin Cleotis - 2/3/09 at 10:03 AM

petrol resistant rubber gasket? Premier fuel systems should be able to help.

did the flange warp whent it was welded in?

Paul


BenB - 2/3/09 at 10:04 AM

I'd go for some blue. Otherwise you could make a cork gasket to sit between the sender and the tank.... Fuel proof and rather maleable...


MikeCapon - 2/3/09 at 10:14 AM

Martin there are masses of different O rings available. There will be one which will do the job and it's far better than bodging with goo. I'll find you a supplier.

Here you go. I don't buy from these peeps but they've got a good site showing all the different metric and BS rings. Linky

[Edited on 2/3/09 by MikeCapon]

Edited again to add. You want to aim for 25-30% compression of the O ring for a good reliable dynamic seal.

[Edited on 2/3/09 by MikeCapon]


nitram38 - 2/3/09 at 10:38 AM

Mike I'll take it out and have a measure and try your people first. If they don't have one, then it is the blue goo!


02GF74 - 2/3/09 at 11:10 AM

quote:
Originally posted by skippad
I used Red Hermitite with no problems.


PEEPS - PLEASE READ THE TUBE!.

blue stuff stays not resistant to petrol whereas the red is.

I've got the blue and the red stuff and have used both to seal senders. I found the blue stuff went soft whereas as far as I know the red stuff is still fine. (i.e. I am not aware of leaks).


AdamR - 2/3/09 at 01:15 PM

quote:
Originally posted by 02GF74
PEEPS - PLEASE READ THE TUBE!.

blue stuff stays not resistant to petrol whereas the red is.

I've got the blue and the red stuff and have used both to seal senders. I found the blue stuff went soft whereas as far as I know the red stuff is still fine. (i.e. I am not aware of leaks).


Sure you've got that the right way around? The Blue Hylomar I've got definitely says it's fuel resistant on the packet - even suitable for sealing injectors apparently.


nitram38 - 2/3/09 at 01:46 PM

Red goes hard and peels off. Blue stays soft to maintain the join.


02GF74 - 2/3/09 at 02:11 PM

quote:
Originally posted by AdamR
quote:
Originally posted by 02GF74
PEEPS - PLEASE READ THE TUBE!.

blue stuff stays not resistant to petrol whereas the red is.

I've got the blue and the red stuff and have used both to seal senders. I found the blue stuff went soft whereas as far as I know the red stuff is still fine. (i.e. I am not aware of leaks).


Sure you've got that the right way around? The Blue Hylomar I've got definitely says it's fuel resistant on the packet - even suitable for sealing injectors apparently.


errr, I think so but will check and post photo.


nitram38 - 2/3/09 at 02:15 PM

Blue Hylomar link


02GF74 - 3/3/09 at 11:04 AM

no photo, but did look at the packaets.

blue stuff states fuel resistant (one assumes to be petrol but may be just deiesel, unlikley though).

red stuff states petrol resistant.


Jubal - 3/3/09 at 12:06 PM

I used blue to seal a leak under my fuel sender plate. Was fine for over a year while I had the car and as far as I know still is. HTH.

[Edited on 3/3/09 by Jubal]


nitram38 - 7/3/09 at 05:14 PM

Update, bought O ring. They come in standard sizes so I could only get one 0.3mm thicker!
No good, still leaks.
Tried the blue goo.....still leaks!

Is it worth making a paper gasket (plus blue goo) ?


:{THC}:YosamiteSam - 7/3/09 at 06:32 PM

i had a fuel tank made with an inspection / access plate in the top. went to a local gasket maker for advice to seal it. he told me the ONLY way to seal it properly was to use a nitrile rubber seal - the plate had to also have very close bolts to stop plate bending.. and use the sheet in one piece rather than a strip right round. now your is a different application but i'm guessing its the problem of 2 or 3 things
1. your not using a totally petrol resistant sealant - nitrile IS the stuff
2. the surface its sealing between - is it actually touching the seal an both sides of the pieces together?
3. is there anything getting in the way? debris? splits? scratches? petrol WILL find a hole no matter how small

i tried alsorts of stuff to seal - thats the best


nitram38 - 7/3/09 at 06:41 PM

I am going to give it one more try tomorrow (I'm at work tonight) and if I can't get a seal, it is tank out and I'll get the blighter who put the o ring groove in too deep, to mill the surface!

Here is a photo when the chassis was upside down and the damn thing was accessible!
[img][/img]


nitram38 - 8/3/09 at 10:10 AM

I've found another option. It would seem that O rings come in standard thickness dependant on the dia of the ring. So I can't get a much thicker one, but they do cord which is basically a length of rubber (in this case because of petrol, NBR) that comes in any thickness. This can be cut with a knife and the ends super glued to form a ring.
I'm going to try this before getting the tank out.
The problem with getting the tank out is that I have to remove a water pipe (drain down) and the handbrake cables just to get at it.


nitram38 - 10/3/09 at 04:19 PM

Finally sorted it!
I used 6.5mm cord to create an O ring (superglued at the ends) and the tank is currently holding 30 Litres of petrol without a hint of a leak! (I built up the level over several hours).
I am just finding out how much it holds (expected 33 litres) for the virtual tank level of the Veypor VR2.