Diesel-proof sealant

Krusty

Krusty

Well-Known Member
Joined
20 Feb 2004
Messages
807
Location
Highlands
Visit site
The last time I flushed and cleaned my fuel tank and came to replace the tapered-thread bung I asked the boat-yard about a truly diesel-proof sealant, and where I could buy some.
They told me none of the commonly available sealants resist diesel for any length of time (I knew that!), but they used a special material which was 'expensive' and not worth my buying for the small amount I would need (ever?). Instead, they let me have a dab of it from their tin in the workshop.
I have to say, that bung has never before stayed as dry.
Now I need another dab, but the boatyard has since come under a new management regime which has jacked up all charges and seems to charge for every minute of time and scrap of material. I am reluctant to ask again.
Anyone know of this magic stuff?
 
fwiw, I have an access hatch in my tank which is held by a couple of dozen bolts, all around the opening perimeter I found the blue sealant, commonly found as gasket sealant (or magic gasket, or whatever other name)

anyway, I replaced the existing seal with a thin cord of gasket sealant and it holds perfectly well; it is not under pressure as the opening hatch is on the top face of the tank, but gets quite a bit of sloshing as I usually keep the tank almost full, never had any problems

cheers
 
I think you may be refering to the sealant called Hylomar Universal Blue. It says on the tube:-
Non-setting universal jointing compound
Resistant to fuels and lubricants
Use on gaskets and metal surfaces.

This product is available at most good automotive spares shops.

An other alternative could be PTFE tape, which is available at all plumbers merchants. Although I could not say definitely that PTFE is proof against diesel, I would expect it to be so.
 
[ QUOTE ]
I think you may be refering to the sealant called Hylomar Universal Blue. It says on the tube:-
Non-setting universal jointing compound
Resistant to fuels and lubricants
Use on gaskets and metal surfaces.



[/ QUOTE ]

yes, that's it !
 
PTFE will not last for long against diesel. I use a compound called Red Hawk which is designed for diesel. I was given a little tin of it by a plumbing friend so I don't know what it costs.
Good luck.
 
locktite do a special product costs though,but realy does the job.

ptfe tape is not recommended as small bits can get intothe fuel, obviously not something to be loose in the injection pump.
 
There are various products which do the job to a greater or lesser degree.

I asked the guys doing a repair on my Derv pump pipework - I have a garage with forecourt - what they used as a sealant as I'm about to re-pipe the fuel system on my boat.

HELDITE Jointing compound (Tel: 020 8577 9167). Comes in a 250 ml tin.

Suggest you do what I did - bung the guys a few quid for a part-used tin. Just keep your eyes skinned for one of the maintenance vans working on a petrol forecourt. Or ask your local friendly garage for the contact details of the guy that fixes their pumps.

It says on the tin " Approved by the Ministry of Defence"
Well, I bet they didn't use it on the Nimrods, 'cos by gum this stuff works....
 
Duncan, I think you have hit the spot!
A 250ml tin seems right: the dab I was given came from such a tin, not a squeezy tube. I'm pretty sure it was not Hylomar (that's too cheap too!)
Thanks.
 
Diesel Proof Sealant

For non hydraulic or O Ring Face Seal (ORFS), the absolute best is Rectorseal Tru Blu, avail from Ballard Hardware, Ballard WA in various sizes. Generally difficult to find locally. For AN style (JIC) hydraulic, use nothing OR the copper cone seals that fit inside the joint. ORFS has replaced a lot of hydraulic fittings in construction/high vibration applications, and for it, just rely on the O ring seal. My Lugger L1276 uses ORFS in the fuel lines.
Diesel is a perfect lubricant, and creeps wherever it finds an anomaly in the sealing arrangement, so make sure everything is aligned, lubricated (o rings) and flanged up correctly. Verify the item you are installing or replacing is "on spec" as manufacturers can make dimensional errors. And, installers, esp we non professionals, CAN make little installation errors that cause these problems. Hard to believe but true.
 
milfordman said:
I think you may be refering to the sealant called Hylomar Universal Blue. It says on the tube:-
Non-setting universal jointing compound
Resistant to fuels and lubricants
Use on gaskets and metal surfaces.

This product is available at most good automotive spares shops.

An other alternative could be PTFE tape, which is available at all plumbers merchants. Although I could not say definitely that PTFE is proof against diesel, I would expect it to be so.
Click to expand...

DO NOT USE PTFE TAPE ON DIESEL FITTINGS

I found out the hard way - spent 6 months searching for the leak.
 
Hylomar Blue or Instant Gasket is loosely based compound called RTV Silicone.
Having used it to rebuild engines of all shapes and sizes.
I serviced the f-i-l's 35hp Evinrude at the beginning of the season and noticed that there was some corrosion on the pump mating face and fuel was leaking. I rooted about and found some RTV and it still be sealed (under pressure) today makes me think it may be suitable for you.
Most motor factors worth their salt will stock it, about £8 a tube and you'll chuck loads away!
 
CT1

CT1 is diesel and petrol resistant. I have sealed my inspection hatch on my diesel tank with it 2 years ago. No leaks. It is also easy to clean up.Its adhesion qualities are the same as polyurethane sealants and sets under water too.
 
Skatt said:
CT1 is diesel and petrol resistant. I have sealed my inspection hatch on my diesel tank with it 2 years ago. No leaks. It is also easy to clean up.Its adhesion qualities are the same as polyurethane sealants and sets under water too.
Click to expand...

+1. Great stuff. ;)
 
Skatt said:
CT1 is diesel and petrol resistant. I have sealed my inspection hatch on my diesel tank with it 2 years ago. No leaks. It is also easy to clean up.Its adhesion qualities are the same as polyurethane sealants and sets under water too.
Click to expand...

I used this to seal some urinals to the wall, was spec'd for by the customer. Didn't think it was that verstaile but having a look at http://www.ct1ltd.com says otherwise.
 
You must log in or register to reply here.

Share this page

Top