Suitable sealant for diesel filler hose/tank joint.

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Ghillie
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Suitable sealant for diesel filler hose/tank joint.

Postby Ghillie » Mon Jan 07, 2019 5:04 pm

Discovered lots of diesel in the bilges. Traced it, after much grief, to the filler hose/tank joint. The filler hose comes horizontally into the side of the tank (near the top) , 2" dia, held with 2 jubilee clips. There was evidence of some sealant used with a fillet of it visible (red hermatite?) at the upper side of the joint, however, underneath (and out of sight) there was a gap between hose and steel..... The hose is a stiff plasticky afair and I am not sure how well the jubilee clips will compress the hose around and against the steel 2" dia tank projection (can't think of its name) to make a diesel-tight seal. Hence my perceived need for a sealant. Do the august membership have any recommendations for the sealant?

Yours
Roger

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Re: Suitable sealant for diesel filler hose/tank joint.

Postby SteveN » Mon Jan 07, 2019 6:03 pm

I've always used polysulphide for anything dieselly. It fills large gaps and cures to, basically, rubber yet isn't too adhesive that you can't get things apart if needed. Arbokol 1000 is the one that I keep a tube of for jobs like yours.
"Resistant to most dilute acids and alkalis, petrol, diesel, jet fuel and many solvents and vegetable oils".

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marisca
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby marisca » Mon Jan 07, 2019 6:39 pm

Rather than fill the gap would the application of heat (hot air gun?) soften the pipe enough for the jubilee clip to do its job?

Ghillie
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby Ghillie » Tue Jan 08, 2019 5:31 pm

Many thanks both for your useful replies. Was planning to take my heat gun just to get the hose fully off, but heating it prior to tightening the j clips sounds gallus. A smear of your sealant for good measure should do it.
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Roger

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marisca
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby marisca » Tue Jan 08, 2019 8:38 pm

Oh good, you can blame both of us when it leaks!

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Aja
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby Aja » Thu Jan 24, 2019 8:52 pm

I would renew the hose. A new replacement hose will compress better and remove the need for sealant.

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claymore
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby claymore » Sat Jan 26, 2019 10:57 am

Stating the obvious - I'd give the nozzle a good seeing to as well and check its weld/solder to the tank
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Re: Suitable sealant for diesel filler hose/tank joint.

Postby Corona » Wed Jan 30, 2019 7:24 pm

The word you guys are looking for is 'spigot'. The sealant referred to was applied around 14 years ago and was indeed Hermetite, the filler hose is now 30 years old so may have stiffened up a bit, I am fairly sure it is fibre reinforced neoprene so will be difficult to manipulate. If I was fixing it again I would be tempted to continue with the Hermetite and plan to renew it again in 2033.

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Re: Suitable sealant for diesel filler hose/tank joint.

Postby Ghillie » Sun Feb 10, 2019 11:56 pm

The hose is indeed extremely stiff and I have yet to pull it entirely off the spigot, although it is nearly there. (the spigot tank join is ok) Replacing the hose looks like a nightmare, so a further botch looks likely. Hermatite hasn’t been made for some years(afaik), however, I unearthed a boxed tube of it…..perhaps a candidate for Ebay?…..In retrospect the leak has probably been there since end of 2017, so since 2031 will come round in no time I will try the polysulphide sealant, not being convinced that I can form an intimate contact betwixt hose and spigot. On planning to heat the hose, however, I was somewhat alarmed to read this from the internet.

When compared with natural rubber, neoprene is more gas permeation resistant and can tolerate higher temperatures: up to 200 degrees Fahrenheit (F). Even at such high temperatures, neoprene will not physically degrade, making it better suited to long-term use in high temperature applications than natural rubber. When heat degradation does occur it does not manifest itself in the form of melting or stretching, as with many applications, but instead exhibits hardening. When operating at temperatures below 0 degrees Fahrenheit, neoprene will become increasingly stiff and hard, becoming nonfunctional for most applications at around minus 40 degrees F.

Hmmm.


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