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FabioC · 08-07-2019, 08:08

Is there a way to tell if the diesel in a jug went bad (short of putting it in the tank and seeing what happens)?
How long does diesel last in a jug, typically?
Thank you!

**a64pilot** · 08-07-2019, 08:50

If it’s not the red dyed stuff, it will turn brown and doesn’t smell “right”
The smell isn’t as strong and it’s sort of musty smell.
It still burns though.
I’ve burned the old Diesel that was at least a decade old, but it wasn’t in a plastic jug on deck in the sun being subjected to huge temp swings either, and it was the old non ULSD.
I’d think how long it will last has a lot to do with is it treated and how it’s stored. I’ve had fuel on deck for six months that seemed fine, that was ULSD.

I think it will still burn, but maybe be smoky etc even after it’s gone “bad” but if it gets bugs, dispose of it, don’t seed your tank with bugs.
Bugs often look like snot in the fuel. Just a gross slimy substance.

FabioC · 08-07-2019, 08:59

Thank you for the info.
The diesel in question has been stored below deck in a metal jug rated for diesel, but I cannot remember when I got it, hence the question. It has not been treated in any way, I filled the jug at the fuel dock and stored it away. I'll try to smell it as you suggest.
I agree, it is not worth to get slime in the tank, just to reuse some old diesel.

Cheechako · 08-07-2019, 09:13

Put some in a glass jar and get a look at it. Old contaminated diesel will be cloudy, you will even see things suspended in it, it may be brown and a bit opaque.

wayne.b · 09-07-2019, 09:45

Quote:

Originally Posted by FabioC

Is there a way to tell if the diesel in a jug went bad (short of putting it in the tank and seeing what happens)?
How long does diesel last in a jug, typically?
Thank you!

===

It will last a long time as long as it hasn't become contaminated with water. I routinely use diesel that is a year old and think nothing of it. If you really want to be safe, buy a filter funnel from West Marine and pass it through that.

CarinaPDX · 09-07-2019, 12:41

I agree that the best approach is to start by pouring some into a clear glass and look at/through it. If it is clear with probably a little yellow color then I would use it after adding some Star Tron enzyme treatment. Every time you buy diesel from a new source you are risking contamination, and this is no different either way. Being sealed in a metal container is likely better than storing diesel in a vented tank aboard, which breathes moisture-laden air on a daily basis.

Greg

dennismenace111 · 09-07-2019, 13:22

Quote:

Originally Posted by wayne.b

===

It will last a long time as long as it hasn't become contaminated with water. I routinely use diesel that is a year old and think nothing of it. If you really want to be safe, buy a filter funnel from West Marine and pass it through that.

Buy the same filter funnel at Northern Tool and pay half of what Worst Marine will charge!

Secondshift · 09-07-2019, 15:41

Quote:

Originally Posted by dennismenace111

Buy the same filter funnel at Northern Tool and pay half of what Worst Marine will charge!

Big plus 1 on the filter.

Removes contaminants and water. We also use ours to polish. Filter out filter back.

Mr Funnel medium Advance Auto $14.99.

ferrailleur · 09-07-2019, 15:57

Quote:

Originally Posted by CarinaPDX

I agree that the best approach is to start by pouring some into a clear glass and look at/through it. If it is clear with probably a little yellow color then I would use it after adding some Star Tron enzyme treatment. Every time you buy diesel from a new source you are risking contamination, and this is no different either way. Being sealed in a metal container is likely better than storing diesel in a vented tank aboard, which breathes moisture-laden air on a daily basis.

Greg

would it be good to shut off the vented hose with some type of valve during winter/spring storage?

ferrailleur · 09-07-2019, 16:00

Quote:

Originally Posted by dennismenace111

Buy the same filter funnel at Northern Tool and pay half of what Worst Marine will charge!

ahah.

CarinaPDX · 09-07-2019, 16:00

Quote:

Originally Posted by ferrailleur

would it be good to shut off the vented hose with some type of valve during winter/spring storage?

I wouldn't - pressure changes could have undesirable results. The traditional answer is to keep tanks topped up so there is very little air (and moisture) at the top.

Greg

dennismenace111 · 09-07-2019, 16:00

Damn! I paid too much. $19.99 at Northern Tool!

My new to me, 35 year old boat came with a full tank so the seller said....what he neglected to tell me before I left on a 5 day trip bringing the boat home the weekend before Christmas, was that at least 25 % of the 20 gallons in the tank was water. Pumped the contents of the tank through one of these filters into some brand new Jerry cans using one of these magic funnel filters....ended up with about 13 gallons of clean fuel . They truly are magic!

Secondshift · 09-07-2019, 16:03

For the vent line. There are inline moisture filters available. H2out comes to mind.
The media is reusable.

thinwater · 09-07-2019, 16:32

Quote:

Originally Posted by Secondshift

For the vent line. There are inline moisture filters available. H2out comes to mind.
The media is reusable.

I'm a fan of vent filters. I've used them on my boat for nearly a decade (30 years in industry) and they really do work.http://sail-delmarva.blogspot.com/2017/05/100-best-buys-chapter-3.html.

Remember to shake the can before you pour some out to look at it; if there is sludge, it will have settled. The top few inches will be clear. Or siphon some from the bottom. In fact, it can be good to siphon some from the bottom of your tank. A used oil extraction vacuum is good for this.