Fuel Vent Overflow

rmbrown · February 19, 2018, 10:57:06 AM

Howdy folks... It's been a while since I posted because my searching chops are much improved, but I came up short on this one and surely I'm not the only one?

My boating experience is typically that I can fill the diesel tank until I see fuel in the fill hose, then I stop. In my C34, my vent is such that I start to make that pretty rainbow skim on the water that attracts so much attention before that happens. (Tongue firmly in cheek)

How do you guys fill the tank, in preparation for a trip or for winter storage, without making this mistake? Do you trust the gauge or have some other technique?

Mike

Stu Jackson · February 19, 2018, 11:52:50 AM

S L O W L Y

R e a l l y S L O W L Y

I use fuel consumption as a starting point, and know how much I need to put in before I start. Search on fuel+log.

KWKloeber · February 19, 2018, 02:14:32 PM

I put a fuel level whistle on my vent line. It pretty much needs to be from a fuel pump as the quickly escaping air causes the whistle (stops when the level rises to the unit.)

There are kits you can suction cup to the hull below the vent to catch overflow. Basically a plastic container with lg suction cups that sits against the vent hole and I'm sure one could be home made.

rmbrown · February 19, 2018, 02:18:06 PM

I have my tank out for cleaning (and forced air heater installation) right now so I have my vent line off and was seriously considering the whistle... but there were three reviews on west marine and two of them said it didn't work, so I backed away. You have one and you can hear it? You'd do it again it sounds like?

rmbrown · February 19, 2018, 02:19:49 PM

Stu, I found your fuel log post and like the idea. I'm a bit of a spreadsheet junkie so this works well for me. One question though... when you have an entry on that log of "x" gallons, are you always refilling to the same point, presumably "full"? If so, how do you determine that... your fuel gauge or the spit out of your vent?

KWKloeber · February 19, 2018, 02:23:54 PM

Mike I put it on when I was in bflo and filled from a marina pump, but I don't now so by cans there's too much air escaping for the whistle to do much.

K

rmbrown · February 19, 2018, 02:29:05 PM

Now I understand... As of yet, I haven't had the fuel pump option, just jerry cans. Might be nice to add one but might not help in my normal use case. Hmmm...

Stu Jackson · February 19, 2018, 02:46:48 PM

Quote from: rmbrown on February 19, 2018, 02:19:49 PM
Stu, I found your fuel log post and like the idea. I'm a bit of a spreadsheet junkie so this works well for me. One question though... when you have an entry on that log of "x" gallons, are you always refilling to the same point, presumably "full"? If so, how do you determine that... your fuel gauge or the spit out of your vent?

Mike, it's based on "full" trying very hard to not spill any out the vent. I'm hard of hearing, but concentrate when filling, and slow way down when I'm getting to 3/4 full. Since the spreadsheet shows the consumption to three figures, as long as it's in the range of 0.450 to 0.550, it means I've pretty much fueled up to "full." It is NOT an exact science, but has worked for me for 20 years.

If one of the consumption numbers is drastically different, it simply means I haven't, for whatever reason. For example, on our cruise from SF to Vancouver Island in 2016, I began noting higher consumption levels because in one spot there was a Coast Guard ship right behind me when I was fueling and I was extremely cautious. In one of the next stops the gauge on the pump was wacko and it overflowed a tad, but then the consumption numbers steadied back to "normal," meaning I'd been under-filling. And in many cases, having the right amount of fuel meant whether or not we'd make it to the next harbor!!! After a while, you get the hang of it. My fuel gauge hasn't worked since 1999.

Craig Illman · February 19, 2018, 02:59:06 PM

There's this option, but I can't attest to it's effectivity. https://www.parker.com/literature/Racor/Racor_Fuel_Filtration_-_LifeGuard_Fuel-Air-Separators_-_RSL0184.pdf

Down my to-do list.....

Craig

Ron Hill · February 19, 2018, 03:09:59 PM

Guys : The whistle is not a panacea!! After overflowing too many times and it get clogged and stops whistling!!!

I do as Stu mentioned, calculate the amount of fuel. Then fill slowly (so there is little foam) and take a fuel diaper and put it on the fuel vent. You can feel the overflow and see the RED fuel. That also helps keep the fuel from staining the transom and port side.

If you are filling for winter storage fill a gallon or two less because the yard might block your boat more nose up. Also the couple of gallons less helps compensate for warmer day fuel expansion!!!!

A few thoughts

rmbrown · February 19, 2018, 04:52:33 PM

Thanks one and all!

rmbrown · February 19, 2018, 05:06:29 PM

Craig:

That thing is kinda slick. I'm tempted to get one while I'm in there anyway, although I haven't quite yet convinced myself it's worth the $90.

Anyone know if our vent lines are the 5/8 that seems to be standard? Or are we 1/2?

britinusa · February 19, 2018, 05:56:22 PM

I have just purchased (and received) a Fuel Tank Vent from Amazon. very nice product.

Using it as part of my dry bilge system.

Paul

Noah · February 19, 2018, 07:00:52 PM

Adding more to the conversation:
https://www.boatus.org/findings/40/

KWKloeber · February 19, 2018, 07:06:21 PM

Quote from: rmbrown on February 19, 2018, 05:06:29 PM

Anyone know if our vent lines are the 5/8 that seems to be standard? Or are we 1/2?

Mike

Here's the sizes I have written down for my 30, I would think yours would be the same.

Sheilds #
282194    5/8" fuel tank vent 9' replaced 2010
282251    5/16" tank > Racor filter > pump > fuel line filter 10' replaced 2010
282244    1/4" fuel line return to tank 9' replaced 2010

k