Fuel filler back splash prevention?

williwaw

New member
I'd like to find a way to eliminate the fuel back splash that can occur when filling the tanks. It especially annoying when I have the camper back on as the fuel filler is inside the canvas so fumes tend to linger. I don't mind a burp out the vent as it's outside below the gunnel.

While looking around I noticed Perko has an inside-the-hose check valve for the filler hose that looks pretty easy to install. Info here.

Has anybody installed something like this?
 
williwaw":332lmewv said:
I'd like to find a way to eliminate the fuel back splash that can occur when filling the tanks. It especially annoying when I have the camper back on as the fuel filler is inside the canvas so fumes tend to linger. I don't mind a burp out the vent as it's outside below the gunnel.
Ouch. Man, I would find some way to adjust that to avoid generating fumes inside the living space. That could lead to tragic results.
 
I would try this: next time you fill to burp point mark the level on the outside of the opaque tank with tape or paint line. The top of your tanks taper down. As a result the last gallon or so to go in is really fast. Stop or slow filling before it reaches that mark. As the doctor says: if it hurts when you do that, don't do it anymore.
 
I have the same problem. When filling the tanks I can get about a 6" fountain of fuel out of the filler before the nozzle cutoff kicks in. Even when watching closely it is difficult to prevent the fountaining if I want the tanks full.

On my boat I cannot see the fuel level when is it near the top of the tank so I have to guess when to cut the inlet flow.
 
On my Stingray the fuel fill and vent are combined(pictures in my album). Because it has a relatively short fill hose it likes to burp back when nearing full. A lot of other Stingray owners have added a fuel vent whistle. When filling you listen for the whistle to change pitch as it nears full. Another thing Stingray did to help alleviate the problem was to install a larger dia. fill hose.

Another problem I have is my tank is 35 gal. but in the water, with the attendant standing on the swim platform it is hard to get more than about 30 gal. in it.

Regards, Rob
 
I fill very slowly as our tanks are tiny compared to some bigger boats. Fuel delivery rates are geared to the big boats. I keep a fuel pad tucked under the camper back near the vent and go slow witha pad handy on the fill port. You don't want fuel in the water. Very illegal. Just go slow and let them wait. You don't want to rush thru refuelling. George
 
One attendant actually took his shoes off and filled my boat from the cockpit. In my case it was to keep his weight farther forward(off the swim platform). If you could do this in a CDory could you not view the fuel level if you have the transparent plastic tanks?

Like AstoriaDave said having the fuel fill inside the canvas would cause me some concern as well.

Rob
 
Robert H. Wilkinson":36c56lpl said:
If you could do this in a CDory could you not view the fuel level if you have the transparent plastic tanks?

Yes, you can do this - at least on boats with the translucent tanks (started somewhere around 1990). I was surprised at first by how slowly I needed to fill, but now I'm used to it. I have found that when it really gets bad is when the incoming fuel starts to "turbulate" as it hits the fuel in the tank (which of course is when the tank is nearing full). So I go a bit faster in the beginning and then slow way down as I see the incoming fuel starting to cause a commotion on the surface of the tank.

Another factor is that the port side fill hose takes a "dog leg" as it goes around the forward wall of the lazarette. This makes the port side tank more likely to sputter or burp out the filler at speed. If I were to do it again (I put in all new fuel hoses/parts), I would cut away part of that "wall" so as to make the fuel fill hose go down without a dog leg on that side - the space would hardly be missed from the lazarette, at least in my case, and the mod wouldn't show, so no need for gelcoat perfection.

I haven't ever read glowing reviews of those combination fill/vent fittings, although I've only used one a couple of times, so can't really say from experience. I slightly wonder how water resistant they are since the vent needs to let air in and it's in with the fill (?) I guess they must have figured something out!

So for the most part I'm with ghone - just fill slowly ('course it's a good question, because hey, maybe someone does have a good way).
 
Sunbeam":3rjuzf7s said:
I haven't ever read glowing reviews of those combination fill/vent fittings, although I've only used one a couple of times, so can't really say from experience. I slightly wonder how water resistant they are since the vent needs to let air in and it's in with the fill (?)

Sunbeam, this is the first boat I have owned with this type of set up. My Campion had the traditional separate vent. Comparing the 2, I would say my current fill with integral vent is less likely to suffer water intrusion. If you look at the pictures in my album - the fuel cap is sealed with a rubber O ring. The incoming air has to go through a bit of a maze to get in. My Campion was a much deeper hull but supposing a following sea did get up to the top of the transom I would trust my cap as opposed to the vent on the Campion.

I think more boats are going to this style for environmental reasons. I believe they are designed to only let air in while the engine is running causing a negative pressure and out when moored on a hot day and the fuel expands causing a positive pressure. The vents that let air come and go as it pleases let too many hydrocarbons escape(or something like that). This leads me to think that my type of set up would be less susceptible to condensation in the tank as well ??

Regards, Rob
 
Going slow--and I never put the fuel fill on kick off--always manual filling. I listen to the sound as the tank fills, and watch the level. Rare to have a problem with this technique. Takes more time.

I have a combo vent fill on the Caracal, and no problems--again go slow.
 
Yeah, I'm sure this is a topic familiar to all of us. But perhaps I should have been more clear: I have a 23 Venture which has two 32 gallon aluminum tanks. The fill hose is short - something like 2 feet. I usually listen for a change in pitch through the fill hole then slow down but even so it tends to burp. And going slow too early makes for long fill times.

So... that leads back to the Perko in-line check valve (link in first post). I was thinking that this would prevent fuel from going back up the fill hose but have no experience with such a device.
 
I'm sorry I assumed you had translucent plastic tanks. I'm also sorry I can't offer any experience with the device you are considering. That said, you must then have a gauge which should give you a fairly accurate estimate of the amount needed to fill, right? Just slow down a gallon before that. i just can't see throwing money at a problem that is easily corrected by a slight change in technique. Every boat has its own personality. If people have to wait to fuel it's part of the deal. I've waited lots of times for passengers in the restrooms and shopping for t-shirts, getting ice etc. I would not ever use the automatic shut off clip on the nozzle. I don't even do that on the car. Can't stand gas soaked underware.
 
We added whistles that are sold by Defender that go in line on the fuel tank's vent line. Easy to install. When refueling listen to the whistle as air is being pushed out the vent whistle stops; stop the fueling process. We just cut the existing vent hose installed the whistle in line and a couple more hose clamps and your good to go. If you are interested just go to www.defender.com and type fuel whistle into the search box.
D.D.
 
I think I'll try adding the whistles as it seems low risk and easy to install. Hopefully the pitch won't conflict with the ringing from my Tinnitus :)
 
williwaw, if you do get the fuel fill check valve could you re post here to say how it works. A lot of Stingray owners have installed the vent whistles and seem to like them. The only thing, if you fill on the trailer most stations are in a noisy place.

Regards, Rob
 
Yes, we are very tired of having the fuel exit from the fuel vent or burp out the fuel fill. We can take care of the burp by wrapping a fuel towel around the fuel filler, but still have the fuel vent problem.

You can just not fill the tanks fully, but we like to get as much fuel as possible to extend our range (within reason).

So, we just recently purchased this No-Spill fuel recovery container for the fuel vent. We have used the No-Spill on our trawler when the fuel docks would hand them to us to use on the vent. We just hate spilling fuel into the waters that we love cruising.

http://www.tgmmarine.com/nospills/pages/products.html
 
We have used one of the No-Spill recovery containers for yrs. Work great. Also when we think we are getting near full we put our ear down by the hose fill and listen. On our Tomcat we can hear when the rushing of the fuel changes sound and we stop......that means we are at least to near the top and most often have no fuel going into the No-Spill container. Filling up a boat is very different than a car.
 
We're also very familiar with this problem. On our boat, we don't have the problem with fuel coming out the filler opening, but it will burp out the fuel vent and down the side of the boat if we're not careful. It does this regardless of the level of fuel in the tank and is always dependent on how fast we are filling.

So far my solution has been to hold a couple of paper towels over the vent, and fill slowly. This is especially annoying if I have two low tanks, and have to fill them all the way up. By the time they are full, 10 minutes has gone by and I have a back and neck ache from holding the position.

When filling at a dock, its even more critical that no fuel burps out so I take it even slower. I know it's just a minor inconvenience, but is there an easy fix?

I like the idea of the vent whistles, but that still doesn't solve the problem of how slow the tanks need to be filled to prevent this from happening. It's not really worth the trouble if it doesn't solve anything for me.

I'm very interested in hearing from folks that have actually solved this problem. I'd be inclined to fix the problem if there is an easy fix, but probably not brave enough to attempt to go at it alone and potentially cause an even bigger problem.
 
Geez, I just checked out the whistles and they cost $30 each (I need two). Still... it's low risk and easy :)

I was asking around locally and was told that some fuel tank builders actually drop the vent tube into the tank an inch or so to help with this problem. I believe the idea is that as the fuel level reached that point the vent is essentially plugged and the fuel backs up the filler neck. I suppose this could be retrofitted by placing a check valve into the vent line.

This begs the question: what would happen if you put a check valve in BOTH the vent line and filler hose? Would that eliminate vent overflow and allow for a more orderly shutoff of the nozzle? Any volunteers?
 
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