Sight glass

[Dick Geving]

I'm getting old and can't see as well as I used to, especially in the bilge. I have sight glasses back in the corner(s) of my 38 OA trawler. Can't see where the fuel is in the glasses. Is there anything one can float on the top of the fuel in the sight glass to make it easier to see the fuel level. I was thinking about a fluorescent fishing float or something that diesel fuel won't destroy.

Dick

 

[SomeSailor]

Most local fishing places have these small floats called "Corkies". They're about the right size to fit in the tubes. I'm gonna see if they'll work on mine. They can't get into the tank, but would be a good way to see tank levels. They're a bit larger than a pea.

 

[Dick Geving]

Ya, that's sorta where I was going. My glass tubes are 1/2 to 3/4 inch so the corkie would fit. Wonder what the red diesel will do the plastic float? I'm thinking they make cork corkies also. Seems redundant.

 

[SomeSailor]

I'll have to conduct some 'research'

Diesel is pretty mild and I think they're just Styrofoam inside.

 

[Dick Geving]

My son works at Home Depot for the summer. They had a demo this week on a product called "Never Wet" and it made by Rustoluem. It's the wildest repellant I've ever seen. Repels everything. I've been looking for a reason to buy the stuff, think I will spray it on a corkie and drop it in the sight glass. There are video's on U tube about this stuff, would have to be a great boat product if it holds up.

 

[FlyWright]

The instructions FAQ section on Never Wet states

"Can Rust-Oleum NeverWet be used on surfaces that are continuously submerged?

Rust-Oleum NeverWet relies on a layer of air to form the superhydrophobic coating on the surface of the object. For this reason the product is not recommended for surfaces continuously submerged in water or liquid."

While a float would not technically be 'submerged', its bottom surface would be and therefore its superhydrophobic properties would be lost.

Cool product. Interesting information on durability, color and transparency on the instruction page. At first I thought it'd be great for my burgundy canvas and windshield, but that's clearly not the case (pun intended). At $20 for 15 sq ft of coverage, it's not too expensive for specialized uses.

 

[CPseudonym]

The instructions FAQ section on Never Wet states

"Can Rust-Oleum NeverWet be used on surfaces that are continuously submerged?

Rust-Oleum NeverWet relies on a layer of air to form the superhydrophobic coating on the surface of the object. For this reason the product is not recommended for surfaces continuously submerged in water or liquid."

While a float would not technically be 'submerged', its bottom surface would be and therefore its superhydrophobic properties would be lost.

Cool product

I agree, it is a cool product Al. But I'm willing to bet a tank of fuel somebody will post here in the next two years how its better than prop speed.

 

[psneeld]

Not sure why red fuel is hard to see in a clear tube. Cleaning/replacing the tube and if necessary installing a small LED light or light strip on it should be the easiest in my book.

 

[gwkiwi]

An old cop trick from the street is to hold a flash light at about 45 degrees down to the side or rear of the tube and you should be able to see the level pretty easy.

I have 4 sight tubes and they are all visible from a good distance - but the tubes are all very clear against the red dye diesel.

Good luck

 

[Hendo78]

Not sure why red fuel is hard to see.

Red is a colour that goes first when your eyes start to go whilst green is the last colour that goes hence why (in Australia) all safety showers and emergency exits are green. For that exact reason. Whilst on colours, a blue LED will Travel further in water than any other colour.

Sent from my iPhone using Trawler

 

[psneeld]

Red is a colour that goes first when your eyes start to go whilst green is the last colour that goes hence why (in Australia) all safety showers and emergency exits are green. For that exact reason. Whilst on colours, a blue LED will Travel further in water than any other colour.

Sent from my iPhone using Trawler

all true but it's the contrast that is important here...as much as the color....red fuel has enough contrast if the sight tube is clear to be seen quite a distance as long as the lighting is sufficient.

I'm sure hope the OP knows that...maybe it's the angle or something else making it difficult...but then even colored floats probably wouldn't help.

I really have a hard time believing that it would be an issue with new/clean glass and some decent light.

 

[Hendo78]

all true but it's the contrast that is important here...as much as the color....red fuel has enough contrast if the sight tube is clear to be seen quite a distance as long as the lighting is sufficient.

I'm sure hope the OP knows that...maybe it's the angle or something else making it difficult...but then even colored floats probably wouldn't help.

I really have a hard time believing that it would be an issue with new/clean glass and some decent light.

Totally agree mate. New glass would/should suffice.

Sent from my iPhone using Trawler

 

[RickB]

I have sight glasses back in the corner(s) of my 38 OA trawler. Can't see where the fuel is in the glasses.

You don't say if the fuel is dyed or not but either way, a backplate with diagonal black stripes will help a lot.

The fuel in the tube acts as a lens and the angled stripe changes its orientation very visibly.

If you have old stained tubes, replace them with new clear ones, it is time anyway. And please note that it is not a good idea to have a sightglass valves open except when reading the glass.

 

[SomeSailor]

And please note that it is not a good idea to have a sightglass valves open except when reading the glass.

Good reminder. I always forget to close mine.

 

[Duvie]

Paint the background white or hold a piece of paper behind it. I use this trick all the time to make things easier to see. You could probably paint the back of the tube white!

 

[psneeld]

Paint the background white or hold a piece of paper behind it. I use this trick all the time to make things easier to see. You could probably paint the back of the tube white!

Good idea...I wonder if reflective paint or tape would help even more?

 

[Steve]

Are the tubes Plastic tubing/hose, or Glass?

 

[Wxx3]

And please note that it is not a good idea to have a sightglass valves open except when reading the glass.

Please explain. It's it just to eliminate one more potential fuel, air leak?

 

[drb1025]

Please explain. It's it just to eliminate one more potential fuel, air leak?

If there was a fire in the engine room that melted the sight tubes, having them closed would limit the fuel that could potentially burn to that in the sight tubes rather than the entire fuel tank.

 

[Shoalwaters]

This is my setup: yellow Tygon tubing (from McMaster Carr) against a white background. Very easy to read under engineroom lighting or flashlight.

I DO have a problem seeing through the bowls of my Racor primary filters. They are new bowls and relatively clean, but I have great difficulty seeing if there is muck in there. I have tried shining a flashlight on the back board and sliding a piece of white cardboard behind them - still a struggle. Any ideas?

 

[Dick Geving]

I bow to the gentleman with the toothbrush cleaned bilge. A thing of beauty. My sight glasses are glass tubes. I'm thinking the Captain with the white reflective tape might have the winner for me. My glasses are in a corner where there is little light. Adding reflective tape behind and shinning it with a flashlight should do it. The flashlight by itself won't do it. Thanks to all the great input.

Dick

 

[captrigney]

A contributing factor in the loss of the HMS Bounty was a broken sight glass on the day tank which drained the tank causing the generator to quit. I haven't been closing the valves but I think I'll start.

 

[drb1025]

Shoalwaters, you have given me a couple of good ideas with those two pictures. Thanks

 

[Tom.B]

A contributing factor in the loss of the HMS Bounty was a broken sight glass on the day tank which drained the tank causing the generator to quit. I haven't been closing the valves but I think I'll start.

I used to close mine all the time, but it's such a PITA that I have stopped... I know... I might start again though.

OP--- Is the tube faded and old? Mine were in horrible shape and I couldn't see thru them either. VERY brittle too! I just replaced my plastic tubes a few weeks ago. Pretty easy job on Skinny Dippin' and now they are easy to see.

Tom-

 

[Peter B]

You don't say if the fuel is dyed or not but either way, a backplate with diagonal black stripes will help a lot.
The fuel in the tube acts as a lens and the angled stripe changes its orientation very visibly.

That's a cunning idea...make use of parallax...

 

[AllanY]

Spring loaded valves are common on commercial vessels

Allan

 

[RickB]

Automatically closing valves are a requirement. They are not optional.

Round tube type sight glasses are no longer approved at all. A flat glass is required along with self closing valves. Many installations now use a sealed metal tube with a magnetic float that causes a little flap that is white on one side (for no liquid) and red on the other to "flip" and indicate liquid as the magnet passes. As the level changes the other direction, the little flaps change color accordingly.

 

[funangler]

Here a nice fix for hard to see sight tubes take a bright colored yard stick and mount it behind the tube in your line of sight. You kill to two problems at once and daily running logs are easier to do.