DIY Float switch story.

[Ex-Calif]

Originally Posted by minaret

I think you may be confused. This is what the Coast Guard uses, float switches are SO 20th century. These units are bombproof compared to a float switch. They are a bit more complex than just sticking two leads into water. Personally I would not go to sea with an old style float switch, they are gauranteed to fail just when you need them most, just as occurred in the OP. The Model 257 is the way to go, the secondary backup is genius....



Water Witch Bilge Switches

One thing for sure - the combo pump and integral switch is a really bad idea...

[Sailmonkey]

Originally Posted by bobconnie

Everyone should have a "Manuel" bildge pump ! Used to be standard equipment for sea going folks ! I guess in these days of Fancy electrical stuff they have just gone out of style??

Most boats still have manual bilge pumps, but they very rarely break, so you don't hear about them

[rebel heart]

Originally Posted by bobconnie

Everyone should have a "Manuel" bildge pump ! Used to be standard equipment for sea going folks ! I guess in these days of Fancy electrical stuff they have just gone out of style??

I have two manual pumps. A fixed mounted ~10 gallon per minute jobber, and then my monster Edson portable that will do one gallon per stroke. But if you're motoring around getting some drips in via the shaft for 24 hours of motoring, why not have the electric handle the stuff?

[donradcliffe]

Originally Posted by Sailmonkey

Most boats still have manual bilge pumps, but they very rarely break, so you don't hear about them

My boat had a Plastimo manual bilge pump, and it had a 100% failure record. Every time I tested it, it didn't work--cheap plastic parts were cracked. After rebuilding it twice, I replaced it with another brand.

I used to use a "Manuel" bilge pump, but nowadays they come after you for hiring illegals

[LJH]

Originally Posted by bobconnie

Everyone should have a "Manuel" bildge pump ! Used to be standard equipment for sea going folks ! I guess in these days of Fancy electrical stuff they have just gone out of style??

They should still be standard equipment. I have two. One in the cockpit for day to day use and one large volume pump.

[Cheechako]

Originally Posted by jcapo

Really nice fix!

13 years ago I bought a float switch made by the folks that also make tef-gel.

Pump Float Switch Jr. 12 Volt (Switch Only)

It still woks as advertised but a bit spendy. They have several different versions now.

John

Yep, best one made.

[boden36]

Every electric bilge pump should be wired so that it may be activated by a manual switch in addition to a float.
Regards,
Richard.

[Tony B]

Originally Posted by bobconnie

Everyone should have a "Manuel" bildge pump ! Used to be standard equipment for sea going folks ! I guess in these days of Fancy electrical stuff they have just gone out of style??

This brings to mind an old expression: "the best bilge pump in the world is a scared man with a bucket"

[stillbuilding]

Originally Posted by skipmac

Never mind the previous post. Just saw your second post and followed the link. Seems like oil doesn't bother it.

I will have to read more. What it actually says is that it "will not pump oil". I wonder what happens if there is oil in the bilge by accident. Maybe enough to disable the sensor.

[skipmac]

Originally Posted by Cheechako

Yep, best one made.

Well did a lot of internet researching and that's the one I bought. Haven't launched yet so can't give any firsthand report but I expecting good things.

[stillbuilding]

Originally Posted by skipmac

Well did a lot of internet researching and that's the one I bought. Haven't launched yet so can't give any firsthand report but I expecting good things.

So there would appear to be a choice between two items - the Tefgel well constucted float switch without fancy electronics and the Waterwitch with fancy sealed electronics but no float to fail. Hmmm....

[skipmac]

Originally Posted by stillbuilding

I will have to read more. What it actually says is that it "will not pump oil". I wonder what happens if there is oil in the bilge by accident. Maybe enough to disable the sensor.

I read more on the Water Witch website and didn't find an explanation of the technology it uses but from descriptions and comments in the manual I am pretty sure I know.

My guess is the switch works on sending a small electric current across two external contacts. So when the switch is submerged in water, the water will carry a current and the current closes an internal solenoid that switches on the bilge pump.

Since oil doesn't carry a current if there is oil in the bilge, floating on top of the water the switch won't turn on as long as it is sitting in the oil. Once more water comes in the oil floats higher and then the switch is in water again so turns on. When the water pumps out the level in the bilge is lower and the switch is again in oil, no current flows so the switch turns off. This is so you don't pump oil into the water and violate pollution laws.

My concerns are two. If the bilge is really nasty and oil sits in there and turns into a gooey, slimy mess it could coat the contacts on the switch so even when the switch is under water it won't carry the current and won't turn on. Had an electrical contact type switch that came on my boat and that happened. Wasn't a Water Witch but worked on the same principal.

The other concern is very unlikely but theoretically a weak point, even mentioned in the Water Witch manual. Pure water does not carry electric current. It takes free ions like you get from salt or some type of pollution in the water. If you had really clean bilges, you were in pure fresh water it is possible that the switch wouldn't work at all. Unlikely but very possible.

[bobconnie]

I was taught as a boy, That the first thing ya do when ya relieve the watch(after cking course and location) was to stroke the Manual pump to see if any water was in the bilges! if it took more then a couple of strokes, we personaly cked the bilges to see if there was a problem ! Not a big deal these days of plastic boats ! But it's still done on my boats !!!

[stillbuilding]

Originally Posted by skipmac

I read more on the Water Witch website and didn't find an explanation of the technology it uses but from descriptions and comments in the manual I am pretty sure I know.

My guess is the switch works on sending a small electric current across two external contacts. So when the switch is submerged in water, the water will carry a current and the current closes an internal solenoid that switches on the bilge pump.

Since oil doesn't carry a current if there is oil in the bilge, floating on top of the water the switch won't turn on as long as it is sitting in the oil. Once more water comes in the oil floats higher and then the switch is in water again so turns on. When the water pumps out the level in the bilge is lower and the switch is again in oil, no current flows so the switch turns off. This is so you don't pump oil into the water and violate pollution laws.

My concerns are two. If the bilge is really nasty and oil sits in there and turns into a gooey, slimy mess it could coat the contacts on the switch so even when the switch is under water it won't carry the current and won't turn on. Had an electrical contact type switch that came on my boat and that happened. Wasn't a Water Witch but worked on the same principal.

The other concern is very unlikely but theoretically a weak point, even mentioned in the Water Witch manual. Pure water does not carry electric current. It takes free ions like you get from salt or some type of pollution in the water. If you had really clean bilges, you were in pure fresh water it is possible that the switch wouldn't work at all. Unlikely but very possible.

That seems likely .
So we can choose our poison/flaw clearly understanding the issues. Small risk with both technologies.

[minaret]

Originally Posted by skipmac

I read more on the Water Witch website and didn't find an explanation of the technology it uses but from descriptions and comments in the manual I am pretty sure I know.

My guess is the switch works on sending a small electric current across two external contacts. So when the switch is submerged in water, the water will carry a current and the current closes an internal solenoid that switches on the bilge pump.

Since oil doesn't carry a current if there is oil in the bilge, floating on top of the water the switch won't turn on as long as it is sitting in the oil. Once more water comes in the oil floats higher and then the switch is in water again so turns on. When the water pumps out the level in the bilge is lower and the switch is again in oil, no current flows so the switch turns off. This is so you don't pump oil into the water and violate pollution laws.

My concerns are two. If the bilge is really nasty and oil sits in there and turns into a gooey, slimy mess it could coat the contacts on the switch so even when the switch is under water it won't carry the current and won't turn on. Had an electrical contact type switch that came on my boat and that happened. Wasn't a Water Witch but worked on the same principal.

The other concern is very unlikely but theoretically a weak point, even mentioned in the Water Witch manual. Pure water does not carry electric current. It takes free ions like you get from salt or some type of pollution in the water. If you had really clean bilges, you were in pure fresh water it is possible that the switch wouldn't work at all. Unlikely but very possible.

If the bilge is so nasty that it gums up the contacts, a float switch would have been jammed long before. To clean the water witch you wipe the contacts with a paper towel. To clean the float switch you remove and disassemble it.