Bilge Pump

[Mick FavagerParticipant @mickfavager60486]

I would like to fit a bilge pump to a Model Slipway AZIZ. The rear deck allows a lot of water to gain access to teh inside of the hull. Does anyone a have a design for a float switch to turn a pump?

regards

Mick

[Penny LeeParticipant @pennylee76979]

If you cover the postage you are welcome to my old model submarine bilge/compressor switch.It is 0.9 x 2.5 inches and will handle very big pump.

Alternatively, I got the above circuit from an old article.

For your application I see no reason why R2 can’t be replaced by 1M and the probes be at Q2 input and the negative supply and Q1 be omitted.

The positive probe will become pitted due to electrolysis on d.c. probes.

I’ll bet problems occur if the bilge water comes into contact with the negative supply (unless the probe sensitivity is increased by reducing R1to 10k or the more positive bilge probe shroulds the lower probe.)

If fitting a float switch is no problem,it could replace R4 while ensuring Q3 is turned “off” by a pull down resistor when the float switch is open.

The simplest solution of all could comprise a “TOPFET” in place of Q3, float switch and one resistor.

Regards

Lee Penny

[Mick FavagerParticipant @mickfavager60486]

Lee,

I am more than willing to cover postage, thanks for all the information too.

Please let me know, how much and how I should pay.

Thanks

Mick

[Penny LeeParticipant @pennylee76979]

Hi Mick,

Just P.M.your address and I’ll check it before sending it off with the connections and my own address.

I haven’t posted a packet since the new rates but I doubt it will even come to a book of four 2nds.

Lee

[Mark LeighParticipant @markleigh72576]

 Hi Mick,

 Reference the above you can also get a 6 volt version with water sensor from Hunter Systems. The link is below though the cost is definately not "a book of four seconds!!!!"

http://www.huntersystems.co.uk/acatalog/Misc.html – 28k

Mark

[ManxmanParticipant @manxman]

OK – I admit it – I’m thick !

water comes into the hull and operates the float switch or circuit probes and switches on the pump which pumps the water out, when the water is gone the float switch drops back down and stops the pump.

This much I understand, now comes the thicky part of me asking WHY, do you need a float switch or a fancy circuit board ?

if you connect +12v to the pump and run -12v to one of 2 small nails/screws set in a small block and fixed near to the hull floor and a 2nd wire from the other nail/screw to the pump.  surely water coming into the hull, which is a damned good conductor of 12v would, when reaching the nails make a connection and switch the thing on – when the water is gone the connection would be lost and it would stop !

Either there is something seriously wrong with my way of thinking or people just like to make life harder for themselves.

Ken – the stupid

[60wattParticipant @60watt]

You may not be stupid but just you have not crunched the figures.

Lee says "The positive probe will become pitted due to electrolysis" and that circuit has the probes leaking less than a milliamp !

It’s also called sacrificial corrosion.

If you get your system to work the nail should disappear before your eyes and the boat will be full of an explosive mixture of gases. LOL

It won’t actually work as the pump needs a rotating torque to overcome friction.The motor torque is proportional to the current through it.

You will get the full voltage bubbles at your probes because the pump is a tiny resistance compared to a few mm of water.

Tom

[Mike DavidsonParticipant @mikedavidson22772]

MIck   Regarding your bilge pump, I reckon the best way to go about this problem is to gey a smallD.C motor driven pump that works, and get an electronics chum to build a little sensing circuit with a 731 integrated circuitthat looks at the resistance between two electrodes right down in the bilges, and as soon as water is present, the circuit will enable a driver transistor which switches on a power transistorthat applies power to your little pump motor. there are lots of published application circuits available, so you don’t have to worry about infringing copyright asthere are plenty in the public domain. the one I have in mind is very economical on power, as it only switches on when needed, and off again when the water’s gone. just remember the word application when you are searching for the right one.

Cheers………………..Mike     D

[Mike DavidsonParticipant @mikedavidson22772]

  Tom     the RNLI combat electrolytic or dissimilar metal corrosion by introducing a sacrificial anode placed strategiclyin a position where it will present an easier path for the electron flowthat erodes essential parts of the boat’s anatomy, so it is that which is eaten away by the electron flow. you should wander down to a slipway when a lifeboat is up on the blocks, I have, and it opened my eyes I tell you. The only time I have seen worse corrosion is when I went to Cape Kennedy NASA space museum and I saw a Saturn Moon launcherassembled on its side in cradles. You know that rockets are manufactured from very light weightmagnesiun alloy, and that cape Kennedy is situated right next to the sea, Well, the onshore breeze carried with it a hefty amount of salt water spraywhich reacted with the magnesium alloy quite violentlyand you could see quite solid lumps of metal almost eaten through by the corrosion. The Saturn launch rocket was gradually turning itself into a pile of grey dust. NASA Put out a tender for an inhibitor which would stop this and an enterprising company came up with an oily based aerosol which could be sprayed on to stop the corrosion, and it didn’t take a genius to work out the name of this inhibitor, they called it Rocket WD 40….Clever boys, so take note, WD40 is NOT a lubricant, it just stops things corroding. I use silicone oil in my propshafts, and WD40 on the rudders and propellors

[Bob Abell 2Participant @bobabell2]

Simply get a fuel pump and motor…connect it to the battery…fit an on/off switch…and use that when necessary

Bob

[Paul TParticipant @pault84577]

Hello Bob

Nice to see you posting again perhaps the site might be a little more interesting. have you had your flash of inspiration yet and if so what what can we look forward to?

Paul

[Bob Abell 2Participant @bobabell2]

Good morning Paul

We didn`t get to Blackpool afterall!…………………Had a nice day at New Brighton……….Saw the Illustrious leaving port………………..Had the wrong camera with me……Hence no pictures!

Apologies to Mick for going off topic………………that`s your fault Paul!

I`ve got bilge pumps in most of my big boats…..some simple on/off and some servo operated.

Bye…………..Bob

[Paul TParticipant @pault84577]

A very good morning to you Bob

I use windscreen washer pumps as bilge pumps and just like yours mine are servo operated..nice and simple and very effective.

But to go off the subject……what kind of behemoth are we to be treated to for your winter build……it will have to be something special to top the Great Eastern……talking about Illustrious how about an aircraft carrier…..with all of those working lifts it would be a challenge worthy of your building skills.

Paul

Just to wet your appetite

[Bob Abell 2Participant @bobabell2]

Hello Paul

That`s the problem!………………….The Great Eastern is a hard act to follow!………………………I`m really struggling for the right subject to appear on the horizon………………something will turn up soon I hope………my workshop looks like a British shipyard at the moment………………….idle hands and total desolation!

Bob

[DuckyParticipant @ducky]

Like I said Bob…….A Mississippi Show boat with your woodworking skills and Joyce to make the red white and blue banners round the sides and an ipod in it to play Al jolson singing “Swanee “

Paddles as well now you’ve perfected how to make them ,and for Mike a bilge pump fitted and illustrated.

Here is one seen at Birchwood this year.You would have to enlarge it though Bob.Ducky

[Bob Abell 2Participant @bobabell2]

Thanks Duckie

Guess what I`m looking at……..at the moment?…………………Hmmmmmmmmmmmmm?

SS Jeanie Deans as she appeared in WW2!……………………..This could be it!

Camoflage….guns……mine racks……..no rivet counters about……windows covered…now portholes……and I`ve got the plan already!

What a pity, I messed up the formers making Great Eastern

Even more apologies to Mike for going off topic…….but I will be fitting a bilge pump!

Now where`s that plan?

Bob the Builder!

[Paul TParticipant @pault84577]

Hi Bob

Not much of a challange though is it?

Paul

[Bob Abell 2Participant @bobabell2]

Paul………………I`m quite excited about the project……………..and that`s good enough for me!

It`s also quite a challenge………………because I can`t remember a damned thing how I built the original Jeanie Deans!………all the photos got wiped off in error!

It will look very nice with the camo colour scheme and not forgetting the card and rivets trick!………and for a novelty…..how about some explodong mines?

And as far as I am aware………………….it ain`t been done before!

Going out for the wood this afternoon!

Bob the Builder

[Paul TParticipant @pault84577]

Good Afternoon Bob

I hope that you got all the wood home safely.

I have been looking at the career of HMS Jeanie Deans from troop ship to mine sweeper to auxiliary anti-aircraft vessel

Here is a brief description of her armaments:-Two 2pdr guns fore and aft and eight 0.5ins machine, sixteen 0.303 ins guns and eight 0.303 machine guns.

The best picture that I could find of her in camouflage colours.

It will certainly be something to see them side by side on the water.

Paul

[Bob Abell 2Participant @bobabell2]

Thanks a lot Paul………………..I knew you would sniff something out……………….haven`t seen your picture before.

Got the wood and a large PVA………………It`ll be like old times again, especially now that I`ll rarin` to go!

Bob

[Mick FavagerParticipant @mickfavager60486]

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