Making and using an electromagnet?

[softdown]

My dad helped me make one for Show & Tell when I was a kid. They are pretty simple really. The challenge lies in dealing with saltwater.

Basically you run copper wire around an iron core then run current through the wire. The problem, of course, is that corrosion would quickly destroy the copper wire.

I have a lot of copper wire from my solar business that never took off. So I am playing with the idea of making an electromagnet for use as a saltwater hobby.

The question would be in dealing with corrosion issues.

[SURV69]

doesn't the wire remain sheaved?

[softdown]

Originally Posted by SURV69

doesn't the wire remain sheaved?

Possible though there has to be contact between the wire and the iron in order for electricity to flow through the iron...I think. It has been been a long, long time since we made one.

I seem to recall doing a lot of wrapping of bare copper wire then hooking the wire to a large flashlight battery. The magnet was surprisingly strong.

Wrecking yards use electromagnets to lift cars.

[Iaangus]

Originally Posted by softdown

Possible though there has to be contact between the wire and the iron in order for electricity to flow through the iron...I think. It has been been a long, long time since we made one.

I seem to recall doing a lot of wrapping of bare copper wire then hooking the wire to a large flashlight battery. The magnet was surprisingly strong.

Wrecking yards use electromagnets to lift cars.

No, there is no contact between the copper and the iron. The copper wire is insulated, the number of wraps and the voltage and amperage determine strength.

[softdown]

Originally Posted by Iaangus

No, there is no contact between the copper and the iron. The copper wire is insulated, the number of wraps and the voltage and amperage determine strength.

So 60 pounds of 4/0 copper welding cable attached to a 1600 pound forklift battery would be pretty strong I may guess. What about the iron piece that supports the copper wiring?

[Maka]

And you are making an electromagnet because ?

[Sailmonkey]

The wire that looks bare is insulated with laquer.....however as an echo to the above. What is the point?

[oleman]

Instead of inventing a magnet, just use a clutch magnet from an automotive air conditioning compressor. It is sealed and has lot's of pull, plus runs from +13.6V at less than 10A. It would be great to retrieve ferrous objects dropped overboard. In a place like New Foundland where the water is so clear you can see down 20 feet it would be easy fishing.

[Brewgyver]

He wants to wipe the hard drive of a laptop, from outside the police evidence room...

[Ivansgarage]

Originally Posted by Sailmonkey

The wire that looks bare is insulated with laquer.....however as an echo to the above. What is the point?

It is called Magnet Wire, coated wire, google it.
I use it all the time to wind motors.

[Sailshabby]

Electromagnetic and saltwater hobby - two things I never thought I'd see in a sentence together...

[skipmac]

Originally Posted by softdown

Possible though there has to be contact between the wire and the iron in order for electricity to flow through the iron...I think. It has been been a long, long time since we made one.

I seem to recall doing a lot of wrapping of bare copper wire then hooking the wire to a large flashlight battery. The magnet was surprisingly strong.

Wrecking yards use electromagnets to lift cars.

The wire does not have to be in electrical contact with the iron core. The core serves just to focus and concentrate the magnetic flux lines.

[Steve Bean]

To clarify: the copper winding wire MUST NOT be in electrical contact with the iron core, or with itself. Direct contact would be a short circuit! Lacquer-insulated copper looks somewhat like bare copper to young eyes.

[softdown]

Originally Posted by Maka

And you are making an electromagnet because ?

I am playing with ideas while my boats bottom dries out.

A lot of us have sacrificed a good anchor to King Neptune. Some of us would like it back.

[rwidman]

Originally Posted by softdown

Possible though there has to be contact between the wire and the iron in order for electricity to flow through the iron...I think. It has been been a long, long time since we made one.

I seem to recall doing a lot of wrapping of bare copper wire then hooking the wire to a large flashlight battery. The magnet was surprisingly strong.

Wrecking yards use electromagnets to lift cars.

1) The copper wired does not make contact with the iron core. It is insulated.

2) If you wrapped bare copper wire you would have nothing but a large short circuit and it wouldn't lift anything. The wire was insulated with enamel so one turn wouldn't connect to the next.

You should get some science experiment books and look up what you are trying to do.

As far as saltwater, once you make and test your magnet, dip it in some sort of waterproofing compound so water can't get to the wires or core. Encapsulate it.