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Discussion Starter · #1 ·
I love DIY projects. I have done a lot of research on the web trying to find out how to connect these, but to little avail. I plan to use it for a miniature fountain/riparium. I need to make a water tight connection with these wires to something that will connect to the DC power adapter. Does anyone have experience with this kind of thing?



Thank you in advance!
 

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Waterproof heat shrink butt splice


You can either cut male plug off power supply and splice them together permanently or buy a female pigtail which would be my choice.

Female pigtail


Do a offset butt splice to waterproof it into a slender junction then go over that whole area with some black heat shrink to make it look nice.

Offset butt splice
 

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Discussion Starter · #3 ·
DaveKS you rock! Thank you so much. I will do the pigtail method. However, the link for the "offset butt splice" did not come through. Could I assume it means making the splice at different places on each wire to minimize bulk at the same spot?



I cannot tell you how much I love this forum and how you all help with sharing the things you have learned! I appreciate it so much!
 

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An alternate method which requires less shopping?
I like to do any splice as if it was going to get wet and I want permanent, so solder joints are my main method. In this case, I cut off the end plug, do a test to see which wire to which wire (polarity) is needed to make the pump turn the correct direction, then do a splice. To make it smoother and smaller diameter, stagger the splice in each wire just a bit, twist and solder the joint. Then to make certain it is watertight even though not critical at this voltage, I cover the splice with silicone, or other handy waterproofing and then add heat shrink, first as a cover for each splice and then when those are done, add a second heat shrink over the total to form it back into one wire.
Notice the gap at each end of the ready made heat shrink connector? Those tend to collect water and hold it there as it searches for any weak spot in the seal and can eventually fail.
 

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Discussion Starter · #5 ·
An alternate method which requires less shopping?
I like to do any splice as if it was going to get wet and I want permanent, so solder joints are my main method. In this case, I cut off the end plug, do a test to see which wire to which wire (polarity) is needed to make the pump turn the correct direction, then do a splice. To make it smoother and smaller diameter, stagger the splice in each wire just a bit, twist and solder the joint. Then to make certain it is watertight even though not critical at this voltage, I cover the splice with silicone, or other handy waterproofing and then add heat shrink, first as a cover for each splice and then when those are done, add a second heat shrink over the total to form it back into one wire.
Notice the gap at each end of the ready made heat shrink connector? Those tend to collect water and hold it there as it searches for any weak spot in the seal and can eventually fail.

Those are excellent ideas! I think I will not cut off the plug at this point as I am not sure of the quality/longevity of these pumps, and that would allow ease of transfer of the power source if it fails. I did not think about heat shrinking both solders before joining into one, that is a good safety point. Thank you for the advice. When I get better at this and more familiar with the pumps, I will splice it all into one wire.
 

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Nothing at all wrong with adding a plug to match as those tiny pumps can be fickle and it's always nice to have an easy way to disconnect. One big point on this is the low voltage and current we get out of the adapters most use. It is not near the same danger as if we were using 110 AC, so we can be a lot more free with the chance of getting the connection wet. Worst case is something stops working if we get it wet, not the big bang and smoke or hazard of 110 wiring.
My main "nuisance" thought is finding the exact right size connector but that varies with where we each need to shop. If I can walk it in a try it for fit, I like it, but when I need to order and wait, I hate matching the fussy little things.
 

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Nothing at all wrong with adding a plug to match as those tiny pumps can be fickle and it's always nice to have an easy way to disconnect. One big point on this is the low voltage and current we get out of the adapters most use. It is not near the same danger as if we were using 110 AC, so we can be a lot more free with the chance of getting the connection wet. Worst case is something stops working if we get it wet, not the big bang and smoke or hazard of 110 wiring.
My main "nuisance" thought is finding the exact right size connector but that varies with where we each need to shop. If I can walk it in a try it for fit, I like it, but when I need to order and wait, I hate matching the fussy little things.
I got some AC/DC power converters that only put out the 4.5W that the pump requires, so I should be okay there (I got a variable rate one as well). I live in a very small town in the Pacific NW with very little access, so most everything comes from online. I order something, then find a better way to do something, order more supplies, then find it was the wrong size. Repeat above steps until I find something that works. Life in a small town. Would not change it for the world! Thanks again!

Yikes! I received the pigtail and stripped and cut the wires to solder them at different lengths. When putting them together to measure them, I see that....

Pigtail - Red wire is copper and black wire is silver
pump - Red wire is silver and black wire is copper

They are also different gauges, but I figured since I am using the proper power source that shouldn't be a problem. So...what is the suggestion for soldering? Copper to copper or red to red?

Thanks again and again!
 

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It's hard to say which way they need to go. You could always check and see if it's marked somewhere which is +/-. Since it is low voltage DC, I would just temporarily twist them together, making sure they won't touch each other and short out, and check to see which way the pump is running. If it pumps the direction you want it to, mark that as "good" and go ahead and make the "real" connection that way. If the pump turns the wrong direction, reverse the sequence and then make your connection.
 

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Discussion Starter · #9 ·
It's hard to say which way they need to go. You could always check and see if it's marked somewhere which is +/-. Since it is low voltage DC, I would just temporarily twist them together, making sure they won't touch each other and short out, and check to see which way the pump is running. If it pumps the direction you want it to, mark that as "good" and go ahead and make the "real" connection that way. If the pump turns the wrong direction, reverse the sequence and then make your connection.

Okey dokey. I will give that a try. Thank you so much!
 
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