How to Make the Ultimate WEATHERPROOF Extension Cord! Great For Christmas Lights

In this video I show you how I build a very rugged and waterproof extension cord that can be used inside or outside. I also upgraded it with larger, better, and weatherproof components to make sure it could handle higher amperage and last a very long time. This can also be done to repair or fix an extension cord that has been damaged.
Items Used In The Video:
Leviton Red WR 20 Amp GFCI: amzn.to/3a2kQww
Leviton White WR 20 Amp GFCI: amzn.to/3wNf8aB
Leviton WR 20 Amp Receptacle: amzn.to/3GralyF
2 Gang Weatherproof Electrical Box: amzn.to/3LVmayc
2 Gang Weatherproof Cover: amzn.to/3x32IvD
50 Foot SJO 12/3 Wire: amzn.to/3t13IOk
25 Foot SJO 12/3 Wire: amzn.to/3MXRcXR
20 Amp Male Plug: amzn.to/3t145II
or 15 Amp Male Plug: amzn.to/3wWcEWn
Strain Relief: amzn.to/3wViwA8
Rare Earth Magnets: amzn.to/3a1K2mA
Southwire Wire Strippers: amzn.to/3lRqQuF
Channellock Pliers: amzn.to/3GuA7Cu
Klein Screwdriver: amzn.to/3t12rGX
Where you can find my most used tools and even the shirts you see me wearing in the videos. How To Home Storefront: amzn.to/38tuIio
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Blessings,
Adam
How To Home assumes no liability for damage or injury. How To Home highly recommends using proper safety procedures and professionals when needed. Our content is for entertainment purposes only. No information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not How To Home. How To Home will not be held liable for any negligent or accidental damage or injury resulting from equipment, tools, electrical, fire, electronics or any items contained in this video. Attempt projects and repairs at your own risk.

[@anthonyguess5528]

Retired OSHA here, what you're saying only applies to Construction. If you're a manufacturing facility you're allowed to make your own chords and also properly repair them if needed. Just to give you some info

[@LuLu_World]

this box would be an OSHA violation. box is not designed for portable cords. NEC violation

[@HowToHomeDIY]

@LuLu_World and yet again, guess you missed the whole part about how this is not OSHA compliant. But that doesn’t really matter unless you’re trying to use this on a jobsite as OSHA has no jurisdiction or authority over homeowners. NEC does not pertain to extension cords other than they cannot be used as permanent wiring. So not really sharing anything that wasn’t covered in the video or relevant.

[@LordoftheCats]

I saw an additional upgrade for an extension cord like this one. Cut a round disk a bit larger in diameter than the box and use that as a base for the box to sit on. That way when you pull the cord along the floor/ground, it helps prevent that square box from getting hung up on objects along the way. Thought that was an idea worth sharing here. Great vid!

[@Steve-ps6qw]

Great stuff. Im using this to put electricity in my shed. I just saw the title of this video and now see the value for Christmas decorations....my wife goes nuts over Christmas decorations so this is great stuff!

[@HowToHomeDIY]

Glad you liked it. Yeah my wife also goes a little nuts when it gets to be Christmas time. This thing made places that needed quite a few receptacles a breeze!

[@joseph7105]

Would not recommend. Get an electrician and power your shed the correct way

[@defomatt2684]

Just made one of these today. Used the same wire, 30’ of it. Same box and strain relief as well. Didn’t use 20 amp receptacles like you, but used a gfci and receptacle that had 2 female USB ports

[@markej4801]

Good example of how to tie the two outlets together to use the GFCI. Thanks!

[@LilRedDog]

I, just the other day, made one of these and my box, also, had two ground screws. I crimped the braided wire (extension cord) with a round connector and let it share one ground with the GFI and let the metal box (I presume) share ground through the second ground, in the box, on the regular/second receptacle. I 'think' wire nuts are not good for (well, really anything) connecting braided and solid wire. The box is aluminum: am I wrong to think they are, effectively, a 'common ground'? I would appreciate any feedback on this.

[@wingnutbert9685]

I like the magnet and hanging wire ideas. Though, the magnets wouldn't be so good in my welding shop! LOL! I'd have three little Buckwheat's in no time! LOL!Something else I like just as a backup to the backups backup is a heavy zip tie or two on the cord, inside the box, as a secondary pull-out preventive. Also seal any empty screw holes in the box. As well as a dab of Locktite on the face plate mounting screws. Getting tossed around the shop or worksite can rattle them loose. I've got a welding shop. Water isn't an issue, per say, but metal dust floating in the air and on surfaces can get into the small openings. It'll collect and at some point cause an arc.

[@llewellyn56]

Thank you. Love it

[@JohnThomas-lq5qp]

Was told at an IAEI continuing education class that type WR are only required outdoors. They add a UV stabiliser to prevent long term sun exposure from degrading the plastic face plate. Believe most HG ( hospital grade ) receptacles have a nylon face that I tried to crack hitting it a few times with a hammer. The HR survived but cheaper $1 receptacle are no match for a hammer. Hubbell spec grade devices always had great material for mounting strap that never rusted.

[@HowToHomeDIY]

Thanks for the feedback John!

[@jamesreizner2673]

WR receptacles are a lot more than the plastic. The metal needs to be of a corrosion-proof material. Often the metal yoke of a WR receptacle is of stainless steel. Same goes for the screws.

[@JohnThomas-lq5qp]

@@jamesreizner2673 Thanks. I completely forgot that the WR receptacles have a much better corrosion resistant metal yoke along with the SS screws. Back in the 1970's while working at a large slaughterhouse we found that brass 6/32 screws with a lot of anti seize compound held up the best in salt filled hide cellar ( had thousands of salted hides, 60,000 # salt storage pit & a salt water soaking pond ) and chill & cooler box that had salt water defrost for ammonia coils. Salt deposits were every where. We used aluminum FS & FD boxes for switches & receptacles and steel screws would seize up & break first attempt to remove. Old timers told me to not use SS screws for some reason.

[@LuLu_World]

@@jamesreizner2673 back in the day….most straps today are steel. Hubbell still makes HBL8300 with stainless. contractors like cheap stuff so they lean to low grade steel if it meets div 26 spec

[@johnpicard4909]

Thanks! I will definitely be making one of these. There are some other videos out there but this one makes the most sense and has the best directions!

[@imlon2]

If I did something down my privacy fence do you think that would work. Need it for Landscape lighting.

[@gregorymark6014]

In hospitals, we install red outlets to designate that it is connected to backup power (a generator). That way if the utility power goes out, we know that the ventilator that is breathing for the patient will not stop working if the regular power supply is disrupted.

[@patrickcooley272]

Wow…that really helps us all😂

[@CarlyPlanck-zp2og]

I need to power a sump pump about 50 feet out from the house. Could I use this same idea with some 12 3 wire, burying it in underground conduit? I would be plugging into an outside outlet, on a GFCI.

[@hendu213]

Great video!!!

[@marksleeper9385]

very nice I like this one

[@Royce1982]

is this good to plug in a space heater?

[@victorbruce5772]

Years ago, all cords and tools required regular inspection and repair of any damage, replacing cord caps with approved parts, an easy afternoon job. Don't just strip and mash untwisted wires in the holes, good chance of a few strands sticking out. Twist them and bend them to fit.

[@marcvandaele1878]

Can i use these receptacles also for 220V or only US 125 V,it’s for home use, or can you send me a link for this,industrial grade quality

[@TomCee53]

If you pay attention to the layout of the wires, one end will easy match the black&white without have to cross them in the plug.

[@LuLu_World]

few people know that

[@HIDLad001]

If you are using these with string lights, the best addition would be a photocell and a bypass switch so the lights can turn on as soon as the sun goes down.

[@jannay77]

Or a smart outlet like one the Kasa brand makes

[@jovetj]

Wire: a single conductor. Cable: a bundle of conductors, typically inside a common outer jacket.

[@surferdude642]

This looks like a good project. It seems fine if you're plugging into a regular receptacle. If you're plugging into an outdoor receptacle or in a garage the receptacle there should be a GFCI by code. You shouldn't plug one GFCI into another one. I would use 2 duplex receptacles. I'm not an electrician, but this is my understanding. Please correct me if I'm wrong.

[@HowToHomeDIY]

Hey Ted, so you are correct that if using outside or a garage for instance, that there should already be GFCI protection if the house was built when or after that code was established. However, I cannot find anywhere in the NEC that says one can't have more than one GFCI on a circuit. And I know we are talking about an extension cord which the NEC does not cover but as far as 2 GFCI's on a circuit, it seems one of them would be redundant and probably have no added benefit. But like you said if plugging into a non GFCI protected receptacle then the benefit is definitely there. If I am just not seeing something though feel free to correct me. Thanks a lot for the feedback Ted!

[@surferdude642]

@@HowToHomeDIY Thank you fot the reply. I can't really disagree with anything you said and it is ok to have multiple GFCI'S on on circuit as long as the load is not being used to feed the next GFCI in the circuit. I think your design is fine as this is an extension cord and not a permanent installation. As you mentioned, you'll get some redundancy, but I don't see any problem with that.

[@LilRedDog]

@@surferdude642 Yeah, this is a question/issue for me as well! All my outdoor receptacles are GFI and I am using this setup (I.E. GFI after another GFI). I thought this was okay because my hair dryer has a GFI from the factory and, since it is intended for use in a bathroom, it plugs into a GFI, as code requires. Anyone know, for sure, if this is a problem.

[@surferdude642]

@@LilRedDog I don't think it's a problem at all. Your hair dryer like the extension cord is a temporary load which is unplugged or turned when not in use. The case where it's problematic is when one gfci is powered from the load of a previous one. This should never be done that I'm aware of. As for your extension cord box it would be optional but not necessary to put a GFCI receptacle in there.

[@danlux4954]

11:19 but it looks like the right side plug is missing part of the cover.

[@sinclairpages]

Some people call that braided wire holder and 'Chinese Finger Puzzle' wire retainer.

[@shootthemoon6072]

Locktite- Blue- for stuff you may want to take apart at a later date...takes some force to break the bond. Red- For "permanent" bond; has to be heated to 500 degrees f. (260 c) to break the bond.

[@Wongburger]

I am scared I screwed up, I have a 100 foot 10g extension cord. Cut the female end off and wired two 20a outlets to the end in a metal box, one 20a GFCI feeding a duplex 20a. My extension cord says its rated for 15a max... do I need to switch to 15a outlets?

[@bigbrooklyn25]

No

[@dukenukem1031]

Great looking box. The only thing I would change is I would use wagos in lieu of wire nuts...

[@jovetj]

Woulda looked a lot nicer if both outlets were Decora.

[@juanruiz2308]

Whats the size of wire your’e using pigtails? Thanks in advance

[@HowToHomeDIY]

They are #12.

[@mackellyman5642]

Mr. Red receptical is also TR.

[@nodavemenz5923]

The red outlets designate that it is connected to generator power. Not a big deal for your home, but you should be using a standard color.

[@shockcoach]

It might be a standard for certain buildings, but there is no such code article.

[@pixlplague]

@@shockcoach correct. Pretty common convention though, especially in hospitals.

[@HowToHomeDIY]

The receptacles I used are just red industrial grade receptacles. Hospital grade receptacles will have markings on them like a green circle or an orange triangle for example, denoting exactly what they are for or do.

[@jovetj]

@@HowToHomeDIY The green circle is the only symbol to designate a Hospital Grade device. The hollow triangle denotes Isolated Ground, which is completely different and unrelated to Hospital Grade.

[@AWIERD1]

I appreciate all the attention to safety unlike "The King of Random" version where it was suggested to splice a lamp switch inline (rated for 2 amps max!) so you can cut power with a flip of a switch....yikes!

[@HowToHomeDIY]

Oh wow. I don't believe I have seen that. May have to look for it just to watch. Appreciate the feedback John!

[@AWIERD1]

@@HowToHomeDIY Check out some of the earliest videos such as his diy carbon arc furnace or the backyard foundry. Unfortunately Grant Thompson died from a freak accident (hang gliding?) but not before he sold his channel to another host and that's where the videos took a dive.

[@AWIERD1]

@@HowToHomeDIY I wish you might went deeper into the NEC for sizing wire and explaining how long a 12/3 extension cord can be used at what amperage, and how high amp draw can strain the life of your power tools. Otherwise great video and I look forward to seeing more of your videos 🙂

[@maxrx7]

I mean is this really necessary? why not just the traditional extension cord and ass the 4 outlet to the end plug and play...?

[@lazynihilist203]

How would you make something like this safe for a job site while still being weather safe?

[@HowToHomeDIY]

Well extension cords are easy targets for osha and “modified” cords are not allowed on a jobsite. They have to be “listed.” So no matter what one did to make one, it still would not pass an osha inspection on a jobsite unfortunately.

[@MysticWanderer]

Form a company to make them and submit it to Underwriters Laboratories for testing and hope to get listed.

[@LilRedDog]

Put a GFI in the front of the cord. IOW: spend ~ $30.00 on a male inline GFI. That will trip if you have a short downline. But really: No receptacle is waterproof in the rain when something is plugged into it...

[@wingnutbert9685]

@@LilRedDog It's labelled water resistant, not water proof. Big difference. Also, the indication of water resistance is applied to the correctly assembled box, not the separate outlets you install in said box. Manufacture has no control over that variable so can not and does not apply. The terms "Proof" vs "Resistant" is a commonly confused.

[@LilRedDog]

@@wingnutbert9685 What are you replying to? OP is asking about 'weather safe'. A GFCI inline extension cord will trip if there is a ground fault from water. It will, also, be OSHA compliant.

[@johnsaake2303]

I would’ve 1 ) used THHN for your jumpers and 2) Filled the mounting holes in the back of the box

[@jamesreizner2673]

The holes do not go all the way through the box. The box is rated with those holes.

[@jamesreizner2673]

And it could be argues that a wire rated for use in wet areas would be better for the jumpers than THHN, which is not rated for use in wet areas.

[@JMJWill]

Helpful if you explain why it’s not OSHA compliant.

[@jamesreizner2673]

Here is what OSHA says: www.osha.gov/laws-regs/standardinterpretations/1992-06-17

[@LuLu_World]

the box is not UL listed for portable applications. designed for permanent mount

[@HowToHomeDIY]

Guess you missed the whole part about how this is not OSHA compliant. But that doesn’t really matter unless you’re trying to use this on a jobsite as OSHA has no jurisdiction or authority over homeowners. NEC does not pertain to extension cords other than they cannot be used as permanent wiring. So not really sharing anything that wasn’t covered in the video or relevant.

[@mackellyman5642]

@@HowToHomeDIY The cord set must meet all applicable requirements of 1910 Subpart S and 1926 Subpart K. For example, the assembly must be marked appropriately (1910.303(e)) and (1926.405(g)(2)(iv)); boxing intended for use in a permanent installation may not be used (1910.303(b)(1)(i) and 1926.403(b)(1)(i)); cords must be connected to devices and fittings so as to provide strain relief (1910.305(g)(2) (iii) and 1926.405(g)(2)(iv)); cords passing through holes in enclosures must be protected by bushings or fittings designed for the purpose (1926.405(g)(2)(v) - fittings designed to fasten cables to metal boxes are not acceptable); and no grounded conductor shall be attached to any terminal or lead so as to reverse designated polarity (1910.304(a)(2)) and (1926.404(a)(2)).

[@livestrong1976]

What length of extension cord do you recommend?

[@jameshill4900]

It depends on your need but use the shortest possible. More length equals drops in volts. 25 ft is handy size but don't go longer than 50 feet unless you have to.

[@NiNjaTurtLe697]

what is the max length of this cord type ?

[@johnsxterra9020]

You can buy SO cord in any length but you have to take into consideration the voltage drop calculations

[@NiNjaTurtLe697]

@@johnsxterra9020 hey thanks, I'd like to have 15amps at 150 feet. Does that work?

[@LuLu_World]

back in the day we. all saw boxes like this hanging in shops n factories…until OSHA cracked down and only portable boxes designed for the application

[@michaelburke1023]

Isn't this strain relief not waterproof? Thought these were intended for stamped metal boxes. I'm afraid water will seep through and get trapped inside the box between the cord and fitting. The threaded portion seems to be water tight with the threadlocker. There are wire glands with dual gaskets for the wire to fitting as well as for the fitting to the box, then a strain relief on the other half the fitting. 🍻

[@AntwonDaBusiness]

Red loctite is overkill for this. Just use blue.

[@LuLu_World]

does not meet NEC Code. Box is not rated as a. portable outlet box. Hubbell, woodhead make boxes that meet code..

[@HowToHomeDIY]

Guess you missed the whole part about how this is not OSHA compliant. But that doesn’t really matter unless you’re trying to use this on a jobsite as OSHA has no jurisdiction or authority over homeowners. NEC does not pertain to extension cords other than they cannot be used as permanent wiring. So not really sharing anything that wasn’t covered in the video or relevant.

[@davidjohnson129]

Could I pay you to make me one of these?

[@jovetj]

I'd make you one.

[@johnsxterra9020]

I make you a hundred of them

[@cafemolido5459]

If you make it with a 20 AMP plug, you'd be more limited as to where you can use it. 20 AMP male plug does not work with a 15 AMP outlet

[@HowToHomeDIY]

Then make it with a 15 amp plug and receptacles.

[@Sylvan_dB]

I'm older than OSHA. They can't tell me what to do. 😎

[@HowToHomeDIY]

😂 I can get behind that thinking.

[@wingnutbert9685]

I get OSHA poopooing diy extension cord stuff like this. Inspectors would have to dissemble every one they find to approve they were built correctly. But there is some irony that cheap garbage extension cords made with the schitiest quality materials are just fine! LOL!

[@benjaminwilliams3568]

WHOOOOAAAA There bud!!! You Need to WRAP Both Electrical Outlets with electrical tape insuring to cover the Outlets Side Screws . Shame On You For Not Doing This. You were good Up until this point. Epic Epic Safety Step Failure On Your Part.

[@HowToHomeDIY]

No not necessary. This in not required in the NEC anywhere on typical wiring. Wrapping receptacles is purely a preferential item.

[@timothysteadham331]

OSHA has zero jurisdiction or authority of what homeowners do. The word that “O” stands for should make that clear. 😄

[@fatherfoxstrongpaw8968]

AAAHHH!!!!! wire nut!?! your EVIL!!!! love the rest. lots of room for improvement, but otherwise ok. seriously tho...wirenut? brah! *smh*

[@wingnutbert9685]

Because wire nuts haven't been just fine for how many decades now????.........🤔🤦‍♂✌

[@fatherfoxstrongpaw8968]

@@wingnutbert9685 exactly! can't count how many F-up i had to fix cause someone thought twisting wires carrying electricity like a twist tie on a sack of bread was ok, then couldn't figure out why the wires were hot, a breaker kept tripping or there was no power in the circuit from the caps or *shudders* electrical tape making it LOOK like it was a good solid connection. trust me, if there's a way to F something up, i've either done it or fixed it. my last was wire nuts on a ceiling fan light. it was an "illuminating" experience. *fzZZzzt*

[@jamesreizner2673]

OSHA does not prohibit job-made extension cords. www.osha.gov/laws-regs/standardinterpretations/1992-06-17 OSHA does not apply to homeowners, as you note. You have a male plug using a 15 amp NEMA 5-15P. The receptacles are 20 amp NEMA 5-20R. This is unsafe and a violation of the NEC (if you don't understand why this is a problem ask). It would be a good idea to fix that.

[@HowToHomeDIY]

No it isn’t. It is a 20 amp male plug. You can see me clearly wiring it up at the beginning of the video. Nothing needs fixed.

[@bigbrooklyn25]

It's clearly a 20amp plug 🔌 you can see the one terminal turned sideways