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Electrical Tape Tips by KFF

K0FF (K0FF) on April 11, 2003
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Electrical Tape Tips by KFF

Did you ever notice that electrical tape, like a hammer, comes with no instructions? Perhaps the makers figure that everyone automatically knows all the "tricks of the trade". Read on, you may pick up a new wrinkle.

Vinyl electrical tape has been around since 1945, but for a long time after it was introduced, black cotton friction tape was still used for most applications, partly because of the cost difference, partly because of tradition. I remember tearing long strips of half-inch friction tape into quarter-inch wide strips as a cost savings. A unique feature of the adhesive on the friction tape is that it gives off an eerie blue light when the tape is peeled from the roll. It is bright enough to be easily seen in a darkened room. Aside from that trivial fact today's friction tape is used for special applications only as a topcoat for delicate rubber tape as used on high voltage cable spices. Modern materials are superior in every respect. The first vinyl tape I ever saw on the job was gray in color, not black, I suppose it was a telephone company spec.

Today I recommend using only Scotch 33+ tape for all ham radio uses, except as noted at the end, as it has predictable characteristics and is good for every indoor/outdoor application. The temperature range is zero F to 220 F.

Make sure to get the type with the + sign, as there is also a plain type 33.

3M also makes product called Temflex, but again type 33+ is suitable for every application, especially outdoors.

When taping over coax connectors, or coax splice kits, it is helpful to first wrap the connector with a self-amalgamating Silicone Tape product. The 3M version is Type 70, and Radio Shack also sells it in small rolls under the part number 64-2336.

This is NOT the same product as the coax-seal, or Radio Shack #278-1645 "sealant for RF connectors". I do not care for that sticky material, dum-dum, or any other putty type material that is hard to remove later. The silicone-tape peels off cleanly and easily, so easily in fact that it needs to be covered with a topcoat of Type 33+ to protect it. This two layer approach, when applied as explained below will give a waterproof seal that is weather resistant, and stays flexible for years, but can easily be removed if changes need to be done to the system.

Any time you wrap tape on a threaded component, make sure you wrap it in the direction that tends to tighten the screw threads, not the other way. That means if you are taping a splice, for example two PL-259's screwed into a double barrel female (PL-258/83-1J) you must tape each connector from the cable end to the barrel center.

Always run the tape "uphill" that is from the smaller diameter to the larger diameter.

Start at the smallest end, make several tight turns of one-quarter lap for a good seal, then run the tape in one-half laps to the center, with moderate stretch so the diameter of the 33+ is reduced to about five-eighths of it's original width. On the last few turns reduce the stretch tension until it is zero at the last turn, to prevent flagging. Use a scissors to cut the tape end square, as a knife or ripping will add stretch to the last lap and cause it to come loose. Repeat the same strategy from the other side, and meet in the center (if it is a splice kit), overlap the left hand side tape with the right hand side tape. If the connection is to be removed at a relatively short timeframe, fold the last hat does not stick. If the tape job is permanent, simply lay the last lap down flush. Now for the best-kept secret, spray the entire assembly with clear coat enamel or other dielectric spray. I use Krylon Crystal Clear. The over-spray absolutely seals the joint and keeps the ends flat.

Non-electrical uses for electrical tape.

For taping cables to tower legs and other such jobs, consider using the Temflex or straight Type 33 as they both are less expensive and have a slightly higher breaking strength. The superior conformal qualities of the 33+ are not needed in these applications.

One of the most common non electrical uses of vinyl tape is to secure rolls of wire, bundles of tubing, cables to rungs, and many other odd jobs that use the material for other than it's weatherproof or electrical qualities. To tie up a roll of cable, the cheapest grade of black vinyl tape is adequate, except that it leaves a gooey mess behind when removed. The secret here is to make the first full two turns with the sticky side OUT. Then simply twist the tape around on itself and continue making a few more turns with the sticky side IN. This same trick can be used with cellophane tape to secure hardware store bundles of conduit, pipe etc, so that it removes cleanly. Wish I had a nickel for every minute wasted trying to get that sticky mess off copper water pipe before soldering!

Another slick idea Scotch came up with is the color-coded vinyl tape. I've tried many schemes over the years of using red, blue, green white and other color tapes to identify certain cables, for example coax cables in a bundle run up the tower. After toughly confusing myself, I decided to simply use the white tape, and mark the ID on it with a Sharpie permanent marker. Foolproof, and lasts for years.

A final note, the better tapes like 33+ have a shelf life rating of 5 years, but still be careful of "surplus finds", as the age and storage conditions are unsure. Best to buy fresh tape from a known, trusted source.

Have Fun


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Electrical Tape Tips by KFF  
by KE6PKJ on April 11, 2003 Mail this to a friend!
Excellent article! As an added note, I'd also like to mention that when leaving the last turn of electrical tape on your coax you should secure it with an ultra violet resistant (black) tie wrap. This prevents the tape from unwinding itself from exposure to the elements, especially if your using cheap tape.
Electrical Tape Tips by KFF  
by KA0OXH on April 11, 2003 Mail this to a friend!
Great article from George. I would like to add some of my experiences that have been handed down to me in my travels.

I started out in the radio gig about 22 years ago as a tower hand for the local Motorola service shop.Work now as a Senior RF Engineer for a wireless carrier. Still play HAM radio since day one...
Things I have used and my comments:

Scotch 33+ is great but you need to stretch it as you apply it to get the maximum adhesion. I have found Scotch 88 has better cold weather characterisics.

Weatherproofing compounds such as "Butyl rubber", "Vapor Wrap", "Andrew weather proofing kits" "Scotch Kote" and the like work well but are very messy. I have tower crews now that always put a layer of tape underneath the weather proofing. This practice may cause your vapor bloc to fail and condensation to form in the coax connector.

I like to use the self vulcanizing tape or vinyl mastic tape. 3M Scotch sells all it under different names, such as "scotch 23 tape","vinyl mastic tape" or
"electical insulation putty" tape. When you apply this stretch it just like you were taping the connector and I always follow it up with a couple wraps of 33+ or 88 tape which every Ham operator should have as standard tape! Makes a perfect vapor bloc to the connector if applied properly. Not messy at all!

73's Keep the water out of those connectors.


RE: Electrical Tape Tips by KFF  
by W0FM on April 11, 2003 Mail this to a friend!
Nice article and great advice, George. Glad there's someone willing to to tackle the "sticky" subjects.

73 de Terry, WFM
RE: Electrical Tape Tips by KFF  
by WA9SVD on April 11, 2003 Mail this to a friend!
Good article, but one comment (from a friend formerly in the Army...)

When wrapping with tape, such as a barrel connector and two coax connectors, start at the MIDDLE of the connection, wrap the tape in one direction (with a generous overlap) using moderate tension, until about 4-6 inches past the connector. Then reverse direction, again with tension until 4-6 inches past the OTHER connector. Then reverse direction, again under tension, until you are back at the center, and then a couple of turns without tension so the tape doesn't start to unwind over time. This gives you two layers of tape for extra protection, and no exposed "start or stop" points that can leave tiny gaps for moisture entry. I (personally) also use a blact tie wrap on the exposed end to keep it from unwrapping.
The method works for me, but your mileage (or opinion) may vary. Good luck to all.
Electrical Tape Tips by KFF  
by KD5ING on April 11, 2003 Mail this to a friend!
This is great stuff. Just the kind of "elmering" us new kids need! Thanks for the great article!
Electrical Tape Tips by KFF  
by W3DCG on April 11, 2003 Mail this to a friend!
Thank you! Exactly the question on my mind lately... I have the beads on my RF choke "Balun" all placed (did that last night) and am now contemplating the splice I'll have to make which will also be located inside my 1" PVC end-capped housing. I feel like this article was written for me! Thanks again.

RE: Electrical Tape Tips by KFF  
by WB2WIK on April 11, 2003 Mail this to a friend!
Nice article!

It would be good to point out, however, that stretching vinyl tape like Scotch 33+ (or similar) while wrapping *coaxial cable* can be a very bad idea, especially if one is taping the cable to something hard and unyielding like an antenna boom, antenna mast or tower leg.

Reason: Coaxial cable, or most of the cables we hams use, is soft and not rated for any compression strength at all. Stretching vinyl tape while wrapping, especially when making overlapping layers of such stretched tape, can place hundreds of pounds per square inch of compression pressure on the cable -- not good. May be alright for hardline, Heliax(TM), and some very strong cables such as RG217/U, RG17/U, RG18/U, etc -- but a very poor idea for "RG8" type cables, including all of the cellular poly dielectric ("foam"). You can almost squash them flat with compression, changing their characteristic impedance at the taping point, and in many cases causing permanent, irreparable damage to the cable.

Nearly every time I've seen "RG8" cables fail during higher power operation, the failure has been a dielectric breakdown (causing a short circuit between center and outer cable conductors) occuring precisely at a "taping" point.

Electrical Tape Tips by KFF  
by NA2A on April 11, 2003 Mail this to a friend!
One other hint--when finishing the wrap leave short length not taped to cable. Fold small portion back against itself to form a tab for gripping to ease unwinding tape.
RE: Electrical Tape Tips by KFF  
by KE4SKY on April 11, 2003 Mail this to a friend!
All great stuff! Thanks everyone.

I've gotten into the habit of painting a layer of West Marine "Liquid Electrical Tape" over over the vinyl tape to keep it from unravelling in the wind. It also discourges birds and squirrels from fooling with the loose end, by preventing it from coming loose in the first place!

I also use the tape as additional UV protection over cable ties on towers, as even the black ones become brittle with time, and a tape UV protective layer layer liberally sealed on the end with Liquid Electrical Tape will withstand direct run, wind and rain for years.
Electrical Tape Tips by KFF  
by W8OB on April 11, 2003 Mail this to a friend!
Don't forget a couple of simple suggestions from one who uses miles of 33+ and 88+. When you have a tight spot to tape guessimate the amount of tape needed, roll out the length cut it with a sharp knife and roll it back onto itself (sticky side up) the you can wrap around the tight spot and unwind the tape just like a ace bandage. Never stretch and pull the tape to break it free from the roll, use a sharp knife this prevents flagging of the tape. If you live in a cold climate look at using 88+. For taping coaxial connectors I always finish the job with a coating of scotchkote over the tape. Through the years I have learned never to splice coaxial cables outdoors with a barrel connector, it has gotten so cold up here that at times believe it or not the barrel will contract enough to loose contact with the center of the pl-259 plugs. I use proper coax splicing without fittings and have yet to notice any changes in VSWR on the antennas. Of course these jobs are always finished with good old scotch brand electrical tape.
Electrical Tape Tips by KFF  
by KZ9G on April 11, 2003 Mail this to a friend!
Nice Article.

It's great that you mentioned using Scotch 70 self-fusing rubber tape for the first, weatherproofing layer. I've been using Scotch 70 for a few years - it works wonderfully and is removed easily (splits) when a knife's edge is run along the taped joint. Skip the other gooey methods and go the Scotch 70 route. I also liked WB2WIK's comment on reducing the wrap compression when using electrical tape to affix cable to tower legs, etc. We should all treat our flexible RF cables with care - especially if high power is employed. 73 - Steve, KZ9G
Electrical Tape Tips by KFF  
by K5MAR on April 12, 2003 Mail this to a friend!
"Any time you wrap tape on a threaded component, make sure you wrap it in the direction that tends to tighten the screw threads, not the other way. That means if you are taping a splice, for example two PL-259's screwed into a double barrel female (PL-258/83-1J) you must tape each connector from the cable end to the barrel center."

Sorry, but this is just short of clear (to me, at least). It seem to me that the important factor in the above is the direction you are taping in, clockwise or counterclockwise, not the procedure of taping from smaller to larger. So, looking down on a PL-259 connected to an SO-239 on an antenna, do you tape in a clockwise or counterclockwise direction? I would say clockwise, but can think of arguments for either direction.

Other than that, thanks for the tips!

Mark Schneider

Electrical Tape Tips by KFF  
by KG4WBH on April 14, 2003 Mail this to a friend!
Hello everyone,
Had to put my 2 cents in......
I have been doing industrial electrical for around 15 years now and I have used a lot of electrical tape over the years. The comments about the rubber tape are good, I just wanted to add one thing to them. To get the "gooey" tape loose when you need it off, just wrap the connection with the vinyl tape sticky side out just tight enough to keep it from slipping, then put the rubber to it. This makes removal of the rubber tape later a simple matter (since you have to cut it off anyway, just be careful and dont cut your coax.). Also, I think clockwise would be the direction of travel on the connector....:)

RE: Electrical Tape Tips by KFF  
by W9DZ on April 15, 2003 Mail this to a friend!
WB2WIK made a very good point. Too much wrap pressure will distort the 9913 type cables causing an impedance bump. I think this was mentioned in QST (Hints 'N Kinks?) many years ago.
RE: Electrical Tape Tips by KFF  
by AC6DN on April 16, 2003 Mail this to a friend!
If u only hand tighten pl-259's (and other rf connectors), then with temperature changes, they can come loose. I recommend that, they be tightened with pliers. Dont over tighten, though
Electrical Tape Tips by KFF  
by WZ8S on April 16, 2003 Mail this to a friend!
RE: Electrical Tape Tips by KFF  
by N5REL on April 20, 2003 Mail this to a friend!
Scotchwrap 50 is an excellent all-weather tape/wrap which I would recommend layering over a tape-job using 33 or 88. Especially in those critical on the connector of the repeater antenna's pigtail 300' off the ground!

50 is wider (2") than 33 or 88 (which is typically 3/4" wide). The extra width makes it better for moisture resistance due to the capillary effect.

50 goes for about $14 a roll. 33 / 88 is about $4. (I work for an electrical supply company - - a 3M distributor)

Nathan N5REL
Electrical Tape Tips by KFF  
by KC0LPV on November 25, 2003 Mail this to a friend!
Good article, and good guidelines!

While I recognize that tearing tape is not the preferred method, it is sometimes handy (particularly in quick-repair or emergency situations) to be able to tear lengths of electrical tape while one of your hands is occupied.

I take a regular razor blade and make four incisions in the side of a roll of tape, a millimeter or two deep. This makes regular 'nicks' in the tape at about 2-3" lengths. Just unrolling the tape or wrapping a cable, the nics are unnoticeable. But when you go to tear off a piece, you just find a nick with your fingers, and tear there. It isn't perfect, but it's a much cleaner 'cut line' than just pulling the tape until it breaks.

Jim kc0lpv
Electrical Tape Tips by KFF  
by N0RTU on December 31, 2003 Mail this to a friend!
Greetings all!
There are some great tips posted here regarding the use of electrical tape.
However, lets don't forget that in a pinch, this same tape can be used for many things.
As an electrical power lineman, I've seen " tape" used for many things.
1. Have you ever had a radiator hose bulge or split, leaving you stranded along the road?
Allow the offending vehicle to cool and wrap the split hose profusely with 33+ and refill that radiator with water from a nearby pond or creek. You are back on the road. I've had this repair last up to 50 miles. Enough for most of us to get to help.
(Flush your cooling system completely after this trick as pond water may not be the best for your aluminum radiator!)

2. Scotch brand 33+ makes a dandy "rope" or tie down strap in a pinch. I've hauled a 2in. X 12 ft. aluminum pipe (for my gin pole) on the luggage rack of my mini van more than 1 time by liberally taping said pipe to the rack. You don't think this is wise?
Try taping something on in this manner and use at least half to three quarters of a roll. You'll tear the luggage rack off of the roof before you will pull the pipe loose from the tape! (I'm not advising that tape be substituted for rope or tie down straps on a regular basis here. Only when the appropriate tie downs are not available and a bargain that is too good to let go by appears!)

3. In an emergency, tape can be used to hold a splint in place on a broken arm or leg. (make sure you don't wrap said arm or leg too tightly or you will cut off circulation and create a larger problem than the broken arm was to start with!)

4. Although some will cringe at this.......I've used tape as a makeshift "bandaid" on bad cuts until I could get to a first aid kit or other medical help.

There are several other uses for electrical tape. However, I'm sure the moderators of this forum would not appreciate me posting those here at this time. Suffice it to say, Linemen can be quite entertaining and inventive when it comes to the use of "33".(Let your imagination run wild here.....)

73 to all
Electrical Tape Tips by KFF  
by NEVTXJUSTIN on March 31, 2005 Mail this to a friend!
All of your tips are very good, however I noticed the desire to have a "re-enterable" tape job which would be desirable for ham operators, but commercial applications will usually call for a "permanent" seal.

When I was part of a cellular companys GSM rollout, I had to re-enter over 300 connectors in a 2 month period and reseal them. I did a "courtesy wrap" of Scotch 33 or equivalent as the first layer to prevent the self-fusing mastic (self-fusing is more appropriate than "self-vulcanizing" as no heat is involved for true vulcanization of the rubber) from pretty much permanently adhering to the coax connectors. This was followed with a mastic build up to resemble the side view of a football. Next was a layer of 2 in. wide tape to compress and form the mastic down tight. The final wrap was of Scotch 33 for waterproofing.

The coax runs were tagged with strips of colored tape which appeared to have held up for several years, especially if the last inch of the tape was cut and applied with minimal stretching.

Having been doing tape jobs for over 30 years on communications towers, I can say that Scotch Kote only lasts a year or so before sunlight decomposes it. As for the Liquid Tape, I dont know; but so far after 3 years it appears to be like new.

As for the weather and sunlight resistance of black wire tiesthey will eventually fail after several years, but still much longer than one Texas summer of the white nylon type.

As for emergency medical usesOh yeah! I nipped the ends of fingers almost completely off several times. Black tape and a paper tower not even a scar five years later.

Electrical Tape Tips by KFF  
by K1CRA on July 23, 2005 Mail this to a friend!
Great article but I (with motive) remain mystified as to why so many remain committed to electrical tape (or coax-seal or silicone)to waterproof connectors. Performex brand liquid electrical tape and Plasti Dip are much easier alternatives and create a far better seal. It also removes more easily. Think of it as liquid heat shrink tubing that you don't have to remember to put on before you assemble a cable! Liquid Electrical Tape 9and Plasti Dip) applies by brushing it on. It dries fast and actually forms to every feature of the cable and connector by shrinking as it dries and preventing any possible water infiltration. It waterproofs so well cables can be run underground or underwater. Plus, it is far more flexible than tape and adds strength to the joint. When ready to remove, just score it with it sharp blade and it peels off, usually in one piece. And, as an added bonus... it cleans the connector when it comes off too! I know, old ways are hard to change but, change is good! 73! Craig - K1CRA
RE: Electrical Tape Tips by KFF  
by KB9WIS on June 27, 2007 Mail this to a friend!
Let me ask this, which tape is the "stickiest" or have the best adhesive properties, yet has great exteme temperature and weather resistant properties?

I want to bond fiberglass mast sections of a fiberglass mast (such as a windsock. lightweight fishing pole mast or spiderbeam mast), without making the bond entirely permanent and/or adding any metal like clamps to the structure. Want to keep the mast non conductive and don't want any metal interacting with the metal. Something that won't allow the sections to come crassing down on one another.

I would like to use a great tape for this, versus permanently bonding them together with a glue.. Was using electrical tape, but hot summer days tends to cause the tape to start to slip.., which changes the physical and electrial lengths of the wire vertical attached to it..

Any experiences with this,

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