A reader wrote in, bringing “waterproof heat shrink wire connectors” to my attention. Thank you Fred C.!
First, I’d like to remind everyone about our post about scam retailers: Scam or Not? Tips for Assessing Unfamiliar Online Tool Stores. The online retailer that Fred linked had raised immediate red flags, and a closer look deepened my suspicions.
Now about these connectors – they’re available on Amazon from a whole lot of brands (and at lower pricing than the retailer Fred C. had linked to).
Have a beach house. These look pretty functional for an outdoor /marine environment.
The image above comes from a Haisstronica listing on Amazon for a 120pc set of connectors.
Basically, these connectors are precut lengths of special heat shrink with what looks to be a low-temp solder at the middle.
You slide on the heat shrink, mesh stranded wires together, center the butt connector over the splice, and use a heat gun to shrink the tubing and melt the solder. There’s a hot-melt-glue-like adhesive that helps hold and seal things together.
In my opinion, I’d stick to established brands, such as 3M, and traditional connector methods. Some connectors are easy to use, and can be activated with pliers. There are also of course crimp connectors.
But, at least one brand that I’ve used in the past – TE Connectivity – makes something similar. They have SolderSleeve and also SolderGrip end connectors. If this was a product I wanted to try, I’d likely seek out the TE-branded products. Or, there might be other established names that make something similar.
What’s your take on these electrical connectors? Have you used them before? Would you trust them?
Used them and love them. I wired my whole boat with these. Heat gun is necessary. Torch or lighter flame is too focused of a heat source. My problem with the heat shrink crimp connectors is that my old crimpers always penetrate the insulation where I make the crimp meaning I have to use a second layer of marine heat shrink over top of the crimped connector. My only complaint with these is it helps to have three hands to heat them up. You need to hold the connection for a few seconds to let the solder cool and solidify. Rigging up a holder for your heat gun helps to free up your two hands.
The ones I used recommended pinching the solder with pliers to hold it all together while you heat it up.
You are probably using a crimper for non-insulated terminals to crimp insulated terminals. Insulated terminal crimpers will have more of a curved shape while non-insulated terminal crimpers will have a bump like a curvy M shape.
if you look at this klein plier, you can see “INS” and “NON” markings by the shapes.
This is what I’m working with.
My dad has the Kliens you linked and I still break through the soft insulation on heat shrink crimp connectors. Normal plastic crimp connectors are fine but I’m doing marine wiring and I want water tight seals.
I have used these many times for automotive use and they work great. Being a skeptic I still put a piece of black heatshrink over it.
Not sure about the waterproofing qualities, but I have used these for audio connections in car stereos & speakers and they work great for small gauge wire splices (14-18 gauge or so). Needs a VERY hot heat gun for the solder to setup though, mine didn’t get a good melt until about 700-800 farenheit, going by the “max” temperature of the heat gun. Also doubtful on the waterproof qualities, but the solder joint is legit and has a good, strong connection.
There are high grade versions of these from raychem and TE under M83519 spec that are used frequently for military and aerospace products. They are very robust when used correctly. I cannot speak to cheaper ones available from other sources though. Your mileage may vary.
I rarely solder for automotive connectors. There is too much vibration and the solder can fatigue. I wouldn’t trust a solder that melts with a heatgun either. I’ve had spotty results just getting the solder to melt without roasting the heatshrink. A good crimp with an adhesive heat shrink is significantly faster, more reliable, and easier. It’s much easier to carry a cheap stripper/crimper than a 1500+ watt heat gun.
I haven’t used the name brand ones. But I tried some of the cheap ones and it was hit or miss if the heat shrink would start to melt/burn before the solder melted.
Try these instead. Premium without the premium pricing
These are a pain to assemble but they’re amazingly well engineered. I first utilized them to splice 14 gage hanging commercial string lights. We needed to keep the lamp spacing equal throughout a 200+’ run.
And these work just great.
Originally I believe I sourced them through HD and they were made in the USA. I dunno about these but the rating matches.
I for no good reason added black shrink wrap over a few that were visibly hidden but in hindsight it was just to play with a Milwaukee M18 heat gun. No rational need.
IP68 Waterproof External Electrical Junction Box, ELifeApply 2 way 3 Pin Wire Conn… https://www.amazon.com/dp/B07DL2N233/ref=cm_sw_r_sms_c_api_i_vSNPDb6RYVBYP
We have been using a variety of these forever in aviation. They are called Environmental Splices. They work well, in the appropriate circumstances.
I just saw these a few days ago, but the one who was using them was using a bit of solder first and then using these.
I’ve used them for extra low voltage and signal conductors for quite a few years now. They are particularly useful when you need to make a repair with limited spare length of conductors.
Initially I used full price items from a wholesaler, but bought a large mixed box of them from AliExpress for a personal project. The cheap ones were identical in appearance and, as far as I can tell, performance.
Haven’t had a failure yet after about 500 or so connections. I wouldn’t use them on mains voltage or in high tensile situations though, but have had zero issues in some vibrating situations: a repair in a DeWalt multitool has stood up really well to over a year of use.
If soldering is unavailable, old fashioned crimped insulated butt connectors followed by heat shrink tubing (if needed) for me.
I prefer the Ancor Marine heat shrink crimps. https://www.ancorproducts.com/en/products/terminals
They’re not cheap and yes, you need a better than average crimp tool.
Coincidentally just received the Hasstronica set yesterday and used them to wire a light bar on my tractor. Having never used them before I love them so far. The only trick was holding them in place, but I used a bench vise for that.
I bought the same kit. I’m having trouble keeping the shrink from burning/melting before the solder melts? Any thoughts on this for me? I’ll readily admit it might be user error on my part. Jason Tampa
They are keeping the splices to my well pump together and water tight almost two years now. They work. I did go over them quick with some liquid electrical tape just incase. You have to pay attention to how you heat it.
I get some from McMaster sometimes. Depends on where I need to fix the wire, in a cable trough, or an already wet environment (food plant).
These you crimp AND solder
I’ve used a pile of them in various applications and they work like a champ. My dad used to fight connection corrosion from the salt water on his boat trailer. Yearly rewire almost. I reworked his trailer with solder/seal connectors right at 3 years ago and haven’t had an issue since.
In my days of telecom installation work, we had these for “emergency” repairs, and only used one once – in one of many 22g multi-conductor cables, ringing the sheath nicked a wire that broke. It that case, there’s little room, no decent slack to pull, and you don’t want to disrupt the neat parallel runs of cables (and call attention to the repair); so it was a perfect solution.
In my even earlier days of working aerial CATV, I was frequently astonished at what salt air could do to aluminum (the shield in the coax, both solid in trunk lines and braided in drop lines). And we used a high-quality, glue-lined heavy heat shrink boots on the line connections – but all it took was one little nick in the jacket somewhere and you’d be back replacing that chunk. (One still-functioning buried 1″ coax line next to the Intracoastal was swollen up to about 3″ diameter with no observable metal left, due to a nick and lots of salty water.)
So, even with elaborate protection in a marine sort of environment, I’d expect problems eventually. These things, by themselves, would be nothing more than temporary.
I also first learned about solder sleeves in telecom! The guys back then told me they were SUPER expensive, but I’ve never been able to find anyone charging the price I was quoted. I think it was a tactic to make sure we didn’t think of cable damage as “no big deal”.
I’ve used the non-waterproof version quite a bit, and I love them. The waterproof version seems pretty straightforward, like any other glue-lined shrink tube.
It’s a special low-temperature solder alloy to be able to melt before the tubing scorches, but it pays to go real slow and have patience — the tubing isn’t a great heat conductor, so once you’re at the right temperature, it still takes many seconds to overcome the thermal mass of the copper and actually make the joint. Once you’ve achieved the right state of zen patience, they’re a dream to use.
We’ve used these (from wirefy or sopoby on Amazon, which are just generic rebrands, but the stores have given us good service when there’ve been issues, which is not often and was always cases broken in shipping and thus missing pieces rather than bad connector batches) on high school competition robots that get banged around, and like them a lot. The students seem to be able to make better connections with them, whereas even with heat shrink butt splices (and I have the correct insulated terminal crimpers) they’ll get wires that disconnect. Fortunately we don’t really use butt splices on anything critical, more like light effects or auxiliary sensors or similar, but I would be much less hesitant to use these type on critical paths, if we didn’t use Anderson connectors for ease of part replacement.
I’ve also been using these more at home, for the singular reason that the cats seem less prone to chewing these up than regular butt splices on exposed wires. I have speaker wire one decided to chew one day, and put a regular butt splice on, and he chewed through that the next day. Put this on, it looks like he may have bitten it once, then left it alone.
One application I think these work better than butt splices particularly is joining solid wire conductors, or one solid one stranded, particularly when they are different sizes. I fixed a buddy’s boat where bait well pumps would stop working because of pulling out of non-heat-shrink butt splices with these and it’s held up for years, and stopped the corrosion the regular butt splices were getting. That boat has issues though, they treated everything above the deck or in a compartment as if it couldn’t possibly get wet/salty and cut a lot of corners, so it wouldn’t surprise me that they just crimped their connections equally poorly. I also used these on my car stereo, where the car wiring was thin gauge solid core, and the head unit was stranded and thicker enough I had to use blue butt splices. The car wire came out of the splice after a year or so, or loosened up and caused poor connections. Replaced with these, and it’s been fine for several years since.
Any electrical connection with out a proper mechanical connection (westinghouse connection, twisted connection) is not safe or recommended between two wires.
so just by lapping or pushing the strands together then solder is a connection waiting to fail.
I love these waterproof heatshrink connectors. I used them exclusively to wire my lightbar on my truck and it came out great. The splices still look clean and new a year later with no sign of deterioration. As others have said, definitely invest in a heat gun because I used a lighter and it is not optimal.
Having soldered automotive stranded wire for 30 years, I don’t see how these are anything other than a gimmick.
To properly join two stranded 16awg conductors with solder, you must:
1. Mechanically join the two connections (twist them together)
2. heat the wire to a temperature that will allow the solder to flow
3. flow solder into the joint.
Anyone ever sweated a pipe? you know what I mean – the wire sucks or wicks the solder into the joint once it reaches temp.
I can not see how you can heat the wires to a temperature that allows solder to flow without burning everything in a 12″ radius, including the wire.
More likely this creates a very cold solder joint that is relying on the sealant in the heat-shrink for a mechanical connection.
Avoid this product for anything you care about
I use them on my boat all the time. They’re the first connection I’ve used that really seems to be water proof. I’ve a 1 that I found submerged in my bilge that was still good. And although a heat gun is clearly the best way to go, I’ve used a torch in a pinch.
You need a third hand, then twist the joint, and use heatgun with the “wraparound attachment”….it directs the heat evenly around the tubing. They work well, if it’s a concern then just solder the joint and use the heat shrink tubing with the waterproof internal adhesive…..probably cheaper.
I’ve used them on my well and they worked great!
Fwiw, here is what NASA has to say about wire splicing…
Thanks for that link, I learned a lot from it.
Gonna have to confirm that with doresoom!
These are something very similar to these are used on deepwater submersible well pump’s with great success.
I find that the goop filled connectors are the best way to go. Heat shrink can and does fail, but I have dug up old atandt splices and never found a corroded connection on those types. Depends on the application I suppose, but for water resistance over time…
I’ve used the traditional approach which is to use standard butt splices with adhesive lined heat shrink tubing, the 3:1 shrinking kind, to repair 4 conductor #6 cable that was used to feed 480 V power to a dredge for the bilge pumps when it wasn’t in use. This is in SOOW cord (extra hard usage cord). These splices were stronger than the original cable and worked well underwater indefinitely when they fell off the floats and laid underwater. To do this you first slide a big heat shrink tube over the whole thing (loose) and 4 smaller ones over each of the smaller cables. I carefully cut each of the smaller cables so that none of the splices overlapped (staggered) and also left the ground a little longer than the power conductors (lose power first if it gets pulled apart). Then butt splice every conductor together, then slide the little tubes over the cables and shrink them down, followed by the big tube. This is on the water so forget heat gun, I used a MAPP or propane torch.
Would not use ANYTHING soldered these days except on a circuit board. If nobody noticed in the last 50 years solder has all but disappeared out of connections of everything except circuit boards for a reason. Solder is basically metal glue. It holds things in place solidly and thats the problem with a splice. Scratch that…it is more like metal filler, not even glue. It also wicks up inside wiring and stiffens it so that it becomes brittle and easier to break. Since it is made of metals other than copper it expands/contracts at a different rate too. After years of research by the automotive companies they got rid of soldered connectors for that reason…they don’t hold up as well. Today you can still buy soldered butt splices but they are less reliable. Solder is good as long as the two parts that it holds together are solid and never intended to move, as in gluing parts onto circuit boards. Not for connectors on cables. You hardly even see cables soldered in anymore even to circuit boards…they almost always use some kind of terminal or connector for the same reason. So I would avoid the soldered ones.
This is with the bare butt splices which are kind of all you can get on the larger sizes so you need to supply your own heat shrink tubing, which you can often find at Home Depot among other places. It’s a little more rare but you can also buy butt splices that have the adhesive lined heat shrink tubing built in for smaller sizes. So with say #14 you can just butt splice and hit it with some heat. I’ve even used a BIC lighter or a match to shrink them. Get the adhesive lined kind regardless. Heat shrink by itself isn’t quite totally waterproof.
Only heat source I do not recommend is an oxy-acetylene torch. I tried using it ONE time because it was a 40 MPH gale with breakers crashing over me and freezing my insulated stuff, my hands, everything. I couldn’t keep the propane torch lit. The problem with the oxy-acetylene torch is it’s just too much heat. Even aiming from a long distance away I either shrank it way too much way too fast on just one side so hard to get it even or burned it badly. Hard to control it with such a concentrated heat source.
Also I work in a motor shop and motor connections are positively the worst environment for electrical connections. We use strictly crimped connections for a reason. Mechanical lugs have a tendency to squish and squeeze the wiring in a way where the pressure on the cable is not very even with most of them, and the pressure is not very much. Set screws don’t get it done compared to what you can get with lugs that are crimped on making virtually a solid cold welded joint, and then bolting the terminals together with grade 8 bolts washers, and nuts, followed by covering the whole thing in 2 layers of Scotch 88 backwrapped for easy removal in the future, 2 layers of Scotch 130C rubber tape (waterproofing and insulation), and another 2 layers of Scotch 88 for weather protection. Stretch the first of the outer 88 layer to about half it’s width then overlap by half, then do the last outer layer without much stretch. The stretched tape will pull back onto itself keeping everything tightly bound together and sealed.
This is the tried and true method for literally years. I’ve used the same method on not just house wiring but up to 7200 Volt motors without any problems at all for decades. This is without butt splices.
See the following:
One difference of opinion…currently Scotch 88 tape usually costs either the same or a little less than Super 33+ so it’s actually the better buy even though it is intended as an improved version of 33+. So it’s not the most expensive.
Second is that 3M recommends varnished cambric as the first layer. It works and the one big advantage is that it does hold up slightly better to sharp edges compared to 88 or 33+. But it doesn’t stick very well, there is no stretch at all so hard to get an even layer, and it is very expensive and not very common unless you mail order it. I’m not a fan. I carry it on the truck but only for customers that demand it. Backwrapped 88 does the exact same thing (keep the 130C from gluing itself to the connectors and protecting the 130C from damage).
I’ve also used linerless self amalgamating (self vulcanizing) silicone tape aka F4 tape. It works great. It goes on easy…again pull it to half width then do half wraps. It comes off fantastic…the moment you touch it with a knife, it splits wide open. That’s also the huge disadvantage…even the tiniest sharp edge will instantly zip this stuff open. It has too much of a tendency to split open for any reason. But if you can accept that, it is a good alternative to 130C.
I realize taping isn’t butt splices, heat shrink tubing, etc., but it is a lot more flexible and universal. For instance even though I know they make multiple barrel splices, these are pretty goofy and rare. But you can stack up to about 8 butt splices on top of each other (90 degree angles, 4 one way, 4 the other) and then tape the whole thing. And if you’ve done it as many times as I have you can do tape terminations in minutes.
I love them, I’m in the heavy civil infrastructure part of the mining industry. So when I say I put material and tools through trials, I mean it. These hold up well underground. We use them on our tunnel boring machines now. I’m quite proud of myself for finding them. One of the most clever things I’ve brought to the table.