"First time using this. Needed to get a seal on some older style radiators and was struggling with just PTFE tape. Smeared some of this sealer and left overnight. No problem with any of the rads. Perfect."
"Brilliant stuff. I use it on all non soldered copper joints and many plastic ones. It is excellent for sealing some difficult joints like flexible pipes on pond construction. Be careful to keep the cap and screw thread clean or the stuff will dry up quite quickly. A little expensive for what it is but is does the job extremely well and remains flexible. If you should need to break the joint open in the future the stuff peels off easily ready for another application before tightening the joint again."
"I've now been using LS-X across any number of plumbing applications for years and this compound - because contact with water helps it cure - has never let me down. If I want to be doubly sure that a foam ring or neoprene washer is properly seated and secure, I always add a ring of LS-X. You can't go wrong and you save yourself an awful lot of time and repacking seals."
"top quality leak sealer guarantees leak free joints and threads. Ideal for sink overflow wastes and radiator valve connections etc. Instant seal even on wet surfaces.I have used LS-X for years with 100% success. Good price at screwfix and always available."
"After having great fustration repeatedly trying to stop constant dripping from the pipework and thermosat connections on a bathroom towel rail i purchased this based on previous reviews. Drips are gone and no leaks what so ever, will never do anymore plumbing jobs without this."
"Fernox make great quality products and I've used a variety for over 32 years. Their LS-X sealant has been a godsend over the years and provided a leakproof seal throughout numerous plumbing jobs. The ability to coat some bandage and then wrap it around a leaking pipe (as per instructions) allowed me to delay one repair until a more convenient time and better access. Joints can be released quite easily and the sealant cleaned off with your fingernails and a rub of a cloth. Does what you need and want it to."
"If you've ever faffed about with compression joints that keep dripping no matter how much ptfe tape you use or how much you check washers and tighten, tighten, tighten... Then you need this stuff. Discovered it during last house refurb and use it now on EVERY plumbing joint - literally every time something with a thread needs connecting. Taps onto flexible hoses (smear a little around the thread), copper pipe compression joints (smear a little on the olive). Not had ONE leak. Always works to a drip free joint FIRST time. Magic. (I prefer to leave them to next day to test – just to be sure it's all gone off properly.) Dries to a firm rubbery compound that peels away so you can make things nice and clean (if they're on show) OR if you need to take something apart and do it again it's not stuck fast. Love it."
"I've been using this for years, for plumbing and heating installations. I have only used it as a "belt and braces" sealant on threaded and compression/union type plumbing fittings, and have not had a single joint leak since I started using it. On threaded joints (i.e: radiator/valve etc) I still use PTFE tape and then a smear of LS-X. On compression fittings I put a smear of LS-X around the olive before assembling the joint. If you need to disconnect the joints later then no problem, the cured LS-X just peels off, and you can reassemble again without problem. Brilliant stuff, any excess just wipes off with rag, leaves a clean joint. It can apparently be used to stop leaks without disassembling, but I have not tried this so cannot comment. Lasts a long time, but you must replace the cap immediately to stop it curing in the tube"
"I started using LS-X some years ago and can say that it gives me that feel-good-factor when using compression fittings - especially on older pipework. Gone are the days of wrapping PTFE tape round olives that are weeping!!! I use LS-X ALWAYS and I have never had a fitting even bead a drop of water AND it is safe for drinking water .. RESULT!!!"
"Fernox LS-X is a great product to have in your toolbox to fix leaks and seal water pipes etc. The instructions are good and the product is easy to use. I would recommend still using with PTFE tape to seal joints etc to give an instant fix but Im sure on its own given reasonable time to cure it can do the job"