Flomasta External Leak Sealer 50g Product Code: 8487J

Single-part silicone leak sealer for all types of joints and fittings. Ideal for temporary repairs. Cures in 1 hour. Adheres to most wet or dry surfaces. Does not shrink and remains flexible, allowing seal to be undone.


  • 1 Year Guarantee
  • Ready to Use
  • Cures in 1 Hour
  • Resealable Tube


Operating termperature: -40° to 200°C.
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Safety Data Sheet
Additional Information
Technical Specification
  • Brand : Flomasta
  • Product Length : 40 mm
  • Product Type : External Leak Sealer
  • Volume : 50 g
  • Pack Size : 1
  • Manufacturer Guarantee : 1 Year Guarantee
  • Pieces in Pack/Case : 1
Product Contents
Delivery & Returns


Standard delivery service up to 3 working days: €8.95

Free delivery on all orders over €70.00

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Hopefully you won't need to return an item, however, if you do, it is our aim to make this as simple as possible. By following the guidance below you can help us to help you when a product is not what you expected, or is faulty. Your statutory rights are not affected by this guidance.


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€3.65 Incl. 23% VAT

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Flomasta External Leak Sealer 50g is rated 4.5 out of 5 by 24.
Rated 5 out of 5 by from Good Product Haven't used this before but it did the trick. Brilliant.
Date published: 2019-05-09
Rated 4 out of 5 by from Leak repair Good value. Works as sealant as advertised. Tried it to seal against seaping seal. Didn't hold against active seap.
Date published: 2019-04-15
Rated 4 out of 5 by from Stopped my leak I had a leak on a cold water pipe joint under my kitchen sink and using this sealer stopped it. Very pleased as plumbers are expensive and good ones have long waiting times.
Date published: 2019-02-17
Rated 5 out of 5 by from Does what it says Have used this on several sink waste pipes now. Really good at stopping horrible little leaks between seals and sink/pipe.I wouldn't attempt any diy plumbing without this in my tool bag now that I've used it.
Date published: 2019-01-25
Rated 5 out of 5 by from works well... Had a leak from a radiator bleed valve..took it off and applied PTFE tape but it was still weeping...removed and used the Flomasta sealer on the male thread and its now as dry as a bone...good stuff and cheaper than the others...
Date published: 2019-01-25
Rated 5 out of 5 by from Leak saver on Christmas Eve! I was replacing a radiator valve with a new tailpiece and just could not stop a leak around the tailpiece join with the radiator, no matter how much pipe sealing cord I used! Running out of options on Christmas Eve, I read some reviews on the Screwfix site and opted for the Flomasta silicone leak sealer instead of the more expensive Fernox LS-X. Using a smear of this and allowing the recommended time for it to work, sealed the leak and it hasn't leaked since!
Date published: 2018-12-24
Rated 5 out of 5 by from Superb leak fixer Bang on product. Easily fixed a quite inaccessible compression pipe joint
Date published: 2018-12-03
Rated 1 out of 5 by from Third time, still unlucky Tiny pinhole allowing fine spray to escape plastic hot water pipe in boiler. Tried 3 times so far, zero success. Just overpriced clear sealant.
Date published: 2018-12-02
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