Tool Tests



Rislone Liquid Copper block seal and radiator stop leak  

By Adam Watkins
Since liquid cooling systems have been around so have dreaded cooling system leaks. I like many others have been stranded on the side of the road with steam coming out of the bonnet and the temperature gauge screaming turn the engine off! In most cases the radiator has finally given up or a cooling system hose thought that now was the best time to end its service life and no amount of magic stop leak in a bottle will put the coolant back in. Sometimes there is no chemical solution to a mechanical problem! Whilst not a big fan of adding magic stop leak to cooling systems, in modern engines there are some leaks that are much smaller and that magic in a bottle just might come in handy.
Rislone liquid copper block seal and radiator stop leak is one such product that uses some interesting science to seal up those small leaks that can be caused by machining imperfections, small gasket leaks and the like. It stops leaks by forming a physical plug with organic and synthetic fibres, copper and ionic modified minerals. The plug forms as the coolant and sealer flow out of the leak. A wetting agent cleans the sides of the hole or leak and prepares the surfaces for bonding. The first fibres catch the side of the leak of the hole eventually bridging the entire hole. The fibres now act as a sieve trapping more fibres, copper and minerals, creating a composite plug. This plug is stabilised or cemented with a liquid glass. The liquid glass hardens with increased temperature and completes the seal.
The problem with a lot of cooling system stop leak products is that they can cause cooling system blockages leading to hot spots and even engine damage. Rislone states that it can be left in the cooling system without causing such problems.
Like all stop leak products perspective is important. This product under laboratory test claims to seal holes approximately 0.635mm in diameter and a slot or crack of 0.127mm. So, the welsh plug that has rusted through or the radiator top hose mounting that has cracked will require replacement.
A stand out feature of this product is its compatibility with differing coolant types either Glycol based (green), silicate-based (blue) or extended life pink/red/orange (OAT/HOAT). This makes the product versatile with many makes and models with a one-step no draining required process.
Rislone offers a wide variety of cooling system stop leak products that suit specific leaks so make sure you select the correct one for the leak you are trying to fix. In can be an inexpensive solution and a permanent repair.
When used correctly Cooling system stop leaks can be quite an effective product however often they are asked to perform miracles that they were never intended for resulting in costly engine repairs. So, use wisely and remember magic has its limits.

For more information about Rislone products visit their website:

Send this to a friend