hi duzyeverwork - looked in my fridge there for you as I too boil condensed milk for the toffee. Alas there is no ring pull on mine so cannot give you helpful advice. Are you afraid the ringpull would blow off. If it was me I would take the chance and keep an eye on it. I am just after pulling off the ring pull on my dog's food and it seemed quite tight. Good luck
Another way to make the toffee, which is a lot quicker than boiling the can is like this.
Melt 25g of butter in a medium saucepan, add 50g of granulated sugar. Stir until the butter has melted and the sugar has dissolved. Add your tin of condensed milk, and stir over a medium heat for approx.10 - 14 minutes. Make sure you stir it well so it doesn't stick. Stir until the milk turns brown and thickens. Leave to cool.
legend 758 - I got there before you. Was exactly the same answer I gave. You thief.
Enought of the sh it =. For god's sake boil the cans in the simmering water for 3 hours - if the ring can blows - not the end of the world - just the price of about �2.00. Good luck to you. I have actually some boiled toffee an all - and if I knew your addresses I would sent them to you - because they last for 1-2 years in your fridge. (boiled of course) - Love you all