Long term sill patching

[Norfolkandchance]

Hi,

My fun old has a small hole but car isn't worth enough to spend the money I would usually spend on having the hole in the sill repaired properly by cutting out and properly replacing the metal.

However, I do want to keep it for a while so I want a good patch. I realise this might be an oxymoron but the hole is very small, only in one place, and the rest of the car is very solid. I realise that the hole may grow one investigated though I'm fairly sure this is a small one.

My local garage will be doing the work but I want a repair that will last, not one that's just good enough to get it another year's MOT and then need more patching until one day I through the car away.

My previous experience is only the extreme - patch up banger (when I was young) to keep it going or properly repair classic (now I'm old). So I'm looking for a middle way.

What is the best way to make sure that this is a long term repair and prevent the rust from spreading? I'm worried, for example that they'll just seal a load of moisture in.

thanks