Can I re-patent corrugated garden edging if it were to be used for another purpose?
Yes, in principle, with some caveats.
Claims of this nature must satisfy the same requirements as any other claims. Notably they must be novel and non-obvious. There are two approaches you could use depending on the nature of your invention: a method of use claim, and a new product claim.
A method for using corrugated garden edging in flood protection may be allowable, assuming corrugated garden edging has not been used in this way before. However, you would need to satisfy an examiner that this use is not simply an obvious thing to do.
Alternatively, if you are adapting the edging in some way to make it particularly useful for water routing, this may well result in a novel product. Again, you would need to satisfy an examiner that this new product is not an obvious modification of known products.
The cost is impossible to answer, since it depends on what countries you are interesting in and what attorneys you are using. You would be lucky to get less than USD 5000 (including drafting) for your first country though.
How to get a patent is extremely broad. However, at the risk of losing all nuance, the process is generally:
- draft an application;
- file an application in one or more countries; and
- prosecute each application until it is hopefully granted.