There are a lot of variables to answer this question. What is the weather where you are? Is the swing set exposed to rain or moisture? Is it finished in some way?
Unprotected, not galvanized steel starts to rust in a matter or days or even hours, if it contacts water. Of course this will be light rust and your metal swing won’t be in danger that fast. But for an year it can rust pretty much. Here are few ways to project your metal swing from rust:
- Buy only swing sets made of galvanized steel .
- Paint it, coat it, or apply any other type of finish that will prevent corrosion.
- Cover the swing set when it rains. Fully cover it in the winter if you live in area where winter stops you from using the swing set. You can use simple PVC cover folio like the one that gardeners use for their greenhouses.
- Add a swing cushion so there is at least some protection from rain at any time.
You have to examine the key areas of your metal swing for rust set from time to time. If you notice rust, see whether repair is possible. If not, you’ll have to replace the swing as one with seriously rust construction can be dangerous.