Incidentally, I've been looking up various drying oils that should perform in the same way:
Heavy boiled linseed oil is the cheapest and most common (any DIY shop), but it is also the yellowest
Light linseed oil (from a specialist woodworking shop) is what I'm using when I've polished the frame - it doesn't appear yellow, but I've only put two thin coats on.
Walnut oil and poppyseed oil can be found on ebay in small bottles (used to loosen oil-based paints and oil gun stocks) and apparently don't have any yellow tint at all, but I haven't used them and can't vouch for how effective they are at preventing rust.
Incidentally, I've been looking up various drying oils that should perform in the same way:
Heavy boiled linseed oil is the cheapest and most common (any DIY shop), but it is also the yellowest
Light linseed oil (from a specialist woodworking shop) is what I'm using when I've polished the frame - it doesn't appear yellow, but I've only put two thin coats on.
Walnut oil and poppyseed oil can be found on ebay in small bottles (used to loosen oil-based paints and oil gun stocks) and apparently don't have any yellow tint at all, but I haven't used them and can't vouch for how effective they are at preventing rust.