Protecting outdoor bolts

Get some stainless fasteners (Screwfix etc) and fix it permanently - will work out cheaper than faffing around cleaning and trying to protect the existing.

I'd normally agree, but the OP says he has barrel bolts and inset nuts, are they available in stainless?

Yeah exactly. I couldn't find any stainless steel ones. These will all be internal hence the question. Externally I have done nuts which are stainless steel.

For the threads use engine oil. For the external metal, paint. (Oil also works somewhat if you don't mind a rustic look & greasy finish.)

NT

Nickel or bronze anti seize all over the thread

I have used wax for this, where a full de-rust and proper paintjob were overkill. Either melt a pot of candle wax and dip, or scrape a candle over the metal and heat with a propane blowtorch until it melts and spreads.

It leaves a waxy finish (no surprise), lubricates a bit, generally sticks much better to previously rusty or rusty surfaces, is cheap, and requires no particular surface prep. It probably interferes with a future paint finish...

Oh: Do not drip wax on paving. Do not grab hot bolt with naked hand.

Thomas Prufer

get galvanised hardware. Use Stainless hardware Lastly if you paint them it will come off when the nuts tighten and eventually rust. I am thinking about what we use to fit tv aerials, badly plated hardware corrodes very fast and eventually falls to bits as effectively there is no thread, just the rust holding stuff together.

Brian

Get some stainless steel nuts and bolts! :-)

They are surprisingly cheap now if you shop around (e.g. suppliers on eBay)

About the only thing that will keep rust at bay for a long time on steel is galvanising. You can buy kits to DIY this - but you could have problems with threads etc.

I'd replace all you can with stainless and get the rest in ordinary and paint it.

I've got a cheap "stainless steel" Ebay gate stay that has quite a lot of surface rust after a year outside. It actually looked like SS when new. No metallurgical tests performed, maybe it is some kind of SS?

Boiled linseed oil? I use it on everthing wooden now, but since it dries to a sort of soft plastic, I use it instead of Loctite, too. I don't think it likes sunlight, but I think it'll be okay in a thread.

If I have a pair of shoes which are starting to get a bit scuffed and faded, I paint them with BLO. I know it sounds odd (and the missus certainly thinks is is :-)), but when it's sunk in and dried, it works really well. Restores the colour, and leaves them shiny and waterproof once more.

It happens if the alloy levels are too low; although unsightly, it should still last much longer than mild steel. Abrade periodically with steel wool and a bit of 3 in 1. (Or wet and dry plus oil, if the geometry is more favourable for that).

You can get surface rust on low grade SS - but it should take a long time to get really bad, unlike MS.

I only got stainless because I find such maintenance too boring! (I think I'm beginning to sound like Hucker - another visit from the troll fairy seems imminent.)

I think my computer has invisible letters in it because everything I type is ignored so must be invisible,It must be because it originates in Australia and can not be read in the UK :)Other than stainless or galvanized bolts and even with, my suggestion of nickel or bronze anti seize is probably one of the best solutions.

Thanks. I think I shall describe it as a patina.

Not sure I'd want any grease on a garden seat, though. A decent thread sealer which sets hard would prevent it seizing, though, and not get onto clothes. But you've still got the problem of the bits on show looking rusty.