Obstinate Flymo blade

I have bought a new 33cm metal blade for my Flymo hover mower,but the old one refuses to budge. Over the past couple of weeks I have tried to unsieze it with half a gallon of WD40,half a pint of automatic gearbox fluid (worth a try),and various other noxious fluids. The supplied plastic spanner is as much use as a chocolate tea pot. I've tried a club hammer with adjustables and stilsons,but it still won't move. I've checked that it is a standard thread - anticlockwise to undo - and I am smacking it the right way. I've searched the internet,apparently quite a common problem,but not found anything positive. Obviously can't apply heat as the bolt and spacers are plastic (how stupid's that then?).
Has anyone else had this problem and how did you overcome it please.

 

Probably my own fault for not attempting to change the blade before now. It's the original blade and has been on there for around 5/6 years.

 

Tried this a few years ago helping a friend ended up busting the mower before we got the thing off

 

Have you tried tightening it? (only a smidge, but it moves the bolt) the other thing only use a ring spanner or preferably a socket. (as in socket set)

Sorry if you have tried the afore mentioned, but you did ask

 

take it to your nearest lawnmower clinic .... they will charge you a tenner to remove the blade and fit a new one .... if they are good, they won't even charge you, as it takes minutes to sort ... they have the tools and know how

if they cannot remove it, it will cost you nothing ....

 

do what watergarden says, tighten it first if you can (use a wrench or a socket) and give it a whack with a hammer on the top of the nut. if your using a wrench or socket, add a wheel brace on the end for more leverage, it should come free quite easily.

if that fails, take it to your local garage and get them to remove it with their pneumatic impact wrench.

 

Try a kettle or two of boiling water poured slowly on the nut and bolt.

 

Is it maybe a left hander? just a thought........

 

If you can hold the blade still you can try a hammer and punch, we loosen loads of rusty studs and nuts this way at work.

 

I solved my problem by trying everything and reached the do or die point. The drive belt needed replacing and the blade had to come off first.
Nothing to lose. I attacked the plastic blade spacers, drilled and levered them off and the bolt loosened!
The spacers are cheap enough on the internet, so it's worth a go. Cheaper than a new mower...

 

If heat cant be used, try going the other way and using a freeze spray such as Freeze Off by CRC. Then an Impact Driver with the correct sized socket. If the head is not already destroyed by Stilsons and/or the adjustable spanner, that is.