heeellloo nyck
i would say its very unlikly that mdf has taken it from reasonably sharp to blunt in a few days unless he is cutting hundreds of metres

in general its a boring time consuming job thats easy to get wrong
why bother when  you can buy a realy good quality freiud pro blade for about £30 dependant on size


oooo and another thought he hasnt put the blade in backwards has he!!!!

Assuming its a TCT blade these can be sharpened but its not something you can easily do yourself, depending on the number of teeth expect to pay £10-15. But as the others have said if its a cheapo blade to start with there won't be much carbide to regrind.

Jason

yep they will cut any wood perspex even the odd bit of aluminium without problem
http://www.toolstation.com/search.html?searchstr=74883

Yeah, I know, this thread's yonks old, but...

I used to throw away the cheap blades I used for cutting rubbish but then, about eight years ago had the sense to actually ask the firm that sharpens my expensive blades (eg, Makita @ £70) what they'd charge for sharpening the fifteen quid rubbish TCT blades - £6 for a 10" 24 tpi blade. Some of them have been resharpened five or six times and have probably had all their TCT inserts replaced over the years and, if anything, give a good cut if you're ripping, say, oak and will last a surprisingly reasonable time.