B725 Posted July 13, 2023 Report Share Posted July 13, 2023 I have a Mountfield petrol hedge cutter for about 15 years and it will cut upto stuff around 20mm thick. It's never been sharpened until about a month or so ago when someone offered to do it. I don't know why I agreed anyway it came back and you can see where its a a grinder over it. It doesn't hold its edge anymore so would I be better off removing the blade's heating them up and hardening them somehow or is it a lost cause. Quote Link to comment Share on other sites More sharing options...
old'un Posted July 13, 2023 Report Share Posted July 13, 2023 Grinding the blade should not soften it, unless he’s been heavy handed and blued/greyed the steel. Trying to re-harden is not an easy job, it will almost certainly warp and may-well crack. What face as he ground? Quote Link to comment Share on other sites More sharing options...
B725 Posted July 13, 2023 Author Report Share Posted July 13, 2023 He did top and bottom and the odd one has been cut back too far so the top or bottom tooth sticks past the opposing one, it's been done with a grinder so I assume it's gone blue. Quote Link to comment Share on other sites More sharing options...
old'un Posted July 13, 2023 Report Share Posted July 13, 2023 Got any pictures? Sounds like its been butchered, can you get replacement blades? Quote Link to comment Share on other sites More sharing options...
B725 Posted July 13, 2023 Author Report Share Posted July 13, 2023 Not much point in a picture as one tooth broke off so I had to make a new one and I then painted the whole blade, I do believe replacement blades are available, I just wanted to know if it was possible to harden them. Quote Link to comment Share on other sites More sharing options...
old'un Posted July 13, 2023 Report Share Posted July 13, 2023 Yes it is possible to re-harden them. Quote Link to comment Share on other sites More sharing options...
B725 Posted July 13, 2023 Author Report Share Posted July 13, 2023 What would be the best way? Quote Link to comment Share on other sites More sharing options...
old'un Posted July 13, 2023 Report Share Posted July 13, 2023 Deeping on the steel you will need to get the whole blade cherry red and then plunge into a bath of oil, then polish so the steel is bright and temper this to a straw/blue colour, like I said, it can be done, but unless you have experience of heat treating steel it will not be easy. good luck. Quote Link to comment Share on other sites More sharing options...
B725 Posted July 13, 2023 Author Report Share Posted July 13, 2023 Thank you Old' Un not really worth it and I would probably naff it up.I will price up some new blade's mind you I bet they are as dear as buying a new hedge cutter Quote Link to comment Share on other sites More sharing options...
old'un Posted July 14, 2023 Report Share Posted July 14, 2023 Home heat treatment is very doable with smaller pieces of steel but with something like a hedge trimmer blade it needs specialist heat treatment. Yep, bet they are not cheap, pity you could not find one where the engine as gone kaput and is being sold for spares or repair. Good luck. Quote Link to comment Share on other sites More sharing options...
snow white Posted July 14, 2023 Report Share Posted July 14, 2023 Just looked on internet you can buy blades the one I saw was just shy of £13.00 Quote Link to comment Share on other sites More sharing options...
Yellow Bear Posted July 14, 2023 Report Share Posted July 14, 2023 20 hours ago, B725 said: Thank you Old' Un not really worth it and I would probably naff it up.I will price up some new blade's mind you I bet they are as dear as buying a new hedge cutter About 45quid from Mountfield Quote Link to comment Share on other sites More sharing options...
old'un Posted July 14, 2023 Report Share Posted July 14, 2023 2 hours ago, Yellow Bear said: About 45quid from Mountfield Think that is £45 each blade? Quote Link to comment Share on other sites More sharing options...
B725 Posted July 15, 2023 Author Report Share Posted July 15, 2023 £45 each I did have a look just need to measure correctly the length. Quote Link to comment Share on other sites More sharing options...
Morkin Posted July 16, 2023 Report Share Posted July 16, 2023 Go to good gardening shop what sells flat chainsaw files of a good make, OREGON OR STIHL, and that's what I use and have been cutting hedges for work for a while, hope this helps , unless they are really bad👍 Quote Link to comment Share on other sites More sharing options...
strimmer_13 Posted July 16, 2023 Report Share Posted July 16, 2023 (edited) I've tried everything -especially this time of year where I'll be flat out cutting hedges week after week till Nov- and a angle grinder with a 1mm blade is fine for a good sort out if you've whacked fence wire a few times, and pretty much all I've used for years. Until recently. Sat there looking at them I thought I'd give a Dremel a go. Game changer. One of those tube grinding bits about 3mm wide, so much easier to control, smoother finish, gets into the curve in the corner without makeing the pinch point and a lot faster. Thing is to remember to look at the rear of the blade, both sides wear so if you've not removed enough material to take the rear back to flat, it will feel sharp but won't be super sharp and last. You want it like a shear. A flat file is great for getting a even edge. As for over heating, after working for the council and seeing the way they butchered their blades and still cut I wouldn't worry one bit. Also I find eBay helpful for blades, often you can find a set secondhand for a quarter of the price which are nearly new. Chatting to one guy, he didn't sharpen his at all, he just carried on until he'd burn the motors out and then sell the machine, which suited me as I bought 2 units for £70, fixed one which is worth about £250 now and had a free set of blades which admittedly were very very 'blunt' but a emery cloth, alcohol spray to get the sap off and a good file are sharp, balanced and as good as new. Oh that's the other thing, probably as important as the sharpen. Get the sap off. If that's building up, those blades will never shear with that in-between them. Stihl spray is alright, but it's expensive, I use a trend circular saw sap remover and a spray and hard brush will get them up like new. Ignore the teeth, not a great example of even cutting but one side was newer Edited July 16, 2023 by strimmer_13 Quote Link to comment Share on other sites More sharing options...
Stonepark Posted July 16, 2023 Report Share Posted July 16, 2023 3 hours ago, strimmer_13 said: Sat there looking at them I thought I'd give a Dremel a go. Game changer. One of those tube grinding bits about 3mm wide, so much easier to control, smoother finish, gets into the curve in the corner without makeing the pinch point and a lot faster. Do you have a picture of the bit in question? Quote Link to comment Share on other sites More sharing options...
strimmer_13 Posted July 17, 2023 Report Share Posted July 17, 2023 9 hours ago, Stonepark said: Do you have a picture of the bit in question? Quote Link to comment Share on other sites More sharing options...
Stonepark Posted July 17, 2023 Report Share Posted July 17, 2023 16 minutes ago, strimmer_13 said: Cheers Quote Link to comment Share on other sites More sharing options...
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