The problem is I can't see how much line there is when it's running or that the bump head is working unless I bump then let it stop to check, which is really slow.
Is this just a lack of good technique... Can anyone offer tips on best use of a bump head? Should I be tapping it every few seconds or what?
Thanks
I would say that rather than a thicker line you just need a better line and some more practice.
A little more use and a bit of experience will help with knowing how long your line is without stopping the head.
I know that on my machines they rev noticeably faster as the line gets shorter.
You'll also find that when strimming grass you can see the size of the swept path of the line and how far away from the head it is making contact. These two things will help you judge when it needs a bump and you won't need to stop and check it.
Strim from right to left and it clears the debris out of the way as it goes so you can see what its doing easier.
As mentioned by someone else, when you bump the line out the excess should be cut off by the guard. You'll feel and hear the line being cut so if you bump it and that doesn't happen, bump it again. If you've bumped it three times and haven't heard it cut the line then either you've not identified that sound yet, or it isn't feeding the line out (like if you've wound the spool the wrong way, or its snagged for example). Stop and check the line situation.
I use standard round 2.4mm Oregon nylon line most of the time for just grass, but if I'm going to be smashing through some nettles and brambles etc then I go for the Duoline that's pictured above. That is very tough and wears much slower than the plain nylon line. It is more expensive, but it lasts much, much longer. If just using it on grass I find I can sometimes go half an hour between bumping out the line with it. If you aren't paying attention it will cut through plastic plant pots, mark the bark on trees, and damage all sorts of things though, especially if running at 100% on the strimmer, so some care required with it (as with all line really though).
Also be aware that you don't need full throttle all the time, especially against concrete etc where it will just wear the line much faster than if you used half throttle which will cut the grass just as well, albeit a little slower.
I find that with it running quite slowly I can also get it to 'pull' grass out from when its growing through chainlink fencing
Put in a bit of time to practice and experiment with technique and some decent experience with the machine will allow you to get the best out of it.
Hopefully some of that load of waffle helped someone.
