Last week I fitted a 6ft Fluorescent Tube into the garage and it worked fine until today.
Now it starts up fine and after 10-20 minutes turns itself off for a second then back on for a couple of minutes.
This goes on and on until i switch it off and use the lead lamp instead.
Would this be the bulb itself??

Thanx

Have the ends of the tube blackened where the glass meets the metal? Try a new starter in it first as they are cheaper than tubes.

Does it have an electronic ballast?

Does it have an electronic ballast?

Errr. Whats one of them Mike?

Traditionally fluorescent fittings had an inductive ballast to limit the tube current and a "starter" that fitted into a holder somewhere. More modern fittings have a purely electronic ballast (very similar to those used in compact fluorescent "energy saver" bulbs) and don't need a separate starter. You can still buy fittings with the standard ballast though, generally all the cheap ones from DIY stores have them.

If it has a starter, you can rule out this having some kind of intermittent short by simply unplugging it after the lamp has started up (it's not needed to keep the lamp running).

If the lamp particularly noisy in operation e.g. buzzing? Sometimes the ballasts have thermal cut outs in them, if it's getting overheated it could cause your symptoms, though I'd expect it to switch off for longer than a second.

Cheers Pete/Mike.
The tubes not blackened at the ends and it does have a starter, which I have taken out when its been running, but the problem is still there. It also runs really silent.

Hello mate, i fit these every day im a sparky as well as a lift engineer, if you can take the starter out when the tube is on(newer type) let me know how the fitting works for 30mins or so.

If its the ballast, tube, or starter let mw know and ill send you some!