OK to use 13 or 18W Magnetic Ballast on 14W T5 tube?

[aoounfeuifene]

Recently I have a 14W T5 fixture that have its electronic ballast fail(due to it being cheaply made).I have starters, 13 and 18W magnetic ballasts laying around,and I wonder if I can safely use either of them on this T5 tube.I really do not want to spend any money on this crappy fixture.I can bolt these ballasts to heatsinks if necessary.
Thanks for any advice.

 

[333rocky333]

what voltage are you intending to run the light on, your details say your in the uk, but you have posted in the electrics OUTSIDE of the uk forum?