On Tuesday, he appealed against the sentence, but was told by senior judges that the term was richly deserved for the catalogue of offending.
“This is a grave matter,” said Lord Justice Bean, sitting at the Court of Appeal in London with Mr Justice Spencer and Mr Justice Gilbart.
“He abused positions of trust, both at Thorp Arch Grange and elsewhere. Six young victims had their lives very seriously affected or even ruined.
“We are not persuaded that it is arguable that the sentences totalling 28 years were manifestly excessive.”
The court heard the boys at the school had felt trapped, unable to leave or to avoid the abuse.
They felt as though they were regarded as “naughty boys”, not to be believed.
The abuse they suffered would “haunt their adult lives”, said the judge.
In his appeal, Lovatt claimed that 28 years was far too long for a man already in his 70s.
But Lord Justice Bean said that had been taken into account at the crown court and the sentence could not be criticised.
The appeal was dismissed and the sentence upheld.
Lovatt was convicted in February alongside Roy Leonard Allen, 72, of Moseley Road, Burnley.
Allen was found guilty by the jury on nine charges of indecent assault, two of serious sex assault and one of attempted serious sex assault involving four boys in the 1970s. He was jailed for a total of 18 years.
Allen was teaching at the time of his offending and later went on to become deputy head and headmaster at the school.
Richard Wright QC prosecuting told the jury the school was effectively a secure children’s home housing youngsters sent there by courts or local authorities who were among the most vulnerable in society.
Lovatt and Allen abused the children, and in the most extreme cases raped them.