Graham Richardson, 27, battered 56-year-old father-of-two Peter Battle to death and left his body lying in a pool of blood for five weeks.
Richardson did internet research on how to dispose of his victim’s remains with acid, Teesside Crown Court was told.
But he left the body beneath a sheet while he plundered Whisker Cottage in Full Sutton, near Pocklington, of gold, silver, coins and antiques.
Mr Battle was found dead when officers forced their way into the property last February after friends became concerned about his whereabouts.
The killer had struck only three weeks after teaming up with heroin dealer Darren Archer and another man to rob gold dealer Michael Cleaver – who was threatened with an axe by three masked men who threatened to shoot him in a York street.
Desperate for money, Richardson had contacted Mr Battle, who lived alone, and showed up at the cottage posing as a customer shortly before Christmas.
The murder weapon was never found but Mr Battle was stabbed and bludgeoned, probably with one of the heavy ornaments lying around the cottage, the jury heard.
Richardson dragged the body across the living room and covered it with a sheet before posting notes outside the cottage saying Mr Battle had gone away.
Mr Battle’s daughters Lisa and Laura wept yesterday as they told the court how Richardson had torn their lives apart.
Lisa Battle said Richardson had treated her father “like a piece of meat” and “caved his skull in”.
She added: “My dad was a good man – an amazing man.
“He had a heart of gold and was willing to help anyone with anything he knew about – which was a lot.
Mr Battle was not just a father but her best friend and she had had to break the tragic news to her 10-year-old son. “I feel my world has totally fallen apart,” she added.
“It’s so hard to believe someone could do such a thing.
“I have visions in my head every day of what happened that day and what my dad must have gone through.
“It haunts me every day.”
Turning to Richardson, who sat with his head bowed in the dock, she said: “If all you wanted to do was rob my dad why didn’t you wait until he was out?
“You have totally ripped my heart out – and that piece you ripped out will never grow back.”
Jailing Richardson for life, Mr Justice Stephen Males recommended he serve at least 27 years for the murder which came in a “savage and sustained attack with gratuitous violence” which had continued well after he lost consciousness and was defenceless.
Praising the dignity of the Battle sisters, the judge added: “Their courage, love for their father and genuine feeling contrasts with your cowardice, selfishness and lies.
“The ransacking of a dead man’s home with his body lying there is despicable conduct.”
Richardson, of Riverside View, Norton, betrayed no emotion as the sentence was passed.
He was also given concurrent sentences of nine years for robbing Mr Cleaver and one year for theft of Mr Battle’s belongings, which he also admitted.
Prosecutor Nicholas Lumley said Richardson had behaved like a “cornered feral animal” in a case which was “a reminder of the human capacity for chilling inhumanity”.
During the seven-week trial, Richardson was described as a “cold hearted, cold blooded callous murderer” trying “quite literally to get away with murder”.
He claimed he found Mr Battle already dead after seeing Archer and three masked men fleeing the cottage with bags of loot.
But the jury rejected his claims and found him guilty of the murder after deliberating for five days.
They also found Archer guilty of robbing Mr Cleaver, an offence Richardson had previously admitted.
Archer, 43, of Nunnery Lane, York, was remanded in custody while a pre-sentence report is prepared.
A third defendant, Archer’s cousin Peter Egan,47, formerly of Walmgate, York, was cleared by the jury of robbing Mr Cleaver and walked free.
Mr Battle’s family wept when the unanimous guilty verdict on Richardson was announced.