Vaughn Dolphin, then 19, branded himself a "dangerous lunatic" and caused a fireball in the kitchen of the house in Walsall, West Midlands, where he lived with his aunt.

Police discovered he had turned the family shed into a weapons factory where he was manufacturing homemade explosives and an improvised musket.

The inside of the shed was decorated with a badge from the Nazi Waffen SS and there were bags of bomb-making chemicals in a fridge in his bedroom.

Dolphin had downloaded bomb-making documents onto a USB stick in a folder titled "Boogaloo" - a reference to a race war white supremacists wanted to start so they could take control of the government.

In the shed was a length of aluminium tube with a hole drilled into it to make a crude, homemade gun barrel, and a jar containing nitrocellulose, a propellant used in shotgun cartridges.

On June 14 last year, Dolphin posted a series of video clips to a far-right Telegram chatroom called the Segregation Wagon, showing his kitchen filled with smoke.

Wearing a gas mask, he could be heard saying: "The bastard mixture f****** set itself off prematurely, oh my God.

"That was a bad f****** idea, it was so bad the f****** carbon monoxide meter went off. I started choking so I had to put this on. Oh my gosh."

In another clip, a boiling mixture could be seen in a pan on the stove and he explained he was making "homemade fuses." Mathew Brook, prosecuting, said Dolphin was "clearly mixing chemicals in his kitchen."

Read more:
Twitter user 'encouraged beheading blasphemers against Islam', court hears
Conspiracy theorist jailed for planning terror attack to 'topple government'
Drill rapping 'terrorist' 'threatened blood and torment if his girlfriend left him'

Dolphin was using Telegram, an encrypted communications app, which had been organised into a folder called "right wing" with channels including one called Pol/4chan, and others called Hitler Group and Segregation Wagon.

He had downloaded a video of the Christchurch mosque shootings in New Zealand in which Brent Tarrant murdered 51 people, commenting: "Shame it doesn't have the music."

Dolphin used the online login Memento-Moti1488 - a reference a white supremacist slogan and the words "Heil Hitler".

In one message Dolphin boasted: "I am seen as a dangerous lunatic by most" and added: "People will get sick of Black Lives Matter and that is when violence will flare. I am going to make and sell weapons but to the Base side" - a reference to a far-right group.

Dolphin was interviewed by the police two weeks after the explosion, and claimed he had been making a powder from matches, which he hit with a hammer and it caused a "bigger bang than I was expecting" that had worried the neighbours.

He said he was "libertarian" and "a bit nationalist" and had an interest in chemistry and militaria, influenced by the fact his grandfather had served in the military.

Dolphin told the jury he had no interest in the far-right and only visited extremist chatrooms because he was lonely.

A defence psychiatrist found he had a clinical diagnosis of autism spectrum disorder saying he had problems with social interaction, communicating and had developed restricted and repetitive interests.

However, Mr Brook told the jury that Dolphin's excuses were "among other words, complete and utter nonsense."

Dolphin, now aged 20, was found guilty of six counts of possessing articles useful for terrorism, two counts of disseminating terrorist material and two of possessing explosive substances and one charge of possessing a firearm. He will be sentenced later this month.

Detective Chief Superintendent Mark Payne, head of Counter Terrorism Policing West Midlands, said: "Dolphin had claimed he had an interest in chemicals and military memorabilia however he combined a toxic extremist mindset, sharing right wing material online with the real world acquisition of explosive material and homemade weapons.

"His mindset is one of a dangerous individual equipping themselves to harm others who did not look like him or who he disagreed with."