The Windsor Police bomb squad spent much of Wednesday afternoon and night at a house in the 800 block of North Talbot Road.
Emergency crews were called to the house late Tuesday for an armed standoff. A man was taken into custody at that time and no one was injured.
"There was also information that that this particular person had a number of weapons registered to him. What happened is that within a couple of hours he came out to police," Windsor Police Superintendant Michael Langlois said of Tuesday's incident.
Langlois said when the house was searched later, police discovered what they called prohibited chemicals the individual appeared to be using for making rockets. The bomb squad disposed of the chemicals overnight.
"It seems to me, from what the officers are telling me, that the individual had a hobby of homemade rocket making and there was some concern that some of those chemicals were prohibited," Langlois said.
Langlois said the man is in hospital having a medical assessment and will be charged today.