Tell us about yourself!
I appreciate the information and, very importantly, the risks. You are being very responsible, much more than many others who post instructables and use methods which are hazardous.
Your instructable improves the end product's quality by smoothing the surface but you are exposing yourself to dangerous chemicals which, even though you are taking precautions, are damaging your health. I am not willing to take that risk.
The joke will be on you when someone throws it out.
You need to get permission from Vincent John if you use his design.
This clock can tell time in more than one time zone. On the plastic cover, put another line in a different colour at the current time in a different time zone. This can be done for more than one other time zone.