It has taken me a while, but I finished making all versions of the GTR heater cover and took a photo to provide a comparison.
The glass heater covers are held to the base wood using natural cork rings and ss screws. Intake air enters through a hole in the base. Heat migration to the cork ring and base is limited by the thermal conductivity of glass.
The ss heater covers are held to the base wood using ss screws. Intake air enters the slits on the side of the heater cover, which also limit the heat migrating to the base using Heat Island Technology.
The 18mm female glass heater cover uses a 17mm flat screen wedged into the joint bottom as a debris/heater screen, which is also how any 18mm female joint can be used as an injector style roasting bowl for the 18mm male glass or ss GTR heater cover. 19/22mm roasting tubes that use 12mm adjustable position basket screens will fit, as well as 19/13mm roasting tubes that use 16mm fixed position flat screens, so they hold a bit more and don’t extend into the joint as far.
The 18mm female ss heater cover uses a 17mm basket screen as a debris/heater screen. 19/22mm and 19/13mm roasting tubes fit, but have limited engagement to prevent the tubes from getting stuck.
The 18mm male glass heater cover is cut to 19/13mm and uses a 16mm flat screen, similar to the 19/13mm roasting tube for the 18mm female GTR heater covers. Any 18mm female joint can be used as an injector style roasting bowl using a 17mm flat screen wedged into the joint bottom. 14/20mm and 14/13mm roasting tubes also fit into the end of the 19/13mm glass heater covers, for roasting smaller amounts.
The 18mm male ss heater cover is tapered to 19/7mm and uses a 17mm basket screen as a debris/heater screen. Any 18mm female joint can be used as an injector style roasting bowl using a 17mm flat screen wedged into the joint bottom.
The 14mm female glass heater cover uses a 1/2” flat screen wedged into the joint bottom as a debris/heater screen, which is also how any 14mm female joint can be used as an injector style roasting bowl for the 14mm male glass or ss GTR heater cover. 14/20mm roasting tubes that use 10mm adjustable position basket screens will fit, as well as 14/13mm roasting tubes that use 1/2” fixed position flat screens, so they hold a bit more and don’t extend into the joint as far.
The 14mm female ss heater cover uses a 13mm basket screen as a debris/heater screen. 14/20mm and 14/13mm roasting fit, but have limited engagement to prevent the tubes from getting stuck.
The 14mm male glass heater cover is cut to 14/13mm uses an 11mm basket screen as a debris/heater screen. Any 14mm female joint can be used as an injector style roasting bowl using a 1/2” flat screen wedged into the joint bottom.
The 14mm male ss heater cover is cut to 14/10mm and uses a 12mm basket screen as a debris/heater screen. Any 14mm female joint can be used as an injector style roasting bowl using a 1/2” flat screen wedged into the joint bottom.
The end connection of each heater cover size/style/material can also be used as a roasting tube, so in addition to having 8 heater cover end options, there are 8 roasting tube end options.
Check out my latest roasting tube options at Toasty Roasting Tubes