1. T6-6061 Aluminum Mockup of overlap joint. Short piece (< 0.5m) resting on foam insulation Gentle grinding: Max Temp < 50 C Aggressing grinding: Max Temp < 90 C ~1 mm thick emery grinding wheel Work done by Bert Gonzales Temperature monitoring: Jorge Montes

2. Temperature (Celsius) versus time (arbitrary)Monitor 1 Monitor 2 Monitor 3 Aggressive grinding at time ~ 500 Gentle grinding at time ~ 80

3. Bert Gonzales reported that cutting through the weld was not any harder than cutting through T6-6061 Al Dremel tool kit also has a fiber-glass reinforced emery grinding wheel. Bert says that this is harder to control. It tends to jump a bit. Emery wheel is recommended.

4. Type density Thermal Cond. Specific Heat T6-6061 Al* 2.7g/cc 167 W/(m-C) 1.3e3 J/(kg-C) Pure Al* 2.7g/cc 220 W/(m-C) 896 J/(kg-C) AA 1100** 2.7g/cc 222 W/(m-C) 906 J/(kg-C) *http://www.engineersedge.com/properties_of_metals.htm ** http://www.substech.com/dokuwiki/doku.php?id** http://www.substech.com/dokuwiki/doku.php?id= wrought_aluminum_alloy_1100&DokuWiki=5fb40349ffd1dc8213525ba1dde42e6b If aggressively grinding the weld: Worse case temperature = (90 C – 24 C)*(1.3e3/900) + 24 C = 119 C If gently grinding the weld: Worse case temperature = (50 C – 24 C)*(1.3e3/900) + 24 C = 62 C