Trommel repairs

Hi everyone I'm in the the process of overhauling a trommel screen (Hercules) and was hoping for some material and electrode selection help. At the moment I'm looking at hardox 400 sheet at 50mm and I'll cut profiles and spans to match what's removed due to cracks and wear etc. As for electrodes I'm open for suggestions and also what preheats to run to before welded. We have been patching with anything easily available and go smooth arc 3.2 mm rods up until now but time has come for proper repair. Cheers Nick

I would use 7018 rod

preheat and interpass temperatures http://www.brunswicksteel.com/pdf/hardox/welding-hardox-and-weldox.pdf