In detail the "DIY INOX peanut bowl COB-LED reflector method"
1) Measure and mark ,the LES opening and attachment holes at the inside of the bowl's base.
Be as precise as possible at that step.
2) Drill the attachment holes (usually a 3 mm HSS / Cobalt / Titanium drill -bit needed ) .
3)Drill the LES opening . ( A 30-32 mm Dia. drill /saw Cup will be fine.Use low rpm. I used something these ones :
4 ) Make sure that all the drilled openings have smooth edges ,free of metal-work spikez,chipz,etc
Use a 180 grit sand paper .
5 ) Sand paper the whole inner reflective surface .
Make sure you do a good job.
Use 100-200 grit .You want a
rough finish ..
6) Clean & Degrease with a solvent .
7) Dip the reflector in a warm bath (50°-70° ) of 10% w/w citric acid solution.
(Citric acid is sold at most super markets ,usually where salt,pepper and rest are located.. _)
Leave for 30 minutes.Wash with clean water and degrease once again.
8 ) preheat reflector(s) at 40-50 C ,at kitchens oven,...
9) Paint a first thin layer( 25-50 micron ) of HIgh Temperature White . (preferably matte or satin finish )
10 ) bake at ~70 C for 30 min ..
11 ) paint second layer,a tad thicker .(50-70 micron )
12) bake at 100C for 15 min .
Optional steps:
13) paint 3rd layer ,a thick one (80-100micron )
14 ) bake at 150 C for 8-9 min .
---
Leave to cool down and dry for 48 hours .
Re-bake at 100 C for 15 min.
(making sure most VOCs are outgassed )
Reflector(s) ready for use.
Cheers.
.....
looks like your on the way to something with those reflectors. I am a watching and tryin to learn from you dudes. Keep up the good work SDS
... maybe add an deflector for air on front side...
. Almost like you're one of Santa's elves that got banished for getting high with one of his magic reindeer on Christmas Eve and now you just chill with humanity 
. LOL
