Working on a DIY reflector

This is what I have made so far. It is made out of aluminum. I wanted to put two 400w bulbs in it. One on each side. One is MH the other is an HPS conversion bulb. I tried to polish it before bending. It is not a mirror finish. More like a dull mirror. Does anyone think that is good enough or should I sand and polish to a mirror finish? Kinda hard now that it is already bent.

The top is 12" across before it starts to bend. Just over 26" long the other direction. I might go to a siding retailer to get the dimpled aluminum.

I have taken the ballast off of one of my high bay fixtures. It is actually pretty easy to do. I have not extended the wires yet but it looks pretty straight forward. After I got it apart I tested it out with the bulb standing straight up. Don't do that. They get real hot and start to burn.

Feel free to pick it apart. I can make another one or modify this one to get it right. Maybe slot the top to let heat out? Fire away...

looks good podunk-
paint the inside with titanium dioxide white, which most white is anymore, it's very reflective

I was thinking of the same design myself but having the end piece in a 90 degree bend means their is a a lot of waste where I was thinking of just bending a rectangular piece similar to the shape of yours but then cutting a piece of plywood fit snuggly into the folds allowing you to screw the reflector to to the ply for extra rigidity and solid fixing for the light fixture

luckydog82 said:

I was thinking of the same design myself but having the end piece in a 90 degree bend means their is a a lot of waste where I was thinking of just bending a rectangular piece similar to the shape of yours but then cutting a piece of plywood fit snuggly into the folds allowing you to screw the reflector to to the ply for extra rigidity and solid fixing for the light fixture

Click to expand...

What if we put a 45 plate in behind the lights?

Forgive my paint shop skills. Not at work.

Do you intend to bend this out of 1 piece of aluminium ?,how will you fix that 45 to the reflector

It would be a separate piece. I was going to use plastic welder (JB Weld) to attach it. You could weld it in but I don't know how to weld and I am not going to ask someone to do it for me.

Plastic welder will hold it. I use it all the time at work. You have to get it really hot to get it to break loose. I use oxy/acetylene torches to break parts loose off the table on CNC machines. You can hold a propane torch over it forever before it breaks down. On big parts forget about it.

What do you think about having a bulb on each end?

Made the angle pieces today. I put it at a 57.5 angle. 45 degrees would probably hit the bulb. I plan to paint it with flat white paint that is loaded with titanium dioxide. I will post pics when it is all done.

What do you guys think about drilling a few small holes in the top to let heat rise up and out?

i use economy bat wing refletors that are very similar to this and they don't have holes, but i do run about 400 cfm exhaust for an 8x10

how about rivets?

i built something similar for a 250w cfl, made it using a few pieces of aluminum which i riveted together. I'd keep the inside bare Alu, you don't really need to polish it either, and it would be similar to foil and create heat spots, i'll take a photo when i'm near a camera

look up restrike plate

Amphibiosaardvark said:

look up restrike plate

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Is the restrike plate a piece that goes above where my rectangle flat section would be? Adding curvature to the top.

Here is the new reflector in action. I have two 400w bulbs going on the females (only five female out of thirteen from bag seed). One is 4000K MH and the other is a 2100K HPS Conversion. Six 24" (well 48" if you bend them straight!) 40w U-bends around three sides. I will be watching my heat closely.

Enough light for five plants?

That last picture on the right is what I started with!

BTW those damn purple twist caps cost a small fortune! They let you combine aluminum and copper wire. $4.96 for only two caps at Lowes. I needed 8 of them!

The light and reflector has been working great. Getting way more light with the bulb horizontal now. Except for one problem. It is trapping a lot more heat below. Way more than the high bay reflector. I have it almost to the ceiling and the top of the canopy is hitting 90+ degrees. A little lower it is in the 70's. I am only using the HPS conversion bulb too. Running both gets really hot. Over 100 up top. Not sure if drilling a few small holes above the bulbs near the socket will help? I might get a small fan blowing up at the bulbs and out the opening above the shower door.

My tallest plant that I just put in a 5lb grow bag on Sunday is still growing vertical. Like 3" or 4" in one night and that is after a transplant and over 2 weeks in 12/12! She is 3 feet tall from the soil line. I think I will try bending it over with some twine.