Building props with coro

[GRG]

I am planning on starting to make some coro props for this years Christmas season.  Being a newbie I have a number of questions.   When making holes for pixels, is it better to drill the hole or use a punch?  Also, do the holes have to be between the ribs or is it possible to drill/punch cleanly through a rib?  Coro thickness, 4mm (3/16 inch) or 10mm (3/8 inch) better?  Black or white coro work better?

Thanks in advance for any information.

 

[TheDucks]

I did 2 layers of coro. I drilled the back 12MM and the front smaller. I used a Pilot hole and a 'step reamer' and a sharp blade to clear burrs.

I have a Heavy duty 1/2 paper stapler (lots of sheets capacity)

I just put hole where I wanted them.  IMHO Black probably has better UV resistance

[GRG]

Thanks for the info.  Like the idea of using two layers.  10 mm is hard to find.

 

[TheSignGuy]

When I made my coro props, they were cut on my CNC and I used 10mm White coro. It was easy to CNC the holes exactly the size then needed to be, I tried the step reamer but the flutes knock everything off a bit. Try a local sign shop to source the 10mm coro, the 4mm is just to flimsy with the weigh of the lights added. You will spend more time and effort trying to reinforce the flimsy stuff then if you just started with the 10mm.

Don't worry about the color but Black coro will degrade a little faster then White coro. All coro turns White and into dust if you leave it out in the sun long enough...🤣  Just don't leave coro sit outside in the sun all year long and it will last many, many years. You can always paint coro as well to match your siding/grass if needed, personally no one see the color of the coro at night anyway. If you are going to paint it again White would be the best option.

Just my .02....

[Box on Rails]

I used a 12mm Punch for my pixel props It was ok. I also tried a drill  with a regular bit and it was Ok. Finally I used a step bit and it was the best. that's what I use now. 

 

Edited March 29, 2022 by Box on Rails

[Yodlei]

I just made some St. Patrick's & Easter items. My aprx. 24" x 24" shamrocks were 4mm & had 2 70 ct. light sets & aren't flimsy at all. If going 4' or better, higher mm is probably better so some sort of support added. Got my colors at Menard's but they are back in the Window/Door section but also have white by the mail box posts. The colors they carry were green, red, yellow, blue & white (no black, unfortunately) but I made an egg out of the white & spray painted it pink with the Krylon for plastics & it turned out great.

As for the holes, I used the simple solder pen (under $10) also found at Menard's that was mentioned in some other threads. Worked like a charm but only the 2nd time as I held it straight in til it went through & then found holes too small for M6 lights but ok for the incandescent. Just had to go over them again, putting pen back in the hole & then swirled it around in a circle & it make the hole the perfect size.

As others noted, it stinks so use it outside. Cutting even 4mm coro is a PITA but doesn't have to be perfect as you can't even notice from even a short distance.