QUESTION - PVC Prismatic letters ?

[signtist]

Can I use 1/2" or 3/4" PVC to make prismatic letters? Does it work using Aspire to make beveled letters with a 1/8" ball end bit?
Does it work OK or is the finish sanding too difficult?
I plan in painting these 8" letters with Krylon paint not guilding with gold, so the finish only need to be acceptable.
I think 15 lb. HDU is not tough enough from kids touching it.

[dakers]

if you are making individual letters you may need high build primer on cut edges to smooth out the porous finish if that is an issue (look at the raw edge on the pvc compared to the smooth face ). Have never done that with pvc. Do not think flame treating would smooth it. Good idea you have. Nice web site you got too. Hope to hear from others who have done this.

[joewino]

An 8" letter would have to have a very shallow angle to make it prismatic in 1/2" PVC and still have a wall side.

We have cut prismatic letters from PVC, but used a 150 degree V-bit, and we didn't paint them - just left the orginal color of the PVC (white). And the letters were smaller than you are considering.

On the size lettering you are considering, I would use a heavier HDU and just spray them like you had planned to do with the PVC. We find that this process is a lot easier. Like Dick said, the paint will look different on the PVC and I'm not sure that you wouldn't have to do a lot of sanding after using a ball-nose bit.

Keep us informed as you decide what to do.

[hol]

How about using Extira?

It cuts good, leaves a good edge to paint, and will hold up good to the kids.

[signtist]

I was also thinking about a scrap piece of 1" medex I've got laying around.

[jhicks]

We frequently use Medex finished with a polyurethane finish as recommended by the manufacturer but have done them in PVC and HDU as well. Consider a beveled egdge vs a true prismatic and it might give you desireable results, less cut time and complexity.
Paint the surface, mask the painted panel, cut bevel edges with a v bit, paint edges, remove mask, and apply.
Have fun