PVC Thickness

[NMES]

Hi Guys,

I'm new to sign making and have a basic question. I'm making some letters to hang on the outside of a building. The size of each letter is 3' tall. I'm planning to mount each letter in four places, two fasteners at the top two at the bottom.

I had been planning on cutting the letters from .5" komatex. Now I'm concerned that .5" is too thin and that I need to go to .75". Can anyone offer advice here?

I'm mostly nervous about warping and thermal expansion.

Thanks,

Nick

[robtown]

For letters that size you will most likely need more mounting points. Not because of the weight, but because PVC will want to warp because of being outside. Thicker would help.

[NMES]

Here's a proof of what I'm doing. You can see the two rails, one at the top, one at the bottom. Would you suggest having a third rail in the middle?

26376

[joe]

Here's a job where I'd order Pre Coated Red Dibond and screw the letters directly to the building. Even if I needed to create a second drop shade this would be faster and more profitable that using PVC. Your method for attaching PVC is almost guaranteed to bend.

I like to make money!

Joe

[NMES]

Thanks Joe. The 'customer' wants the letters to have some depth and standoff from the building a bit which is why I kind of dismissed Dibond. Does that make you see things any differently?

This is more of a favor than a job...

[joe]

I'm sorry but it confirms what I was thinking. This customer has little or no idea about the materials. One better option is to order the letters from Gemini and put them up. They will outlast anything you can make. You can't buy the materials and paint it for what they will charge. They will even send you the patterns to put them up. Because you have a CNC doesn't mean you can out do the market.

I sure like to make money.

Joe

[bleeth]

For great product that you can't duplicate in your shop the Gemini suggestion is the way to go all the way.
You can get vacuum formed poly letters that will last forever.

If you are dead set on cutting them yourself you are better off with foam a couple inches thick. I know someone who has done a bunch of these in upstate New York.
Also, it would amaze you, unless you already know, how many decorative elements on building exteriors today are pretty low density foam (including columns in front of my house for 14 years and three hurricanes).
They use insulation foam, seal it with shellac, and then paint it. There are also hardcoats out there that make them hail proof. Do some research here on the forum and the net for hardcoat ideas from those who have used them personally.

[bobmoore]

I would make them if it was me. You are apparently new to cnc as you only have 4 posts. An excellent learning experience and pvc will hold your paint so warpage is your only real concern. Hopefully your buddy is appraised of the risk that comes with a new sign guy. PVC has to move like vinyl siding so keep that in mind with your mounting system and have some fun.

[robtown]

Gemini is the best bet for speed and durability. If you choose PVC, then yes a middle rail and .75 thick at least.

Foam would be a good choice as well, I'm not sure if bleeth was referring to HDU or a lighter foam, but HDU would work well, the stuff ain't cheap though... PVC and HDU foam both both cut well.

[rb99]

I hope you don't plan to position the letters where you have them.

[NMES]

RB99 Why is that?

[joe]

NMES

Let me complement you on the illustration. I know the extra time it took to scale the photo and the lettering. You did an excellent job. We need more examples like this showing the final product.

I have one question. Why are the letters so big. Is this the request from the client.

1/2 PVC isn't manufactured for exterior use. It warps like crazy the way you're showing the installation. Even .75 could warp. You'd be better off with good old MDO. It's cheap and tough.

Joe

[NMES]

Thanks Joe,

The story is I'm a mechanical engineer with a CNC router. I have never done sign work and probably won't do much of it after this. I wanted to help the guys out at the gym I go to and offered to cut them a sign. We brainstormed about it and they have a visibility issue with people being able to see the gym from the street, so we figured make the letters as big as possible.

I like the Gemini stuff but they don't have the budget for it, at least currently.

I like the idea of MDO but I've never used it and I don't want to recommend them something that won't last a year. How long would you give MDO in a New England environment?

Thanks,

Nick

[joe]

MDO has been around for fifty years and is often used for billboards. It's a marine grade plywood with a smooth receiver surface. When painted properly it'll outlast just about anything.

We often see fellows offering to make signs for free or very cheap when it comes to the Boy Scouts, Churches, and athletic teams etc. This has always been a thorn for us commercial fellows. After all we have family's to support and kids to purchase clothes for. Not to mention the regular costs of running a business. There's lots of skill required to run one of these businesses.

Joe
www.normansignco.com (http://www.normansignco.com)

[rb99]

RB99 Why is that?

It looks bad to have them running right along the top of the doors. There needs to be a space there. Not just 1/2" either.

I would also want to see the whole building and how they look, not just a piece of the building.