I need suggestions for outdoor sign material.

[Glidergider]

Hi guys.
I'm going to rebuild the letters for our neighborhood entry sign. Pictures of the old sign are below. I will pressure wash the bricks and cut new letters.

My question to you smart material guys. What kind of plastic would you recommend for these replacement letters? Letter height is currently 15 inches.

Thanks.
Dave

[High Seas]

I suppose you considered using the cnc to cut a mold - then cast the letters? I ask, as that opens a new set of questions for materials -- as opposed to milling them out of a plastics. Then you'd be into paint and finish too

They could be cast in any number of resins, solid or hand lay-up as hollow backs with mounts cast in. Justa sideways view you might consider. An added advantage - you'd probably store the molds for replacement when they go "walkabout."

Jim

There are some really awesome cast resin products coming outta China that are extremely detailed and highly polished. Not you'd choose that - just an example of the material processes.

[bclark6716]

I personally would use 18 lb Sign Foam. Nice to work with and uses polyurethane glue to stick to the bricks. Once primed, any type of paint can be used.

Brian

[Glidergider]

Brian, Where would I buy 18 lb sign foam? Is 18 significant to density, such as 18 lb/cuFt?

Jim, Where would I buy the resins you speak of. What material would I use for the mold.

I like both options, and thanks to both of you for your response.

[bclark6716]

Try this one

http://www.signfoam.com/

Brian

[High Seas]

Glidergider -
It can be a bit of a fiddly process -There are heaps of sources on the web you could source/get the resins - or find a auto/boat store for the higher price!
For the molds you could use mdf, foam etc - but then need to prep it with fillers, sand it to finish - use a high-build primer, then wax (all to make sure it will release from the mold), then, layup resin and fiberglass. OK, Ok - it sounds like a lotta work for one-off!

Or - go get the sign foam Like Brian suggested and finish it with the right stuff! You could work the mounts in the back side as needed for blind fastening to the brickwork - but may need resins for mounting/reinforcement. (I'd guess the web sources are as good as anyone but not so cheap - a quick look:
http://www.denversignsupply.com/cate...me=Sign%20Foam)

I suppose you could cut using other low density foams and vacuum bag like a wing (lots of guys building things like that here too. That way you could get a good finish and outdoor - ability too at less cost. I'd probably try using blue foam - glued up to thickness then cut on the cnc.

Be sure and save your files to recut and replace as needed! Less storage than molds! Any way you choose - it'll be a nice feature to have back on the bricks!
Jim

[Glidergider]

Jim,
Thanks for the good ideas and the source of signfoam. Yes it is pricey but I'd like to try that material someday.
Dave

[judleroy]

If you have a local plastic supplier I would talk to him.
Or you can look online for a plastics supplier like www.usplastics.com . Look for something that is UV stabalized.Probably a polyethylene. The material can be purchased in full sheets half sheets or quater sheets most of the time. It would probably be between 50
to 100 dollars for something like this. Just A suggestion
of what I would use.

[Glidergider]

Judleroy,
Thanks for the links. I've bookmarked it for later reference.

Consider this. I just found a surplus store that has lots of $3 12x18 inch white cutting boards. I don't have any idea what composition the plastic is except, its not HPDE, Delrin or UHMW.

A similar cutting board at the kitchen store labels it a Poly plastic. Thats all. Its plenty strong and almost a half inch in thickness.

I don't know its resistance to UV.

Any thoughts?
Dave

[judleroy]

Glidergider
Sorry I did not see you're reply sooner. The Cutting boards you are looking at are almost certainly not UV
protected. UV protection is almost exclusivly used for
materials that are designed for outdoor applications.
Without this protection over time the material will discolor and crack. Sunlight also causes it to degrade
and break down. If you can keep the pieces out of direct
sunlight most of the day it may still last for years. I beleive crylon makes a paint specificly for plastics. Try
seeing if this kind of paint is UV resistant. If it is you
should be fine with those $3.00 cutting boards. If they
are white and somewhat flexable they are probably some form of HDPE or LDPE even if there not labeled
that. They are probably made from recycled milk jugs and such. Good luck.

Judleroy

[chan luci]

Judleroy,
Thanks for the links. I've bookmarked it for later reference.

Consider this. I just found a surplus store that has lots of $3 12x18 inch white cutting boards. I don't have any idea what composition the plastic is except, its not HPDE, Delrin or UHMW.

A similar cutting board at the kitchen store labels it a Poly plastic. Thats all. Its plenty strong and almost a half inch in thickness.

I don't know its resistance to UV.

Any thoughts?
Dave

hi,
the material you say must be Polyrpropylene(PP) and it is pretty UV stabilized. Or else check for any Polyolefine supporting paints, wherein you can paint the letters with black or any UV resistant bright colors. This material has to be cut with high speed band saws, or else the edges wont come sharp. Good luck!

[11bravo]

Check this page out:

http://k-mac-plastics.com/uhmw-uv-sheet.htm

UHMW UV Resistant Sheet and never having looked for the stuff before, I'd say not too badly priced.
Not as inexpensive as the cutting boards though.

Greg