Large two sided sign on Polycarve - need advice

[Rich Fennessey]

I also posted this on the camheads forum.

I may have to make a 4x6' two sided sign as a follow up to my draft sign. I could use some advice on choosing material size and hanging method.

Polycarve is available in 1/2 and 3/4" thickness. I can get 1/2" material for about $180 per sheet or a 4x10' sheet of 3/4" for $360. This will be supported between two posts as far as I know. I'm thinking the two 1/2" sheets would work better for the following reasons:

Advantages
Less risk - if I botch a tool path and ruin a piece of material, then I would ruin at most $180 and at most one side of cutting time.

Hanging - I think metal brackets would be easier to slide between two slabs for support and there would be a full inch of material

Disadvantage of two pieces is having to sandwich them together. I'll have to use some stainless bolts and washers or adhesive (not sure it will stick readily to this) and paint the heads to not show. Also, I get a bit less surface area - those extra pieces can be used for the client for some miscellaneous use.

I carved to a depth of .25" on my draft sign - I'm thinking this might be too deep for 1/2" material and certainly to deep if cutting on both sides of a 3/4" sheet.

Also, on pricing, do you have a ballpark estimate what you would charge? I already gave a price that I won't advertise here but I made it very reasonable because I want to do this particular sign and I haven't used this material before.

[AL Ursich]

I have not done anything like this so I am no expert... But I read allot... My vote would be for 1/4 inch deep in 3/4 inch thick and 2 pieces.... Possibly even a 3rd piece sandwich of stabilizing material like .080 aluminum... I would plan to inlay the hardware into pockets between the sheets. My concern would be wind load pulling the hardware out causing 1 Liability... and 2 damage to the degree of having to do it over at no cost... A penny saved now could be expensive later. A Wrap Around Bar Stock hardware might be a expensive option for durability... Or other surface hardware or even a surface plate routed into the back as a pocket. Lots of options, some better than others... I saw a sign once on the street after a storm that had used lead Anchors to hold a 3 foot oval sign. The sign was on the ground and the lead anchors were still hanging in the eye bolts. A Classic Fail that has had me paying attention to this...

As for mounting the 2 sheets together... not a clue.... Signs 101 might be an alternate place to search hardware and materials too.

[Rich Fennessey]

So you are recommending to use 2 pieces of 3/4" material? I was thinking that I would inlay some metal supports between the two 1/2" pieces. I would also try to trim off the left and right sides so there is some straight material to connect to.

[Keith Outten]

Rich,

I use King Color Core (KCC) which I think is a similar product. There isn't any adhesive that works with KCC so mechanical fasteners are the only option. Personally I would not laminate two pieces since you can't use adhesive to join to panels there won't be any advantage and you are doubling the weight.

You could fabricate 1/8" thick stainless steel attachments for the edges and attach them with screws. I would add tabs to the horizontal sides of the sign and then shape the stainless steel attachments so they complete the radius so the sign still looks like it was designed above. Use the attachments on all four sides of the sign so the plastic is sandwiched in between the steel and counter sink the screw heads on one side then drill and tap the opposite side so there are no nuts showing. This design will give you a clean look and keep the oval shape visible. The fasteners will allow the sign to be removed when the big storms blow.
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[AL Ursich]

Sounds much better than my half baked idea....

AL