MDF HDU or PVC???

[Kyle S. Cross]

Hello, new botter/sign maker here. I am trying to determine the best materials for the work that I will be doing for my employer. I will be building large 3d,layered, single sided signs ( 4'x8' ), all exterior. I am planning on using 1/2" AC for the structure and attaching smaller 3d elements to it (these will vary in detail from letters to intricate forms). I am trying to determine the best material for these smaller pieces. According to my research on this forum I have determined my best options are MDF,HDU and PVC (sign foam?). I am requesting an experienced comparison between the four in terms of:

-Cost
-Finishing techniques
-integrity

I am open to any additional suggestions. Thank you for your time!

[Mike P]

MDO might be abetter choice for exterior signs over MDF, MDF does not stand up to weather at all. I have had good luck with Sign Foam as well

Mike

[steve_g]

Kyle

Do you have a sign supply in your area? You need to get some samples just so you are clear on terminology...

1/2" AC ......To my knowledge never an exterior grade

MDF....... (medium density fiberboard) not exterior, big difference between Big box stores and cabinet supply house grades (i.e. plum creek) Medex.. a moisture resistant brand.

HDU ..... (High density Urethane) also known as sign foam... many densities available higher the number (lbs per cubic foot) the better the quality.

PVC .... (Polyvinyl Chloride) comes in different forms. solid (expensive) Foam (not the spongy kind) one foam brand name is Sintra I think Komatex is another. Has a bad reputation when used as an exterior sign material. Unsupported letters will sag over time and colors will fade. Acceptable when 100% supported (pocketed) and painted.

MDO.... (Medium density overlay) a paintable surface made of plywood with a weather-resistant resin overlay bonded to the wood. A good base material... not as good when the overlay is cut (V-carved) the interior is not as weather resistant as the surface.

I'm sure I've forgotten something, Others will correct and add!

Sg

[Kyle S. Cross]

Thank guys

Steve,
Thank you for this detailed explanation. Based on the information you provided and exercising process of elimination, it seems that the only viable option for my work will be HDU. Do you use this material? If so, what finishing technique would you suggest?

With regards to the PVC; On an exterior sign, does the material have a tendency to sag less when painted?

Thank you
-Kyle

[steve_g]

Kyle

My list isn't extensive and I had hoped others would add to it.

I have used the HDU in the past... I am unhappy with what densities I can get locally (10 and 12 lb.) I prefer a sign material more difficult to vandalize than those. The 20lb. material I like is available mail order, but in the quantities I need its shipped UPS and cut into shippable size pieces. When I paint it I use a "block filler" base coat followed by a top coat of what ever the block filler Mfg has suggested (Sherwin Williams, latex).

Regarding the PVC signs sagging... If supported (100% glued to a backing) and painted It' s fine. I would not use it for lettering on standoffs even if painted. ( I can't say I tried it however)

SG
Clarification: My comments on PVC are when used in an exterior application... It makes fantastic corporate logos etc. on standoffs on a interior wall!

[Charlie Iliff]

Kyle:

Where are you in Pennsylvania? It might be worth your looking at Harbor's website, calling them for advice, and finding out if they deliver to your area.

http://www.harborsales.net/

Charlie Iliff

[Kyle S. Cross]

Steve,

Thank you for your assistance. I will try HDU and PVC and compare results.

Charles,

I am aware of Harbor. They will be my primary resource for materials. Thanks.

[billp]

Kyle,
Harbor used to ship 'sample boxes' to customers which included one piece of just about everything they carried. It served two purposes; one was to let YOU know what each material looked like (so you could see the differences between Komatex, and Komacell for example), but it also was a GREAT sales tool for prospective customers who usually have NO idea of the range of products which are available in today's market place.
And as you probably know, Harbor also does CNC contract cutting for many customers, so if you have any questions regarding HOW to cut some of these materials they can help you there as well....

[Kyle S. Cross]

Thanks Bill

I will certainly look into the sample boxes.

[Kyle S. Cross]

I have a question regarding two brands of HDU: Precision Board and Sign Foam 3. When comparing price for 1/2" white 15ibs density, Sign Foam is twice the cost. Does anyone know the difference between the two?

[steve_g]

My only experience is with 10 lb. Sign foam and 20 lb. Precision board, No direct comparison. Likely the cost difference is how far it was shipped from.

SG

[letterman7]

I've found Precision Board to have the odd void once in a while. It's a little "grittier" than SF as well. Currently I've been using Duna board and love it - much cleaner finish than Signfoam. Again, where are you in PA? If you're local to me you're more than welcome to stop by for samples.

What's 1/2" AC? Depending on the objects being mounted, pvc will be far less in cost to carve and shape.

[steve_g]

What's 1/2" AC?


AC grade plywood

SG

[letterman7]

Ah... shows how much I pay attention to wood anymore. In the long term, plywood will be your undoing in the lifespan of the sign..

[joe]

This is signs 101.

Those of old brush slingers, started grinding our teeth when we saw the vinyl cutter come on the market. Now with the CNC and inexperienced operator we barely have any teeth.