PVC or MDO or ?

[powerlsc]

I have to make a 4' x 4'.5" ranch sign for a barn wall. Heat (Texas) will be an issue and not so much cold.
I have only worked with Signfoam (HDU) before and that was many years ago.
I have a chance to revive my small sign business and realize substrates have changed, especially in price.
Just spent the last 4 hours reading Shop Bot Forum posts looking for info. I cant find out what the PVC is that I'm supposed to order. Open a catalog and I'm overwhelmed!
Because of the size I plan to use at least 1" unless other suggestions are presented.

I have a Shop Bot Buddy but it has been so long since I used it I'm planning to do the sign in layers, letters, silhouette of cowboy roping cow, ranch brand, etc.

If I go with MDO the big box stores look at me oddly when I ask for it. Am I calling it by the right name?

I have attached a sign I did 12 years ago. All HDU and hand carved before my shop Bot. Loved the job and hope to get back to it.

Thanks for any advice you can pass on.

[steve_g]

Yes MDO (Medium Density Overlay) is the correct name… some large lumberyards might call it concrete form board, and you’re right… the big box guys haven’t a clue!
It’s actually my go-to material for several type projects lately… I can’t seem to source a good PVC, just the foamed “Sintra” type material or narrow trim pieces at the lumber yard.
These links will give you an idea what’s out there and what relative costs are.
https://www.plywoodcompany.com/application/common/store/CategoryItemGrid.aspx?categoryid=153
Or
https://www.plywoodcompany.com/application/common/store/CategoryItemGrid.aspx?categoryid=151
SG

[rb99]

I found problems with MDO. It has voids that you cannot see (covered with paper) until the boards are painted. the edges take forever to seal and prime and paint. Then the edges still don't last outdoors very long before the edges are bare and susceptible to moisture and swelling.

Just my take on it. Others may love it though.

[RossMosh]

You probably shouldn't make that type of sign out of MDO. MDO is plywood and when you carve into it, you're going to expose the layers which will have voids and also you're just asking the material to fail. MDO is primarily used as a backer board whether it is for a dimensional sign or a vinyl sign. If you chose to use MDO, you'd be using it as the base and applying letters, designs, ect to the face. I've read of people making pockets into MDO to apply the letters, designs, ect but I personally wouldn't do it. I just think you're inviting the material to fail.

PVC is going to be a foamed product no matter what. There are many different brands out there but there are two main types: interior and exterior. Typically, exterior PVC will be slick faced and interior PVC will be matte finish. This isn't always the case, but is often the case. You're best buying from a sign supplier. Komacel (not Komatex) is the brand of exterior PVC commonly stocked around here. I've used it more than once and have no real complaints about it. Just know after v-carving, you will have to go in and clean up the letters a bit.

Lastly, there is no reason you have to ignore HDU. Many many many people in the sign industry use HDU often and almost exclusively. You should be able to get Duna HDU fairly easily seeing it is made in Texas. It might be your best option considering you have experience with the material in the past.

[powerlsc]

Thanks Steve for the clarification on the MDO.
I see you are in Garland, TX, and looked up several sign suppliers up there searching for HDU. By the time I paid for it then added shipping, I was over $600.00.
None of the suppliers in Houston or Austin carry it and Dallas is an 8 hour round trip.
After spending all day reading substrate related posts there are as many opinions on what to use and what not to use as there are posts.
I'm glad to know you still use MDO frequently and don't have problems. I understand I should seal the edges well. Any suggestions on what to use.
I plan to use layers to build up 3D using the MDO or exterior PVC that Ross has detailed. The decorative pieces I'll carve out of left over Signfoam.
Appreciate the help.

[powerlsc]

rb99, Thanks for sharing your experience with MDO. What do you use primarily as your substrate?

[powerlsc]

RossMosh, Sounds like you too are not a fan of MDO. I'll do some research on Komacel exterior.
Right now I have no access to HDU that is remotely close to being affordable. Used to easily get it when I lived in eastern, PA. and all the workshops I traveled to taught with Signfoam.
I would love to experiment with Duna Corafoam. Baytown, Texas is 2.5 hours from me but you can't buy it there. Raymond Chapman told me you used to be able to to go and get odd size pieces and pay a discounted price. They are on the internet and in magazines but don't ever say where or how to buy it. I have called their offices and the staff is not informed about distribution to sign folks.
Thanks for your input.

[steve_g]

Lynn…
Others issues with MDO are legitimate concerns… Specifications say that any exposed plys must be painted with two or more coats of quality paint. Personally, I’ve never had an issue with voids, in fact, the brand I buy is guaranteed to not telegraph grain or patches to the surface.
I’ve made playground builder boards with MDO and milk crate dividers for plumbing parts. These uses may not be “real world” in that neither is left outside 100% of the time…
I’d like to use the denser PVC but haven’t found a supplier anywhere near me, I’ve had poor success with Sintra with fading and sagging.
https://www.plywoodcompany.com/application/__content_files/Item/00456/Signready%20UV%20MDO%20Tech.pdf
SG

[powerlsc]

Thanks for the link. Is the Olympic Panel what you use and who in Texas carries it?

[steve_g]

Yes, the Olympic panel is what I use, I get it from “The plywood company” in Ft Worth. I tried to see if they (Olympic) have a distributor listing in their web site but no joy…
SG

[rb99]

I use foam board, and for sheet stock I use ACM (aluminum composite material).

Just use the correct materials and charge accordingly.

For your job perhaps the backer board MDO, then the subsequent layers PVC.

[joe]

Lots of good advice here.

For panel signs of size I'm with rb99 except I would also include "DiBond". Or one of those aluminum products. MDO has so many advantages and is relative cheap. I can't see any advantage of using HDU as a panel material. It's expensive and relative delicate.

I love PVC but its HEAVY and can warp without support.

So for me it would be MDO and or one of the Poly Metal sheets.

[GeneMpls]

Joe- ACM is Dibond (a brand name like PolyMetal). We also use a ton of it for a lot of things.

[joe]

Gene,

I'm fond of the 1/4" version. It seems to take on a different character. I've done lots of experiments to find a paint to cover the edges with no success. Have you had any luck?

[steve_g]

Dibond brand has a Polyethylene core… It’s very hard to paint due to its low chemical interaction levels, or at least that’s what I just read! Some people claim success with proprietary primers. Here’s a link to one of them…
SG
http://www.ppglic.com.au/uploads/tds/440%20Polyethylene%20primer.pdf

[powerlsc]

Wow. Lots of good advice here.

Unfortunately I live in an area that substrate supplies are almost impossible to get. I am an hour and a half from both Houston and Austin, TX. The ONLY supplier is Reese supply but they carry a very limited (like 5 sheets) of any brand of HDU. No sign supplier or Lumberyard within 3 hours of me carried MDO. Spend a full day calling around and searching the internet. Plenty of Dibond type products and aluminum products are available.

Like I posted earlier I have only had experience with Signfoam, I'll have to go back and research the forum on bits, speeds and properties of the substrates I do have accesss to.
.
So...after reading all the advice, I purchased (2) sheets of 4x8 of 1" PVC. The sign is 4'x4'. I realize it will be heavy.

I have planned to have the sign hung on the barn side with two large aluminum French cleats attached both on top and bottom.

My question is... Is the 1" PVC AND the support of the aluminum cleats enough to help prevent warping? If I add a backing I'm adding to the weight.

All alternant suggestions are welcomed and appreciated. Thanks.

[joe]

What we've not seen is the image or sign itself. Is this one to have much carving to it.

Here in Oklahoma, we get DUNA from Reese. It's the best HDU.

Last week I proposed a wall sign to a dental clinic. The materials are up to me and I'm considering MDO as the substrate since it's 10' wide. To get the custom, dimensional look I'll apply borders, panels and letters that will be cut from .75" Extira. Although this will make the sign less expensive, that's not the point. I'm wanting a 20 year sign that won''t warp. I'll post the drawing, if anyone is interested, in a few days.

What about HDU. I've had some miserable experience due to hail damage, with this product. Also it's way too expensive and you MUST be careful about it's installation. I've also found that it does harden and become brittle with age. Some of my ten year old signs have cracked. For many people ten years is asking too much but not for me.

If you're running a digital printer for a living, please disregard anything I say.

[powerlsc]

Joe,

I would like to see the interior wall sign for the dentist in progress.

No, wouldn't know any thing about digital printers. When I have the need I'll sub it out.

I live 2 hours from the Duna Manufacturing plant in Baytown, TX. After a call to them they gave me a reps name who referred me to Reese supply in Houston. They only had a 1/2 sheet of Duna Corafoam in stock. They claim there is not enough call for HDU to stock much of any brand. I asked what a 4x8 sheet was when they did carry Duna and they quoted me $247.46. Like you said, that's a bit expensive for a background. They don't carry Extira either. No one around here does. I may have to make a 12 hour trip to OK with my horse trailer just to shop.

I plan to route the edges with a hand router. I'm cutting letters from 1" Signfoam that I have pieces from an old job. Since I haven't learned my Aspire program well enough yet to do a proper layout I have resorted to mocking the sign up on a wall, full size. Way old school but I'm going over the tutorials nightly trying to absorb it all so I can use my ShopBot for more than a storage shelf. Bought the thing then, had financial issues and had to get a steady job for income. Haven't thrown in the towel yet.

If I can get my layout and design on the wall so it can be recognized by anyone but me I will post it for constructive criticism.

[joe]

Lynn,

No apology needed for your learning curve. When I purchased my Bot it took me a full six months to put it together. Then another six months to get it going. I felt like an idiot. Looking back I wish I'd plunked down the money for a more sophisticated machine.

I often call Reese for products they don't have in stock but they're glad to get them for one of their other outlets at no extra charge. Would't they do the same for you. Extira is such an unusual product and carried by lumberyards Only. Reese does have some good MDO.

The sign I'll be making for Carman Family Dentistry is exterior and will be fabricated from MDO and Extira. I'll post the drawing a little later.

You should be able to do all your drawings with Aspire. I'd stay away from the 3d section. It's a waste of time. Don't worry about getting perfect drawings. It's doubtful there's anyone on this forum up for critical advice. Once again I always start out with a pencil. As a matter of fact I'll start off with a pencil drawing on the Carman project and post that. I always get started that way. The pencil is shorthand and fast. I may make a four or five drawings before I turn on the computer. When you have the drawing firmly in your mind setting the type and doing the profile comes easy. Even so, it's best leaving the drawing along for a few days before making a final decision

[GeneMpls]

If you're running a digital printer for a living, please disregard anything I say.

Do I detect a note of condescension?

"When I purchased my Bot it took me a full six months to put it together. Then another six months to get it going. I felt like an idiot. Looking back I wish I'd plunked down the money for a more sophisticated machine"


And what, pray, did that have to do with the Shopbot? Come on Joe- you are better than this. We all recognize that you are talented and successful in your chosen trade and would rather converse with true professionals. If you want to share your obvious wisdom... share it, but I think we all know by now how you feel about us amateurs... please let us luxuriate in our ignorance.

[bleeth]

My take on the sign trade:

The introduction of automated equipment and computer design has changed the traditional signmaker's craft both for the better and worse.
Signmakers now have the ability to turn out a layered or 3-d sign in a fraction of the time that it took years ago, as well as obtain repeatability much more easily.
The flip side of this is that many have come to view signs as an inexpensive throwaway item that can be made up in a few short minutes. Digital Printers, which have made this fast, down, and dirty method of signmaking so available that we now have shops all over the place being run by people with no or little training in the true basics of the trade, such as layout, balance, font selection, readability, and artistry.
We have the same thing in my core business of cabinetmaking.
The relatively small percentage of people making a good living from only well crafted and designed work has resulted from the "mass manufacturing" affordability of product that may serve the function of the user, but has no heart. Many who enter the trades now do so with the idea that in short order they will be a journeyman, and after some time even think they are, when they actually have no idea of what the word actually means.
It is clearly true that, unfortunately, many of the classically trained sign pros that were on this forum earlier no longer contribute. One big reason for this is their being discouraged by the same questions being asked over and over with virtually no prior research being made by the person asking. I'm sure many of us have been amazed by someone asking a question on one thread that has had the same question already answered further down in the same thread!
Many of us who paid our dues the hard way get a little touchy at times when trying to get through to someone who is just looking for the easy way out. I know at times I have been more than a bit ironic in some of my replies and sometimes regret letting my frustration show, and other times not.
For those of you who would like to spend some time on a couple of forums dedicated to fine and/or dimensional signmaking I would suggest the following two sites in addition to Signs 101 mentioned below:

http://www.3dsignforum.com/

This site, like ours, has hobbyists as well but also some very good professionals and a great gallery of members works.

http://creativesignmakers.proboards.com/

This site is almost exclusively pros and includes some of the finest sign artists in the world. There are many technique tutorials shared there and on their website: http://creativesignmakers.com/

I have been a member of both forums for quite some years and when I have the time will go through them just for the educational enjoyment of experiencing the level of professionalism shown there, as I enjoy most the displays of some of the fine creations posted here. It is much like going through the galleries of the carvers and jewelry makers on the Artcam forum. You won't often see people who simply download, carve, and varnish a stock relief and call it their artwork!

Just as anyone, just about, can take a sheet of melamine and build a box with a door and call it a cabinet, one can also cut out a few letters and call it a sign. They are not wrong, but that doesn't make them either a cabinetmaker or a signmaker.


Personally, I have no problem reading a little rant from a professional once in a while as a small price to pay for the fabulous information shared.

Sorry to be so long winded on this and hope that the information on techniques below does not get lost to those who have "newest post first" set up.

Dave

[joe]

Dave,

Thanks for the review. It was correct and a fun read. Gene's OK. I get a chuckle out of his muses. He's doing the best he can.

Lynn has my attention since he's starting back in the sign trade. Fellows like us, down in the trenches making signs find it challenging since there are so many materials and techniques at hand. One wrong move can reduce the profit in a job. For that reason I often offer suggestion in hopes with the intention of helping out. I am guilty of not being all that helpful to novices who don't have any skin in the game. No apology for that.

One of the shortcuts I've found in sign making is to make as few mistakes as possible. As simple as this sounds it's a challenge. For example, material choices are critical. Finishing techniques can be a profit breaker not to mention installation. At one time we had Journeymen positions where you worked along side the experts. Now it's left up to the forums. Older more experienced artists like myself aren't too good in holding hands. We sure do go out of the way to help dedicated newbees.

[powerlsc]

Thanks Joe,

Between you and Dave I finally have faith someone feels what it feels like to feel so helpless. Got slammed a few times on the forum for asking newbie questions. I had done plenty of research before I posted but still didn't understand. Backed off and grew thicker skin. I come from the old schools. My professors would rip up your graph paper in mechanical drawing class if it wasn't up to standard. Pissed you off but you sure did learn.

I'll probably ask further dumb questions but I don't give up easily. I will master this.

I'm trying to post pics of my "design wall". This has been a Tech failure day. Satellite service sporadic on overcast days.

Thanks Joe for the encouraging words and Dave for realizing the craft of sign making has gone way beyond paint, brushes, turpentine and a place to lay it all out.

[David Iannone]

If you're running a digital printer for a living, please disregard anything I say.[/QUOTE]

Hey Joe, I run a Digital Printer for a living, among other stuff......lol. I enjoy your posts and read them all. Thank you for all that you share on this forum as this is really the only one I read, and lately not so much because of workload. As you know I am "ONE OF THOSE GUYS" I have no design talent, but have been in the sign business for 25 years.

Dave R. your post is right on. I started in the sign business at age 15 at a FASTSIGNS franchise back when the Gerber 4b cutting plotters were starting to become popular.

Its funny to me that back then some of the artists that were hand painting signs and vehicles were telling folks anything they could to discount the "vinyl guy" but now a days some of the vinyl guys that still haven't bought a digital printer are saying anything they can to discount the printed graphics. Next on my equipment wish list in 2017 is a 4'x8' Flatbed UV printer to print directly to most any substrate. These machines are beating the snot out of the solvent printers and screen printing industry in terms of labor savings AND material savings in my opinion for most flat "quick signs"

Technology is great. I think as long as you are honest with yourself and know your strong and weak points you will do fine. Just as Joe sends out his CNC cutting and digital printing (to a guy like me) I send out my design work to a firm I have teamed up with in my town. (no where as talented as Joe)

I do the cheap dime a dozen signs every day, but at least in my case with all my expertise in the sign industry I educate the customer. Quoting these type of signs takes seconds over the phone with professional estimating software, and if they want cheap I give them cheap.

If they want high end, well I do that too. I have good subs for anything I cant handle or don't want to. Its all about pulling from your past mistakes and victories. Over the years I have messed up so many jobs and lost money on some its hilarious. I have hit some home runs too......we all have. That's what gets me out of bed every day (the home runs). I am a sign guy with many hats, that's all. Heck I have even cut a few cabinet door jobs this year on the shopbot. Of course my customer knows I know nothing about cabinetry. I know I will never be a skilled woodworker or an artist but when I need help from that talent it is just a phone call away. I am a business man looking to make an honest dollar.

I am starting to build channel letters. Just bought LED wizard software from Aries graphics (very good software). Could I do it without that software? No way. I am not skilled enough unfortunately to be able to pull it off without software. Who cares though right? I think diversification is the key to most small businesses of any kind now a days.

There is even room for the guy that goes to signwarehouse.com and spends $2000 on a vinyl cutter and software combo. If the customer calls him and talks to him then calls me and talks to me I think they will understand the difference. IF they don't then I don't want that customer anyway.

Back to the original question.....PVC


Just my 2 cents.

Dave

[powerlsc]

Back to the original PVC questions. MDO is not available so I have purchased (2) 4x8 sheets 1" and (1) 1/2" sheet. Reese Supply says brand name is Jain America. Looked up the technical sheets on their website and it is primarily house siding.
Anyone heard of or worked with this brand?

I still would like opinions about backing. Is the 1" thickness enough along with 3 1/2" aluminum French cleats installed top and bottom? Sign is 4'x4'.

I have just upgraded to Windows 10 and the shopbot site won't upload my re-sized photos.

[David Iannone]

Hi Lynn,

Thanks for the post. It is a great question and has me thinking like it was my job. I will tell ya how I would do it. Sometimes I fly by the seat of my pants on jobs so take my advise accordingly. Excel is good PVC, what is the color of the background? Is there a lot of material being removed from the main background panel? You said you are gonna do it in layers which sounds good to me. Joe has posted some great pocketing techniques so depending on the layout maybe you do shallow pockets for the layers/letters/logos as you build the thickness up in the design.


Cut, carve, paint the whole sign in separate pieces/layers. Install the first layer directly to the building with screws in all the pockets before you put on the second layer. Then glue the rest of the layers in place like a nice puzzle. They will be all painted and ready to fit right in. Super clean edges and as long as you have enough pocketed areas in the first layer (like maybe a border all around the outside with the second layer being a border that goes over your hardware) I think it will hold up just fine.

Dave

[powerlsc]

Dave,

Thanks for following this thread. Interesting results!

Doing my research I learned to stay away from dark paint on exterior applications of PVC. The lettering and border will be a deep royal blue, the routed lines on border white and background will be tan.

Since I am not up to speed on Aspire this is all being done by hand.

Background and border are 1" PVC. Letters and accents HDU.

I know to use long set up when bonding PVC to PVC. What adhesive is preferred is preferred when bonding HDU to PVC?

Whoops. Two clicks on attachment should turn it around.

[joe]

I'm in agreement with David.

Lynn's idea of cutting all the parts for such a complex sign, by hand, out of PVC, is a mistake. This material does not sand well and corrections are difficult. This is a Router Job.
Dark colors on PVC are not necessarily a problem. Most of my signs are dark but you need some kind of braces just like you would on HDU.
PVC Gorilla Glue is the adhesive to use.

[powerlsc]

Joe,

Only the background is PVC. Letters are HDU, yes and cut with a scroll saw. Primitive but works. The HDU sands well. Even got my hands on some "Duna"!

Thanks,
Lynn

[RossMosh]

I'm not a huge fan of Ex-CEL Jain PVC. Compared to Komacel, it's a bit of a step down, which is fair enough because it is a less expensive product. I had three issues with Ex-CEL. It stunk to cut/engrave/sand. I'm not a big fan of cutting materials that literally stink. I found the interior texture to be more grainy/gritty than Komacel. I've found on all 1" PVC there is a "seam" roughly halfway through the thickness. On the Ex-CEL PVC, it was more pronounced. If it's all you can get, I wouldn't be too concerned but if you can get something else, it might be in your best interest.

The big thing to monitor with PVC is to make sure you get the right stuff. Interior stuff is matte finish. Exterior stuff is glossy. Now this isn't always the case, but it's the case more often than not. If they try to give you a matte finish material, take the time and call the manufacturer and the supplier and make sure you're getting exterior grade PVC.

[powerlsc]

Can't get a break here.

Reese supply sent me INTERIOR PVC (Excel). I called Jain America, their sign and graphics division, and they assured me it could be used outside. I am really n a bind and have to use it. I'll prime it well and use more coats of paint than originally planned. May be a redo down the line.

Sucks being living in the middle of nowhere.

Lynn

[joe]

Thanks for the update fellows. I'll call Jain America for more clarification.
One of the issue's is most PVC manufacturers do a poor job of identification of their products. Most of it doesn't even have a MFG stamp.

[bleeth]

For the future Piedmont Plastics has a distributorship in Houston and carries a pretty full line of PVC and HDU sheet goods as well as a lot of other plastic sheet materials.
I deal with them and they have always been helpful. But they only deliver here through 3rd party delivery service.

[powerlsc]

For the future Piedmont Plastics has a distributorship in Houston and carries a pretty full line of PVC and HDU sheet goods as well as a lot of other plastic sheet materials.
I deal with them and they have always been helpful. But they only deliver here through 3rd party delivery service.

Dave,

They didn't come up on my a Google search under sign supplies, sheet PVC, building supplies or others. I'll call them as soon as I get this mess out of my way.
The manufacturer gave me the names of other comanes in TX that buy from them.
Thanks for your post.
Lynn

[rb99]

Don't use the indoor stuff outdoors.

[bleeth]

They carry Celtec which is outside compliant with high UV resistance.
You can link to the product manuals on their website-lot's of good info there including recommended paints:
http://www.vycomplastics.com/files/technicalInformation/celtec_user_guide1.pdf

[RossMosh]

It's a real shame this industry has so much mixed information floating around. There is no real reason for it but manufacturers and distributors can't get on the same page which just makes the end user's job even more difficult.

Here is a little guide, to the best of my knowledge PVC brand names, manufacturer name, and how the distinguish exterior vs interior grade.

Jain: Interior = Ex-CEL FF. Exterior = Ex-CEL IF
Kommerling: Interior = Komatex. Exterior = Komacel
Vycom: Interior = Celtic. Exterior = Celtic Ultra White
Palram: Interior = Palight Premium/EPS/Project. Exterior = Palight Outdoor
Azek: As far as I know, it's all exterior grade but, it's also matte finish.

As you can see, it's a complete failure in branding which results in the confusion. Only Kommerling makes an attempt to clearly distinguish the two products as being different. Palight also does a good job because they keep it simple and simply call it their stuff Palight Outdoor. No confusion there. The issue with Palight is they offer 3 different finishes and I believe one of them is a matte finish. How is a picker supposed to know the difference between Palight Outdoor with a matte finish and Palight Premium with a matte finish?

[joe]

At least PALITE comes with a translucent cover sheet with their name on it. So far it's my choice but costs approx. $30 a sheet more than EX-CELl by Jain. That stuff stinks to high heaven and sells for about $120. a sheet.

Isn't it great we are even having this discussion. Two years ago few router guys even knew what it was. Even now, most think it can't be used for exterior use because the only thing they've tried is the cheap half inch interior grade.

Another interesting fact is the PALRAM has a 25 year warranty.

[powerlsc]

Definitely wish I'd had all this information on PVC a month ago. I could have made a more educated purchase.

As it was, Reese supply was a disaster. Salesman who claimed he has 26 years there.

After the truck delivery driver claimed he couldn't find my location, I had to send someone into Houston to pick up my order or wait another week. When I got my order the PVC sheets were 3/4" and not the 1" on my invoice. After checking with the manufacturer and the forum I realized I'd be sent interior PVC and not exterior.
When I called Reese to complain salesman said he never knew there was a difference.

So, I worked all day on the interior PVC and just sat down to read the forum.

Does everyone agree with rb99 that the interior PVC will fail. Manufacturer Jain America told me it could be used. Why don't they label this stuff? Not one out of three PVC sheets and one Duna sheet was stamped in any way.

Lynn

[joe]

I agree there's a need for a good forum to get opinions on materials and techniques. Not only that, a good forum can suggest suppliers and their locations. The SB forum has been the leader for years and I hope it continues to set the standard.

From what you've posted I think you have a case against Reese. Hope you make a copy of your post and forward it to their home office. At this time I'm getting ready to place an order for eight 19mm sheets of PVC. Your post made me re-think my order. While the Ex-Cel is (Jain) is cheaper I'm going with PAlight. It's available through N Glantz and Graphics Solution Group. We don't have a good supply for much anything else.

[RossMosh]

I just did a quick measurement of some samples of PVC I have laying next to me.

EX-CEL FF = 3.5"x4.75"x.75" = .250lbs = 49.875 in^3/lb
Komacel = 2.5"x6.0"x.75" = .245lbs = 45.92 in^3/lb

So as you can see, the EX-CEL FF is actually more dense than the Komacel, which is designed for exterior usage. We haven't seen the sign you're making so it's impossible to truly guide you but my guess is you'll be fine using the material they've provided so long as you keep in mind PVC moves and this PVC might expand a bit more than you originally figured.

My personal opinion is I'd stop where you are. Demand a refund. Get an exterior grade product. Why? Because you've just started the project and why take the risk? You're going to dump hours of labor into this project and hundreds of more dollars of materials. Again, why take the risk? I have a hard time believing that you can't get any exterior grade PVC or MDO within 2 hours of you. MDO is relatively common stuff for a lumber yard and even if they don't stock it, they should be able to get it from their supplier as part of their next shipment. I can't imagine a plywood supplier not having a pallet of MDO sitting in their warehouse. It may come unprimed, but many people prefer that as they don't care for the pre-primed boards. To put things in perspective how common MDO should be, Harbor Sales, a "local" sign supplier, has hundreds of sheets of MDO available in different thicknesses and sizes and they focus on selling to the sign industry.

[rb99]

^That's why I say don't use indoor outdoors. You're buying a ticket on the Titanic...

[joe]

Once and for all we have lots of good information about PVC. The only area not very well covered is the expansion factor. Knowing it will happen I've made provisions when putting my signs together. Of all the materials I've used, this one has the most advantages. Lets hope the manufacturers will maintain good standards.

I've just received another order for exterior park signs. The size remains the same 28"x78". The color is dark brown. After two years they all look like new.