Material choices

[tomj]

Hello,

We are exploring cutting some signs for businesses and I am wondering what materials to use. I see some of you guys discussing extira, medex, colorcore, HDU, etc.

I have questions about a few of things:

1)Which type of material withstands the elements best? (northern MN weather - 35 deg. F and raining to 75 and sunny within hours not to mention the occasional -40 deg F)

2)Which is the most forgiving with regards to finish? (with out having to learn the science/art of paint/primer combinations)

3)Of corse, economy comes to mind...which has the most bang for the buck?

I would like to get some opinions and learn what's out there and explore some possibilities. I know that this forum is a bottomless well of knowledge and hence the first place I go with questions.

Thanks in advance!
Tom

[tuck]

Hi Tom. I'll go first. :-)

You just can't beat HDU, as expensive as it is, for most exterior applications and for my money. It cuts and sands easily (if sanding is necessary) and does NOT have to be primed before painting. I use top quality latex enamel paints for the back ground and whatever is called for (One-Shot, etc.), on the letters/graphics. It is impervious to the elements, but not to a vandal intent on destroying it. (Neither is anything else, for THAT matter.) It is fairly breakable. If the signs are to be mounted flush on a solid wall, for instance, then it's no problem. But if they are to be mounted, say, between post, then I always laminate 1/2" MDO plywood to be back of it to give it good strength. I use a little "Gorilla Glue" for that.

That's my 2 cents.

[tomj]

Thanks Mark!

Is the HDU that you use about 15 - 20 lbs in density? We currently use a 19# material for some of the 3D models we do at work. It is called Necuron 301. From what I gather it sounds similar to the HDU that is used in the sign industry, but the supplier only advertises it as a model building material so I'm not sure about the element survivability (is that a word?)


If that is similar to what is used for signs, I can see where it wouldn't be vandal proof. The 301, you can take your fingernail and dent/write on the surface. I can just imagine, if some punk was out next to the sign wittling away with a key or pocket knife....Grrr....that is one aspect of sign making I hadn't considered!

Thanks again for the reply!

[tuck]

Tom, hardly any substrates are "vandal proof". Any punk can take a can of enamel spray paint or a screwdriver and ruin any sign in just a minute if he has a mind to. Your customer should have insurance for vandalism and such for buildings, signs, etc. That shouldn't be your problem.

I've never heard of Necuron 301, so I can't advise. I use HDU 15#. You can get it in higher densities, but I never have. It's specifically made for exterior applications, as well as interior. I've made and put up hundreds of HDU signs and never had a call-back except once. I used a cheaper grade paint and paid dearly for that one. The paint failed, not the HDU. Lesson learned!

Exteria is a much tougher customer than HDU. It's basically a water resistant MDF product. It's considerably cheaper than HDU, but heavy as hell, requires special priming and some sanding. Do a search on these boards for Exteria. I know one thing; it's not good for routing a lot of small detail.

I've never used medex or colorcore, so i can't advise on those either.

[jhicks]

Tom, as far as" bang for the buck" and weather resistance, I don't think one can beat Color Core. Its true that the color choices are limited and there is no comparison to a well designed, dimensional, painted sign BUT there are some redeeming features for this "segment" of the market.
1) Impervious to weather, bugs, rot, and even grafitti. (nothing sticks to it even glues!)
2)Its a "design, cut, and ship" product so no time on prime or painting. You can turn a sign in a day assuming you have stock and can get it designed to the cut path stage that fast.
3) Depending on where you might find a distributor over all the price / sq ft is quite reasonable considering what one can sell it for.
4) Its a perfect bridge between vinly and HDU. Modest mid range sell price satisfies a lot of customers who can live with the color choices and still want something with more sizzle than vinyl or wont pay for the higher end $100.00+/ sq ft type of dimensional signage.

Of course there are so many options depending on the market you are targeting, your capabilities, and your profit vs volume expectations that there is no single answer. Chek earlier posts on color core and all these other options to do some homework, then start to get samples from suppliers and distributors and build some samples and add to your knowlege and capabilities. In the end, you will no doubt work with several materials and begin to offer suitable materials, finishes, and dimensional details as your design and fabrication skills develop and you discover the various price points in your area.
Just remember, what you offer has value and don't get in the "trap" of doing everyone a favor, giving them a "deal" or pricing your work too low. Lots of that discussed elsewhere also.
Best of luck.

[gus]

Tom,

This is who I get some stuff from. The have a branch in Mpls/StPaul They have a salesman who come up north regular not sure if he gets THAT FAR NORTH.

http://www.nglantz.com/

They also sell supplies here http://www.haywardsignschool.com/
have never done anything with them.

[tomj]

Wow, thanks for all of the responses!

I have been considering starting out with a "color core" material (I understand that there are several suppliers - the reason for the quotation) mostly for the quick turn around on the product like you mentioned Jerry.

Thanks for the heads up on the heft of the Exteria, Mark! Some of the material we use around work is enough to break your back the way it is!

Part of the reservation of getting into the painted HDU is just that - paint! I'm a little leary of my painting skills and selecting a good paint/primer to use but, I am willing to learn!

I have thought about visiting our local sign shop and seeing if they may be interested in working together on some things and draw on their wealth of knowledge in the paint department as well as offer an aditional service to them.

Ted, thanks for the links. I'll be contacting those guys shortly! It looks like they have quite a line of products. Even if they don't make it up this way, we have trucks delivering to our door daily so we could always get it on one of those. Would it be possible to check out your operation sometime Ted? I have family in your neck of the woods and make it over there once and a while. I was starting to think that I was the only one with a Shopbot north of Hwy 2!

Thanks again all! It sure is nice to have a collective source like this, and I'm sure I'll be back with a barrage of questions by tomorrow sometime!

Tom

[gus]

Tom,
You have mail

[tomj]

Got a couple more questions...

Mark,

You mentioned MDO plywood for a backer on HDU signs - would treated plywood work? How does it compare in price, preformance etc.? Also, when you cut it do you need to recoat the edges with a resin or paint of some sort?

Jerry,

I've been looking at color core and the question of backer comes up again....is there a need for a backer on color core as well?
Also, can you carve on both sides of the sheet for a front and back sign? If so, how does it hold up? So far, all that I have seen is 3/4" thick sheets and it seems like that would weaken them considerably. I am guessing that one would put an extruded channel surrounding the sign for support?

[jhicks]

Tom, the short answer is YES you can run double sided signs and depending on the size you may not need any backer support. Here is what we have learned. When carving one side, always consider the area to be removed and make sure that the color in the core is the lesser of the surface areas. So if there is a white skin and black letters. Make the core black and don't try to make raised letters by relieving large background areas of the surface color. This will create will be an imbalance in surface tension and the material will warp.
If you do need to relieve large surface areas, carve the same relief on the back regardless if its a single or double sided sign to balance the stress.
This makes it nice for 2 sided signs so go for it.
On "how does it hold up?" Keep in mind that the outer color skin is only about 10% of the total material thickness so .075" on 3/4". You only need to cut deep enough to reveal the core color so maybe .100" to be safe. That leaves .550 in the center of a 2 sided sign and you should be just fine with that. In fact we use 1/2" much more than 3/4" but it does depend on mounting and size parameters.

If you design a suitable mounting system like a post and panel, you might want a center cross support or upper and lower horizontal supports but its not absolutely necessary.

The material is pretty stable but you do want to make sure you plan for the following.
1) predrill any and all mounting pilot holes and clear it before screwing any mechanical pieces to it.
2) If you are mounting "through it" ie post and panel type, drill oversized through holes to allow for some thermal expansion. The color core folks can give you the specs but it expands on the length at a greater rate than the height. About .300" over an 8' sheet with a 60 degree F change from the temp you fabricated at.
3) Nothing sticks to it so anything with 3 colors has to be accomplished by ADDING an additional layer or an inlay and screwing it from the back OR if you do plastic welding, that also works but you cant paint or glue to it.
4) Weight! This stuff is heavy. Approx 3# per sq ft in 3/4" material so beware of hanging signs and how they are mounted.

On MDO, its frequently used by the vinyl guys. From what I've seen they fill any edge voids and prime, then use mostly One Shot for their color coat and let it soak into the edges in particular.

Photos of B/W/B material shows large area clear and smaller white oval and raised numbers to minimize stress relieving. White oval style will relieve less stress making it less prone to warping.
This material is just one weapon in your arsenal so experiment and use where it fits the design criteria, budget, and your fabrication skills.
Remember its NOT a cheaper sign but a sign with qualities that are good for outdoor use, long life, graffiti proof,and easy maintaince IF you can live with the color combinations available.


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[tomj]

Thanks again for answering my questions Jerry. I really appreciate all the help, not to mention the patience everyone on this forum has for newcomers!

I will be ordering up some 1/4" color core on Monday and cutting some name plates for around the offices at our shop. I think that I will be getting some 3/4" to help cut my teeth on as well.

Eventually, I will be cutting a sign for our business that we can put out near the highway that runs past us. I was thinking of using the better part of a 4x8 sheet - maybe an in an elliptical or arched top. Looks like some more sleepless nights of planning! Fortunatly, we have a need for some signs internally that we don't have a deadline to deal with until we get up and running!

Thanks again for all of the help and hopefully soon I will be posting some pics!

Take care!

Tom

[jhicks]

Tom, when you run area clear sections of your signs, call Onsrud and ask about the end mills with the corner radius. These have either an .002 or an .020 corner radius and minimize the sharp corner cuts/ mill marks on the cleared step over area of the material exhibited by conventional square corner end mills. Use no more than 50% step over. The result is a much smoother bottom clear surface between step overs. Also be careful with .062 end mills or O Flute (prefered cut is with Upcut Super O-flutes for this plastic or Plastic O-Flutes) speeds run between 11,000 and 13,000 rpm but move speed on .062 is best at .5"/ sec. Larger bits can be dialed up to 1" to 1.5" / sec so start slow and check both onsrud and chip load before breaking any 1/16" bits. We usually try to use a cut depth equal to bit diameter but could probably go a bit deeper however its not usually necessary. On that 1/4", make absolutely sure the surface and table are dead flat. Since you will only be cutting down .025 to .040" to get to the core. We have had occasions where small area's didn't cut all the way to the color core at the end of a file because an area was lower on the bed than our Z Zero point. Especially on 2 sided signs 1/4" where we want as much inner thickness between sides as possible.Vacuum puck seems to work best for this thin stock.
Post photos when you're running. This sign is 1/4" color core FYI and standard Vector Art border/graphics and .062 area clear to accomplish fine line widths. Enjoy
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[tomj]

Thanks again Jerry, The milling marks from a straight mill was one of my concerns, and I thought that I would just cross that bridge when I get there - now I don't have to! I feel like I should hit the ground running, or at least at a jog with all the pointers!

Do you have to do any post-op / clean up on color core? or is it pretty much cut and deliver?

Thanks again and I'll be sure and have my camera ready when I am running!

Take care!

Tom

[jhicks]

Tom, very little "clean up" is required and IF your speed and feeds generate some "plastic hair" on the edges of the cuts, you need to adjust them to dial them out. Where you do get some fuzz, we generally take a stiff bristle plastic brush and simply "rub them off" Sanding doesn't work but for anything larger than fuzz, a sharp chisel will skive away the material where necessary. In general though its a cut and deliver. One last tip, after the sign is done, brushed off, and blown off, take a rag with WD40 on it and wipe down the entire surface inside the cut areas and over the surface. It shines up the material and also provides a bit of surface protection against the elements. Like armor all on your vinyl dash board. You should have good results on your 1st run if you follow these methods but ALWAYS, run your own test pieces to be sure its effective for you.
V carve bits generally don't deliver the best quality cut compared to core box bits and end mills but they are OK if you have the depth to accomplish them. With Serif fonts, the tips of the serifs don't come out well as the cut depth is so shallow at the ends and you don't get a clear crisp edge of the core color. For these fonts consider an 062 end mill "machine along vectors or inside vectors" to dive into the color around the font, then run V bits on letters OR just avoid v cuts except for borders and less critical line ends/edges. V cuts do seem to deliver a nice outer edge when you want to show some color on a chamfered border. Run a "machine along vector" around the outline with a 90 V and then cut through the rest with an end mill to get through the thicker stock.

best of luck