Alternative to "Sign Foam"

[jerbear66]

Hi
I am looking for a lower cost alternative to "Sign Foam". I need 4'x8' sheets 3/4" thick. I have an opportunity for a large job that I am trying to keep from going overseas. Any suggestions are greatly appreciated.
Thanks
Jerry

[paco]

Hi Gerald!

MDF, Extira, styrene foams...

[billp]

And don't forget "Trupan" !

[pfulghum]

Whats the diff between MDF and TRUPAN?

[billp]

Trupan is made from plantation grown "radiata pine", and when pressed into sheets they use something like 95% LESS formaldahyde binders than standard MDF. It is a light color, which can be stained, and supposedly some of the furniture guys know how to "dry bend"it with the application of heat.
It has a beautiful surface skin for carving (and it carves quietly, almost like a thick piece of cardboard).
But other than not killing yourself with formaldahyde, it's major advantage is that a single sheet of 18mm (.7") only weighs in at about 60 pounds!!! As with ANY composite product (except the ubiquitous Extira) you need to seal it well for outdoor applications. I have a Trupan sign that has been outside through three Northeast Winters, and it shows NO sign of delamination...
Ed Conley located their only office in the US, and here it is;
Arauco Wood Products
5901 C Peachtree Dunwoody Rd.NE
Suite 455
Atlanta,GA 303328
770-379-9270
Fax-770-379-9288
Seems like they would be the people who could tell you where to get it locally, OR you might try to drum up some interest in your area and do a "bulk/group buy" the way the 'Botters in the Atlanta area have lined up.
Once we tried Trupan, we stopped any further use of MDF in this shop...

[jhicks]

You might also try expanded PVC with brand names like Komacel and Celtec.
I see it used and know there are folks who don't prefer it but from what I see, If you can get the finishing down, its a viable alternative.
I think you'll find it at most sign material distributors along with sintra.
I agree with Bill on Trupan over MDF. Its the way to go with that type of composite material.
Then of course there is color Core for a 2 color cut and ship product that lasts forever if the standard colors fit your application.

[gerald_d]

Bill, Trupan (http://www.arauco.cl/panels/products_trupan_mdf.htm) comes in a couple of weight/density grades - Standard, Light and UltraLight. The only one stocked here is Standard (marked "ST" on the edge of the board). Which is about as heavy as the other MDF brands. Are you normally using the lighter versions and are they strong enough?

[Brady Watson]

Trupan Ultralight is usually what most of us who use it, are referring to...It is 40% lighter than MDF...with about 1% the formaldehyde, it puts off a chip and sands like butter.

Strong enough? It depends what you are using it for. If being used as a substitute for sign foam or for decorative purposes, it is fine. I believe that Bill P. used it on his 16' outdoor sign...sealed with shellac & epoxy. Still looks good, with no signs of swelling etc.

I have used it for 3D work and I absolutely love it. It's cheap and carves like a dream...plus cutting tools last about 20X longer than if you were cutting MDF.

-Brady

[billp]

Gerald,
Brady is correct. I should have noted that it's the "Ultralight" grade we use exclusively around here. As with any composite board you have to work with the knowledge that you will put in extra effort to seal it, but at roughly 25% the cost of HDU foam in comparable thicknesses it's well worth the effort..

[gerald_d]

This thread is seeking an alternative to sign foam and I am sure that Trupan does a very good job of that. But a casual reading of this thread can give the impression that Trupan can replace "MDF". Period. (for all applications)

I just wanted to point out that a.) Trupan is a MDF and b.) that it is available in different grades. For signs the UltraLight is obviously fine, but some of our MDF applications need higher strength (eg. walkways on movie sets) and thus we have to keep an eye on the appropriate grade.

Around here, our market has not yet learnt to distinguish between types of MDF. If you walk into a board shop and ask for "MDF", there is a very good chance that you will be given Trupan ST. Before we learnt its name, we were asking for the "yellow" MDF. Before doing some homework because of this thread, I didn't realise that Trupan makes lighter grades - I am sure an enterprising importer is going to bring in the cheapest grade and pass it off as our standard "MDF" and we are going to see some movie set collapses.......

[joe]

Like all of he above posts, I too enjoy using Trupan. When I showed it Bill P., as a carving medium, he instantly became a fan. Up to that point it had used as a spoil board with vacumm hold down quality.

While it has some replecement value over HDU, they are few. A couple of advantages of Trupan is the smooth, easy sanding surface and cost. My last shipment came in at $25. each for a dozen.

The concern with it, posted to adnosium, is waterproofing. We seal off by soaking in epoxy wash, and this works well for letters. I would be very suspecious about it for large exterior panels. If one of our exterior signs failed, over years, we'd be loosing money. I am willing to pay the added expence for the real HDU stuff.

Extira is another animal. I have no porblem using it for our higher priced carved signs. I believe it will withstand the elements, but it doesn't sandblast well and is dang heavy. We like to give our signs a wood texture which is hard in this medium. Also it is a sticky mess when doing an area clearance. That oily dust goes every where and sticks.I still love it anyhow. It carves like butter, but needs to be sealed off just like Trupan in order to get sure good paint surface.

Happy routing

J

[jerbear66]

Hi
Thank you for all the information. The winner is..... 19mm grey Celtec. This color will work very well for us and It should cut down on finishing time since it already has the color on it and in it. I will use all the information above if this sign making thing becomes regular work for us. I may have not mentioned in my original post that this particular sign is inside a jewelry store. Now you helpful, knowledgable people are not off the hook yet. What are your recommendations for a bit to cut the Celtec? Because of the detail of the letters it must be a bit with a diameter of 1/8". For the samples thus far I have used an onsrud spiral cutter, but some have told me that a 2-flute cutter may be better. Let the debate begin and thanks. This job will go a long way towards making our shopbot a profitable machine.
Thanks
Jerry

[jhicks]

Gerald, My 1st inclination would be to call Onsrud tech support and ask. They have o flutes, super O flutes, and also bits specifically for assorted materials BUT my opinion now is that wherever I used to use a 2 flute end mill, I have converted to O flutes. So far we have used 1/4", 1/8" and 1/16" and edge cuts are superior to 2 flute end mill on wood, gator foam, and color core.
I spoke to a guy yesterday who cuts volume corian and he says the Belin O flutes bits are supposedly made better, sharper, and last longer and both belin and Onsrud are owned by the same French parent Company?? (his input but can not verify this is true)
Finally, vacuum hold down is also a critical part of the equation for crisp edge profile cuts and interior area clears.
As always, run pilots and verify speed, feed,cut depth and ACTUAL cut width. A test on a straight line with a 1/8" bit will probably point out to you that the 1/8" bit line you expect to get may really be .123" or .122" wide if tight tolerances are required. Measure twice, cut once or as my daughter says, measure once, curse twice.

[gerald_d]

Onsrud & Belin are controlled by the same German Parent "Leitz Metalworking Technology Group (http://www.leitz.org/leitz_english/unternehmen/lmt.html)". The folk at Belin told me that they produce under a range of labels, depending on the market.

[joe]

Dang, I allways get lost in this type of discussion.

The original help line request was an alternative for HDU at .75". The final product decision was .50 PVC. Well, aside from the fact that they will both go under the router, there is little in common.

Router bits? Wouldn't make a guess as this buss is all over the road!

J

[jerbear66]

HI again
I have talked with Jeff at Onsrud tech support. He suggested a single flute bit in 1/8 diameter, but since I am cutting 3/4 thick material the bit will need some custom machining work done. The standard cutting length on an 1/8 bit is 1/2". For an additional $10.00 onsrud will put an extended reach length on the bit just past the 3/4" mark. This will allow me to cut my desired depth without "rubbing" The cutting length is still 1/2" but we will be cutting in passes so this shoudn't matter. My plastics supplier is sending me some off color 19mm celtec to play with and my wood distributor is sending me some "Trupan" and some MDO to try out for comparison and future consideration. I will let you know how it works out and I will post a picture if I can figure out how. I know there must be a post here somewhere that shows you how. Thanks for all the help and insight. This board is a wonderful asset to "ShopBot" and I hope they realize it.
Thanks again.

[jerbear66]

Hi
Here are some pictures. The purple is "Sintra", the pink is "Owens Corning" insulation foam, and the green is particle board with "Formica" laminated to it. The measurements of the sign are 25.250" by 2.25" and 3/4" thick.
Thanks

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