Anyone here cut HDU board? High Density Urathane sounds very tough! It's over $200 for a 4 x 8 sheet.

I think it's just foam, and cuts very easily.

Signfoam3, I found info on it now. Thanks.

It's signfoam, very expensive. Made for sandblasting, carving by hand, or routing with cnc machine. Not very durable strength wise. It comes in different densities, lbs per sq ft. the heavier ie denser the more expensive.

I'd say! R&J sign supplies - 4' x 8' sheet 15 density 3" thick - $323.00!

HDU represents many improvements over conventional wood and is used by the sign trade for dimensional signage. I would track down a sign supplier in your area for better pricing, or a sign shop to buy some demo scraps. They may have some sheets on hand that have suffered damage and will sell either 1/2 sheet or reduced cost. There are coatings for HDU that will provide a rock-hard finish, if anyone that reads this knows of a tested coating I would like some info on it. I have tested a couple with mixed results. HDU will take soft impact damage and can be snapped without proper cross-bracing. The sheet product has open pores that will not yield a smooth finish without prep coating and wet sanding. That being said its a sign and you look at it, you dont smell it - so prep and finish coat is usually enough.

Negatives aside, as a sign material alternative to real wood Signfoam formula 3 will not check, absorb water, chemically resists almost anything, will not warp, split, interest insects, or have excessive expansion like wood will. HDU boards can be purchased in thicknesses up to 5" and 5x10, and will laminate together very easily. HDU can also be painted, faux wood grained and worked with chisels easier than wood as it is an expanded closed cell without an internal grain. Do not assume that all HDU has the same qualities as Signfoam 3 - I saved a whopping $45 on one sign until I had to redo it in SF3 when the cheaper stuff warped over 1" out in the center. For all of you that have been happliy using cheaper brands I would highly recommend laminating your panels to aluminum panels.

As to the price, your finished HDU sign routed or sandblasted will sell at $55-$75 per foot for simple signs. Grain framing adds another $10-$20 per foot.

And no I don't work for Sign foam - there product just provides a large chunk
of my yearly revenue.

Edit - for gantry cnc users - you must settup a vac system to collect dust at the head and an air system to blow off the rails. HDU dust is talc fine powder that will stick to anything - especially in your rails, gears, and lungs. DO NOT EVER route HDU without a high quality dust mask or supplied air hood. Do not expect to set it up n let it run overnight - dust will accumulate and pack rock hard in less than 30 minutes - I know, it piled up enough to throw my first attempt off over a half foot until the limit switches tripped.

There are coatings for HDU that will provide a rock-hard finish, if anyone that reads this knows of a tested coating I would like some info on it. I have tested a couple with mixed results.

What about this? http://www.fxsupply.com/vanillacryl/vanillacryl.html