Are HDU foam letters durable?

03.15.2007

IN the last decade high density urethane (HDU) has become quite popular in sign making circles. Despite its popularity some clients rightly ask is HDU durable?

To begin it is important to note that, although HDU is technically a foam, it in no way resembles the Styrofoam your tea cup or packing peanuts are made of. No sign should ever be made uf such materials for outdoor or permanent use in UV light. HDU comes in many densities but those used for signs are roughly the texture and hardness of redwood or cedar.

Positives: HDU is impervious to solvents, does not crack or split, waterproof and carves or machines well. Because HDU is granular instead of fiber based like wood it carves like a soft balsa allowing for extreme detail at lower costs for letters and textured signs.

(Pic of logan glass, heading "An HDU exterior sign with 23k gold leaf letters after 9 years outside")

Negatives: there are only three negative aspects to HDU. 1.Although with techniques such as Grain-Frame the look of sandblasted wood can be produced, the warmth of exposed stained or otherwise finished wood tones are not possible with HDU, as they would be with Redwood for example. 2. HDU is extremely long lasting, HDU does not degrade in the natural sense so we request that any HDU signs that have outlived their businesses be recycled. 3. HDU is softer than metal letters or, depending on the wood, even redwood. As a result businesses at a high risk for vandalism such as police stations or high schools are better off using cast metal or other methods that are less susceptible to harm.

In the end HDU has its place in the permanent sign industry and you can trust Harper to use HDU effectively and appropriately for your business and the environment.

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