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signs we've built using high-density urethane |
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| What is it? - |
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"HDU" is short for high-density urethane foam. Unlike other foam
with which you may have experience, it consists of more solid and less air. Using urethane
as a base means that it is impervious to all petroleum-based solvents. Even in it's
"raw" state, it is completely waterproof and unaffected by climatic changes. |
| A material Designed Expressly for the sign
industry - |
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Years ago, enterprising chemists saw the need for a durable, predictable
material for use in three-dimensional signs. They saw many problems with wood and sought
to create a superior replacement. They discovered urethane foam, and then worked to refine
and improve it. Today, "Sign-Foam" and "Precision Board" are brand
names for high-density urethane foam manufactured to precise standards expressly for the
sign industry. |
| Why we're converting to work with it - |
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The answer, for us, is primarily that top-grade redwood is becoming
increasingly difficult to get. The true vertical-grain boards have been scarce
and very
expensive for some time. Now, this seems to be spreading to the clear, all-heart grade.
If redwood is not all-heart, that means it contains "sap wood". This part
of the wood lacks the natural oils that give redwood it's distinctive color and
rot-resistant qualities. "Sap wood" is every bit as subject to dry-rot and
insect damage as pine or fir. |
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