If Intumescents have been available for 20 years, why am I just now hearing about them?
Until recently, most intumescents met with only limited success because they had obvious deficiencies and limitations. Traditionally, intumescents have been thick, gummy, foul smelling, toxic, carcinogenic, ugly, and expensive. They have required exotic preparations like two part epoxy primers and couldn’t be top coated – or you had to buy the manufacturers specially formulated top coat. They had limited shelf life and some had to be periodically reapplied, which, of course, is impossible. For example, some products that claimed to be non-toxic and non-carcinogenic still used formaldehyde and other toxic substances. Other products did not bond well to surfaces and other coatings, like paint, did not bond well to them. The defects in the formulae caused them to produce a fragile char barrier that was easily compromised. Once compromised, fire could undermine the rest of the intumescent layer rendering it useless. That was then – Contego is now.
