What Is

What is = Solid=20 Surface?

By Mike = Duggan

There is = something special=20 about solid surface. The look on the face of a 20-year = woodworker=20 who has just finished his first seam; the look on the face = of the=20 homeowner at a kitchen & bath show who strokes a solid = surface=20 countertop for the first time. We can all remember that = excitement,=20 which probably got us involved with the stuff in the first = place.=20 But what is it?

Listening to one fabricator's = story=20 helped put the question into perspective. "You know how it = goes in a=20 presentation for an architect. You wait an hour, and then = get=20 ushered into a conference room and told, 'You've got five=20 minutes.'

So you go in with your = suitcase, set it=20 up on the conference table and open it up so that the guy = can't see=20 what's in it. While you're doing this you're saying, 'Corian = is=20 sheets and shapes. Here's a sheet.' With that you take a = polished=20 Corian sphere and you roll it down the table at the = surprised=20 architect. Now the guy is jumping up and looking in the = suitcase (at=20 color palettes, another sphere inside a cube, etc.), and now = he's=20 calling out into the hall, 'Hey, come in here and look at = this=20 stuff!'"

What Does it=20 Do?

The heart of solid surface is = that bundle=20 of properties that make it a unique product: its performance = characteristics. Some performance characteristics that all = solid=20 surfaces share are:

1. It's solid. The sheet or shape = must be=20 "homogeneous"--that is, the color or pattern must be = absolutely=20 consistent throughout every part. This makes it very unlike=20 gel-coated products such as cultured marble, or laminated = products=20 such as plywood or plastic laminate. It also makes it a = little bit=20 like wood, but without knots or grain.

2. It's machinable. = Don Slocum might call this a bogus = distinction,=20 since as he says, "With the right tools anything is = machinable," but=20 others see that most solid surfaces are machinable with = woodworking=20 tools. This might be what gives solid surface much of its = magic. It=20 is immediately tied into an ancient tradition --woodworking, = cabinetry, joinery--that remains fresh and vital as ever. = Most=20 woodworkers love solid surface, because, they say, you can = do so=20 much with it. Craftmanship and the skill of the artisan = remain an=20 integral part of the solid surface picture.

Part of being machinable is = that it's=20 repairable, although there are gray areas here, as there are = with=20 most of these characteristics. Quartz sinks are not = repairable--are=20 they solid surface? (if not what are they?) Is a 1/4" = wetwall panel=20 that has been glued to a piece of sheetrock truly=20 repairable?

3. It's hard. (But as we've seen above, maybe not too hard.) = There is a=20 range here, but it is not clearly defined. The tests on the = Spec=20 Data sheets that are supposed to clarify things (steel balls = dropped=20 from different heights, etc.) seem only to make things less = clear.=20 Suffice it to say: harder than wood, not as hard as steel.=20 Hard.

4. It's non-porous. = Speaking chemically and technically, = nothing is=20 100% non-porous. But solid surface is very close. It is = unaffected=20 by water and changes in humidity.

5. It's stain and=20 chemical-resistant. Most=20 household staining agents and chemicals, and even some = industrial=20 chemicals, will not damage it.

6. It's = fire-resistant. Again, = there are gray=20 areas here. Avonite's class III colors, though certainly = solid=20 surface, are manufactured for a specific market requirement = and are=20 not fire-resistant. But most solid surfaces are = fire-resistant or=20 fire-retardant.

7. It endures. This is reflected by all these multi-year consumer=20 warranties. Solid surface, unless damaged, should remain=20 unchanged--for how long? Theoretically, based on what we = know about=20 the chemistry of the stuff, hundreds of years is not = far-fetched.=20 The oldest Corian installations of 29-30 years certainly = seem to=20 support this conclusion.

8. It is esthetically = pleasing.=20 It has beauty, a look, a "feel." = It is a=20 decorative surface, made to be seen.

What's In=20 It?

Most solid surface materials = combine two=20 main ingredients: a natural mineral (the "filler") and a = resin (the=20 "binder"), along with various additives. These are combined = and then=20 cast in a curing process that results in a sheet or a=20 shape.

ATH

The filler of choice in most = solid=20 surface has an unglamorous name: alumina tri-hydrate, or = "ATH." We=20 talked with Don Mills, market manager for cast polymers of = the J.M.=20 Huber Corp.'s Engineered Minerals Division, to get the = "scoop" on=20 ATH.

ATH is refined from bauxite = ore (in a=20 process called the "Bayer" process, in case all this = technical stuff=20 starts giving you a headache), and looks like a tan powder. = Bauxite=20 is a form of clay, which means that when it comes to the = natural vs.=20 artificial thing, solid surface starts as one of the most = abundant=20 and natural minerals on earth. The tan color comes from = organic=20 contaminants called "hubites," and means that most ATH used = in solid=20 surface must be refined again to get a special "white" = grade. This=20 grade has a high degree of translucency and allows for = bright, pure=20 light colors, especially white.

ATH has great physical = properties. It has=20 excellent chemical and stain resistance; excellent = water-resistance;=20 nice translucency; hard enough to give superb = impact-resistance but=20 "soft" enough to be machinable; and one last almost magical=20 property: not only will it not burn, but because it has = "water in=20 hydration," when attacked by heat ATH actually releases = steam. This=20 makes it a natural fire-retardant.

ATH can comprise 45-70% of a = sheet of=20 solid surface. It would stand to reason, then, that the = price of ATH=20 should have a lot to do with the price of solid surface. The = price=20 of ATH today, in fact, is at an all-time high, but why that = is true=20 has very little to do with solid surfacing, according to Don = Mills.=20 Only 5-7% of all the ATH sold in North America goes into = chemical=20 applications, and only about 15% of this number goes into = "polymer=20 applications," like solid surface. The vast majority goes to = make=20 aluminum metal, and therein lies an interesting = tale.

Smelting alumina into = aluminum requires=20 huge amounts of electricity, which meant that the former = Soviet=20 Union, with vast hydroelectric power reserves, was a major = producer=20 of aluminum. With the breakup of the Soviet Union, the world = lost=20 much of this production capacity, so because of the laws of = supply=20 and demand, prices have skyrocketed. Amazing--democracy in = Moscow=20 means pricey countertops in New York!

Other=20 Fillers

Other materials have been = used as fillers=20 for solid surface. Calcium carbonate was used in the first = Corian=20 sheets (see box). Quartz is used to make some sinks, but = yields a=20 material too hard and brittle to be easily machinable. = Swanstone=20 uses glass fibers to add strength and impact-resistance to = its=20 product. Special fillers like glass beads have been tried = and used=20 to achieve specific effects. And then there is the Midwest = company=20 which manufacturers a "solid surface" using a = environmentally-safe=20 filler of recycled newsprint!

No = Fillers

Avonite's Class III colors = contain no ATH=20 at all. This is a conscious choice, according to Wayne = Rutledge,=20 head of Commercial Development at Avonite, a choice which = responds=20 to a specific demand of the marketplace. Scratches in dark = colors of=20 solid surface materials filled with ATH show white (because = of the=20 whiteness of the ATH), and also encounter the finishing = problem=20 called "whitecapping," where sanding results in white = blemishes.=20 Avonite's Class III colors solve this problem by being pure = resin.=20 By losing ATH, they also lose many of its benefits, chiefly=20 fire-resistance, but also some hardness. It is a trade-off,=20 according to Rutledge, but one that allows Avonite to = provide its=20 customers with a range of dark, extremely rich, deep-looking = colors=20 that they can't get anywhere else. "We could make Avonite as = hard as=20 iron if we wanted to. The trouble is, it would look like=20 iron."

Resins

Two main "families" of resins = are used to=20 make solid surface: acrylic and polyester. A purely = acrylic-based=20 resin yields a sheet that is thermoformable--that is, it can = be=20 heated, bent to a new shape, and cooled without any loss of = its=20 performance characteristics. The other chief difference = between=20 acrylic and polyester resins is that acrylics are unaffected = by the=20 ultraviolet rays present in natural light.

Polyester resins (including = those which=20 are "acrylic-modified," that is, mixed with acrylic resins) = are used=20 in many high-strength demanding applications besides solid=20 surfacing, including outdoor applications like boats and = aircraft=20 cowlings. Solid surface products made with these resins are=20 generally not considered to be thermoformable, although some = manufacturers as well as fabricators do in fact cite some=20 thermoformability for their products.

Both acrylic and polyester = resins start=20 life as petroleum, and thus their cost is tied at least = indirectly=20 to the price of oil. But other supply and demand factors = enter in to=20 make the chemical market extremely volatile (no pun = intended)=20 price-wise. At today's prices, acrylic is two to three times = the=20 cost of polyester.

Additives

Every solid surface product = contains=20 numerous additives. These include pigments, but also a host = of=20 additives that improve or enhance chemical and performance=20 properties, or even affect such mundane things as the "pot = life" of=20 the resin in transit and storage : UV absorbers, = cross-linking=20 agents, stabilizers, the list goes on. Every solid surface = product=20 continually changes its additives with improvements in = technology,=20 carefully tweaking their products in a process of = "continuous=20 improvement," in the phrase of Dave Nickles, Supply Chain = Manager=20 for Dupont Corian. One important additive which all solid = surfaces=20 share is a catalyst. This is the chemical, usually a = peroxide, which=20 causes the mixture to harden, or cure.

Casting

The way a solid surface is = "cast" is=20 generally a simple one. The resin "syrup" is mixed with the=20 additives and fillers and then poured into a mold, usually = open,=20 sometimes closed (usually closed for shaped products). It is = important that no air bubbles are entrapped in the mix, as = this=20 would result in voids in the material. This is accomplished = in=20 different ways, from simple adjusting of the viscosity of = the mix to=20 vibrating casting tables and other more exotic=20 methods.

Curing

"Curing" means allowing the = chemical=20 reactions that form the solid surface product to be as close = to 100%=20 complete as possible, leaving a stable, inert material with = all its=20 performance properties intact. Some solid surfaces cure=20 "autogenically,"--by themselves in the open air. Others cure = by=20 being bathed in steam or heated in ovens. Many polyester = resins=20 require "post-curing" operations, usually a heating-cooling = cycle=20 which increases the degree of cure. Careful curing of solid = surfaces=20 is a critical part of the manufacturing process. An = improperly=20 controlled cure can cause "boil"--that is, air bubbles = appearing in=20 the material--effectively ruining it as a solid surface. = Carefully=20 controlling temperatures during curing is an effective way = of=20 reducing this risk.