Materials and Sources Exam 3

Lime Plaster Recipe

Recipe: limestone + water + sand

Lime Plaster Information

-used for historical repair, renovation, true frescos, and interior wet applications

-characteristic extremely hard durable finish, very water resistant

-takes about a month to fully cure

Gypsum Plaster Recipe

Gypsum + sand + water + additives to control setting time/use

Gypsum Plaster Information

Pros: Excellent for sound control, specialty details, naturally fire resistant, good insulators for energy purposes, irregular and complex architectural forms

Cons: Considerably more expensive than drywall, holes and damages are much trickier to repair.

Veneer Plaster

Thin layer of gypsum plaster or other specialty plasters applied to a veneer appropriate substrate or walls primed with orange plaster primer. USE BLUEBOARD specifically made to hold veneer plaster.

Traditional plaster installation method

1. Lath - wood panels

2. Scratch coat - first coat, some kind of aggregate: sand, fibers, etc. fill in lath

3. Brown coat - often includes animal hair to create texture

4. Finish coat - finest coat

Veneer plaster installation

-blueboard: or special orange primer on gypboard is base is recommended for veneer plaster installation

-skim coat or finish plaster

Venetian Plaster

Must include marble dust and pigments. Applied with a spatula or trowel and then burnished to create a smooth surface with the illusion of depth and texture.

Plaster Applications and Aesthetics

Marmorino: basic texture that you would expect if any venetian plaster 

Sgraffito: two layers of finished plaster in different colors, when hardened you scratch off the second color to reveal the first color

Scagliola: imitates other more precious materials, most often marbles

Dry Wall Thickness

Standard thickness for residential 1/2” thick 

Standard thickness for Commercial ⅝” thick

Drywall Boards

Greenboard: water resistant (specify in humid areas, not HIGH water areas)

Type X Gypboard: fire resistant

Blue board: plaster specific

Hang: Attach panels to ceiling or wall using appropriate drywall screws

Metals

Ferrous metals: metals wholly or partly of IRON; usually magnetic are prone to corrosion

Non-ferrous: metals that do NOT contain an appreciable amount if iron; usually not magnetic; more corrosion resistant 

Patina: oxidation on the surface of a metal by either natural or chemical means

Verdigri is the green from patina

Noble vs Base metal

Noble metal: resist oxidation non ferrous

Base metals: corrodes and oxidizes easily

Hot rolled steel

Hot rolled steel is cheaper but will shrink on you, don't need extract dimensions or shape

Anodizing

An electrolytic process used to increase the thickness of the natural oxide layer on the surface of metal parts

Synthetic Recipe

Synthetic resin + fillers + stabilizers +plasticizers +pigments and other materials needed

Synthetics

Most synthetics are based on carbon atoms that are derived from petrochemicals

Categories of sythetics

-thermoplastics: a synthetic that will soften with heat and harden as it cools. High impact strength, easy to process, adaptable to complex designs, easiest to recycle 

-thermosets: can resist higher temperatures, greater dimensional stability, 

-elastomers: must be able to be stretched twice the original size, but then return to their original size/length

Thermoplastics

-acrylics: clear, hard, light weight, but scratches more easily 

-nylon: strong, translucent, rigid, impact and abrasion resistant. Because it wears well and resists abrasion it is often used in textiles and carpet

-polyester: PET is a common polyester. Combustible at high temperatures, but resilient and good abrasion resistance, hydrophobic

-vinyl: strong, heat sensitive, durable, good dimensional stability and impact resistance, lightweight

Thermosets

-melamine formaldehyde (MF): hard, stain, and heat resistant. Commonly used in laminated capacity as counter, floor, or cabinet materials

-fiberglass: epoxy or polyester mixed with glass fibers. Used for decorative 

-epoxy resins: starts as liquid, chemical reaction hardens them permanently. Used for powder coating metal finishes, solid surfacing materials 

-polyurethanes: can be rigid or liquid; often thermoset, but can also be thermoplastic. Used for finish wood, foam seating and mattresses 

Solid Surfacing

Recipe: polymeric resin materials + fillers alumina trihydrate (ATH)
Pros: non porous, homogenous in color, repairable, flexible design options

Cons: med/high price point, can get heavy, plastic industry