p.1 

OAR Box 1413 

Prepped by Ollie Stewart 

Document Number: 

66) 11-1-66 

Docket Number: 

A-94-52 

Printed 7/9/2008 3:11:23 PM Sheet 66 of 114 
P.2 

GEL COATS 

A 9452 

By.JanSta-aleman, Managing Eqiior 

-T221SSS 

GEL COATS — ^y^jS, 

NOT JUST A PRETTY FACE 

Performance depends on gel coats' hidden work. 

Figure 1. Metrocab's 

unconventional taxicabs in 

bright colors pose a contrast to the long traditions 

represented by London's 

Houses of Parliament and 

the Big Ben tower. The 

cabs are fabricated from 

glass fiber-reinforced polyester and protected by 

Jotun's Norpol isopolyester 

primer gel coat. (Source: 

Amoco Chemicals) 

,s,: t first glance, the role of gel coats in the hardf

 ;.; working world of composites may seem supers' . E fidal, but closer inspection reveals an impressive list of job duties they are expected to perform. 

Applied to the surface of a mold at the beginning of 

the fabrication process, these quick-setting resins 

become an integral part of a finished laminate. 

Although gel coats can lend color, texture and 

beauty to the laminate surface, the improvements 

they provide run deeper, including performance 

characteristics such as toughness, corrosion-resistance, flexibility and even conduction. 

TEhis review will highlight what's new on the gel 

coat frontier, examining emerging performance 

requirements and the products developed to meet 

them. But before exploring individual success stories, any complete discussion of gel coats requires 

a brief look at the reduction of volatile organic compound (VOC) emissions, a pressing, industry-wide 

challenge. 

VOC CONTROL TAKES CENTER 

STACE 

listen in on the conversations of gel coat manufacturers today and chances are they'll be talking 

about VOCs. Styrene, the monomer traditionally 

used in unsaturated polyester resins and gel coats, 

has become the subject of government regulation 

because of emissions generated during its use ln 

fabrication processes. The composites industry is 

responding to the challenge of workplace safety, 

with more than one major gel coat producer reporting it is dedicating considerable resources to the 

development of low-styrene alternatives. 

"It's the wave of the future," says Thomas 

Barnett, national market manager for Cook 

Composites and Polymers (CCP. Kansas City, Mo.) 

of his company's efforts to develop low-VOC products. Whereas the typical gel coat monomer content is 35 percent, Barnett says CCP's Lovocor 962 

series has a monomer content closer to 25 

percent, producing a 30-35 percent 

decrease in styrene emissions. 

Aker Plastics (Plymouth, Ind.) has been 

using CCP's low-VOC gel coat for more: 

than a year in the fabrication of bathtubs 

and shower stalls. Plant Manager Jeff 

Birchmeier says although the product 

handles differently than hlgher-styrene 

versions, the company has had no problems with spraying or with properties of 

the finished product. 

Jotun Polymer AS (Sandefjord, Norway) 

is also hot on the trail of low-VOC alternatives. It investigated 50 different 

monomers, as candidates for partial 

styrene replacement, for properties 

including water and weather resistance, 

solubility, curing tendencies, and physical 

and mechanical characteristics. Jotun 

reports that its low styrene emission (LSE) 

gel coat, Norpol STyLe, provides good 

\ 
P.3 

esion properties and perforice. The LSE formulation 

aces some of the styrene 

tent with a low vapor prese monomer coupled with a 

J additive. Jotun's testing of 

ite. spray-quality . Norpol 

'Le showed styrene emisis of approximately 10 

or, compared to 110 g/rrr 

a standard gel coat. 

tPPING WASTE 

MD EMISSIONS 

; emerging technology of elecstatic application of gel coats 

:rs several advantages to fabitors. including VOC control, 

tic electricity drain-off and 

ter transfer efficiency. 

. CCFs Barnett says his comny's Polycor conductive sand-

•; gel coats have been used for 

'eral years to enable electrostapost painting of FRP parts. The 

iductive gel coat on the part 

s like a metallic surface and, 

ten grounded, attracts electroitically sprayed paint, cutting 

wn on paint wasted by overray and the amount of VOCs 

litted. 

CCP's Polycor conductive gel 

at. which utilizes isophthalic 

ilyester polymers, impedes 

itic electricity build-up on the surface of ground-

. FRP parts. According to Barnett. this product is 

:ing used in oil lield applications and chemical 

ants to avoid sparks that could cause a fire or 

plosion. 

Barnett also describes the potential for an elecDstatic application that could be used during the 

brication process in the future. Tlie process 

voives preparing a mold with a conductive tooling 

;1 coat surface so the production gel coat can be 

)plied by electrostatic spraying. 

GS Manufacturing (Costa Mesa. Calif.) provides 

ectrostatic spraying equipment which puts a sta2 electrical charge directly on gel coat droplets. 

hus charged, the droplets are attracted to a 

-ounded conductive mold. 

The electrostatic spray gun operates as an interal-mix. air-assist airless spray gun. It has an airriven alternator built into it which places the 

narge on the gel coat droplets. The finer the gel 

Figure 2. This 52-ft steeple on the First 

Baptist Church of Henderson. Texas is one 

of many standard steeple designs offered by 

Fiberglass Specialties. It is protected by a 

Neste neopentaglycol isophthalic gel coat. 

(Source: Fiberglass Specialties) 

coat is atomized, the better it 

will be charged. 

The gel coat is brought to a 

mixing block attached to the 

bottom of the gun by a high 

ratio pump. Attached to the gel 

coa,t pump is a catalyst- slave 

pump which pumps the catalyst 

separately to the mixing block. 

The gel coat and catalyst pass 

through a static mixer and then 

to the gun. A switch on the back 

of the gun allows the alternator 

to run when the trigger is 

pulled. The alternator generates 

the charge, which is fed to a pin 

protruding from the air cap. The 

gel coat is charged as it passes 

around the pin. 

CCP's Barnett says although 

this process holds promise for 

the future, it is not in wide use 

yet because preparing molds 

and tools with a conductive surface is a process that "can't happen overnight." 

BRITS HAIL 

TAXICAB TO A 

BETTER FINISH 

Metrocab Ltd. (Tamworth. 

Staffordshire. UK) took a bold 

step away from a long-held 

British tradition with the manufacture of its taxicabs fashioned from glass fiber-reinforced/polyester. Unlike 

their predecessors, tlie cabs sport a variety of 

bright colors painted over a high-performance 

isopolyester primer gel coat from >Jotun Polymer. 

Although Londoners were accustomed to seeing 

taxicabs only in black. Metrocab reports that initially mixed public reaction has evolved into appreciation for the vehicles' comfort and good looks. 

Metrocab. which also produces emergency, 

ambulatory care and delivery vehicles, states composites are a superior construction material for 

their vehicles because they provide rust-resistance, flexibility in design, stronger mass and 

lower weight. In addition, by using composites the 

company can produce larger, more comprehensive 

body parts than would be possible vvith steel. 

Metrocab selected the Jotun Norpol primer gel coat 

because it provides the cab bodies with a sandable 

surface suitable for painting. The Norpol surface is 

less porous than those provided by other general • 2 -
P.4 

purpose gel coats, according to Metrocab, and is 

soft enough to be worked at lower pressures and in 

less time, yet hard enough to prevent gumming and 

improper abrasion. 

Jotun manufactures isopolyester resin and gel 

coats with purified isophthalic acid from Amoco 

Chemical SA, (Geneva. Switzerland). According to 

Jotun Polymer Marketing Manager Henning Rorvik. 

isophthalic resins, which are used both in the cabs' 

laminate and in the gel coat, provide a higher temperature resistance, which is important when the 

final paint coat is cured at elevated temperatures. 

Metrocab's fabrication of the cab body parts 

begins with a 20-mil layer of Norpol primer gel coat 

which is laid over by various processes (depending 

upon the part), including hand lay-up, spray-up 

and others, to thicknesses of 3-4 mm. The company uses woven and chopped strand mat firom PPG 

Glass Fibre (Wigan. Lancashire. UK) and isophthalic resins firom Jotun. The cabs are painted in 

Metrocab's own paint facility, employing the 

Glasurit two-pack paint system (PPP International, 

Burton-upon-Trent, Derbyshire. UK). 

GEL COATS REACH SKYWARD 

Ben Bradshaw. sales and marketing manager for 

Fiberglass Specialties Inc. (Henderson, Texas) says 

60-70 percent of his company's business is in fabricating church steeples and similar cupolas, 

which are protected by white, UV-inhibited, 

neopentaglycol isophthalic gel coats (WG3000L 

and MaxGuard 29) manufactured by Neste (Fort 

Figure 3. Fiberglass 

Specialties created eight 

dome-topped cupolas for 

the Grand Victoria gambling casino in Rising Sun. 

Ind. Neste's white 

WG3000L gel coat protects 

the lower cupola, while the 

dome's UV-resistant finish 

is provided by Neste's 

MaxGuard 29 in a light 

green formulated to match 

existing buildings. (Source: 

Fiberglass Specialties) 

16 COMPOSITES TECHNOLOGY JULY/AUGUST 1997 

Smith, Ark.). Although for the most part composites are new on the architectural scene, this market's good news is its maturity. With Fiberglass 

Specialties alone producing 1.000 a year, fiberglass steeples are quickly replacing more traditional aluminum models. 

Bradshaw says a strong selling point for fiberglass steeples is the finished white surface, provided by gel coat, which requires no paint and very little maintenance. The steeples, which are sprayedup in an open mold with chopped glass and unsaturated polyester resin, are durable, light-weight 

and strong. Bradshaw says the company uses the 

Neste gel coats because of their UV protection, fade 

resistance and resistance to chalking. The company recently began using CCP's (954 series) HighGloss Buffback isophthalic gel coat and (951 

series) Armorcote in-mold coating, as well. 

Although Fiberglass Specialties fabricates additional features for churches, such as baptistries 

and wall-mounted crosses, the company produces 

domes, cupolas and other structures for secular 

buildings, as well. In fact, one recent custom Job 

gussied up a facility on the far end of the spectrum 

— a gambling casino. 

The Grand Victoria Casino in Rising Sun. Ind.. 

provides riverboat gambling for area residents, 

including inhabitants of nearby Cincinnati. But it 

was the casino's hotel and pavilion on the banks of 

the Ohio River that were the recipients of Fiberglass 

Specialties' most recent architectural creations. 

Eight large, dome-topped cupolas protected by 

Neste gel coats were fashioned in an open-mold, 

spray-up process using unsaturated polyester 

resin from CCP and glass roving from Vetrotex 

CertainTeed Corp. (Valley Forge, Pa.). The company fabricated the two largest domes on one-use 

molds and, because of their size, shipped them In 

sections and assembled them on site. 

Neste used color samples provided by the casino to produce gel coats that are color-matched to 

the existing buildings. For the six smaller fabricated structures, the color of the lower cupola is 

a shade of white (provided by Neste's WG3000L 

gel coat) and the upper dome ts tinted light green 

(using Neste's MaxGuard 29). In an unusual 

marriage of composite and traditional materials, 

the two larger fiberglass domes are ccwered with 

conventional shingles to match Lhe existing roof. 

According to Bradshaw, the actual production 

took 12 weeks and the on-site construction 

process (assembling die two large domes and. 

bolting all the fabricated features to the buildings) took only one week. As with their steeples. 

Fiberglass Specialties chose the Neste gel coats 

primarily because of their UV resistance. 

- ) 
P.5 

ire 4. Scott Shipley competes for the US. in last year's Olympic white water 

am event in a kayak fabricated by Dagger Canoe. Dagger creates its racing 

aks' durable, impact-resistant finishes with a thin, lightweight layer of Futura 

5 urethane in-mold coating. (Photo by Jimmy Nations; courtesy of Dagger 

ioe.) 

EL COATS PROTECT 

NORTHODOX VEHICLES 

rnipic athletes and weekend warriors alike benefrom the performance advantages brought to 

;ir chosen modes of transportation by a urethane 

mold gel coat developed by Futura Coatings Inc. 

:. Louis). 

To athletes competing in the Olympic whiteiter slalom event on the Ocoee River north of 

lanta last summer, every gram of added weight 

is a liability and every partially submerged rock a 

reat. That's why nine countries chose to compete 

th kayaks from a specialty line of racing craft 

tilt by Dagger Canoe (Knoxville, Tenn.). 

"We needed a gel coat that was extremely light-

;ight and very tough for impact on rocks," 

plains Dagger's composites manager Andy Bridge, 

ridge says Dagger chose Futura's Ultrachrome 

IC) 4005 because it is lightweight, tough and has 

gh flexibility and impact resistance. "We can spray 

very, very thin to keep the weight down, so it 

orks well for our application." he says. 

UC 4005 is a rapid-curing, solventless. twoDmponent. aliphatic urethane in-mold coating 

hich can be used with a number of different 

tructural resin systems and processes. According 

) Futura. it has greater flexibility than typical polyster gel coats, providing better resistance to stress, 

racking and impact. 

Dagger begins fabrication of the racing boats by 

praying an 8- to 10-mil-thick coating of UC 4005 

:i a female mold. (The product can be sprayed as 

thin as 5 mils.) The Pro-set epoxy 

resin system from Gougeon 

Brothers Inc. (Bay City. Mich.) is 

employed with various sandwich 

configurations (depending on the 

model) incorporating PVC foam 

core from the DIAB Group 

(DeSoto, Texas), Kevlar fabric and 

woven carbon fiber from Lydall 

Manning (Hatboro, Pa.) and Sglass fabric from Clark-Schwebel 

(Anderson. S.C). Unidirectional 

carbon tape is applied for localized 

reinforcements, and the boats are 

cured by vacuum bagging. 

In addition to providing the allimportant properties of durability 

and toughness, the gel coat provides the boat's glossy finish. 

Bridge says the company tried 

other products, such as marine 

polyurethanes. but couldn't find a 

product that worked as well as 

Futura's. 

Because of a narrow time window for laminating, precise mixing requirements and its higher 

cost. Dagger doesn't anticipate using UC 4005 for 

its general recreational products. But Bridge says 

Dagger is pleased with the results for its racing line. 

"Athletes have been very impressed with the material." he says. 

Gloss retention and resistance to UV light are 

the Ultrachrome benefits more likely to be desired 

by weekend recreationists who are cruising to their 

leisure-time activities in converted vans created by 

Leisure Travel Vans Ltd. (Gretna, Manitoba). The 

company, which transforms two Dodge Maxivans 

per day into luxury travel vehicles, chose UC 4005 as 

its in-mold coating for all exterior FRP components, 

such as roofs, side panels and running boards. Tlie 

Figure 5. Leisure Travel 

Vans are the only converted vans sporting a UVresistant. glossy finish provided by the Futura 4005 

aliphatic urethane in-mold 

coating. Other converted 

vans rely on polyester gel 

coats or paint. (Source: 

Leisure Travel Vans) 

4 COMPOSITES TECHNOLOGY JULY/AUGUST 1997 17 
P.6 

is U "tJJc^j 

erglass side panels and roof, combined 

li a drop-floor design, expand the chaswidth to 7 ft and its height to 6 ft 3 

:h. 

Dean McTavish. composites consultant 

Leisure Vans, says prior to use of die 

tura product the company had a severe 

jblem with yellowing of the white gel 

it it was using. He explains that an 

'estigation of gel coats determined UC 

4005 "offered superior weathering over all 

the polyester gel coats." The product is an 

aliphatic urethane. which is stable and 

resistant to ultraviolet (UV) light, the principal energy wavelength responsible for 

chalking. Futura reports that after two 

years of independent testing in Florida. 

UC 4005 retained over 80 percent gloss 

compared to less than 5 percent for 

neopentaglycol polyester gel coats. 

Why FLOW CHOPTM 

With conventional spray equipment, 

resin is atomized into a spray pattern at 

high velocity. This creates misting of the 

resin material which results in lower 

resin and glass transfer rates and higher 

styrene emissions. Chopping into nonatomized streams of resin have proven 

to significantly reduce styrene emissions 

in the workplace. 

Don't Be Fooled 

Some Flocoat equipment on the market 

mixes resin and catalyst at a manifold 

several feet behind the gun which 

requires excessive flushing. This 

technology also requires a high velocity 

resin fan combined with blown air into 

the chop to create acceptable glass 

distribution, actually increasing both 

styrene emissions and atomization. 

•VVENUS-GUSMER.Inc' 

i ^ * Sutlidwry el GUIIM ' Macf-unary Group, int. 

1862 Ives Avenue • Kent, WA • 98032 • USA 

Phone: (206) 554-2860 • Fax: (206) B52-0294 

httpyAvww.gusnier.com 

Engineer s of 

The Venus-Gusmer Solution 

Venus-Gusmer has long been 

recognized as the industry leader of 

internal mix technology, and now 

offers the most effective FLOW CHOP 

equipment available. Mixing the resin 

and catalyst at the nozzle eliminates 

excessive solvent flushing. The VenusGusmer FLOW CHOP nozzle dispenses 

resin through a series of specially 

configured orifices which virtually 

eliminates resin atomization. A specially 

designed chopper chute eliminates the 

need to blow air over the resin fan. 

further reducing emissions. 

Venus-Gusmer's 

New FLOW CHOPTM 

Nozzle end Chute System 

For a distributor located near you call toll 

free in the United Stales and Canada: 

1-800-265-0458 

t h e Industr y 

Circle 117 on the reader service card 

COMPOSITES TECHNOLOGY JULY/AUGUST 1997 

5 

UV light not only causes yellowing of 

white gel coats but can also cause color 

fading, which is especially critical in dark 

colors. McTavish says colors don't fade in 

the color-fonnulated UC 4005 gel coats. 

He says Leisure vans are the only converted vans currently relying on the 

Futura finish rather than on paint or 

polyester gel coats. 

According to McTavish. large parts 

such as the roof and side panels are laminated in open molds, beginning with a 

thin, spayed-on layer of UC 4005 (5-8 

mils thick). The fiberglass parts are then 

sprayed up using a low-profile isophthalic polyester resin from Reichhold 

Chemicals Inc. (Research Triangle Park, 

N.C.) and 6000 series chopped strand 

from PPG. Doors are resin-injected using 

the same components plus FRP ribs for 

additional reinforcement. 

McTavish contends that although the 

Futura product is more expensive than 

polyester gel coats, it can be sprayed 

much thinner, making it more cost-effective in the long run. 

Use of the Futura product is just one 

part of a whole new approach being 

adopted by Leisure Vans — what might 

be considered a major conversion of its 

own facilities. In a new, quick-curing 

twist on the spray-up process, a faster 

in-mold coating from the Futura 4000 

series with a 7-second cure will be 

sprayed on the mold, followed by a sprayup of the PPG glass with a proprietary 

hybrid matrix of urethane. polyester and 

acrylic resins. According to McTavish. 

the material will be curing as it is 

sprayed-up, and parts will be de-molded 

in 10-15 min. McTavish says with the 

new process. Leisure will be able to convert five units per day without increasing 

its manpower or number of molds. 

"In the composiles industry, we have 

been doing the same things since the 

1950s." says McTavish. who has been 

working in the industr}' since 1956. "It's 

about time vve modernized our trade with 

modern technology." Q. 

For more mformaiion. circle the number 

on the Reader Service Card: gel 

coais/resins. 251: reinforcements, 

252: electrostatic spray equip.. 253: 

core. 254.