masking materials for preventing hot -dip galvanizing - american

Copyright © 2010 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of the AGA. Anyone making use of this information assumes all liability arising from such use.

Protecting Steel for Generations

MMAASSKKIINNGG MMAATTEERRIIAALLSS FFOORR PPRREEVVEENNTTIINNGG

HHOOTT--DDIIPP GGAALLVVAANNIIZZIINNGG

BY BERNARDO DURAN, III AND THOMAS LANGILL, PHD

BACKGROUND

Masking materials, also called stop-off

materials, are products applied to steel in

specific areas prior to hot-dip

galvanizing to prevent zinc from

reacting with and adhering to the steel.

Masking is done for a myriad of reasons.

For example, sometimes it is preferable

to prevent galvanizing on large areas of

steel that will be welded, rather than

removing the zinc coating later. Masking

materials are also sometimes applied to

threads when precise fit is necessary and

the additional width of the galvanized

coating would cause fit issues. Another

reason to mask steel is to give a higher

slip factor on some faying surfaces.

Many different types of products have

been used as masking materials. Some

products are specifically designed for the

purpose of preventing galvanizing, and

other products from other industries or

for other uses have been found to work

1


well at masking steel prior to

galvanizing.

INTRODUCTION

An American Galvanizers Association

(AGA) study was conducted to

determine the effectiveness of masking

materials at preventing adhesion of zinc

to steel during galvanizing.

This study is important because masking

materials are commonly used, and until

now, there was no definitive study that

looked at the efficacy of various

products used to prevent galvanizing.

The information obtained in this study

will give galvanizers and fabricators

detailed facts on the performance of

various masking materials, as well as

provide data on application and removal

of the masking materials after hot-dip

galvanizing.

TEST PROCEDURE

In this study 15 masking materials were

tested. Some of these materials are

currently used to mask steel, and others

have been used in the past with some

success. In addition to past performance,

the products were chosen based on their

availablility and recommendations from

AGA members.

The study consists of two phases. The

goal of Phase 1 testing is to determine

the effectiveness of the various masking

products in masking the steel surface

from zinc. The products that successfully

masked steel in Phase 1 were included in

Phase 2 testing. The goal of Phase 2 is to

determine the performance of the

successful materials from Phase 1 testing

when given shorter cure times.

Attempting to restore the original

appearance of the steel (by chemical

cleaning) is also a goal in Phase 2.

The masking materials were tested on

three different types of surfaces; flat

plate, buried threaded holes, and bolt

threads. Two types of flat plate were

used in the study. The first type of flat

plate (see Figure 1, next page) was

approximately 3” x 6”. The masking

materials were applied to the steel away

from the hole. The masking area had a

width of 3” and a length of a little less

than 4”.

All masking materials were applied to

the steel prior to the cleaning steps of the

2


galvanizing process, meaning the

masking materials were subjected to a

caustic bath, pickling bath, and flux

bath. It was important to determine if the

masking materials could survive the

cleaning chemicals, because if they

could survive, the masking materials

could be applied at the fabricator’s

facility, and thereby save the galvanizer

the time and trouble of applying the

materials.

Figure 1: Flat Plate

Figure 2: Buried Threaded Holes Plate

Some of the plates were drilled and

tapped to provide a plate with a buried

threaded hole to test the masking

materials (see Figure 2). The buried

threaded holes were 2½” deep holes

drilled into a 3” thick plate (see Figure

2). Buried threaded holes were used only

in Phase 1 testing. The bolts used in the

study were ¾” in diameter and

approximately 2 ½” in length (see

Figure 3).

Figure 3: Coated Bolt Threads

The masking materials were applied to

the plates with a foam brush and then

spread in the masked areas until an even

consistency was achieved.

For the buried threaded holes the

masking products were simply poured or

squeezed into the holes.

For the bolt threads, the masking

materials were applied by either dipping

3


the bolts directly into the bottle of the

material, if there was enough room, or

spread onto the threads using a foam

brush. The material was spread onto the

threads to achieve even thickness.

The masking materials for all surface

types were applied prior to the chemical

cleaning steps of the galvanizing

process. This ensured the masking

materials could stand up to the cleaning

agents and would remain on the steel

prior to galvanizing.

Masking products were removed by

using a metal-bristled brush. The

materials were scrubbed off the surface

and then compressed air was used to

blow off the debris. In Phase 2 testing,

scrubbing the cleaned steel with a nylon

bristled brush and Simple Green solution

was also performed to determine if the

original steel finish could be restored. A

grinder was also tested in Phase 2 for

removing the materials on flat plate.

PHASE 1 TESTING

MASKING MATERIAL TESTING

Fifteen different masking materials were

tested in Phase 1, including:

• Duct Tape

• Kapton Tape

• VHT Header Paint (tested only

on flat plate)

• Dow Corning Compound #111

• DAP Household Adhesive

Sealant

• Stop Galv

• NAPA RTV Red

• GE 100% Silicone Caulk

• Galva Stop

• Valmont Masking Compound

• Macropoxy 846

• 3M High Temperature

Aluminum Tape

• Maskote Zinc Stop-Off

• ZYP Boron Nitride Lubricoat

• ZYP Boron Nitride Hardcoat

Determining the effectiveness of each

masking material came down to

observing how much of the masked area

galvanized. The smaller the area that

galvanized, the more effective the

masking material.

For flat plate, greater than 90% of the

masked area had to remain ungalvanized

to proceed to Phase 2 testing. For buried

threaded holes, almost the entire

4


threaded area needed to remain free of

galvanizing. If a few small spots of zinc

were observed, the masking material was

still considered effective. For bolt

threads, the same criteria applied as that

for buried threaded holes – almost the

entire threaded area must remain

ungalvanized to be considered effective.

TEST 1 RESULTS

On the flat plate, nine products failed to

prevent galvanizing on a minimum of

90% of the masked area. Six products

successfully prevented zinc coating a

minimum of 90% of the masked area on

flat plates including:

• Stop Galv


• NAPA RTV Red

• Galva Stop



Only 14 of the masking materials were

tested on buried threaded holes and bolt

threads. The VHT Header Paint was not

tested because paint cannot be easily

removed from threaded areas.

Eight products failed to prevent zinc

coating on the buried threaded holes.

Six products successfully prevented zinc

coating on the buried threaded holes,

including:


Sealant




• Macropoxy 846

• ZYP Boron Nitride Hardcoat

Six of the 14 products failed to prevent

galvanizing on bolt threads. The

masking materials that did prevent zinc

coating on bolt threads include:

• Galva Stop

• Stop Galv


Sealant

• NAPA RTV Red


• Macropoxy 846


The bolts masked with Valmont

Masking Compound were lost during the

galvanizing process during testing.

For more detailed information on how

each masking material performed on the

various surface types, and application

5


and removal data, please see the charts

in Appendix 1.

PHASE 2 TESTING

SHORTER CURE TIME TESTING

AND CLEANING

The first goal of Phase 2 testing was to

determine how the products that

performed well in Phase 1 testing

performed were applied using shorter

cure times. Products tested in Phase 2

included:

• Stop Galv

• Galva Stop


• NAPA RTV Red



Sealant

Although Valmont Masking Compound

did well in Phase 1 testing, it was not

included in Phase 2 testing. Also, as

mentioned earlier, buried threaded holes

were not tested in Phase 2.

Shorter cure times were tested in Phase

2. These tests demonstrated the limits of

the masking materials. However, it is

important to note these materials should

be used in accordance with the

manufactures curing instructions to

achieve optimum performance.

The second goal of Phase 2 testing was

to determine if the original steel finish

could be restored after removing the

masking materials from the steel.

The criteria for determining the

effectiveness of these masking materials

in Phase 2 testing was the same as in

Phase 1 Testing. Ninety percent or more

of the masked area on plates had to

remain free of galvanizing to be

considered successful. For bolts, only a

few small areas of zinc on the masked

threads were allowed for the material to

be considered successful.

For the flat plate specimens, each

masking material was applied to the

same areas used in Phase 1 testing. The

plates had been stripped of all zinc and

remaining residues from Phase 1 testing.

Masking products were applied to only

one side of the plates to decrease

application time. Cure times included 1

and 2 hours for flat plate specimens.

For bolt threads, the masking materials

were applied to the same bolts as those

6


used in Phase 1 Testing. The bolts had

been stripped of all galvanizing and

debris from the Phase 1 tests. Three

different cure times were tested on the

bolt threads; 30 minutes, 1 hour, and 2

hours.

For both the flat plate specimens and the

bolt thread areas, cleaning the baked on

masking materials after galvanizing was

attempted by scraping the steel with a

metal-bristled brush and then scrubbing

with a nylon brush and Simple Green

solution (see Figure 4). The goal of

cleaning with the Simple Green solution

was to determine if the original finish of

the steel could be restored after the

various masking materials had baked on

the surface while going through the

galvanizing process. Cleaning with a

grinder was attempted on the flat plate

specimens only.

Figure 4: Simple Green and Nylon Brush

TEST 2 RESULTS

FLAT PLATE

For the 1 and 2 hour cure times only

Stop Galv and Galva Stop were

successful at preventing galvanizing.

Some ashy material from Stop Galv and

Galva Stop remained on the plates even

after scrubbing with a metal-bristled

brush.

Cleaning the plates with the Simple

Green solution had a negligible effect on

removing the debris left from the

masking materials.

Using a grinder to remove the baked-on

masking materials was excessive and is

not recommended. The grinder

immediately went through the masking

materials and attacked the steel

underneath.

BOLT THREADS

Three different cure times were tested

for each masking material on bolt

threads, including 30 minutes, 1 hour,

and 2 hours. For the 30 minute cure time

Galva Stop and NAPA RTV Red were

the only products that successfully

prevented galvanizing.

7


For the 1 hour cure time, five of the six

masking materials were successful at

preventing galvanizing, including Galva

Stop, Maskote Zinc Stop-Off, DAP

Household Adhesive Sealant, NAPA

RTV Red, and Stop Galv.

For the 2 hour cure time all six masking

materials successfully prevented

galvanizing on the bolt threads.

After galvanizing, a metal-bristled brush

was used to scrape the big chunks of

baked-on masking material from the

threads. A Simple Green solution and

nylon brush were then used to remove

the remaining baked-on debris. The

appearance of the bolt threads was

improved for all the masking materials

after cleaning with the Simple Green

solution.

The cleanest bolts were those masked

with Maskote Zinc Stop-Off, GE 100%

Silicone Caulk, and DAP Household

Adhesive Sealant. It was necessary to

wash the bolts masked with NAPA RTV

Red twice because of the gummy

residue. Some baked on masking

material remained on the bolts masked

with Galva Stop and Stop Galv.

Cleaning with the Simple Green solution

was done after the 1 hour curing time. If

the masking materials had been given

their full recommended curing time it is

likely the products would have been

easier to remove and would have cleaned

even better.

Cleaning the masking materials from the

bolt threads with a grinder was not

attempted because it would damage the

threads.

CONCLUSION

The goal of this study was to determine

which commercially available masking

materials work best at preventing

galvanizing on masked areas.

Six commercially available masking

materials were identified to successfully

prevent galvanizing on one or more

surface types, including flat plate, bolt

threads, and buried threaded holes. The

successful masking materials included

(in no particular order):

• Stop Galv



• NAPA RTV Red

• (cont. on next page)

8


• Galva Stop


Sealant

Additional and detailed performance

data is presented in the charts in

Appendix 1 and additional pictures are

presented in Appendix 2.

SAFETY AND HEALTH INFORMATION

Material Safety Data Sheets (MSDS)

should be obtained and adhered to when

using these materials. Necessary

personal protective equipment should be

employed when appropriate. Almost all

of these masking materials had

nauseating smells and should be used

only in well ventilated areas. It is

important to note some of these products

were not designed to be used in the

temperature ranges of the galvanizing

process.

COSTS OF THE MASKING MATERIALS

The masking materials tested in this

study have a wide range in price, which

can be found in Appendix 1. In addition

to the purchase price, additional costs to

be considered include labor time for

applying and removing the materials.

Detailed application and removal times

are included in the charts in Appendix 1.

9


Appendix 1.

Detailed Performance Data of Masking Materials

10

PHA

SE 1

TES

TIN

G -

OV

ERV

IEW

OF

SUCC

ESSF

UL

MA

SKIN

G M

ATER

IALS

FLAT

PLA

TEBU

RIED

TH

REA

DED

HO

LES

BOLT

TH

REA

DS

Prod

uct

Pric

eSt

anda

rdiz

edPr

ice

Succ

ess

App

licati

on

Tim

eRe

mov

al

Tim

eSu

cces

sA

pplic

ation

Ti

me

Rem

oval

Ti

me

Succ

ess

App

licati

on

Tim

eRe

mov

al

Tim

eD

AP

100%

Si

licon

e A

dhes

ive

$3.9

8 /

2.8

oz. t

ube

$1.4

2 /

oz-

N/A

N/A

Yes

6 m

ins.

, 30

sec

s.12

min

s., 5

se

cs.

Yes

9 m

ins.

, 30

sec

s.4

min

s.,

22 s

ecs.

Gal

va S

top

$48.

00 /

lite

r$1

.42

/ oz

Yes

2 m

ins.

, 21

sec

s.2

min

s.,

38 s

ecs.

-N

/AN

/AYe

s3

min

s.6

min

s.,

50 s

ecs.

GE

100%

Si

licon

e Ca

ulk

$4.9

7 /

10.1

oz.

tube

$0.4

9 /

ozYe

s1

min

.,

22 s

ecs.

1 m

in.

Yes

1 m

in.,

15

sec

s.

5 m

ins.

, 18

sec

s.Ye

s10

min

s.,

30 s

ecs.

7 m

ins.

, 30

sec

s.

Mac

ropo

xy 8

46$8

9.78

/

gal.

of P

art A

& B

$0.3

5 /

oz-

N/A

N/A

Yes

32 m

ins.

, 26

sec

s.8

min

s.,

40 s

ecs.

Yes

37 m

ins.

, 10

sec

s.1

min

.,

11 s

ecs.

Mas

kote

Zin

c St

op -

Off

$120

.00

/ ga

l.$0

.94

/ oz

Yes

2 m

ins.

, 37

secs

.1

min

.Ye

s5

min

s.,

13 s

ecs.

3 m

ins.

Yes

5 m

ins.

, 1

2 se

cs.

3 m

ins.

, 5

secs

.

NA

PA R

TV R

ed$1

4.19

/ 1

1 oz

. tub

e$1

.29

/ oz

Yes

1 m

in.,

32

sec

s.1

min

.-

N/A

N/A

Yes

9 m

ins.

, 45

sec

s.4

min

s.,

18 s

ecs.

Stop

Gal

v$4

5.00

/ q

t.$1

.41

/ oz

Yes

4 m

ins.

, 26

sec

s.5

min

s.,

48 s

ecs.

-N

/AN

/AYe

s5

min

s.10

min

s.,

20 s

ecs.

Valm

ont

Mas

king

Co

mpo

und

$4.7

5 /

smal

l tub

e$0

.37

/ oz

Yes

2 m

ins.

, 3

2 se

cs.

1 m

in.

Yes

10 m

ins.

, 30

sec

s.5

min

s.,

28 s

ecs.

-N

/AN

/A

ZYP

Boro

n N

itri

de H

ardc

oat

$170

.00

/ ga

l.$1

.33

/ oz

-N

/AN

/AYe

s3

min

s.,

24 s

ecs.

7

min

s.,

52 s

ecs.

-N

/AN

/A

11

FLAT

PLA

TE -

PHA

SE 1

TES

TIN

GPr

oduc

tA

pplic

ation

Ti

me

App

licati

on N

otes

Mas

king

Su

cces

sN

otes

Rem

oval

Tim

eRe

mov

al N

otes

3M H

igh

Tem

pera

ture

A

lum

inum

Tap

e17

min

s., 2

6 se

cs.

Thor

ough

ly e

nsur

ed th

e ed

ges

wer

e se

aled

.A

lmos

tA

bout

12%

of t

he a

rea

ga

lvan

ized

. See

page

at e

nds

ca

used

gal

vani

zing

in th

ose

area

s.9

min

s., 2

4 se

cs.

Use

d a

flath

ead

scre

wdr

iver

to s

crap

e

the

tape

and

then

pul

led

it off

.

DA

P H

ouse

hold

A

dhes

ive

Seal

ant

3 m

ins.

, 20

secs

.Sq

uirt

ed th

e pr

oduc

t ont

o pl

ates

, the

n

spre

ad it

with

a fo

am p

aint

bru

sh.

Mat

eria

l was

ver

y ea

sy to

wor

k w

ith.

-O

ne p

late

gal

vani

zed

com

plet

ely

and

the

two

othe

r pl

ates

had

la

rge

area

s th

at g

alva

nize

d.2

min

s., 1

1 se

cs.

Scra

ped

off w

ith a

sm

all m

etal

-bri

stle

d br

ush.

Th

e m

ater

ial w

as v

ery

gum

my

and

hard

to re

mov

e.

Dow

Cor

ning

Co

mpo

und

#111

3 m

ins.

, 42

secs

.Sq

uirt

ed th

e pr

oduc

t ont

o pl

ates

, the

n sp

read

ar

ound

with

a fo

am p

aint

bru

sh. M

ater

ial s

prea

d ea

sily

, but

was

mes

sy b

ecau

se it

doe

s no

t dry

. -

At le

ast 8

0% o

f the

are

a ga

lvan

ized

.40

sec

s.Sc

rape

d w

ith a

sm

all m

etal

-bri

stle

d br

ush.

Duc

t Tap

e25

min

s.W

rapp

ed 2

tim

es a

roun

d pl

ates

.-

Less

than

90%

rem

aine

d ba

re10

min

s., 5

2 se

cs.

Scra

ped

off b

urnt

tape

with

a m

etal

-bri

stle

d

brus

h. S

crap

ed o

ff v

ery

easi

ly.

Gal

va S

top

2 m

ins.

, 21

secs

.Sh

ook

can,

pou

red,

then

spr

ead

us

ing

a fo

am b

rush

.Ye

sEn

tire

area

was

com

plet

ely

fr

ee o

f gal

vani

zing

2 m

ins.

, 38

secs

.U

sed

a sm

all m

etal

-bri

stle

d br

ush

to s

crap

e

sinc

e th

e bi

g m

etal

-bru

sh w

as in

nefe

ctive

. Had

to

scr

ape

very

har

d to

get

this

mat

eria

l off.

GE

100%

Si

licon

e Ca

ulk

1 m

ins.

, 22

secs

.U

sed

a ca

ulk

gun,

then

spr

ead

usin

g a

fo

am b

rush

. Wen

t on

very

thic

k.Ye

sTh

e m

ater

ial p

reve

nted

gal

vani

zing

, bu

t the

sur

face

was

sta

ined

bla

ck.

1 m

in.

Use

d bi

g an

d sm

all m

etal

-bri

stle

d br

ushe

s to

sc

rape

aw

ay th

e pr

oduc

t. It

cam

e off

fair

ly e

asily

.

Kapt

on T

ape

30 m

ins.

2 w

raps

. Ta

pe d

id n

ot s

tick

wel

l, m

uch

ha

rder

to w

ork

with

than

the

duct

tape

.-

Less

than

90%

rem

aine

d ba

re18

min

s., 3

9 se

cs.

Scor

ed ta

pe w

ith a

flat

head

scr

ewdr

iver

, the

n us

ed a

m

etal

-bri

stle

d br

ush

to s

crap

e aw

ay re

mai

ning

deb

ris.

Mac

ropo

xy 8

46

32 m

ins.

, 14

secs

. (3

1/32

min

s.

spen

t on

prep

tim

e fo

r ep

oxy)

Pour

ed o

nto

the

surf

ace

and

sp

read

with

a fo

am p

aint

bru

sh.

-A

bout

15%

of t

he a

rea

galv

aniz

ed1

min

.. 37

sec

s.U

sed

a sm

all m

etal

-bri

stle

d br

ush

to

scr

ape

the

mat

eria

l off.

Mas

kote

Zin

c St

op -

Off

2 m

ins.

, 37

secs

.Ve

ry r

unny

- d

ries

ver

y qu

ickl

y, m

akin

g it

hard

to

spre

ad a

roun

d. U

sed

a fo

am b

rush

for

spre

adin

g.

Yes

Entir

e ar

ea w

as c

ompl

etel

y fr

ee

of g

alva

nizi

ng; v

ery

clea

n.1

min

.U

sed

a bi

g m

etal

-bri

stle

d br

ush.

Th

e m

ater

ial c

ame

off v

ery

easi

ly.

NA

PA R

TV R

ed1

min

., 32

sec

s.U

sed

a ca

ulk

gun,

then

spr

ead

usin

g a

foam

br

ush.

Wen

t on

easy

, but

kin

d of

thic

k.Ye

s A

lmos

t the

enti

re a

rea

re

mai

ned

free

of g

alva

nizi

ng1

min

.U

sed

a bi

g m

etal

-bri

stle

d br

ush

to

scr

ape

away

the

mat

eria

l.

Stop

Gal

v4

min

s., 2

6 se

cs.

Pour

ed th

e pr

oduc

t on,

spr

ead

with

a fo

am p

aint

br

ush.

Pro

duct

wen

t on

thic

k an

d dr

ied

quic

kly.

Yes

Very

slig

ht s

eepa

ge a

t per

imet

ers.

5 m

ins.

, 48

secs

.U

sed

a sm

all m

etal

-bri

stle

d br

ush

to s

crap

e th

e m

ater

ial o

ff. T

he m

ater

ial a

dher

ed to

the

surf

ace

tena

ciou

sly,

whi

ch re

quire

d m

uch

hard

er s

crap

ing.

Valm

ont M

aski

ng

Com

poun

d2

min

s., 3

2 se

cs.

Very

thic

k, li

ke a

pas

te. U

sed

a

foam

bru

sh to

spr

ead

arou

nd.

Yes

Entir

e ar

ea w

as c

ompl

etel

y fr

ee o

f gal

vani

zing

.1

min

.U

sed

big

and

smal

l met

al-b

rist

led

brus

hes

to

scr

ape

mat

eria

l off

the

met

al.

VH

T H

eade

r Pa

int

1 hr

., 33

min

s.A

pplie

d 2

coat

s of

pai

nt.

Allo

wed

fo

r dr

y tim

e be

twee

n co

ats.

-A

ll th

e pl

ates

gal

vani

zed

N/A

- pr

oduc

t fa

iled

com

plet

ely.

N/A

ZYP

Boro

n N

itri

de

Har

dcoa

t3

min

s., 4

8 se

cs.

Two

min

utes

of a

pplic

ation

tim

e w

as to

stir

th

e pr

oduc

t. P

oure

d on

to th

e su

rfac

e

and

spre

ad w

ith a

foam

pai

nt b

rush

.-

Abo

ut 2

0% o

f the

are

a ga

lvan

ized

.2

min

s., 3

2 se

cs.

The

burn

ed p

rodu

ct a

dher

ed to

the

stee

l ver

y w

ell.

I ha

d to

sco

re it

with

the

edge

of a

flat

head

scr

ewdr

iver

an

d th

en s

crap

e it

with

a s

mal

l met

al-b

rist

led

brus

h.

ZYP

Boro

n N

itri

de

Lubr

icoa

t4

min

s., 1

6 se

cs.

Pour

ed o

nto

the

surf

ace

and

spre

ad w

ith a

foam

pa

int b

rush

. Mat

eria

l had

the

runn

ines

s of

pai

nt

and

was

ver

y m

essy

. 3 m

inut

es o

f the

app

licati

on

time

was

due

to s

tirri

ng th

e pr

oduc

t lik

e pa

int.

-Th

e en

tire

area

gal

vani

zed.

N/A

N/A

12

BURI

ED T

HRE

AD

ED H

OLE

S - P

HA

SE 1

TES

TIN

GPr

oduc

tA

pplic

ation

Ti

me

App

licati

on N

otes

Mas

king

Su

cces

sN

otes

Rem

oval

Ti

me

Rem

oval

Not

es

3M H

Igh

Tem

pera

ture

A

lum

inum

Tap

e

9 m

ins.

, 41

sec

s.Ba

lled

up ta

pe, h

amm

ered

it in

to

hole

usi

ng a

woo

den

dow

el.

-4

hole

s ga

lvan

ized

com

plet

ely,

th

e ot

her

2 ha

d co

nsid

erab

le

amou

nts

of z

inc

in e

ach.

6 m

ins.

, 17

sec

s.U

sed

flath

ead

scre

wdr

iver

and

sm

all,

m

etal

-bri

stle

d br

ush

to p

ry o

ut th

e ta

pe.

DA

P 10

0%

Silic

one

Adh

esiv

e6

min

s.,

30 s

ecs.

Sque

ezed

mat

eria

l out

of t

ube

and

into

ho

les.

Har

dene

d lik

e ca

ulk,

stil

l flex

ible

. M

ater

ial r

emai

ned

wax

y aft

er 1

4 ho

urs.

Yes

Non

e of

the

hole

s ga

lvan

ized

.12

min

s.,

5 se

cs.

Scra

ped

blob

of m

ater

ial o

ut w

ith fl

at-h

ead

scre

wdr

iver

. Use

d a

met

al-b

rist

led

brus

h to

scr

ape

the

rest

of t

he m

ater

ial o

ut.

Cons

iste

ncy

of d

ry c

aulk

. Som

e sm

all c

rum

bs re

mai

ned.

Dow

Cor

ning

Co

mpo

und

#111

3 m

ins.

Sque

ezed

pro

duct

out

of t

ube

and

into

hol

es. T

he

mat

eria

l was

ver

y ha

rd to

sque

ez o

ut o

f the

tube

s.-

4 ou

t of 6

hol

es d

id g

alva

nize

3 m

ins.

, 50

sec

s.Sc

rape

d pr

oduc

t out

with

flat

-hea

d sc

rew

driv

er.

Har

d, fl

exib

le c

onsi

sten

cy li

ke d

ry c

aulk

.

Duc

t Tap

e5

min

s.Ba

lled

up ta

pe, t

hen

stuff

ed in

the

hole

s.-

5 of

the

6 ho

les

galv

aniz

ed6

min

s.,

17 s

ecs.

Scra

ped

w/

met

al-b

rist

led

brus

h. S

ome

un

mas

ked

area

s ar

ound

hol

es d

id n

ot g

alva

nize

, w

hich

cou

ld fa

il in

spec

tion

after

gal

vani

zing

.

Gal

va S

top

2 m

ins.

, 30

sec

s.Po

ured

into

hol

es-

In 5

of t

he 6

hol

es, a

sm

all

area

gal

vani

zed.

The

are

a

was

abo

ut 1

0% o

f the

hol

es.

8 m

ins.

, 26

sec

s.U

sed

a m

etal

-bri

stle

d br

ush

to s

crap

e

mat

eria

l out

, whi

ch w

as v

ery

hard

to d

o.

GE

100%

Si

licon

e Ca

ulk

1 m

in.,

15

sec

s.Sq

uirt

ed in

to h

oles

w/

a ca

ulk

gun

Yes

The

very

top

of o

ne h

ole

galv

aniz

ed

a tin

y bi

t, b

ut it

cou

ld h

ave

been

an

app

licati

on e

rror

, as

the

hole

w

as n

ot fi

lled

to th

e ve

ry to

p.

5 m

ins.

, 18

sec

s.U

sed

flath

ead

scre

wdr

iver

to b

reak

apa

rt m

ater

ial,

then

use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

mat

eria

l out

.

Kapt

on T

ape

8 m

ins.

Slig

htly

har

der

to w

ork

with

than

duc

t tap

e.

Balle

d up

, the

n st

uffed

in th

e ho

les.

-3

out o

f the

6 h

oles

gal

vani

zed

5 m

ins.

, 40

sec

s.

Use

d fla

t-he

ad s

crew

driv

er to

scr

ape

out t

ape,

then

use

d a

met

al-

bris

tled

brus

h to

get

the

rest

. Som

e un

mas

ked

area

s ar

ound

hol

es

did

not g

alva

nize

, whi

ch c

ould

fail

insp

ectio

n aft

er g

alva

nizi

ng.

Mac

ropo

xy 8

4632

min

s.,

26 s

ecs.

Prep

arati

on ti

me

for

prod

uct t

ook

31 m

inut

es.

Pour

ed in

to h

oles

; ver

y ru

nny

and

mes

sy.

Yes

Non

e of

the

hole

s ga

lvan

ized

.8

min

s.,

40 s

ecs.

Use

d fla

thea

d sc

rew

driv

er to

bre

ak a

part

mat

eria

l ins

ide

the

hole

s. M

ater

ial w

as e

xtre

mel

y ha

rd, r

equi

red

cons

ider

able

fo

rce.

Use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

out r

est o

f th

e m

ater

ial,

whi

ch a

lso

requ

ired

cons

ider

able

effo

rt.

Mas

kote

Zin

c St

op -

Off

5 m

ins.

, 13

sec

s.Po

ured

into

hol

es; r

unni

er th

an G

alva

Sto

p or

St

op G

alv.

Drie

s fa

ster

than

oth

er p

rodu

cts,

too.

Yes

Non

e of

the

hole

s ga

lvan

ized

. H

oles

look

ed v

ery

clea

n.3

min

s.

Use

d a

smal

l met

al-b

rist

led

brus

h to

cle

an m

ater

ial

out o

f the

hol

es.

Mat

eria

l cam

e ou

t ver

y ea

sily

.

NA

PA R

TV R

ed1

min

.Sq

uirt

ed in

to h

oles

with

a c

aulk

gun

-2

of th

e ho

les

galv

aniz

ed c

ompl

etel

y,

4 ho

les

galv

aniz

ed p

artia

lly.

5 m

ins.

, 51

sec

s.U

sed

flath

ead

scre

wdr

iver

to p

ry o

ut m

ater

ial,

then

use

d a

smal

l m

etal

-bri

stle

d br

ush

to c

lean

the

rest

of t

he m

ater

ial o

ut.

Stop

Gal

v4

min

s.Po

ured

into

hol

es.

-1

of th

e 6

hole

s ga

lvan

ized

11 m

ins.

, 30

sec

s.U

sed

a m

etal

-bri

stle

d br

ush

to s

crub

the

m

ater

ial o

ut. H

oles

wer

e ch

arre

d bl

ack

insi

de.

Valm

ont M

aski

ng

Com

poun

d10

min

s.,

30 s

ecs.

Had

to c

ut in

to th

e si

de o

f the

roll,

sin

ce a

n in

dust

rial

siz

e ca

ulk

gun

was

not

ava

ilabl

e.Ye

sIn

add

ition

to m

aski

ng in

tend

ed

area

s, it

cau

sed

bare

spo

ts

in s

urro

undi

ng a

reas

.

5 m

ins.

, 28

sec

s.U

sed

flath

ead

scre

wdr

iver

to b

reak

apa

rt m

ater

ial,

then

use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

out r

emai

ning

mat

eria

l.

VH

T H

eade

r Pa

int

N/A

N/A

N/A

N/A

N/A

N/A

ZYP

Boro

n N

itri

de

Har

dcoa

t3

min

s.,

24 s

ecs.

2 m

inut

es o

f app

licati

on ti

me

was

due

to

stirr

ing

prod

uct.

Pou

red

mat

eria

l int

o

the

hole

s. M

ater

ial d

ried

fast

.Ye

s

Non

e of

the

hole

s ga

lvan

ized

, but

th

ere

was

som

e fr

ozen

zin

c in

side

th

e ho

les

that

had

to b

e w

edge

d ou

t. W

edgi

ng o

ut th

e zi

nc m

ight

not

al

way

s be

pos

sibl

e fo

r all

fabr

icati

ons.

7 m

ins.

, 52

sec

s.

Use

d fla

thea

d sc

rew

driv

er to

bre

ak a

part

har

d as

h, th

en

used

sm

all m

etal

-bri

stle

d br

ush

to s

crap

e ou

t the

rest

. So

me

smal

l par

ticle

s re

mai

ned

insi

de th

e ho

les.

ZYP

Boro

n N

itri

de

Lubr

icoa

t4

min

s.,

16 s

ecs.

3 m

inut

es o

f app

licati

on ti

me

was

due

to

stir

ring

the

prod

uct.

Pou

red

into

hol

es.

-A

ll of

the

hole

s ga

lvan

ized

100

%.

N/A

N

/A -

all h

oles

gal

vani

zed

100%

.

13

BOLT

TH

REA

DS

- PH

ASE

1 T

ESTI

NG

Prod

uct

App

licati

on

Tim

eA

pplic

ation

Not

esM

aski

ng

Succ

ess

Not

esRe

mov

al T

ime

Rem

oval

Not

es

3M H

igh

Tem

pera

ture

A

lum

inum

Tap

e

11 m

ins.

, 16

secs

.W

rapp

ed ta

pe a

roun

d bo

lts 3

tim

es.

Adh

esiv

e is

ve

ry s

ticky

, and

diffi

cult

to g

et o

ff r

oll a

nd a

pply

.-

Man

y ar

eas

galv

aniz

ed.

So

me

bare

are

as, b

ut a

bout

ha

lf of

thre

ads

galv

aniz

ed.

7 m

ins.

, 55

secs

.Sc

rape

d ta

pe w

/ a

flath

ead

scre

wdr

iver

un

til it

cou

ld b

e pe

eled

off.

DA

P H

ouse

hold

A

dhes

ive

Seal

ant

9 m

ins.

, 30

secs

.Ve

ry th

ick,

mes

sy. S

mel

led

awfu

l. S

mea

red

on

w/

foam

pai

nt b

rush

. D

ried

har

d, li

ke c

aulk

.Ye

sA

few

sm

all a

reas

pic

ked

up

a litt

le z

inc.

Got

5 b

olts

bac

k.4

min

s., 2

2 se

cs.

Use

d bi

g m

etal

-bri

stle

d br

ush

to s

crap

e aw

ay m

ater

ial.

Thre

ads

wer

e ve

ry c

lean

aft

er s

crap

ing

mat

eria

l off.

Dow

Cor

ning

Co

mpo

und

#111

8 m

ins.

Sque

ezed

mat

eria

l ont

o th

read

s, sm

eare

d on

w/

foam

pai

nt b

rush

. H

ad w

et, w

axy

feel

ing

after

dry

ing.

-A

ll bo

lt th

read

s ga

lvan

ized

to

som

e ex

tent

. Got

4 b

olts

bac

k.2

min

s., 4

0 se

cs.

Crus

ty w

hite

mat

eria

l cam

e off

ver

y

easi

ly w

/ a

smal

l met

al-b

rist

led

brus

h.

Duc

t Tap

e5

min

s., 3

0 se

cs.

Wra

pped

5-6

tim

es a

roun

d ea

ch b

olt.

-H

ad la

rge

bare

are

as, b

ut

man

y ar

eas

still

galv

aniz

ed.

5 m

ins.

, 44

secs

.U

sed

a bi

g m

etal

-bri

stle

d br

ush

to s

crap

e aw

ay th

e m

ater

ial,

whi

ch c

ame

off v

ery

easi

ly.

Gal

va S

top

3 m

ins.

Dip

ped

bolts

into

bott

le to

app

ly m

ater

ial.

Har

dene

d, b

ut s

till fl

exib

le.

Will

stic

k to

its

elf i

f it t

ouch

es o

ther

coa

ted

prod

ucts

.Ye

sA

few

tiny

are

as d

id g

alva

nize

.6

min

s., 5

0 se

cs.

Brus

hed

off b

lack

ash

y m

ater

ial v

ery

ea

sily

with

a b

ig m

etal

-bri

stle

d br

ush.

GE

100%

Si

licon

e Ca

ulk

10 m

ins.

, 30

secs

.Sm

eare

d m

ater

ial o

n w

/a fo

am p

aint

bru

sh.

Som

ewha

t eas

ier

to h

andl

e th

an N

APA

RTV

red.

Yes

Thre

ads

w

ere

com

plet

ely

bare

.7

min

s., 3

0 se

cs.

Use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

aw

ay th

e m

ater

ial,

whi

ch c

ame

off p

rett

y ea

sily

.

Kapt

on T

ape

6 m

ins.

, 30

secs

.N

/A-

Coul

d no

t rem

ove

mas

king

mat

eria

l. O

ne b

olt w

as lo

st d

urin

g

the

galv

aniz

ing

proc

ess.

Tape

was

nea

rly

impo

ssib

le to

re

mov

e fr

om

thre

ads

Una

ble

to re

mov

e ta

pe fr

om th

read

s. T

his

mat

eria

l w

ould

not

wor

k as

a m

aski

ng m

ater

ial,

as it

ca

nnot

be

rem

oved

w/o

dam

agin

g th

e th

read

s.

Mac

ropo

xy 8

4637

min

s., 1

0 se

cs.

Prep

arati

on o

f the

pro

duct

took

31

min

s.

Dip

ped

bolts

into

mas

king

mat

eria

l to

appl

y.

Mat

eria

l was

run

ny, l

ike

pain

t.Ye

s

Rece

ived

onl

y 1

bolt

back

(the

rest

m

ust h

ave

falle

n ou

t of t

he b

aske

t du

ring

the

galv

aniz

ing

proc

ess)

. A

few

ver

y sm

all a

reas

did

gal

vani

ze.

1 m

in.,

11 s

ecs.

Use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

away

the

prod

uct,

whi

ch c

ame

off p

rett

y ea

sily

.

Mas

kote

Zin

c St

op -

Off

5 m

ins.

, 12

secs

.

Very

run

ny, h

ard

to s

mea

r ar

ound

. Rat

her

th

an s

mea

ring

, it d

ries

, lum

ps u

p, a

nd c

omes

off

the

met

al.

Very

str

ong,

nau

seati

ng

smel

l - s

imila

r to

nai

l pol

ish

rem

over

.

Yes

Som

e sm

all a

reas

did

gal

vani

ze.

3 m

ins.

, 5 s

ecs.

Use

d a

smal

l met

al-b

rist

led

brus

h to

scr

ape

off

the

mat

eria

l, w

hich

cam

e off

ver

y ea

sily

.

NA

PA R

TV R

ed9

min

s., 4

5 se

cs.

Smea

red

mat

eria

l on

w/

a fo

am p

aint

br

ush.

App

lied

thic

k in

man

y ar

eas

be

caus

e of

pro

duct

con

sist

ency

.Ye

sA

few

sm

all a

reas

pic

ked

up

a li

ttle

zin

c.

4 m

ins.

, 18

secs

.U

sed

a sm

all m

etal

-bri

stle

d br

ush

to s

crap

e

away

the

mat

eria

l, w

hich

cam

e off

ver

y ea

sily

.

Stop

Gal

v5

min

s.D

ippe

d bo

lts in

to b

ottle

to a

pply

mat

eria

l. T

hick

er

than

Gal

va S

top.

Har

dene

d, b

ut s

till fl

exib

le.

Stick

s to

itse

lf if

it to

uche

s ot

her c

oate

d pr

oduc

ts.

Yes

Got

5 b

olts

bac

k. A

lmos

t all

th

read

s w

ere

com

plet

ely

bare

.10

min

s., 2

0 se

cs.

Scra

ped

the

mat

eria

l off

with

a b

ig m

etal

-bri

stle

d br

ush.

The

mat

eria

l cam

e off

ver

y ea

sily

an

d th

e th

read

s ha

d ve

ry li

ttle

resi

due.

Valm

ont M

aski

ng

Com

poun

d9

min

s., 1

0 se

cs.

Goe

s on

ver

y th

ick,

so

it co

uld

get e

xpen

sive

. U

sed

a fo

am p

aint

bru

sh to

spr

ead

arou

nd.

Nee

d an

indu

stri

al s

ize

caul

k gu

n.-

All

bolts

lost

dur

ing

testi

ng.

N/A

N/A

VH

T H

eade

r Pa

int

N/A

Not

test

ed, a

s pa

int c

anno

t be

ea

sily

rem

oved

aft

er g

alva

nizi

ng.

-N

/AN

/AN

/A

ZYP

Boro

n N

itri

de

Har

dcoa

t4

min

s., 5

sec

s.Th

ree

min

s. o

f app

licati

on ti

me

due

to s

tirri

ng.

Dip

ped

bolts

into

mat

eria

l. D

ries

ver

y fa

st.

-M

any

area

s ha

d zi

nc fr

ozen

be

twee

n th

e th

read

s.4

min

s., 5

7 se

cs.

Use

d sm

all m

etal

-bri

stle

d br

ush

to s

crap

e m

ater

ial

off. B

aked

-on

mat

eria

l was

muc

h ha

rder

than

oth

er

prod

ucts

. Co

uld

not r

emov

e al

l of t

he p

rodu

ct.

ZYP

Boro

n N

itri

de

Lubr

icoa

t5

min

s., 1

4 se

cs.

Thre

e m

inut

es o

f app

licati

on ti

me

w

as s

tirri

ng th

e pr

oduc

t. D

ippe

d bo

lts

into

mas

king

mat

eria

l to

appl

y.-

All

bolts

pic

ked

up e

xces

sive

zin

c.

A lo

t of t

he z

inc

was

just

froz

en,

but m

any

area

s ga

lvan

ized

too.

N/A

N/A

14

PHA

SE 2

TES

TIN

G -

OV

ERV

IEW

FLAT

PLA

TEBO

LT T

HRE

AD

S

Prod

uct

Pric

e1

Hou

r Cu

re

Tim

e Su

cces

s2

Hou

r Cu

re

Tim

e Su

cces

s30

Min

. Cur

e Ti

me

Succ

ess

1 H

our

Cure

Ti

me

Succ

ess

2 H

our

Cure

Ti

me

Succ

ess

DA

P H

ouse

hold

Adh

esiv

e Se

alan

t$3

.98

/ 2.

8 oz

. tub

e-

--

Yes

Yes

Gal

va S

top

$48.

00 /

lite

rYe

sYe

sYe

sYe

sYe

s

GE

100%

Sili

cone

Cau

lk$4

.97

/ 10

.1 o

z. tu

be-

--

-Ye

s

Mas

kote

Zin

c St

op -

Off

$120

.00

/ ga

l.-

--

Yes

Yes

NA

PA R

TV R

ed$1

4.19

/ 1

1 oz

. tub

e-

-Ye

sYe

sYe

s

Stop

Gal

v$4

5.00

/ q

t.Ye

sYe

s-

Yes

Yes

15

PHA

SE 2

TES

TIN

G -

OV

ERV

IEW

FLAT

PLA

TEBO

LT T

HRE

AD

S

Prod

uct

Pric

eSt

anda

rdiz

edPr

ice

1 H

our

Cure

Ti

me

Succ

ess

2 H

our

Cure

Ti

me

Succ

ess

30 M

in. C

ure

Tim

e Su

cces

s1

Hou

r Cu

re

Tim

e Su

cces

s2

Hou

r Cu

re

Tim

e Su

cces

s

DA

P H

ouse

hold

Adh

esiv

e Se

alan

t$3

.98

/ 2.

8 oz

. tub

e$1

.42

/ oz

--

-Ye

sYe

s

Gal

va S

top

$48.

00 /

l.$1

.42

/ oz

Yes

Yes

Yes

Yes

Yes

GE

100%

Sili

cone

Cau

lk$4

.97

/ 10

.1 o

z. tu

be$0

.49

/ oz

--

--

Yes

Mas

kote

Zin

c St

op -

Off

$120

.00

/ ga

l.$0

.94

/ oz

--

-Ye

sYe

s

NA

PA R

TV R

ed$1

4.19

/ 1

1 oz

. tub

e$1

.29

/ oz

--

Yes

Yes

Yes

Stop

Gal

v$4

5.00

/ q

t.$1

.41

/ oz

Yes

Yes

-Ye

sYe

s

16

BOLT

TH

REA

DS

- PH

ASE

2 T

ESTI

NG

30 M

INU

TE C

URE

TIM

E2

HO

UR

CURE

TIM

E2

HO

UR

CURE

TIM

E

Prod

uct

Succ

ess

Not

esSu

cces

sN

otes

Succ

ess

Not

es

DA

P H

ouse

hold

A

dhes

ive

Seal

ant

-2

of th

e 5

bolts

gal

vani

zed

Yes

Mat

eria

l was

gum

my

and

to

ok a

long

tim

e to

rem

ove.

Yes

App

lied

w/

a fo

am b

rush

. One

bol

t out

of t

he 5

had

a li

ttle

zin

c on

it. T

he m

ater

ial w

as v

ery

gum

my

and

took

long

er to

rem

ove.

Gal

va S

top

Yes

One

bol

t had

a ti

ny

spec

of z

inc

on it

.Ye

s1

bolt

galv

aniz

ed a

litt

le le

ss

than

10%

. Oth

er b

olts

had

m

inis

cule

am

ount

of z

inc.

Yes

App

lied

with

a fo

am b

rush

. Wen

t on

very

thin

. The

out

erm

ost

part

of t

he th

read

s lo

oked

like

ver

y litt

le if

any

mat

eria

l wen

t on

thos

e ar

eas.

The

pro

duct

stil

l pre

vent

ed g

alva

nizi

ng th

ough

.

GE

100%

Si

licon

e Ca

ulk

-3

of th

e 5

bolts

gal

vani

zed

-

3 of

the

5 bo

lts h

ad z

inc

betw

een

the

thre

ads

at th

e to

p 25

% o

f th

e th

read

s. M

ater

ial w

as

gum

my

and

hard

to re

mov

e.

Yes

App

lied

with

a fo

am b

rush

. One

bol

t out

of

the

5 ha

d a

little

zin

c on

it.

Mas

kote

Zi

nc S

top

- Off

-3

of th

e 5

bolts

gal

vani

zed

Yes

The

prod

uct s

crap

ed o

ff th

e bo

lts

very

eas

ily.

Yes

App

lied

with

a fo

am b

rush

. One

bol

t out

of t

he 5

gal

vani

zed

abou

t 10-

15%

. Thi

s m

ater

ial d

ries

ext

rem

ely

fast

, whi

ch

can

mak

e w

orki

ng w

ith it

har

d. A

fter

app

lyin

g m

aski

ng

mat

eria

l the

out

er e

dges

of t

he th

read

s ap

pear

ed to

be

bare

. It

stil

l mas

ked

the

zinc

effe

ctive

ly th

ough

.

NA

PA R

TV R

edYe

s

Non

e of

the

bolts

gal

vani

zed,

bu

t the

mat

eria

l was

ext

rem

ely

stick

y an

d w

as n

early

impo

ssib

le

to g

et o

ff th

e th

read

s.

Yes

Mat

eria

l was

ver

y gu

mm

y

and

took

a lo

ng ti

me

and

cons

ider

able

effo

rt to

rem

ove.

Yes

App

lied

with

a fo

am b

rush

. Mat

eria

l was

the

gu

mm

iest

out

of t

he o

ther

mat

eria

ls a

nd to

ok th

e

long

est ti

me

to c

lean

from

the

thre

ads.

Stop

Gal

v-

All fi

ve o

f the

bol

ts

gal

vani

zed

to s

ome

exte

nt.

Yes

A fe

w s

mal

l spe

cs o

f zi

nc h

ere

and

ther

e.Ye

sA

pplie

d w

/ a

foam

bru

sh. W

ent o

n sl

ight

ly th

icke

r th

an G

alva

St

op a

nd s

eem

ed to

cov

er s

urfa

ces

bett

er th

an G

alva

Sto

p to

o.

17


Appendix 2.

Pictures of Masking Materials During Phase 1 Testing

18


3M High Temperature Aluminum Tape

19


DAP Household Adhesive Sealant

20


Dow Corning Compound #111

21


Duct Tape

22


Galva Stop

23


GE 100% Silicone Caulk

24


Kapton Tape

25


Macropoxy 846

26


Maskote Zinc Stop-Off

27


NAPA RTV Red

28


Stop Galv

29


Valmont Masking Compound

30


VHT Header Paint

31


ZYP Boron Nitride Hardcoat

32


ZYP Boron Nitride Lubricoat

33


Additional Pictures

34

masking materials for preventing hot -dip galvanizing - american

Documents