Sealants (nfm) |
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primary use |
substrates |
cure time |
shrink |
total joint movement |
comments |
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acrylic latex interior, non moving joints |
porous |
slow |
yes |
15% |
5 -20 years, paint will help protect, no standing water |
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polysulfide single (all joints except traffic) |
all |
slow |
yes |
25% |
5 - 20 years |
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polysulfide multi (all joints except traffic) |
all |
variable |
no |
50% |
5 - 20 years |
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polyurethane single (all joints) |
all |
slow |
no |
50% |
resists traffic abuse, 5 - 20 years |
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polyurethane multi (all joints) |
all |
variable |
no |
50% |
resists traffic abuse, 5 - 20 years |
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silicone single (all joints except traffic) |
all |
slow |
no |
50% |
will not accept paint 5 - 10 years |
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silicone multi (all joints except traffic) |
all |
variable |
no |
50% |
will not accept paint 5 - 10 years |
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structural silicone single (all & glass ext.) |
all |
slow |
no |
50% |
will not accept paint 20 years |
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structural silicone multi (all & glass ext.) |
all |
variable |
no |
50% |
will not accept paint 20 years |
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CSPE chemical resist memb.or coating |
porous |
slow |
yes |
25% |
5 - 20 years, resists water, chem & petroleum prod. |
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Chloroprene swimming pools |
porous |
slow |
yes |
25% |
5 - 20 years see CSPE |
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non-skinning acoustic seals |
porous |
non |
no |
none |
2 - 5 years do not paint |
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Butyl, water seal, small joint movement |
all |
slow |
yes |
10% |
5 - 20 years, protect from UV & ozone |
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preformed resilient sealant |
all |
non |
no |
100% |
up to 20 years all types of joints |
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TLV & other Safety Data on Paint & Cleaning Solvents NOTES: (1) Relative evaporation time is the relative time required for the solvent to completely evaporate, based on an arbitrary value of 1.0 for ethyl ether. The higher the number, the longer the time required for evaporation. (2) Flash point is the temperature of the solvent in degrees F at which the solvent releases sufficient vapor to ignite in the presence of a flame. The higher the value, the safer the solvent with respect to flash point. (3) Explosive limits define the range of solvent vapor concentration in air for which the vapor could explode or ignite. Below the minimum concentration and above the maximum concentration, the vapor will not ignite. These values are expressed as the percentage of the solvent vapor in the total volume of vapor plus air. They are also called flammable limits. (4) Threshold limit values (TLV) were obtained from the American Conference of Governmental Industrial Hygienists (ACGIH), Threshold Limit Values for Chemical Substances and Physical Agents in the Workroom Environment. TWA is the time weighted average exposure limit for an 8-hour workday or a 40 hour week. STEL is the short-term exposure limit for a maximum 15-minute exposure. Both values are expressed as parts per million (ppm) of vapor per volume of air. The higher the value, the safer the solvent. These TLV's are ACGIH's recommendations; Occupational Safety and Health Administration (OSHA) limits may be lower. |
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|
relative evapo -ration time |
flash point °C |
evaporative limits % by volume |
threshold limit values |
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min |
max |
TWA |
STEL |
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Acetone |
4 |
-12 |
2.6 |
12.8 |
750 |
1000 |
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Benzene |
8 |
-12 |
1.4 |
7.1 |
10 |
32 |
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Butyl alcohol (butanol) - skin |
70 |
40.55 |
1.4 |
11.2 |
50 |
|
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Carbon tetra chlro -ryde/skin |
8 |
not flammable |
5 |
|
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Di-isobutyl ketone |
150 |
60 |
0.8 |
6.2 |
25 |
|
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Ethyl acetate |
8 |
4.4 |
2.5 |
9.0 |
400 |
|
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Ethyl (grain) alcohol (ethanol) |
20 |
15.5 |
4.3 |
19.0 |
1000 |
|
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Ethyl ether |
1 |
|
|
|
|
|
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Ethylene dichloride |
|
|
|
|
10 |
|
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Ethylene glycol monoethyl ether/skin |
100 |
43.3 |
2.6 |
15.7 |
5 |
|
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Ethylene -diamine/ skin |
|
|
|
|
10 |
|
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Ethylene glycol monoethyl ether acetate |
32 |
54.4 |
1.7 |
nd |
5 |
|
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hi flash naphta (aromatic) |
105 |
40.55 |
1.0 |
7.0 |
|
|
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Isopropyl acetate |
10 |
10 |
1.8 |
7.8 |
200 |
250 |
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Isopropyl alcoholiso propanol/ skin |
25 |
18.3 |
2.5 |
12.0 |
200 |
250 |
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methyl alcohol (methanol) - skin |
10 |
12.77 |
5.5 |
36.5 |
200 |
250 |
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methylene chloride (dichloro -methane) |
4 |
not flammable |
50 |
|
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methyl ethyl ketone |
8 |
-1.1 |
1.4 |
7.5 |
50 |
75 |
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methyl isobutyl ketone |
20 |
18.33 |
1.4 |
7.5 |
50 |
75 |
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mineral spirit (petroleum thinner) |
150 |
40.55 |
0.8 |
7.0 |
|
|
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refined kerosen |
800 |
65.5 |
0.7 |
5.0 |
|
|
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trichloroethylene |
|
|
|
|
50 |
100 |
|||||||
toluene - skin |
15 |
7.22 |
1.3 |
7.0 |
50 |
|
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turpentine |
100 |
40.55 |
0.8 |
nd |
100 |
|
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VM & naphta |
20 |
10 |
1.1 |
5.9 |
300 |
|
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water |
100 |
not flammable |
|
|
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xylene - skin |
35 |
29.44 |
1.0 |
6.0 |
100 |
150 |
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Commonly Used Metods for Surface Preparation for Coatings |
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Cleaning method |
Equipment |
Comments |
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organic solvent |
solvent such as mineral spirits |
removes oil & grease not readily removed by other methods; precautions must be taken to avoid fires & environmental contamination; local VOC regulations may restrict use |
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detergent, power washing |
pumps, chemical sprayers, brushes |
at pressures not exceeding 13.7 MPa, removes soil, chalk, mildew, grease & oil, depending upon coposition, good for smoke, stain, chalk &dirt removal |
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Acid |
chemical sprayers & brshers |
removes residual efflerescence & laitances from concrete after dry brushing; thoroughly rinse afterwoods |
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Chemical paint strippers |
chemical, sprayers, scrapers, washing equipment |
removes coatings from most substrates, but slow, messy & expensive may degrade surface of wood substrates |
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Steam |
heating system pump, lines & nozzles |
removes heavy oil, grease & chalk; usually used prior to other methods |
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Water blasting |
high pressure water pumps, lines & nozzles |
at pressure of 13.7MPa and above, removes loose paint from steel, concrete & wood; can damage wood or masonry unless care is taken; inhibitor generally added to water to prevent flash ursting of steel |
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Hand tool |
wire brushes, chipping hammer & scrappers |
removes only loosely adhering contaminants; used mostly for spot repair; slow & not thorough |
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Power tool |
wire brushers, grinders, sanders, needle gums, rotary peeners, etc. |
faster & more thorough than hand tools because tighly adhering contaminants can be removed; some tools give a near-whit condition on steel but no an angular profile; slower than abrasive blasting; some tools are fitted with vaccuum collection devices |
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Heat |
electric heat guns |
can be used to soften coatings on woods, masonry or steel, softened coatings are scraped away, torches should not be used |
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Abrasive blasting |
sand, metal shot & metal or synthetic grit properled onto metal by pressurized air, with or without water or centrifugal forces |
typically used on metal & with care on masonry; can use recyclable abrasives; special precautions are needed when removing lead containing paint. Water may be added to control dust, so require use of inhibitors. Vaccuum blasting reduces dust but is slower than open. Centrifugal blasting is a closed cycle system in which abrasive is trown by a spinning vaned wheel. |