1、Designation: E1773 10E1773 18Standard Practice forSealing Rigid Wall Tactical Shelters with Polysulfide BasedSealants1This standard is issued under the fixed designation E1773; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This practice covers the p
3、rocedures for sealing rigid wall tactical shelters. It outlines the techniques for the storage, mixing,handling, and application of polysulfide based sealants.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI u
4、nits that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenviro
5、nmental practices and determine theapplicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, G
6、uides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D907 Terminology of AdhesivesE631 Terminology of Building ConstructionsE1749 Terminology Relating to Rigid Wall Relocatable Shelters2.2 Society of Au
7、tomotive Engineers (SAE) Specification:Specifications:3SAE-AMS-S-8802 Sealing Compound, Temperature-Resistant, Integral Fuel TankaTanks and Fuel Cell Cavities, HighAdhesionSAE-AMS-3819 Cleaning Cloths3. Terminology3.1 DefinitionsDefinitions:See3.1.1 For definitions of general terms related to buildi
8、ng construction used in this practice, refer to Terminology E631 and forgeneral terms related to rigid wall relocatable shelters, refer to Terminology E1749. Terminology E1749 for definitions of generalterms used in this practice.3.2 Definitions of Terms Specific to This Standard:3.2.1 acceleratorus
9、ed by sealant formulators to denote an ingredient included in the formulation to accelerate the rate of cure.It is also used separately in a mixture to accelerate surface curing only of applied polysulfide sealant, that is, tack free timeaccelerator.3.2.2 adhesionThe state in which two surfaces are
10、held together by interphase forces. D9073.2.3 application time (sealants)the time available for sealant application after mixing or time available after thawing apremixed and frozen cartridge of sealant.1 This practice is under the jurisdiction of ASTM Committee E06 on Performance of Buildings and i
11、s the direct responsibility of Subcommittee E06.53 on Materials andProcesses for Durable Rigidwall Relocatable Structures.Current edition approved Nov. 1, 2010Oct. 1, 2018. Published December 2010November 2018. Originally approved in 1995. Last previous edition approved in 20052010as E1773 05.E17731
12、0. DOI: 10.1520/E1773-10.10.1520/E177318.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from SAE
13、 International (SAE), 400 Commonwealth Dr., Warrendale, PA 15096-0001,15096, http:/www.sae.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically pos
14、sible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
15、est Conshohocken, PA 19428-2959. United States13.2.3.1 DiscussionAcceptability limits for Class B extrudable sealants are expressed in terms of the extrusion rate of a sealant from a 6 fl oz (180mL) cartridge through a nozzle with a 0.125 in. (3.2 mm) diameter orifice, using air pressure of 90 6 5 p
16、si (620 6 34 kPa) in apneumatic sealant gun. The extrusion rate is expressed in grams per minute or on cc per minute. A minimum extrusion rate afterthe stated application time is given as the acceptable limit. Sealant applied after the application time is exceeded tends not to wetthe surface well an
17、d thus not to form a good bond. This term should not be used interchangeably with work life.3.2.4 assembly timethe amount of time available after a two-part sealant is mixed, before the faying surfaces, to which sealantis applied, shall be assembled and the sealant squeezed out.3.2.4.1 DiscussionIf
18、the assembly time is exceeded, the cure will have progressed too far to permit most of the sealant to be squeezed out for thedesired surface to surface contact. The term assembly time is used in reference to faying-surface sealants. Also called work lifeand open time.3.2.5 base compoundthe major com
19、ponent of a two-part curing sealant that contains the polysulfide polymer.3.2.6 bridgingsee Terminology E1749.3.2.7 cartridgea plastic container which contains an integral plunger.3.2.7.1 DiscussionThe cartridge is used to contain either a frozen quantity of premixed base compound and curing compoun
20、d or simply the basecompound in unmixed injection kits.3.2.8 cohesion strength (sealant)the internal forces holding a cured sealant together.3.2.9 contaminantany foreign substance that degrades the performance of the sealant.3.2.10 cure ratethe rate at which a sealant polymerizes or crosslinks (that
21、 is, solidifies), a measure of which is the hardnessof a sealant at a specified cure time.3.2.11 cure time (sealants)the time required for a sealant to polymerize and develop its full physical/mechanical properties.3.2.11.1 DiscussionIn practice, however, it is the time required to reach a designate
22、d hardness.3.2.12 curing compoundthe crosslinking agent for the base compound.3.2.13 hardnesssee Shore A hardness and REX Hardness in Terminology E1749.3.2.14 interference seala seal produced between a given diameter mechanical fastener and a smaller diameter hole in amember into which it is inserte
23、d.3.2.14.1 DiscussionAn interference seal is also produced when a fastener shank is expanded by the installation process.3.2.15 primary seala seal which, in combination with the structure and optional brush coat or secondary seal, forms acontinuous, durable seal in the sealing plane and requires no
24、additional seals.3.2.16 self-sealing fastenera fastener that provides a tight seal without the need for sealant materials or the use of amechanical seal.3.2.16.1 DiscussionAn interference fit fastener is an example.3.2.17 tack free timethe time required for a curing sealant to lose its surface tacki
25、ness to polyethylene.3.2.17.1 DiscussionRefer to SAE-AMS-S-8802.E1773 1823.2.18 tooled filleta fillet formed by working an applied bead of sealant to a feathered edge using a shaped tool.3.2.18.1 DiscussionThe goal is to ensure good surface contact at the feathered edges, to eliminate voids, trapped
26、 air and re-entrant edges, and toproduce a contour of the correct thickness and shape over the area being sealed.3.2.19 two-component sealant injection kita kit designed for the mixing and application of a two-part sealant. The kit consistsof a plastic (usually polyethylene) cartridge filled with ba
27、se compound, a hollow dasher rod containing curing compound, and aplunger. The dasher rod extends into one end of the cartridge; at the end of the dasher rod inside the cartridge, a multi-armedagitator is attached. The plunger caps the other end of the cartridge.3.2.19.1 DiscussionTo use, a ram rod
28、is inserted into the dasher rod and the curing compound is forced into the base compound. The dasher rod isthen pulled back and forth at a specified rate with periodic rotation to add to the efficiency of the agitator. When the sealant is mixedthoroughly, the dasher rod is unscrewed from the agitato
29、r and removed.Anozzle is screwed onto the cartridge and the unit insertedinto a sealant gun. Sealant is dispensed as the plunger is pushed further into the cartridge.3.2.20 wet installed fastenersfasteners that are coated on the shank and under the head with a curing-type sealant to providea corrosi
30、on barrier and a secondary seal.4. Significance and Use4.1 This recommended practice is intended to provide information on the storage, mixing, handling, and application ofpolysulfide based sealants. Tooling and equipment requirements for the satisfactory application of the sealants to joints in tac
31、ticalshelters are also provided.5. Hazards5.1 MaterialsThe precautions outlined in the manufacturersmanufacturers material safety data sheets (MSDS) for thematerials being used shall become a part of this practice.5.2 Work Place:5.2.1 All lights and other electrical equipment used for the sealant ap
32、plication within an enclosed shelter shall be explosionproof. Extension cords shall be long enough to make electrical connections outside the shelter.5.2.2 When use of compressed air is required, proper safety equipment shall be provided and used.6. Storage6.1 Premixed and Frozen SealantSealants tha
33、t are supplied premixed and frozen shall be stored in a cold box or a roommaintained at 40 6 5F5 F (40 6 2.8C)2.8 C) or within 65C (2.8F)65 C (2.8 F) of the manufacturersmanufacturersrecommended storage temperature.6.2 Two-Component Sealant KitsTwo-component sealants supplied as either injection kit
34、s or bulk sealant kits shall be storedin areas maintained at a temperature not to exceed 80F (27C).80 F (27 C).7. Labeling7.1 Sealant containers shall have attached labels which clearly identify the product, manufacturer, matched base and curingcompounds (if applicable), batch and lot numbers, date
35、of manufacture, recommended mix ratio (if applicable), and expiration dateunder specified storage conditions.8. Material Handling8.1 Premixed and FrozenSealants are supplied premixed and frozen, used prior to the manufacturers expiration date on thelabel, and shall be ready for immediate use followi
36、ng thawing of the contents. With the addition of a nozzle, the material isdispensed directly from the cartridge.8.2 Two-Component Sealant Injection KitsSealants supplied in this form shall be mixed according to themanufacturersmanufacturers instructions and used before the expiration date provided o
37、n the label and within the applicationtime determined for that sealant.8.3 Bulk SealantTwo-part sealants are supplied in a wide range of kit sizes from 12 pt to 50-gal drums plus 5-gal pail of curingcompound. In every case there is a small percentage of extra curing compound included, ranging from 2
38、 to 10 % to compensatefor losses in the transfer of the curing compound. Although kit sizes are generally quoted in terms of volume, the base and curingcompound are matched on basis of weight ratio. Both weight and volume ratio are usually included on the label.E1773 1838.3.1 Mixing:8.3.1.1 Hand Mix
39、ingKits under 5 gal are packaged such that the base compound container will permit the addition and mixingof the curing compound. Mix the entire kit at one time and use all the curing compound. By mixing and using the entire kit at once,the user is assured that the correct amounts have been used and
40、 the resultant sealant properties will be those expected. Some ofthe pitfalls of attempting to use partial kits include: (1) the possible use of incorrect ratio; (2) incorrect weighing; (3) failure tothoroughly stir the curing compound in the container before removing the desired quantity; (4) incom
41、plete transfer of base orcuring compound, or both; and (5) compromising the remaining material by failure to supply an inert atmosphere or failure to setthe can lid completely.NOTE 1In all cases it is of paramount importance that the batch of base be catalyzed only with the batch of curing compound
42、to which it was matched.(Batch number of batch of matched base and curing compound should be given on each label.) Hand mix thoroughly by folding the material over itself.Frequently scrape down the walls of the container to ensure complete mixing. Avoid whipping the material as this will incorporate
43、 air into the mixtureand result in void formation. High mixing speeds may also cause excessive heat which will advance the cure of the sealant, shortening the applicationand assembly time. If the storage area temperature is greatly different from normal (standard) temperature, the kits should be pre
44、conditioned to standardtemperature 77F (25C);77 F (25 C); also, local humidity shall be on the order of 55 % RH if data sheet performance is expected. If the surfaceto which the sealant is to be applied is decidedly different from 77F (25C),77 F (25 C), the cure rate will vary accordingly. For examp
45、le, aSAE-AMS-S-8802 B-2 system at 50 % RH will have a work life of 3 h at 60F (16C),60 F (16 C), 2 h at 80F (27C),80 F (27 C), but only 1 hat 100F (37.8C).100 F (37.8 C). While if the temperature is held at 80F (27C),80 F (27 C), the work life will be 3 h at 35 % RH, 2 h at 50 %RH, and at 65 % RH th
46、e work life is only 1 h.8.3.1.2 Machine MixingMeter/mix machines are used when large quantities of mixed sealant are required. Separate pumpsforce base compound and curing compound through a metering system which measures the proper ratio of the components. Thetwo streams are then fed into a mixing
47、head where a uniform mixture is produced. The sealant is then usually dispensed into lowdensity polyethylene cartridges ranging in size from 2.5 to 12 oz (74355 (74 to 355 mL) for immediate use or quick frozen (see8.5) for future use. The mixed sealant should exhibit no visible streaks or evidence o
48、f entrapped air (bubbles or voids) during thedispensing operation. When using meter mix machines the following steps should be made a part of the standard operatingprocedure:(a) Stir the 5-gal pail of catalyst thoroughly with a mechanical agitator, being careful not to whip air into the curing compo
49、undor excessively heat the material.(b) Scrape down the walls of the pail.(c) If the curing compound sits for 48 h after stirring, stir again.(d) Start with clean lines and an empty meter/mix machine or purge the lines and machine with at least 2 gal of base and theequivalent catalyst.(e) Calibrate a variable ratio machine frequently. (At the start of each shift or the change of containers, or both).(f) If a static mix head is used, clean it if the flow rate decreases substantially. Purg
