Series: Construction of solvent-free epoxy coatings in the ship's freshwater/drinking water tank (I)

Ship and offshore project freshwater module
/
drinking water tank belongs to the special coating chamber, solvent-free epoxy coating is a special product, so the construction of solvent-free epoxy coating in the freshwater cabin needs special attention, I according to
10
years nearly
20
freshwater tank construction Experience, standing in the position of coating shipowners, inspectors and service providers, the freshwater cabin solvent-free epoxy coating construction process, precautions and other sub-conclusions as follows, not according to this section, do not copy the standard, no nonsense, full of dry goods, very practical ground gas, but also only on behalf of personal position, for the reference of those in need.
1.
Construction phase.
1)
Phased stage does not blast coating, after the platform closed before the water to carry out the overall blasting paint construction of the fresh water tank, construction to ensure that the surrounding chamber fire industry is all over, this paper will focus on this construction program;
2)
there are also some processes for the phased phase sand blasting construction once recognized temporary primer
50um
, after the close of the overall grinding and re-construction of solvent-free epoxy .
2.
Construction season.
1)
General solvent-free epoxy coatings have a minimum curing temperature requirements, small compilation of contact with solvent-free epoxy coating curing temperature is required
10
degrees C
or more, in addition to the temperature is too high (more than
23
degrees C
) solvent-free epoxy curing speed is very fast, so the spring and autumn season is the most suitable for freshwater tank construction season, the least recommended winter construction solvent-free oxygen;
2)
if winter construction is necessary, it is important to have heating equipment in place during construction, including temperatureing the cabin and heating the coating. If there is an area where the outer side of the cabin wall is directly exposed to the atmosphere, it is necessary to keep the outer wall warm to avoid the loss of heat too quickly, and
3) during
the summer construction, shade measures should be taken for the area where the outer wall is exposed to the atmosphere according to the situation. When the outer wall of the roof is an exposed deck, in the case of direct summer sunlight, the surface temperature of the roof can reach
50-60
degrees C
, air conditioning equipment can not play its full role, high temperature will make solvent-free epoxy coating quickly cured; In addition, if there is no corresponding shade measures, the cabin temperature is too high may cause workers to experience heat stroke.
Photo
1
: Freshwater cabin exterior wall as the main deck, summer construction to prevent excessive cabin temperature
Photo
2
: Winter paint pre-warmed
3.
Construction equipment.
1)
Dehumidifier. Dehumidifier is one of the necessary equipment, generally requires that the relative humidity during blasting, paint construction and curing process remains below
60%


; It is recommended to use a mobile air compressor with air pressure of
7
kg or more. The biggest disadvantage of plant pressure is not stable enough, especially when the pressure is not reached at peak gas, painting may be due to insufficient pressure resulting in poor atomization of the paint
3)
high-pressure airless spray pump. The recommended compression ratio
65
:
1
airless spray pump;
4)
paint hose. It is recommended to use a new oil pipeline, the old hose due to the surface of more pollutants in the pull process will contaminate the paint surface. Some contractors, in order to save money, wrap a glue around the surface of the hose to prevent contaminants from falling off the hose;
5)
brushes and rollers. Prepare a little brush and roller, not in the construction process hair
loss, there is an experience on the site is to soak the brush in the thinner to
minimize bristles; Shoe cover, plastic film, tape, rags, etc.
Photo
3
: Paint hose surface wrapped in tape to avoid contaminant drops on the hose
Photo
4
: Paint hose surface wrapped in tape to avoid contaminant drops on the hose
Photo
5
: In-cabin wearing shoe cover
Photo
6
: Wearing shoe cover in the cabin
Photo
7
: Brush hair is severe, pre-coated stuck in the pre-coated area
Photo
8
: Brush hair-dropping serious, pre-coated when glued to the pre-coated area
4.
Coating matching.
small-edited contact with the coating matching as follows:
1)
segment stage
1 x 50um
temporary protective primer, closed after
1 x 250um
solvent-free epoxy;
2) 1 x 120um
inorganic zinc silicate;
3) 1 x 300um
solvent-free epoxy;
4) 3 x 100um
solvent-free epoxy;
5) 2 x 150um
(
1
degrees red
-1
degrees white) solvent-free epoxy, the most common is
2 x 150um
solvent-free epoxy package. This article discusses this supporting construction.
5.
Construction process.
the solvent-free epoxy construction process
2 x 150um
the small compilation generally has several steps.
1)
Structural defect treatment;
2)
in the cabin to reduce the soluble salt content;
3)
pre-blast to further deal with structural defects;
4)
blasting;
5)
cleaning, protection;
6) 1
degree paint pre-painting

degree paint spraying;
7)
protection, pipe replacement, coating defect treatment, primer leakage site repair;
8) 2
-degree paint pre-coated
-2
-degree paint spraying;
9)
defect treatment and repair (repairing), scaffolding above completion inspection
10)
scaffolding;
11)
scaffolding position polishing repair;
12
temporary manhole blocking polishing paint.
6.
Human arrangements.
1)
It is best to have a dry special coating team dedicated to freshwater cabin coating construction, generally they have special construction equipment and operating procedures, the quality and experience of workers are higher, but at present, to see the major shipyards in order to save costs, or special coating cabin and other cabins together subcontracted to the same contractorIn order to seize time, freshwater cabin construction time may not be fixed, this team in addition to dry fresh water cabin no longer carry out other work, as needed at any time into the cabin to work, work home to rest on standby;
3)
The construction party must be equipped with self-inspection personnel, film thickness measurement, coating defect inspection and marking, etc.;
4)
Freshwater cabin construction time is not equal, in order to obtain good construction results, sometimes shipowners, service providers or quality inspection will directly guide the construction, the process is well controlled, the result is water into the canal.
7.
temporary hole.
1)
In order to facilitate the entry and exit of personnel and equipment materials, the general shipyard in the freshwater chamber sanding before the design and the owner agreed to open zero-hour manholes in the bottom flat position of the ship;
2)
temporary holes as large as possible, easy to access personnel, equipment, materials, and sometimes wind pipes from temporary holes (wind pipes can also be entered from the design manhole or surrounding compartment), large enough temporary holes will make you more smooth and convenient access to the cabin.
8.
Scaffolding.
scaffolding is different according to the structure of the compartment, there are the following points to note:
1)
it is recommended to set up along the freshwater cabin wall into
""
back
"
type structure, the top scaffolding full;
2)
tubes or pedals and steel plate surface distance of
30cm
is the most suitable, can not contact with the four walls
3)
reasonable arrangement of the layer height, to ensure that the top scaffolding and roof distance is appropriate, to avoid the top height is too low personnel to walk;
4)
the head of the rack pipe with a plug or tape to seal, to avoid sand blasting when the abrasive into the frame tube, difficult to clean.
photo
9
: according to the cabin structure set up
"
back
"
glyph
Photo
10
: according to the cabin structure set up
"

back

Glyph
Photo
11
: Unqualified scaffolding for rectification Photo
12
: Scaffolding tube head sealed with tape