dk nkf - Nordisk Konservatorforbund Danmark
dk nkf - Nordisk Konservatorforbund Danmark
dk nkf - Nordisk Konservatorforbund Danmark
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Figure 5: Impedance versus frequency plot for panel coated with LPS3 (TTG), two panels coated with Poligen ES91009 (KKG, KKH)<br />
and two bare Q panels<br />
variables so that materials which showed potential<br />
as protection systems for use in conservation could<br />
be compared on an equal basis and using standard<br />
techniques.<br />
When applied as recommended by the suppliers or<br />
as used in conservation practice, the thicknesses<br />
of protection systems selected from literature<br />
varied from less than 1 micron to 50 microns. Such<br />
variation in dry film thickness has great influence<br />
on the physical properties of the materials and does<br />
not permit equal comparison of test results. In the<br />
present research, all materials were applied so that<br />
they attained 20-25 microns by adjusting the number<br />
of applications or concentration of material applied.<br />
In addition, standard tests developed and used by<br />
the surface coatings industry are used to evaluate<br />
and compare all materials equally.<br />
Evaluation of the 18 protection systems which,<br />
based on literature, are most likely to meet the<br />
current project’s specifications of longevity,<br />
appearance, function, reversibility, stability and<br />
safety is not complete. The crosshatch adhesion<br />
test indicated that waxes showed poorer adhesion<br />
to Q panels and formed less cohesive films than<br />
corrosion inhibitors or solvent-based coatings. EIS<br />
suggested that poor adhesion of films over time<br />
could reduce the resistance to corrosion of treated<br />
panels until it resembled that of bare steel. The<br />
EIS results also suggested that coatings which are<br />
slightly mechanically damaged can still offer steel<br />
protection against corrosion as shown by LPS3.<br />
A simple test to compare hardness suggested that<br />
solvent based barrier coatings and waxes were<br />
resistant to abrasion from airborne particles and<br />
impact from handling while coatings containing<br />
corrosion inhibitors showed little resistance.<br />
The next stage of the project is to apply all the<br />
coatings to pre-corroded Q panels. Most industrial<br />
objects require conservation because they are<br />
corroded. Removing corrosion layers completely is<br />
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