04/10/2024
I had one of the tacks that hold the panels in tested.
They are pig iron with a coating.
Pre 1700 at the latest.
I found a specialist in NY
Next step.
Summary
The tack sample as received and was analyzed using XRF. The same sample was polished
and analyzed in XRF. The following are inferred:
• The as-received sample had ~87% iron, 3% silicon, ~3% sodium, ~2% chlorine,
~1% aluminum. Individual concentrations of calcium, magnesium, sulfur,
potassium, copper, manganese, nickel, phosphorus, and zinc were less than 1%.
All other elements identified were less than 1000 ppm each.
• The polished sample had ~96% Fe and ~2.5% silicon. Individual concentrations of
manganese, nickel, aluminum, copper, and sulfur were less than 1%. All other
elements identified were less than 1000 ppm each.
• The sample is a cast iron material with a varnish like coating on it. The
concentration of iron increased in the polished sample which indicates the coating
has been removed during the polishing process.
• Tacks made of cast iron with coatings are found in antique materials while the
modern tacks are commonly made of steel and brass. Thus, this tack material is
considered antique.
Anderson Materials Evaluation, Inc.
Materials Characterization and
Failure Analysis Laboratory
E-Mail: [email protected]
Website: www.AndersonMaterials.com
9051 Red Branch Rd, Suite C
Columbia, MD21045
(410)740-8562
Fax (410)740-8201
DATE 4 April 2024
TO Douglas Walter; 609 Jacksonville Rd, Warminster PA 18974; [email protected];
215-531-4759
FROM Vaidheeshwar Ramasubramanian, Ph.D
SUBJ WD-XRF analysis of a tack sample
XRF Spectrometry Analysis
Our wavelength-dispersive XRF spectrometer can quantitatively measures the
elemental concentrations for all elements from fluorine through uranium and when the
material has a low density, as in polymers, we can also analyze carbon and nitrogen using
an additional crystal. The depth of analysis depends upon the characteristic x-ray energy
emitted from the detected element and the density of the material. This depth can vary
from a micrometer to a millimeter. XRF analysis has very low detection limits for the
elements. Wavelength-dispersive XRF systems have greater elemental sensitivity and
higher energy resolution than do less expensive energy-dispersive XRF spectrometers.
We can detect all but the lightest elements at concentrations as low as 10 ppm. Solid
samples, powders, and liquids can be analyzed with XRF analysis. Our spectrometer also
has an unusual small spot capability to measure spots of 0.5 or 1.5-mm diameter, as well
as the capability to measure areas of 10 mm and 29 mm diameter. Of course, large area
measurements offer lower detection limits and greater accuracy of measurement. For this
work, the 10 mm aperture was used. The samples were analyzed in a vacuum
environment. The elemental concentrations are reported in terms of wt% (oxygen is not
detected in XRF).
Figure 1 shows the normalized elemental composition of the as received tack
sample. Figure 2 shows the normalized elemental composition of the polished tack
sample.
The as-received sample had ~87% iron, 3% silicon, ~3% sodium, ~2% chlorine,
~1% aluminum. Individual concentrations of calcium, magnesium, sulfur, potassium,
copper, manganese, nickel, phosphorus, and zinc were less than 1%. All other elements
identified were less than 1000 ppm each.
The polished sample had ~96% Fe and ~2.5% silicon. Individual concentrations of
manganese, nickel, aluminum, copper, and sulfur were less than 1%. All other elements
identified were less than 1000 ppm each.
Figure 1. Elemental composition of the as received tack sample analyzed by WD-XRF.
Figure 2. Elemental composition of the polished tack sample analyzed by WD-XRF.
Anderson Materials Evaluation is an independent materials analysis laboratory established in 1995 offering materials testing and characterization, root cause materials failure analysis, quality control, materials verification, materials problem-solving for manufacturers, and materials and process re...
