None of the cores taken exhibited any signs of biodeterioration, Sounding and probing of all the pole stubs (42 in ground contact, 42 in above-ground exposure = 84 total) failed to indicate any decay including colonization by soft rot fungi. Heavy checking in the above-ground portions of most of the pole stubs placed in ground contact was noted. However, no colonization by wood-destroying fungi was evident. The same was true for attack by insects. No termite or beetle activity was noted. The only insect activity was some fiber pull by wasps for nesting material.
Preservative gradients and copper losses for air-dried (AD) stubs in ground contact are shown in Figure 1 , Figure 2 and Figure 3 Gradients in the above-ground (AG) and below-ground (BG) portions of the exposed stubs are compared with the original gradients obtained immediately after treatment. Copper losses in both zones are shown by bars. Loss data for CuN by treatment combination can be found in Table 3. Both the initial gradients for AD stubs and those after exposure were relatively flat and linear. Copper loss across the outer three inches in the AG portion of the air-dried stubs averaged 35% for stubs with no final conditioning, 30% for stubs which were steamed after treatment, and 7% for stubs undergoing a final fixation cycle. In the BG portion of the stubs, the loss values were 38%, 34%, and -4% for no post-treatment conditioning, final steaming, and fixation, respectively. The negative value represents a gain in preservative, most probably from movement by gravity from the top portion of the stub and/or radial movement from the interior of the pole stubs. These data suggest that the incorporation of a fixation cycle at the end of the pressure period may enhance the resistance to leaching.
The copper gradients shown (Figure 4) are very similar to those for penta with the penta gradients being slightly steeper in the original outer assay zones. The inner assay zone portions of the gradients were nearly identical in slope. Losses in both systems averaged 35% over the outer three inches of the pole stubs. In the below-ground portions of the pole stubs (Figure 5), penta had depleted more (66%) than CuN (38%). Trends for the BG gradients were similar to those found above-ground. Thus, with air-dried stock, no negative effects of post-treatment conditioning on CuN retention or gradient shape were observed. Preservative depletion for CuN was similar to or less than that for penta.
Gradients for steam-conditioned stock are shown in Figure 6 and Figure 7. The effect of treating temperature on the preservative gradient is what was expected. Higher temperature yields better treatment. However, other than the initial steepness for the 200°F gradient (Figure 6), little practical difference in gradient shape is noted between the two temperatures after exposure.
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