\n
![\"\"](\"https:\/\/thefinishingstore.com\/wp-content\/uploads\/2022\/03\/blogs_posts-flexner-may-2015-testing-for-dry-heat-resistance.jpg\")
On the other hand, with factory pre-sanded veneered plywood or mdf, beginning with 150-grit sandpaper is usually adequate.<\/span>As an example, 100- or 120-grit sandpaper is usually coarse enough to begin with. Beginning with 150-grit sandpaper is usually inefficient because you have to sand too long to remove the problems.<\/p>\nThese are general observations. We all sand differently, so you may want to adjust the beginning grit you sand with depending on the problems you want to remove. But the basic rule still applies: It\u2019s most efficient to remove all the problems with the coarsest grit you\u2019re using before moving to finer grits.<\/p>\n
Testing Finishes for Heat Resistance \u00a0<\/strong><\/p>\n Resistance to damage from hot objects is an important finish quality for tabletops and counter surfaces in kitchen and dining areas. The type of finish you\u2019re using will be a strong clue to its resistance. For example, oil-based polyurethane and catalyzed lacquer are very resistant to heat damage, while shellac, lacquer and water-based finishes are less so.<\/p>\n There are two tests for heat resistance that are easy to do.<\/p>\n To test for dry heat resistance, place a metal cup or pot containing water heated to just below boiling on a fully cured finish, as shown in the accompanying picture. Remove the cooled container after an hour and look for splits, \u00a0indentations or discoloration in the finish.<\/p>\n \u00a0To test for wet heat resistance, do the same as for dry heat resistance, \u00a0but place a cotton cloth or cheesecloth wetted with the same hot water \u00a0under the cup or pot. After an hour check the surface for splits in the \u00a0finish or discoloration.<\/p>\n Begin by buying a set of architect\u2019s drawing pencils ranging in hardness from about 2B (soft) to 5H (hard). Sharpen each pencil using a knife so you leave the sharp cylindrical edge of the lead intact. If you damage this edge, or if it becomes worn, sand it flat, holding the pencil 90 degrees to the sandpaper.<\/p>\n Beginning with one of the softer pencils, hold it as you would for writing and push it forward across the fully cured finish as shown in the accompanying picture. Maintaining equal pressure, follow with pencils of increasing hardness until you find one that cuts into the finish.<\/p>\n The hardness rating for that finish is the number of the previous pencil \u2013 the hardest lead that doesn\u2019t cut.<\/p>\n [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n<\/span>","protected":false},"excerpt":{"rendered":" When sanding wood in preparation for a stain or finish, you need to remove all the problems in the \u00a0wood \u2013 mill marks, tear outs, gouges, etc. \u2013 with the coarsest grit sandpaper you\u2019re using before \u00a0moving on to finer grits (to remove the coarse-grit scratches). This means that the coarse-grit \u00a0sandpaper you begin with […]<\/p>\n","protected":false},"author":0,"featured_media":231937,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":" When sanding wood in preparation for a stain or finish, you need to remove all the problems in the \u00a0wood \u2013 mill marks, tear outs, gouges, etc. \u2013 with the coarsest grit sandpaper you\u2019re using before \u00a0moving on to finer grits (to remove the coarse-grit scratches). This means that the coarse-grit \u00a0sandpaper you begin with should be able to remove the problems quickly and efficiently to reduce \u00a0the amount of work required.<\/p>\r\n These are general observations. We all sand differently, so you may want to adjust the beginning grit you sand with depending on the problems you want to remove. But the basic rule still applies: It\u2019s most efficient to remove all the problems with the coarsest grit you\u2019re using before moving to finer grits.<\/p>\r\n Testing Finishes for Heat Resistance \u00a0<\/strong><\/p>\r\n Resistance to damage from hot objects is an important finish quality for tabletops and counter surfaces in kitchen and dining areas. The type of finish you\u2019re using will be a strong clue to its resistance. For example, oil-based polyurethane and catalyzed lacquer are very resistant to heat damage, while shellac, lacquer and water-based finishes are less so.<\/p>\r\n There are two tests for heat resistance that are easy to do.<\/p>\r\n To test for dry heat resistance, place a metal cup or pot containing water heated to just below boiling on a fully cured finish, as shown in the accompanying picture. Remove the cooled container after an hour and look for splits, \u00a0indentations or discoloration in the finish.<\/p>\r\n \u00a0To test for wet heat resistance, do the same as for dry heat resistance, \u00a0but place a cotton cloth or cheesecloth wetted with the same hot water \u00a0under the cup or pot. After an hour check the surface for splits in the \u00a0finish or discoloration.<\/p>\r\n Begin by buying a set of architect\u2019s drawing pencils ranging in hardness from about 2B (soft) to 5H (hard). Sharpen each pencil using a knife so you leave the sharp cylindrical edge of the lead intact. If you damage this edge, or if it becomes worn, sand it flat, holding the pencil 90 degrees to the sandpaper.<\/p>\r\n Beginning with one of the softer pencils, hold it as you would for writing and push it forward across the fully cured finish as shown in the accompanying picture. Maintaining equal pressure, follow with pencils of increasing hardness until you find one that cuts into the finish.<\/p>\r\n The hardness rating for that finish is the number of the previous pencil \u2013 the hardest lead that doesn\u2019t cut.<\/p>","_et_gb_content_width":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[1209],"tags":[1761,1785,1602,1214,1786,1254,1227,1372,1228,1533,1297,1546],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/posts\/231936"}],"collection":[{"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/comments?post=231936"}],"version-history":[{"count":2,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/posts\/231936\/revisions"}],"predecessor-version":[{"id":239711,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/posts\/231936\/revisions\/239711"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/media\/231937"}],"wp:attachment":[{"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/media?parent=231936"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/categories?post=231936"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thefinishingstore.com\/wp-json\/wp\/v2\/tags?post=231936"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n![\"\"](\"https:\/\/thefinishingstore.com\/wp-content\/uploads\/2022\/03\/blogs_posts-Pencil-Marks.jpg\")
The easy way to do this is with architect\u2019s pencils because these vary in hardness themselves.<\/span>Finishes vary in hardness and scratch resistance. To a large extent the \u00a0relative hardness of various finishes are known. For example, oil-based \u00a0polyurethane is more scratch resistant than lacquer or shellac. So are catalyzed finishes and water-based finishes. But what if you want to be \u00a0more exact about the differences, or want to compare brands within any single type of finish?<\/p>\n![\"\"](\"https:\/\/thefinishingstore.com\/wp-content\/uploads\/2022\/03\/blogs_posts-flexner-may-2015-testing-for-dry-heat-resistance_large.jpg?12782395226035680781\")
On the other hand, with factory pre-sanded veneered plywood or mdf, beginning with 150-grit sandpaper is usually adequate.<\/span>As an example, 100- or 120-grit sandpaper is usually coarse enough to begin with. Beginning with 150-grit sandpaper is usually inefficient because you have to sand too long to remove the problems.<\/p>\r\n![\"\"](\"https:\/\/thefinishingstore.com\/wp-content\/uploads\/2022\/03\/blogs_posts-flexner-may-2015-using-architect-s-pencil-to-test-for-hardness_large.jpg?12436195149934589580\")
The easy way to do this is with architect\u2019s pencils because these vary in hardness themselves.<\/span>Finishes vary in hardness and scratch resistance. To a large extent the \u00a0relative hardness of various finishes are known. For example, oil-based \u00a0polyurethane is more scratch resistant than lacquer or shellac. So are catalyzed finishes and water-based finishes. But what if you want to be \u00a0more exact about the differences, or want to compare brands within any single type of finish?<\/p>\r\n