{"title":"Flat Laps for Pumice","description":"\u003cp\u003e\u003cstrong\u003ePumice pre-polish is the stage between smoothing and final polish\u003c\/strong\u003e — it takes the grey haze off a smoothed glass surface and leaves it ready for cerium oxide. What you run the pumice \u003cem\u003eon\u003c\/em\u003e decides how fast that stage goes and how even the result is. These are the two laps built for it.\u003c\/p\u003e\u003ch3\u003eWhich one do I need?\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eSynthetic felt pads (.050\" thick)\u003c\/strong\u003e — optical-grade felt with a solid, unperforated face. The felt holds the pumice slurry evenly right across the disc, so the cut stays consistent edge to centre. At .050\" they match the thickness of resin diamond smoothing pads, so they drop into the same lap sequence without re-setting the machine — which also makes them a good facet-work pad with cerium oxide. Four sizes: 8, 12, 18 and 24 inch.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eMJ urethane laps\u003c\/strong\u003e — extruded urethane carrying fine fibres that generate friction against the glass, with an open pore structure that holds pumice in place. Faster and more aggressive than felt, and the choice for larger production work. Two sizes: 24 inch (magnetic backed) and 30 inch.\u003c\/p\u003e\u003ch3\u003eSizes and thickness at a glance\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eLap\u003c\/th\u003e\n\u003cth\u003eDiameter\u003c\/th\u003e\n\u003cth\u003eThickness\u003c\/th\u003e\n\u003cth\u003eBacking\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eSynthetic felt\u003c\/td\u003e\n\u003ctd\u003e8\"\u003c\/td\u003e\n\u003ctd\u003e.050\"\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSynthetic felt\u003c\/td\u003e\n\u003ctd\u003e12\"\u003c\/td\u003e\n\u003ctd\u003e.050\"\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSynthetic felt\u003c\/td\u003e\n\u003ctd\u003e18\"\u003c\/td\u003e\n\u003ctd\u003e.050\"\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSynthetic felt\u003c\/td\u003e\n\u003ctd\u003e24\"\u003c\/td\u003e\n\u003ctd\u003e.050\"\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMJ urethane\u003c\/td\u003e\n\u003ctd\u003e24\"\u003c\/td\u003e\n\u003ctd\u003e15 mm\u003c\/td\u003e\n\u003ctd\u003eMagnetic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMJ urethane\u003c\/td\u003e\n\u003ctd\u003e30\"\u003c\/td\u003e\n\u003ctd\u003e2-3\/4\"\u003c\/td\u003e\n\u003ctd\u003e—\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eUsing them\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMatch the lap diameter to your flat lap grinder platen.\u003c\/li\u003e\n\u003cli\u003eKeep the pumice wet and worked into the face — a dry lap glazes and stops cutting.\u003c\/li\u003e\n\u003cli\u003eRun pumice and cerium on \u003cstrong\u003eseparate\u003c\/strong\u003e laps. Cross-contamination is the usual cause of a polish that will not come clear.\u003c\/li\u003e\n\u003cli\u003eRinse the lap down at the end of a session so the slurry does not set in the pores.\u003c\/li\u003e\n\u003c\/ul\u003e","products":[{"product_id":"synthetic-felt-polishing-pad-050-8-inch","title":"Synthetic Felt Polishing Pad - .050 Thick - 8 Inch","description":"\u003cp\u003eOptical-grade synthetic felt polishing pad, .050\" thick with no perforations — the standard carrier for pumice pre-polish on a flat lap. The dense, unperforated face holds the pumice slurry evenly right across the disc, so the pre-polish stage cuts consistently and hands a uniform surface to your final cerium polish.\u003c\/p\u003e\u003cp\u003eAt .050\" it matches the thickness of resin diamond smoothing pads, so it drops straight into the same lap sequence without re-setting the machine. That also makes it a strong choice for facet work with cerium oxide.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 8 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e .050 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFace:\u003c\/strong\u003e solid — no perforations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice pre-polish, or cerium oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191645311226,"sku":"HG-HGF8-050","price":19.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/hgf8-050_1.jpg?v=1787923814"},{"product_id":"synthetic-felt-polishing-pad-050-12-inch","title":"Synthetic Felt Polishing Pad - .050 Thick - 12 Inch","description":"\u003cp\u003eOptical-grade synthetic felt polishing pad, .050\" thick with no perforations — the standard carrier for pumice pre-polish on a flat lap. The dense, unperforated face holds the pumice slurry evenly right across the disc, so the pre-polish stage cuts consistently and hands a uniform surface to your final cerium polish.\u003c\/p\u003e\u003cp\u003eAt .050\" it matches the thickness of resin diamond smoothing pads, so it drops straight into the same lap sequence without re-setting the machine. That also makes it a strong choice for facet work with cerium oxide.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 12 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e .050 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFace:\u003c\/strong\u003e solid — no perforations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice pre-polish, or cerium oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191645343994,"sku":"HG-HGF12-050","price":49.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/hgf-12-thin.jpg?v=1787923814"},{"product_id":"synthetic-felt-polishing-pad-050-18-inch","title":"Synthetic Felt Polishing Pad - .050 Thick - 18 Inch","description":"\u003cp\u003eOptical-grade synthetic felt polishing pad, .050\" thick with no perforations — the standard carrier for pumice pre-polish on a flat lap. The dense, unperforated face holds the pumice slurry evenly right across the disc, so the pre-polish stage cuts consistently and hands a uniform surface to your final cerium polish.\u003c\/p\u003e\u003cp\u003eAt .050\" it matches the thickness of resin diamond smoothing pads, so it drops straight into the same lap sequence without re-setting the machine. That also makes it a strong choice for facet work with cerium oxide.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 18 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e .050 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFace:\u003c\/strong\u003e solid — no perforations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice pre-polish, or cerium oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191645409530,"sku":"HG-HGF18-050","price":120.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/hgf18-thin.jpg?v=1787923815"},{"product_id":"synthetic-felt-polishing-pad-050-24-inch","title":"Synthetic Felt Polishing Pad - .050 Thick - 24 Inch","description":"\u003cp\u003eOptical-grade synthetic felt polishing pad, .050\" thick with no perforations — the standard carrier for pumice pre-polish on a flat lap. The dense, unperforated face holds the pumice slurry evenly right across the disc, so the pre-polish stage cuts consistently and hands a uniform surface to your final cerium polish.\u003c\/p\u003e\u003cp\u003eAt .050\" it matches the thickness of resin diamond smoothing pads, so it drops straight into the same lap sequence without re-setting the machine. That also makes it a strong choice for facet work with cerium oxide.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 24 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e .050 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFace:\u003c\/strong\u003e solid — no perforations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice pre-polish, or cerium oxide\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191648719098,"sku":"HG-HGF24-050","price":233.24,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/hgf24-thin.jpg?v=1787923836"},{"product_id":"mj-urethane-flat-lap-pumice-24-inch","title":"Wheel - MJ Urethane Flat Lap - for Pumice - Magnetic - 24 Inch","description":"\u003cp\u003eMJ urethane flat lap for pumice pre-polishing on glass. The extruded urethane carries fine fibres that generate friction against the glass surface, while its open pore structure holds the pumice in place — giving a fast, controllable rough polish right across the lap.\u003c\/p\u003e\u003cp\u003eSupplied with a magnetic backing, so it mounts and swaps on a magnetic flat lap platen in seconds.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 24 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e 15 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBacking:\u003c\/strong\u003e magnetic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191648784634,"sku":"HG-LAPIT-24-MJ","price":293.02,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/lapit-24-mj-b.jpg?v=1787923836"},{"product_id":"mj-urethane-flat-lap-pumice-30-inch","title":"Wheel - MJ Urethane Flat Lap - for Pumice - 30 Inch","description":"\u003cp\u003eMJ urethane flat lap for pumice pre-polishing on glass. The extruded urethane carries fine fibres that generate friction against the glass surface, while its open pore structure holds the pumice in place — giving a fast, controllable rough polish right across the lap.\u003c\/p\u003e\u003cp\u003eThe 30 inch lap is the large-format size for production flat lap grinders.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDiameter:\u003c\/strong\u003e 30 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThickness:\u003c\/strong\u003e 2-3\/4 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUse with:\u003c\/strong\u003e pumice\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e flat lap grinders\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cem\u003ePart of the \u003ca href=\"\/es\/pages\/flat-laps-for-pumice\"\u003eFlat Laps for Pumice\u003c\/a\u003e range — see all six sizes, a comparison of felt vs MJ urethane, and how to get the best out of them.\u003c\/em\u003e\u003c\/p\u003e","brand":"Glass","offers":[{"title":"Default Title","offer_id":50191648882938,"sku":"HG-LAPIT-30-MJ","price":476.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/files\/lapit-30-mj.jpg?v=1787923837"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0685\/8162\/2010\/collections\/lapit-24-mj-b.jpg?v=1787923892","url":"https:\/\/johnsonbrotherslapidary.com\/es\/collections\/flat-laps-for-pumice.oembed","provider":"Johnson Brothers Lapidary","version":"1.0","type":"link"}