Polishing is the make or break for most cutters.So having the best final polish lap is the key to most successful cutters. I started 35 years ago with a locally made pure tin lap that was nothing more than a few millimetres of tin on a thin steel backing plate. Tin laps notoriously ripple very easily due to there soft nature.So to avoid the necessity of the regular trip for re-machining I purchased my own lathe and found a tin supplier.I was soon making all my own laps,the first was a 50/50 tin lead ,then type metal then I ventured into alloying pure tin using bearing metal formulas.All gave good results,some better than others with the best being type metal.
Along came the new age and lead being a dirty word I switched to Zinc and sat with that for many years. I started splitting my laps around this time adding the pre-polish into the process and abandoning oxide polish to an all diamond finish.The search continued and finally the special alloy
Its not a harder alloy,but has characteristics of retaining diamond well and having good machining and surface finish,is brittle and porous so it needs to be mounted on a backing disc. The down side is the cost. Its not tin or lead dominate, the alloy is much more expensive and denser. It is the best polishing lap I have ever used.It likes fast speeds but still works well at low speeds.I split it into pre-polish at 3000K with a 100,000K final polish.Another feature is that I have seen very little if any scratching not related to too much polish or negligence.It always give a perfect finish on both grades the pre-polish is so hard to tell from the final finish when it is well worn in that i have to double check to see if I already did that facet.Its still very fast and solves all the issues of facet peel.
I sold one recently to an experienced cutter who has the Batt Lap and he commented that splitting the lap increased his cutting speed and the finish was much flatter than his batt lap. I spoke to John from Gearloose and got the impression he was aware of this alloy and he commented that as a solid lap which is his trade mark the cost would be prohibitive. The difference is noticeable to a seasoned professional but don't rush out and change as batts are the best of the tin laps and John is dedicated to his brand and bringing you new and proven quality products.
As my signature I always add it to a cutting system and above is a 1200 sintered bronze rim.
I produce this lap in 6 inch A$125,and 8 inch A$195.00 It is balanced for higher speeds and split for dual action polishing.You will also need a knurling tool and I make a specially formulated polishing compound as a kit for an additional A$75.00 At present the rims are still being finalized in both price and alloying.
