Jeff's Opinion on Laps
Jeff R Graham shares his opinions and thoughts on various topics in Just Ask Jeff. See what his answers are to What is my opinion on laps? What do I use?
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What is my opinion on laps? What do I use?
OK, I have a lot of people ask me what my personal opinion(s) are on laps. So here is what I think, remember that other people may have different experiences, but these are my personal experiences.
Note: I only sell what I think people need, if you are looking for a lap I do not have listed ask me about it.
Note2: There people are selling solid Brass, Bronze, and Aluminum laps to beginners. These dealers are knowingly selling beginners laps they will probably never use (and that generally do not work well) to line their own pockets. These laps are not used in general and I do not know anybody who has ever used them. I do not recommend these types of laps.
My experience with split laps has always been mixed - Laps that have two grits are usually coarse(r) on the outside ring (so that there is less chance of contamination as the lap is turning, the loose dust and diamonds goes towards the edge of the lap on the outside of the lap) and a finer grit on the inside.
There are several disadvantages to them. First because they are different grits, the finer grit often ends up contaminated by the larger grit, polishes in particular. The second big problem is that because the coarse part of the lap is on the outside of the lap you cannot use the fine part of the lap for the girdle of your stone. This is a major problem.
You will end up buying a fine lap anyway. So your are not saving any money and because you cannot fine cut the girdle with the coarse on the outside of the split lap (the fine grit is on the inside ring, the stone/quill will not reach when cutting the girdle) you have to change to a fine lap so it is no faster or no cheaper. I do not recommend these types of laps.
8" Solid Steel Laps Solid steel laps are generally the way to go, at least in my opinion.
60 Diamond. (extra extra coarse) - I usually do not recommend this lap. It is just too aggressive for most faceting rough, it will cause large chips and fractures.
100x Diamond. (extra coarse) - I use and recommend that most people have this lap, eventually. It is ideal for taking a lot of material off of a piece of rough fast. But while it will leave some chips (especially when new), it does not tend to chip excessively like some coarser laps do. If you are on a budget or not cutting larger stones then you can probably do without this lap, at least when starting to facet.
180 Diamond. (medium coarse) - I do not own one of these laps and do not really recommend one. Some people like them. This is kind of in between the 260 and the 100x and while it is not a bad lap, I prefer the other grits. I find that a worn in 260 lap is much better.
260 Diamond. (coarse) - This is my standard roughing in lap. I recommend this for about everyone. I like this lap especially when it has worn in a bit, it works much better than a 360 lap. It cuts fast but leaves a nice, although coarse finish.
360 Diamond. (medium coarse) - I do not own one of these laps and do not really recommend one. Some people like them, but I generally find that once this lap has broken in a bit, it cuts too slowly for my taste. I prefer a worn in 260 lap it's much better.
600 Diamond. (medium) - I like and recommend that most people use a 600 lap. I use it mostly for cutting Quartz and Beryl (to be honest), and then use a 1200 Nu Bond composite lap for a pre-polish. On other materials (like Tourmaline and Garnets) I generally go right to my worn 1200 steel lap, skipping the 600 lap.
1200 Diamond. (fine) - This is my all around working lap, when new they need to be worn in a bit, steel laps start out a little coarse. I use and recommend it for almost everything I cut. With the exception of Quartz and Beryl, I use a Nu Bond 1200 for them.
3,000 Diamond. (extra fine) - I am 50/50 on this lap, it is usefull and the 1200 Nu Bond has been difficult to get from the factory, so yes it is recommended. It has been my experience that the plating on these laps is not of sufficient quality and will not wear well unless treated carwefully. Heavey handedness will ruin this lap fast.
Note: If you need a 3,000 grit pre polish lap. I recommend you buy a Zinc, Tin, or Copper lap and charge it with 3,000 grit diamond bort.
8" Sintered Metal Bond Laps These are steel laps that the cutting diamonds have actually been imbedded into and through out the metal the lap is made from. These laps are very expensive and while worth the money in the long run, not worth considering for the average or new faceter.
Dyna Discs These laps are made from a computer circuit board type of material and coated with diamonds of various grits. I do not recommend them, and in my opinion I think people are much better off with steel laps.
Note: As of Jan 2005 I haev been told Dyna Dics have been discontinued.
Some people like them, and they are a little cheaper in the short run and if you are only going to cut an occasional stone, they might work well for you. However they do not wear all that well (you will wear out several of them, in the same time it takes to wear out a steel lap, thus there is no savings over time).
Other considerations are... They are not very flat, causing alignment problems from lap to lap (they vary). I have had several students using them over the years that had so much trouble, that they almost gave the hobby up.
Care must be take when using them. If you nick the coating, the tiny spot will soon become a large spot making the lap unusable.
One thing that I like is the smooth fine cutting that they do and the nice pre-polish they leave.
Note: Nu Bond laps cut the same way and are a better deal if you plan to cut a lot of stones.
8" Nu Bond
Nu Bond laps are actually available in almost all cutting grits. However, I find that the only ones that I like are the finer grits. These laps are not as flat as a steel lap, but they leave a nice fine finish on most materials and cut almost twice as fine as the grit they are marked as. A 600 Nu Bond cuts like a 1200 steel (or a little finer), a 1200 Nu Bond cuts like a 3,000 steel or finer.
600 Diamond/Composite. (fine) - This lap is really quite nice and works well for a pre-polish on most materials. I do recommend this lap, depending on what you want to cut and your budget. It is ideal for a person that needs a good pre-polish lap and is on a budget.
1200 Diamond/Composite. (extra fine) - This is the magic bullet for pre-polishing Quartz and Beryl, I highly recommend it for both of these materials. I do not use it for much of anything else, because it can leave an orange peel finish on some materials (when it is broken in), which can be hard to polish off.
8" Polish Laps
Aluminum. I do not recommend this lap for most people. These are a specialty lap and to be honest not used, at least I do not know anybody that uses one.
Brass. I do not recommend this lap for most people. These are a specialty lap and to be honest not used, at least I do not know anybody that uses one.
Bronze. I do not recommend this lap for most people. These are a specialty lap and to be honest not used, at least I do not know anybody that uses one.
Ceramic. Love them or hate them. I am somewhere in between, although I must admit that I very seldom use one. I have always had mixed results with a Ceramic lap (some people love them) and find that I usually prefer other laps. I do not recommend that a new cutter buy one when starting. They can always get one later if they want to.
Copper. This is basically a left over from the old days before plated laps, when people used to charge/make their own laps. Some people still like to make their own laps, but frankly I prefer the plated laps. I do not recommend them in most cases (with the exception of using one for diamond pre-polish depending on the material). Plated laps are a lot cleaner (no oil slurry).
Tin. I use and recommend a tin lap to everybody. A tin lap charged with aluminia oxide is one of my favorite polishing laps for Garnets and Tourmaline. I would not be without one. I also use tin laps cherged with 8,000 and 50,000 diamond for polishing harder materials.
Zinc. No longer available.
Last Lap. (Crystalite) - A composite lap. I really do not use or recommend this lap. I have used them with decent results, but I found that it heated the stones more than I liked (caused some wax shifting if I was not careful) and while I got it to work, the results were just so, so... I prefer other laps for polishing.
Fast Lap. (Raytech) - A composite lap, similar to the Last Lap... I really do not use or recommend this lap. I have used one, it heated the stones more than I liked (caused some wax shifting if I was not careful) and while I got it to work, the results were just so, so... I prefer other laps for polishing.
Phenolic Lap. I really do not use or recommend this lap. I have used them with decent results, they do heat your stone quite a bit. I find that other laps work better for me. Some people like them, they are a bit flatter for polishing some materials like Quartz.
Lucite Lap. I really do not use this lap, but some people do, I prefer Spectra Ultralaps. I have used them with decent results, they will heat your stones and sometimes cause odd smear type polishes on some facets if they are too dry during polishing.
Wax Laps. I really do not use wax laps, they are mainly used for very soft stones, which I almost never cut. Most of the materials that you need a wax lap for are noncommercial materials.
Ultralaps These are basically a thin plastic sheet of film coated with a high grade of polish on one side. The only one I recommend is the Spectra Ultralaps. They work the best and you can do about any material with them. No need to buy all of the other types, save some money.
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