sheltie
freely admits to licking rocks
Member since January 2012
Posts: 982
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Post by sheltie on Mar 9, 2012 12:05:05 GMT -5
Our first attempt at using our 16" lap didn't go particularly well as the slabs were merely smoothed, rather than polished. We think it is probably because we didn't have enough weight and we have now corrected that (we will use about 3 lbs of weight per slab where before it was less than a pound).
I've seen that some people use rubber bands to keep their slabs from damaging other slabs in the mix. Is this the "best" way or are there other good ways?
Any other tips from those who use this type of machine would be greatly appreciated.
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kevin24018
spending too much on rocks
Member since February 2012
Posts: 284
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Post by kevin24018 on Mar 9, 2012 13:51:25 GMT -5
I have one as well, and no idea how to use it, there's some youtube videos and making bumpers for the outer rim but I don't recall if they did anything to the pieces they where polishing, might not have to but I'm not sure.
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Post by Drummond Island Rocks on Mar 9, 2012 15:56:38 GMT -5
The extra weight should help. I have used the rubber bands but I think either using sections of pvc pipe cut like 2" long that fit around the rocks or using the tubes like shown in the picture I attached do a better job. Chuck Attachments:
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Post by johnjsgems on Mar 9, 2012 20:50:00 GMT -5
I used rings made of scrap tubing for bumpers around the individual rocks.
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sheltie
freely admits to licking rocks
Member since January 2012
Posts: 982
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Post by sheltie on Mar 10, 2012 10:44:45 GMT -5
The extra weight should help. I have used the rubber bands but I think either using sections of pvc pipe cut like 2" long that fit around the rocks or using the tubes like shown in the picture I attached do a better job. Chuck We do the same thing except the piping is hollow and we fill it with caulk. Our problem has been keeping the ends where they meet from coming apart. How do you manage yours? We also set the slabs on circles of plexiglass that we cut to fit. I suspect we don't need to worry about damaging the edges of the slabs because of the plexiglass protecting them, but it is double protection this way.
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Post by johnjsgems on Mar 10, 2012 21:47:36 GMT -5
I joined mine together with scraps of copper tubing. I've seen people use plastic tubing inside also. In both cases if tubing is 3/8" ID you use tubing 3/8" OD to join them. If they fit snug they stay without glue.
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Steve
has rocks in the head
Member since June 2005
Posts: 506
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Post by Steve on Mar 10, 2012 22:31:17 GMT -5
I've had good luck using wooden dowels to connect plastic tubing for bumpers. I recently buildt crosses of PVC pipe to seperate the pan into 4 segments. I've also seen this done with regular water hoses.
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Mar 20, 2012 2:00:56 GMT -5
"...I've seen that some people use rubber bands to keep their slabs from damaging other slabs in the mix. Is this the "best" way or are there other good ways?..."
This works "ok" for a day or maybe two with brand new rubber bands. After that, they start to break or sometimes they slip of of smooth textured and sharply slanted "end cut" type nodules and many times cause one heckuva ruckus in the pan.
The other rocks end up running over them and that can cause little "squirrelies" (My word for those dang corkscrew-like scratches) on your rocks. The worst thing that happens is, if a number of bands get lodged under the bumper ring, they can cause "gridlock" in the pan and smaller/lighter rocks get shoved over and end up hammering - go figure, typically the side you're polishing - against the rind/matrix of some other rock, which results in some pretty deep dings that can take a week or more to grind past and you lose the pattern that you wanted on the face. With my 20in., there can be 25-40lbs of rocks in the pan and all this weight - Newton's Laws of Inertia - is effectively rotating around the pan and if one rock decides it wants to stop rotating, you can have 35lbs of other rocks shoving on it and flip it right over and maybe the rock that's in the front of the pack, too.
The safest thing, imho, is 2-3 layers of duct tape. Doesn't come off and, if you're doing something like thunder eggs that usually have a pretty gnarly/crumbly surface, it keeps little pieces of debris out of the pan.
A little more spendy and certainly it's a pain to have to "dress up" 25 nodules per grind but it saves a ton of heartache by keeping your rocks from getting ruined. The phase where rubber bands can do the most damage is the polish phase, where you don't want much water and therefore have more drag on the rocks to begin with. Even a band that's just laying in the pan can cause gridlock because it won't slide on a polish pad like it might on a smooth metal surface of a grind pan. If the bands cause the rocks to stop rotating on a polish pad for a good number of seconds, I've read here that this holdup also can cause "squirrelies".
I haven't been too happy using tubing, either. What happens a lot is that some sharp-edged end cut rocks will get under some adjacent rock's ring and push it right off. Next thing you know, you have a bunch of empty rings taking up space or, worse, shoving one rock on top of another and causing it to get hammered with dings.
Just my experiences. I've had my Lortone running almost 24/7 for the last 9 months. BTW - you said "3 lbs" of weight. What are you using for weight and - where can I get some? I've been stuck with using either quartz "river rocks" from my landscaping (the only rocks there are in Fla.), "ugly" jasper or agate nodules, or fairly thick slabs of slate I got at a plant nursery. Local tire shops won't part with their used lead balance weights - recycle them for $$ - and big surf fishing weights cost like $2+ for 4oz. ones - not "fiscally feasable" for someone as lousy at picking lotto numbers as me...
BTW - Here's a neat trick i figured out to weight down small, round-ish nodules like Coyamitos: Get hold of some larger, hollow geodes that you don't care about, put some duct tape around the edge of their cavities, and then tape them atop your small agates. Works pretty good and, as long as you make sure to balance it right atop the agate nodule, it lets you get a heavy weight on top of a small rock. C-ya, Rick
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Post by chad on Mar 20, 2012 8:26:50 GMT -5
I use aquarium airline tubing for bumpers. Very flexible and the hollow middle makes for nice shock absorbing, plus available in bulk for cheap. Secure in place with a dab of hot glue every few inches. (non permanent but sturdy).
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sheltie
freely admits to licking rocks
Member since January 2012
Posts: 982
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Post by sheltie on Mar 20, 2012 9:08:37 GMT -5
Rick - to make the weights we got a box full of used lead weights from our local auto store (about 15 lbs in our case) and mixed Diamond Crete (used for making stepping stones) in ZipLoc containers (they make several sizes). This way you can have several size weights. I have no clue how much weight we should use per slab so we just use the 3 lbs until someone tells us differently. Our slabs seem to average about 5-6" long and maybe 3" at the widest by 1/4" thick.
We cut our plexiglass to be slightly over the size of whatever slabs we are doing, take acquarium tubing, slice it in two and put glue inside to slip over the plexiglass and hold in place. So we have the slab on top which is affixed to the plexiglass with sticky floral tape, the plexiglass is also held to the top of the weights by the sticky clay, and then finally the weight. They look like bumper cars when the lap is operating.
Now if I could only get that "varnish" look from the slabs. We are using the polish stage for about 10 hours and while they look good, they don't blind you.
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Mar 20, 2012 16:54:25 GMT -5
"...Now if I could only get that "varnish" look from the slabs. We are using the polish stage for about 10 hours and while they look good, they don't blind you...."Yeah, I'm not sure the glassy look is possible with a vibe lap. I think I may have read that somewhere on this site. I've gotten a pretty darn nice shine on agate nodules/slabs, Polychrome Jasper, Cady Mountain Jasper, Morisonite (yep - he spelled his name with ONE 'r'), and lots of different thunder eggs. Not the deep, deep glass but pretty shiny. I have a 20" Lortone "jiggle pan" that I picked up cheap on ebay and VERY used but I've fixed it up and have run the heck out of it for almost 10 months, now. I have done slabs up to 8 or 9in. and nodules as big as 10-11in. I have some even bigger slabs to do after I get all my nodules done right. I HAVE had a bit of trouble with some rocks, though. Mainly Montana Agate slabs, Bruneau Jasper slabs, and Obsidian. I was getting them shiny but they had a sort of "orange peel" texture. One of the guys here suggested I might have been running them in the polish too long. I was, typically, running like 20 hours. Start at night, run while at work (b4 I got laid off in Nov.), and stop sometime after work. Another guy suggested a session with 1200grit on a spinner lap before polishing. I tried both suggestions - ran some in the jiggler with 1000grit aluminum oxide and then only approx. 8hrs polish - and it seemed to help the Montanas a LOT. I haven't tried a Bruneau (in process right now) yet. the Obsidian took a couple hours longer. I was using Tin Oxide polish. Crazy Lace Agate seems to be problematic in that it undercuts between all of the millions of bands. Also - and I've seen this on some other agates - if you have an agate that's what I call a "slacker" that stopped banding agate and has macro-crystal quartz in the center (If they also have a cavity, I call them "quitters" - lol) lots of times the crystal refuses to shine up very well. I'm guessing maybe the crystal in Crazy Lace might not be mohs 6-7 hard and maybe more like Calcite. Dunno. What I DO know is that it's possible to shine these guys up because you can see it on Brazilian agates that you buy already polished. Either they polish them on some big wheel or there is some kind of coating they put on them before polishing. I've tried a coating of Zap-a-Gap glue (a cyanoacrylic like Hot Stuff) and it shows promise but I think you have to do it multiple times because, since it shrinks when it cures, it's uneven and it's really easy to grind too far and have a pocky surface. And if you grind it all off, you end up with a nice shiny matrix on a thunder egg.... with really SUPER shiny cracks because the glue does take a great shine. Just looks funky with the shiny cracks. So maybe what you have to do is apply it, polish it, apply again, polish that, etc. Kinda like how they varnish wood, ya know? I think that may work because I inadvertently tried it with a big Wave Hill agate "slacker" - most have quartz centers. I'd started out with an Inland 8" spinner lap and worked that dang rock for months (not non-stop, of course) and could never get it perfectly flat. Then I got the jiggle pan to solve the flatness problem and to do huge rocks. Applied Zap-a-Gap yet again and, after grinding it flat in the grind pan, voila! Shiny as all get-out, even the macro-crystal. That dang rock took 6 months and probably had 4 coats on it! lol I'm thinking that maybe Zap-a-Gap just isn't hard enough. A telling feature of the Brazil slabs is that you don't see any outline to the crystal areas in them so they must use SOMETHING. Maybe 330 epoxy is harder? Better git - BTW - here's a link to a thread I started that I add to occasionally that has some vibe lap tips i'd figured out. Might find something helpful - forum.rocktumblinghobby.com/index.cgi?action=display&board=tips&thread=47954&page=1C-ya, Rick
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Mar 25, 2012 10:52:49 GMT -5
I've read everything I can find on vib. laps, tried most of it, learned a bunch, and it seems we all have the same problems. One thing I will add; I cleaned the edge of mine very thoroughly and sprayed on a couple coats of auto undercoating, stuck on well and cushioned the banging on the sidewall.
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Post by johnjsgems on Mar 25, 2012 12:55:00 GMT -5
Doesn't the undercoating embed with grit? Seems like it would. A hose bumper is removable so pan can be cleaned between stages
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Post by Pat on Mar 25, 2012 19:25:08 GMT -5
We solved our problem with the big vibrating flat lap. We sold it. ;D
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Post by johnjsgems on Mar 25, 2012 19:39:02 GMT -5
Pat, that's how I solved my Lortone lap issues also.
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Post by Pat on Mar 25, 2012 19:42:40 GMT -5
John, sometimes that is the only way. We bought an Ameritool 6" flat lap. Works like a charm for preforming for carving, and for doing the backs of cabs. Haven't finished a cab yet, but they are on their way.
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sticksinstones
starting to spend too much on rocks
Member since February 2012
Posts: 117
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Post by sticksinstones on Apr 7, 2012 11:38:32 GMT -5
The finish quality you see on agate with quartz in the center isn't due to a coating, it's a different process and there's nothing going on but sanding and polishing, just different equipment that works faster and therefore doesn't have time to undercut.
My suggestion is to continue to look for the right mix to shorten your polish time. There is a very good chance that most of what you are seeing that comes up short of a mirror finish is the direct result of the medium (not the media) wearing on the various hardness differences in the stone or inadequate cleaning carrying residue to later stages. The less time it takes you to polish, the less of that you will see. The variables are media, medium, time, cleanliness and moisture. Not all polish pads are created equal (including those sold through some lapidary supply outfits as vibrating polish pads). Try to find pure wool and not anything with a synthetic in it. Yes, you can polish with a piece of cheap carpet. No, it won't look optimal.
When I was using vibrolaps I used tin, wool and a pretty wet (almost milk like) slurry. And I didn't polish more than 4-8 hours as I recall (it's been a while). I still have some of the bookends and other pieces I worked up on those laps and they are as mirror perfect as the process I use today. The undercutting you are seeing is something you can solve if you keep tinkering with those four variables. My first suspect is your polish pad.
The other big breakthrough I made in my results was the purchase of an electric pressure washer for about $90 at Wal-mart. The cheapest one you can find is all you need. You can wash FAR more effectively with this and that is important when you're dealing with slurry. Hit every cavity and every surface from every angle and get it CLEAN! Something like a plastic milk crate makes a good rock holding area for the relatively wide spray you'll use to get past the rock instead of blowing it down the driveway. It's also critical that nothing is ever allowed to run dry. Rocks come of the laps and go into a bucket of soapy water to keep that crud from embedding (and later contaminating) from tiny crystal openings, etc. Soap in the water helps. Try losing everything you own that hasn't been thoroughly pressure washed in the past and might be contaminated and isolate as much of the gear to one stage as you can (I had different plastic tubing rings for different stages for example as I knew grit would embed in the plastic). Separate pans is better still but metal pressure washes well so just be dilligent if you only have one. Keep your polish pads in plastic bags when not in use. Be PARANOID about contamination - it will only help! Every time you catch yourself saying "that isn't going to matter" ask yourself if you're the person getting the best vibrolap finish you've ever seen yet... Then ask me for a sample :-) (footnote: I do believe I get a better polish now on my sanding wheels and rotating polisher, but I climbed a steep learning curve on vibrating laps first and was close to where I am now).
I'd skip the coating - nothing is going to polish to the degree agate and quartz can be. Crazy Lace is another story because it is full of white calcite zones in larger pieces - that isn't going to polish as well as agate, but I still wouldn't put anything artificial on it.
I avoided slabs because they didn't have enough weight, but I did buy some stuff at an estate sale one time that included a bunch of plywood squares with good sized led disks secured to the top center of them with screws through the center of the lead and into the wood. The edges of the plywood squares had maybe a 3/16" thick lip of hardwood glued or tacked on that stuck down below the edge of the plywood about 1/4" to make a box top that would sit over a slab and keep it safe (and weighted) while polishing on a vibrating lap. I suspect this would work well, and with that kind of weight you'd be able to polish in less than 2-3 hours I bet. More weight is definitely your friend when polishing both to improve the finish and to reduce undercutting. You'd need something that would hold the slab centered in this little box top but that could be done with tacks or glue or something (I'd go for the tack heads personally).
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Post by chad on Apr 8, 2012 18:02:52 GMT -5
Good idea with the concrete and weights. I melted wheel weights into catfood cans and muffin pans and things like that to make various sizes and shapes. Also can embed stuff like picture hangars in the lead before it cools to clip or grab onto odd shapes. Just don't breathe too heavy while you're doing it
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Apr 10, 2012 16:42:23 GMT -5
Hey, SIS - Thanks for all the helpful info. Hope I'm not "hijacking this thread - seems sheltie is done with it anyhow.
"...My first suspect is your polish pad..."
The pads I use are the ones that Kingsley North sells. They do ok for maybe 2-3 days and then become flattened out and too thin to polish the middles of large slabs or nodules. I've only found one other place online that sells a 20" vibe pan pad and that is Reciprolap. Most of the carpet shops around here seem to have gone out of business. The couple I've asked don't sell remnants and the area rugs cost hundreds. If anybody on this forum reading this can get hold of woolen carpet pieces, I'd be super glad to pay them for it along with any shipping/handling!
"...Rocks come of the laps and go into a bucket of soapy water to keep that crud from embedding..."
Now there's somewhere where i HAVE gotten a little lazy. I used to soak the rocks for a day or more and then take a toothbrush and garden hose sprayer to them. I still use the brush/hose but don't soak them because I had a really pretty thunder egg disintegrate into 3 pieces when it spent a lot of time in the wet grit and soaking in a bucket. I also have gotten to where I tend to leave the same rock/weight taped to the slabs or smaller nodules thru all the grit phases (120/220/5or600) though I wash the nodule/weight rock assemblies in between grits. Really tedious dressing, undressing, and redressing 25 rocks. Especially since I choose each weight rock to match whichever slab/nodule it's taped to. I do redo the whole bit b4 polishing, though and also scrub the weight rocks. Duct tape can be an expense. I have a separate pan for polishing and a good lid - one for the grind pan and a separate one for the polish pan - to keep stuff from blowing into the pans. *Seems* to work ok but one problem I HAVE been having is corkscrew scratches that appear after the 500-600 phase. I have theories on how they are happening: 1) Bits of thunder egg matrix either on the face or rind might be getting into the slurry? 2)]Maybe when "gridlock" happens in the pan? 3)Maybe from times when the pan is somewhat dry? and/or 4) I sometimes use a cyanoacrylic glue similar to Hot Stuff (it's "Zap-a-Gap") to seal fractured areas or the macro-crystal centers of "slacker" agates that stop agate-izing at some point in their history. I've, also, tried to coat softer stuff like aussie Print Stone with it. I does polish up really nice but takes a number of coats/grinds. I wonder if small pieces of this glue might be flaking off and are hard enough to scratch even porcelain jaspers like Bruneau? 5) I got all my 500 and 600 from the same seller - might it be contaminated with bits of something?
I'm redoing 500g on a batch of rocks with corkscrew "squigglies" making sure that none are t-egs nor agates with crumbly rinds as an experiment..... once I readjust the dang bearing on my rig for the umpteenth time - lol C-ya, Rick ("cyborgsam" on ebay)
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sheltie
freely admits to licking rocks
Member since January 2012
Posts: 982
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Post by sheltie on Apr 10, 2012 18:39:12 GMT -5
I haven't gone anywhere. I'm still lurking and (hopefully) learning.
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