rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Dec 14, 2011 1:40:14 GMT -5
Hi, all - I was running low on Tin Oxide grit in my vibe lap polish pan last week. I had almost a pound of optical grade cerium oxide that i had used in my tumbler and figured, whattheheck, and added some to the pan. Is/was this a bad move or no big deal? Thanks! Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 31, 2011 0:41:24 GMT -5
"...I learned the hard way (for me) to never start with anything coarser than 120 grit..."
That's what I use, now. I did use 60/90 on maybe 3 batches in the very beginning. It's what I had around and was used to from tumbling and I didn't think about pan wear until reading about it here. Was just hoping it was something you could get away with - impatience!
"...Your slab saw should have NO play in the vise or blade..."
Yeah, I pretty much didn't think it should. I'd pointed it out to the guy who maintains the saws at the club but he couldn't figure how to adjust the play out of the vise carriage. On both their 18" and 10" Lortones, the blades also move a LOT side to side when you press on them. I can't see inside but wonder if the flange washers are either too small or are somehow bent out of whack. I don't reckon the play would be from the blades being loose or they would bind as soon as the feed brought the rock into contact(?). I'm gathering stuff to build my own saw soon. Just need to talk the machinist at work into fabricating one of those sorta "L" shaped pieces that fit into notches in the vise base and that tighten the clamp. At least that's how these Lortones are set up and it seems pretty good. I have designed a vise system that should keep the "nubs" from happening... if it works - lol.
The saws the club has were donated and I guess they're pretty old. The big one has a real bad habit of "walking" on you, especially on thin cuts. I spent almost 2 hours today trying to smooth out an 8" Teepee Canyon agate slab but am still looking at either 4-6 "wiggles" with 120 grit or a lot of hours on a spinner lap with a 100 grit disk because the middle is a good 30-50 thou high still. Really bugs me because I saw a slab like it at ebay but it sold for like $193 so this chunk was/is my only chance to have one like that unless I get really lucky sometime.
The 10" saw's feed seems uneven, which may be why there are wide, shallow grooves in some of the rocks I've cut on it. They're a real "she--nine" to grind out and sometimes it loses you the pattern you liked. It has a couple of threaded brass blocks that clamp down onto a threaded rod for the feed. The rod seems like it wobbles slowly where it's attached to the end of the pin that drives it. You can hear it in the sound of the cut. These are my only real options right now. The home-built saw will happen like that sort of thing usually does... someday... when work isn't too demanding... when I have time...lol.
I've been, lately, sort of doing what you suggested as far as starting the cut. what I do is either put my finger or hold a piece of wood on the side of the 10" blade (18"-er is under a cover and slings lots of oil) for the first bit of a cut so that it doesn't walk to one side and then let it go once it gets seated.
I have a few more batches of 600 grit with one or two batches of 220 grit "re-grind" slackers to do and then I can switch to the polish pan. That'll take a good few days, so maybe I can get our machinist to either mill a grid or just end mill a pattern of dimples. BTW - about what is the diameter of the dimples in your Reciprolap? I'm guessing 1/4" dimples 1/8" deep would be pretty close? For that matter, I could probably rough out the job by myself close enough to work using a hand drill, ya think? Thanks a TON for all the tips y'all, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 29, 2011 23:26:42 GMT -5
Thanks! I may have asked about this a while back... or just guessed on the first pad. I reckon I'll go big with the glue and use contact cement. I tend to load the pan at least 90% with some of the rocks being really heavy so it'll probably need some pretty strong glue to keep the pad still.... and from shrinking again. c-ya, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 29, 2011 16:07:06 GMT -5
Hi, y'all - Well, I just got a new 20" polish pad for my vibe lap from Kingsley. I saw - somewhere - that it you're supposed to glue the pads down in the pan. (that oughtta fix the problem I had with the other pad spinning). So, can anyone tell me which side is up on these pads? One side is rather fibrous looking and the other is more smooth and sorta "tufted" like carpet.
Seems to me, the carpet-like side would be better for polishing but, on the other hand, it might also be glued down more successfully... The blurb I read said to use "rubber contact cement" but that seems like it's 4ever once you glue it - would that 3M feathering glue work, or might that be too wimpy to hold with the inertia of 20lbs of rocks trying to get it to "dance along with them" as they rotate around the pan?
Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 19, 2011 17:37:37 GMT -5
".... grind a very slight bevel all the way around the piece...."
Thanks, Don - That makes a lot of sense. I did that for a while when I was trying to polish these rocks on a spinning lap so that the rock wouldn't dig into the felt pad and get yanked out of my hand. Recently, I was watching a video by Phil Stevenson on polishing Bruneau nodules with a wheel and he let drop a comment about how he found the beveled edges "unattractive" so, me being a rube/noob and all, I figured, "hmmm, maybe I shouldn't do that". I reckon it *does* look kinda funky if the bevel is really wide and deep but a slight one like you advise ought to really help.
In the meantime, to get a little more "wiggle to the jiggle" on my rig, I changed the balls from some approx. 3.5" rubber ones to some golf balls. I theorized that this would increase the travel by lowering the axis of the vibration and also by making the springs a bit looser. Seems to have helped some. The vibration is noticeably more vigorous and all of the rocks I ran for about 17 hours got flat... except for a couple of these darn Royal Sahara Jasper slabs that seem they'll take a dozen grinds to get all of the low spots out. And that's with some pretty hefty rocks strapped onto their backs, too. Might have to start getting a little picky about which ones I polish because they take up space in the pan and tick me off so much when they won't wear down.
I've started feeling out the machinist guys to see if they might mill a shallow grid into my pan. Does anyone have a ballpark idea of how deep the cuts are in those grind pans that have them? I'm guessing no more than like 20-30 thousandths. It would seem like, the deeper they are, the longer they'd last b4 the pan wore flat but, at some point, they could be too deep to where the grit can't escape them and it would take a good bit more grit per grind, too...(?)
C-ya, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 16, 2011 15:36:47 GMT -5
Thanks, Don - Hard to really tell just how thick my grind pan is. I bought it new a month or month and a half ago, so I reckon it isn't all that worn. Though some of the nodules I've had in it are pretty darn big. A couple of Ky. Agates - one about 8-9in across but only maybe 2.5in thick and another that's like 7in but is a good 5in deep. And a Black Rock t-egg that is about 6in across and 4in deep with hardly any slope. I'd had the same thought about machining the bottom. There's a machine shop where I work and I thought maybe they might be able to handle something this large. I googled around a bunch looking for anything with a 20" machined pan that I might buy an extra pan and stick onto my Lortone but all I found of that size was a "Reciprolap" and it *looks* like that one might have a pan that a machined plate goes into(?). Looks like that one has shallow, round holes in it and I'd also thought that maybe our machinist might ba able to do that if the grid was too difficult. Seems like the grid might work better than the "dimples", though, just from looking at it. Yeah, I figured out the weight bit pretty quick Though all I have right now are chunks of quartz/schist/feldspar from the Diamond Hill Mine in SC. or landscape "river rocks" to strap on top of them. Sometimes hard to get them to not be top heavy and flip. And really small t-eggs or agates with rounded tops are always an adventure - lol.
RH97058 - re: the manual - Ok, I'll figure out how to do the PM thing. Thanks!
As to the low spots. Most of what I've got was already cut. And they almost ALL - slabs, too - have that blasted "nub". Aaaarrrgh! It REALLY bugs the heck out of me, too, because you have to grind it off b4 you can even think about putting it into the pan. I hate that! And after you get it flat, there's almost always this deep, wide groove right before where the nub started and you have to lap for half an hour to get THAT manageable. My theory is that, right at the end of the cut when there's just a thin piece attaching the slab or nodule half to the clamped main rock, the loose slab vibrates or wiggles before it drops off and that this makes the blade wiggle. Not sure if I'm right about that. I'm slowly getting together metal scraps and odds and ends to build my own saw and my design for a vise should stabilize everything a lot better than any of the commercial ones I've seen. The rough I have I've been cutting on 10" and 18" Lortones at the local rock/gem club. On the bought rocks, the low spots that aren't from the nubs are small rounded places near the edges.
The low spots on what I've cut, myself, are mostly either from the 'nub" thing or sometimes right at the beginning of the cut where it seems like the blade started and then jogged over maybe .030". Seems to happen, mostly, on rocks with a very smooth rind and that are sharply sloped like end cuts or very irregular ones where the blade might have started on a pointy spot on the rock. The vise carriage on the 18" Lortone at the club has some wobble to it on the cross-feed. I showed it to the old(er) guy who maintains them but we couldn't figure out where an adjustment was for that so I *guessed* that maybe it was intentional to allow for if the vise feed wasn't absolutely, dead-nutz perpendicular. Maybe to let the vise float a bit to find it's "happy place"? Hard to see in down there, but maybe there isn't a big enough flange washer on the blade? The blade seems to have play in it, too.
Was going to start another thread but, since we got on this subject - I notice that agates many times have sorta *hidden* wide grooves across their faces. It *seems* like* these grooves don't show up until you start to lap the agates on a spinning 100 grit diamond disc to prepare them for going into the vibe pan. I could almost swear that they aren't visible/there until after you lap the slabs/nodules! Makes for a TON of spinner lap work/time wearing the rest of the rock down to smooth it out. The grooves seem to match the blade marks' pattern but they aren't there until you start grinding. Have you ever seen this? Could it be that maybe diamond is too hard to lap agates? Or from pressing too hard or not keeping the slab moving or it getting too hot? It doesn't happen all the time but enough to where I'm leery of grinding agates and, on my best ones, I just toss them into the vibe pan and repeat the 220 for as many times as it takes to smooth them out.
Oh yeah - the real subject - lol I reckon I'll have to just stick with 120/220 grit then or maybe graded 120 grit occasionally. I've tried using Zap-a-Gap CA glue (like Hot Stuff, I think) for rocks with softer bits in them like t-eggs. One, that I coated completely and thickly, turned out awesome. The other - thinly coated so glue wore off the harder areas - had no undercutting and was glass smooth but the moss ended up super shiny and stuck out because the Zap-a-Gap was so much shinier than the rest of the rhyolite of the t-egg. The glue soaks into softer moss or plume inclusions. I reckon this might be considered "cheating" by some pros, but I just want these all shined up for my own collections. Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 15, 2011 12:18:08 GMT -5
Thanks - yeah, I bought some tubing last week and also some 1/8" aluminum tube to make connecting inserts.
I have a Lortone because that's what happened to pop up (very) used on ebay and I won at like $270. I've made some mods and repairs and it seems to work decent. Except for getting rocks flat when using the not-so-coarse grits I've seen recommended. I have an 8" Inland spinner lap that I try to get mst of the heavy work done on but, it's really hard to get a fair-sized slab or a thunder egg perfectly flat with one of those. The main reason I wanted a vibe lap was for the flatness.... and it does 15-20 rocks at one time.
You ended up answering a question I'd asked earlier in a different thread about the Lortone grind pan being flat. Do you reckon that, if I got one of the gridded bottom pans made by whatever other company it is, it would work on the Lortone base? Seems to me that, as long as it's the same OD as the pan I have now, that I should be able to just swap it in, right? I reckon I *could* just go for broke and use the 60/90 grit on this pan and then get a gridded one whenever this one wears out.
Haven't had an answer to that question yet but I'd imagine that *whatever* the signs or symptoms of a pan being worn out are, they should be pretty obvious whenever they appear, no? C-ya, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 15, 2011 0:15:38 GMT -5
I've read here that it's not a good idea to use 60/90 SiO2 grit in a vibe lap. Problem is, if I use 120/220 or straight 220 grit, my t-eggs and agates don't seem to get flat even after multiple 12-16hr grinds. Always seems to be a low spot somewhere - usually on the edge - or a low side or a groove that I don't notice until after the polish phase. Not the greatest light on my back porch and the only time I have to look at them is after work when it's usually dark. My grinds all start at night - typically 11:00PM to as late as 1:00AM - and go at least until 8 to 10 the next evening. Takes a good bit of time fashioning little duct tape "girdles" for all of the ones that are too slope-sided for rubber bands to stay on.
When I first got my 20" Lortone working, I used 60/90 grit on a couple of batches and they all got good and flat. All my rocks get flattened out on a 100 grit spinning lap b4 they go to the pan. Ever since I quit the 60/90, my polished batches usually have a good 25-35% fallout and I end up having to stick the biggest rock I can fit on top of them and send them back to the first stage worried that the pattern I liked so much might get worn off.
So - Just exactly HOW BAD is 60/90 grit for your pan? Is it just a difference between a pan lasting 5 years and it only lasting 2? Or does it kill the pan after a few weeks? And what are the symptoms of a pan being worn out in the first place? Grooves? A hole? Or just really thin on the bottom? How long do grind pans usually last?
I've got a ton of rocks I want to polish - and life is short, lol. I run the pan pretty loaded - probably TOO loaded - but with as much space as they take up, I doubt any area of the pan will wear more or less than another. Though, maybe the outside, as it seems the larger rocks tend to gravitate (literally! lol) there after a while by shoving everybody out of their way. Thanks! Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 11, 2011 12:21:10 GMT -5
Well, I tried some rain gutter sealer and some mostly dried out wet/dry Oatey cement but neither stuck the pad to the pan. Boy was the pan ever SHINY! lol I ended up having to do a second polish on the ones that went 12hr with the pad spinning. Made it thru by jamming two clothespin halves down onto the pad and clamping them to the rim of the pan. Helped to stretch it back out, too. (only temorarily while the sticks held it) I watched for an hour and didn't get any "traffic jams" like I did the night before. Probably because I had a few less rocks - especially this p.i.t.a Cady Mnt faced chunk that is really thin on one end (one of those "wedgiestones" you see a lot of at ebay) and would lever up its neighbor whenever some rock got stuck on the toothbrush I was using to hold the pad still. Plus the wooden pins are a lot narrower than the toothbrush. Why the heck do they make toothbrushes fatter than a 1st grader's pencil these days, anyhow? I have two really nice, big Montana aggie slabs from that night that got these long, curly, spring-like looking scratches on them. I'm pretty sure they happened when there was a traffic jam and they rode up on top of another vibrating rock. Not a good idea to stick anything into the pan that stops the circular progress of the rocks because, inevitably, one will hang up on the impediment and everyone behind it jams together with the lighter or more top heavy from weighting ones ride up on top of the others and/or tip over. Reckon those to will have to go all the way back to 200 grit. I do tend to fill the pan like 80-90% and there are rounded ones mixed with long sharp ones so sticking that thick plastic toothbrush in their way caused a lot of trouble. I'm going to try to finish the last batch of 600 grit ones I've got 2night and then toss this piece of coprolite polish pad. I'll just do some 220 grinding while I look for a better option for a pad. Don, I don't know about any RV dealers but will look. Can you describe this felt-like stuff a bit more? Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 10, 2011 9:15:59 GMT -5
Thanks, man! That's what I thought but had to make sure. fyi - A 13 hour polish with the pad moving only gave a shiny but definitely matted/hazy result. I'll probably get some Oatey PVC wet glue or some other glue that works on wet surfaces since I don't want to lose the 3/4 pound of TiO2 that's in the existing pad. Just gotta make sure I can dissolve the glue when I need to.
That's pretty darn gyppy how this pad actually SHRANK like an old pair of Levis! I'll head out at lunch break and get some short pile marine carpet. The "carpet" type, not the "astro-turf" kind. Thanks again, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 9, 2011 23:31:57 GMT -5
Hi, all. I'm kind of new to vibratory laps and have a very used Lortone 20" that I got a couple of months ago. I had to buy a polish pad for it and got one from US$J or Kingsley for a decent price.
The problem? I'm only on my 4th batch of t-eggs/agate nodules and the pad is rotating in the pan at the same rate as the rocks. Not sure, but I THINK it didn't do that when I first got it. This definitely doesn't seem like how it's supposed to work and the pad looks like it has shrunk 3/8" to 1/2" in diameter from when it was new, so the bumper ring barely touches it. I'm fairly sure the pad didn't spin around on the first uses and I'm almost positive that this can't but slow the heck out of the polishing process. Is the pad supposed to spin around along with the rocks on these machines? If so, I'd imagine the pan is pretty darn shiny by now from 10 hours of tin oxide - lol
Someone please let me know if this is working right or if I need to come up with a different/better pad. I've thought I might just contact cement the dang thing down to the bottom of the polish pan and clean it out with acetone whenever the pad needs to be replaced. Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 9, 2011 22:25:03 GMT -5
I got a used 20" Lortone a couple of months ago and it came with unmatched balls and only two - again unmatched - springs. Here's what calmed - and quieted! - things down for me. I doubled the springs. The springs I got are about 3/8" diameter and about 2 1/2" long with the metal being about the size of maybe 26AWG wire. Not super thick, not too wimpy. I then found some rubber (not foam!) balls at Toys r Us that are about 2 1/2" in diameter that work really well and don't flatten out. Look up near the front in the "seasonal" stuff. They look like little basketballs and soccer balls. I've never found anything that tells just what size the balls are supposed to be. BTW - You DO have the springs attached, right? They go on the 3 metal loops on the underside of the pan base and stretch over to 3 tiny holes in the main base near the top of the rim. (Please don't be offended that I asked - it wasn't mentioned, so...)
You didn't mention it but mine made one heckuva racket at first. This was because the balls were too small for the wimpy springs the guy sent and the 3 hard plastic spacers/pylons that go between the pan base and the motor mount plate were banging against the rim of the main unit base. You could see where the spacers had grooves worn into them. I also took one of those cut-off/waffle wheels that go onto a drill motor and cut an approx. 1" notch in the rim of the base unit next to where the 3 spacers are just in case. In Googling around, I'd found a drawing/manual for one of the newer Lortones and I noticed that the rim is a LOT narrower than on the much older one that I have. So they must have noted the same problem.... or the "bean counters" there might just have been trying to save $$ in materials.
Took a LOT of Googling, but I finally found an old Worthpoint listing where the person was selling a motor and mount plate for a 20" Lortone. It said the motor was 1/15hp and spun 1550RPM. The motor that came with my rig crapped out (bearings seized, old style thermal circuit let it keep drawing current until it melted the internal fan blade and kicked open the GFI in my house) after two days and so I had to find a replacement. I got one from Grainger - model 3M569 - for around $75 that works. I only had one problem with it and it was pretty major - The thermal protection would trip after less than an hour. (Note - It's summer and I'm in Florida) The new motor doesn't have an internal fan like the original did and is only rated for 40deg C, which is only 104F. Didn't take a rocket scientist to figure what the problem was since it was 98F to 100F in the shade, ya know? I ended up strapping a 12V computer rack fan blowing up thru the motor and it works great, now. I was snooping around ebay for a cheap spare in case the new motor died and got one real cheap that was the right size and a little stronger - 1/10hp, same rpm. What a surprise when it arrived - it looks EXACTLY like the original from the Lortone! It's model # is, 3M576. Looking at the Grainger website, I can't tell if the one they sell now has the internal fan or not. The specs only say that the cooling is "air over" with an open frame. It's about $40 more than the 3M569. The one I got at ebay is used but works ok.
Anyhow, these are really just motors for big fans or for air conditioners. They are "4.4in, stud mount shaded pole" motors. Probably too much info but, since I had so much trouble finding out ANYTHING about this motor, I figured I'd put it somewhere where the next guy might not have to spend over a week on Google trying to find it... C-ya, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 9, 2011 20:20:06 GMT -5
Sheet metal? What keeps it from making a racket when it vibrates? Does the bumper ring hold it down? Or does your metal circle and pad rotate in the pan along with the rocks?
My rig came with a ring, as well, but it *looks* like the pad has actually shrunk in diameter since I started using it (on the 4th batch now) and the ring just mostly sits on the metal of the pan itself rather than the entire pad. The pad was only like $13. Is it possible that it has shrunk from being wet sorta like some clothes shrink when you wash them?
I have the thing running now without a lid on the pan. Doesn't seem like a really good idea but I took a plastic toothbrush (only thing handy of the right shape/material) and clamped it to the rim of the pan with the stub end pressing hard down onto the pad to keep it from moving so my lid wouldn't fit. (see my later post for a cool lid idea) I'm running low on tin oxide so I couldn't stop and swap the pad for a piece of carpet. It has a bunch already in it that would be wasted. I did have the thought that I might try to wring it out onto whatever piece of carpet I could come up with but I figured a lot of the TiO2 would still be in the pad... Rocks! - it's always something. :-) Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 9, 2011 15:40:28 GMT -5
Ha! Sorta my problem in reverse. I've wondered about how saws work in winter up north. Like, what happens to the viscosity of the blade's lube oil? Do y'all come out in the AM to find that the sump is sludge with a viscosity of like 2W and the oil slings off the blade in clumps? lol
Since this thread is getting some replies, I have another question: Is the polish pad suposed to move/rotate with the rocks? Last night I started another polish batch and was trying to figure out which 2 rocks were clattering together every now and then. I noticed something that I don't *think* I saw with the first three batches, though I maybe just didn't notice. - I noticed that, not only were the rocks all merrily circling CCW around the pan and doing their usual dances with each other but the polish pad itself was also spinning at the same rate as the rocks were. Seemed to me that this would somewhat hinder the polish process/time since the only friction would be the jiggle of the pan without the added friction of the rocks moving round and round across the surface of the pad. It seems like the pad has sorta shrunk as it has a maybe 3/8" gap all the way around between its edge and the inside of the pan rim. Are you maybe supposed to glue the polish pad down in the pan? I'd thought all you needed to do was toss it in and insert the plastic bumper ring that came with the pan. Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 8, 2011 23:01:34 GMT -5
Ah - ok, I see. That's a great feature! The rig I have only has a rectangular block of steel maybe 2" wide by 5-6in long that mounts to the shaft like a flag using a set screw. Dunno if that's the "original" setup or not since I got it used and pretty cheap.
Kinda funny story - When I first got it, the motor seized up after less than 2 days. It had an internal fan in it and that had completely melted. Bearings, I reckoned. I got a new 1/15hp from Grainger but that one would only go for about half an hour before the thermal protection shut it down. They didn't have anything with an internal fan - that wasn't super expensive and too big. Anyhow, I finally looked at the spec sheet for the new motor and it's only rated for 40deg C ambient temp. 104deg Fahrenheit. Well heck, I'm in Florida! It was freaken 98F in the shade already so the poor motor had no margin. I ended up taking some steel roofing truss straps and strapping an 8" high velocity 12v computer rack fan to the motor plate blowing up through the bottom of the motor and it works fine for a long time! I had a 12V "wall wart" laying around that supplied enough current for the fan.
Here's what I figure: Since Lortones are made in Wash. state, they didn't expect such high ambient and folks up there might never see this problem! lol And, also, motors rated for 50C cost $400! C-ya, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 8, 2011 22:34:21 GMT -5
Ok - First the question: I've read here about not using 60/90 grit on a "jiggle pan" because it's supposed to wear them out a lot sooner. How do you tell if your grind pan is worn out and needs replacement? My used 20" Lortone came with one pan that the guy said was a polishing pan. It's flat and smooth. I bought a new grind pan from US&J and what came was a pan that was kinda flat but had some random swirls in it that wore down after the first use. So, basically, it is also smooth. I've seen a few pix online of grind pans and those had like a grid etched/milled into the bottoms. Did they maybe send me a polish pan by mistake? (ok, I lied - TWO questions)
It seems to work ok, though it does take 2-5 grinds with 120/200 grit to flatten even the super heavy 10" Kentucky agate I'm trying to do. Royal Sahara Jasper (fair-sized slabs weighted with a good sized rock) takes 4ever, too, even though I try to flatten and take out saw marks as much as I can with a 100grit diamond disk on a spinner lap.
Some things I've learned: 1) Tape Them Eggs! - Cover t-eggs really good with duct tape - especially in the polish phase - because they tend to shed little pieces every now and then that could scratch the rocks.
2) 20" Pan Anti-Splash Guard - For a 20" pan, get a 16" bicycle inner tube, hack-saw the air filler nozzle, and take a pair of scissors and cut a 1/4" strip off the edge all the way around while it lays flat. Then stretch it around the outside of a 20" pan, letting it overhang the rim by an inch or so, and this will stop almost all gritty water splash from coming out of the pan. If it still makes a mess, probably there is too much water in the pan. Take the maybe half inch wide strip you cut off the edge of the inner tube, cut it in half, poke 4 evenly spaced holes in the inner tube where it is in contact with the outside of the pan maybe a half inch up, an then use the two strips to tie the inner tube to the pan across the bottom. Tie the rubber strips using opposing holes in an "X" pattern. this will keep the tube from riding up and slipping off.
3) Quiet the Pan - Get some 1/4" thick sheet rubber, cut three 3in wide rectangles, and put one over each of the 3 bolt heads in the bottom of a Lortone pan base to quiet things down a LOT. Since water will get in either from splashing or just washing the rig, replace the bolts with stainless steel and put wide, stainless fender washers under the bolt heads to prevent rusting. I also laid down a layer of RTV (some paper thin nylon/mylar would be better) under the fender washers first and then covered everything before sticking down the sheet rubber. On my (VERY used, I reckon) rig, one of the bolts had actually embedded into the pan base, rusted, and was about to break right thru the metal, so that's why the washers.
4) Quiet the Springs - If you use golf-ball sized or other under-sized balls on a Lortone, either because that's all you could find or to get the pan to wiggle more aggressively, stick a piece of sheet rubber to the bottom of the pan base where the springs are to keep them from rattling against the underside if/when the balls start to flatten out.
5) 20" Pan Lid - Here's what I did to make an excellent lid to cover my 20" vibe pans: Go to a hardware store and buy one of those 20" water heater pans that go under the water heater in your house. They're about 3-4in deep. About $10 is all they cost. Discard - or stow away - the PVC connector that comes with it. Take an X-acto or heavy scissors and cut the pan where the hole for the connector is (doesn't matter where - this just saves 1 1/2" of cutting - lol) from the rim, up the side and to the center of the pan. Mentally divide the pan into thirds and make two more cuts across the pan from the center except on these two cuts, only go to the edge of the pan and not down the side like the first cut did. Like cutting a pie into thirds. Then, where you made the first cut thru the curled rim and up the side, cut the outside edge of the curl back about 6" or so from the cut that goes up the side. This is so that the cut back part will slide inside the curled rim on the other side of the vertical slice. Now - voila! - The pan will go over the top of the vibe pan and be able to contract like a sort of sphicter (don't laugh - that's what they're really called!) valve so that it can be tight around the pan. Helps a lot to have made the inner tube anti-splash thingie I described, above, as the rubber will keep the lid quiet and give "traction" to keep the hard plastic lid from shifting. The last step is to get yet another 16" bike tube and either stretch the whole thing around the lid when it's on the pan or - like I did - cut the tube in half lengthwise leaving you two approx. 2" wide bands (save the other for a second pan lid)... and it's a good bit easier to stretch around the pan. The 3 "leaves" of the lid will fold over each other to decrease the diameter of the lid to that of the pan and the cut back part of the rim slides right around inside the rest of the curl. Getting the tube to go around the lid/pan without slipping off like a rubber band takes a little practice to do alone but it isn't too tough. An extra pair of hands helps a lot with this, though.
6) And - even if you DID see some little t-egg pieces on your polish pad the last time you used it, and even if you AREN'T sure you got them all out before stowing your wet pad in a garbage bag - DO NOT shake/snap the wet pad when you get it back out just to be sure there are no bits left!! That's what I just did. Made a heckuva white H2O/tin oxide mess of my face, glasses, shirt... and the sliding glass doors to the back porch that my wife made me clean off with a sponge since, like most women, she "doesn't do windows"...... at least the house is already white, so she didn't notice THAT... LOL
C-ya! Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Oct 8, 2011 21:50:06 GMT -5
Thanks, Jason. Good tips!
Well, I've done 3 loads now and man did they turn out nice! Wasn't expecting much after one of the replies here.I used the pad that I got from US&J and it seemed to work ok. The carpet sounds like a great idea, too, for when this pad wears out. Though I don't know how to tell unless maybe a hole wears in it after a while? Or do they just get really thin?
On my Lortone, since it came with 3 balls that didn't match each other, I've found that the yellow hard foam practice golf balls that Walmart sells seem to work pretty good. They do flatten out a little after a couple weeks but they're cheap so whattheheck. I also found some racquet ball sized ones at Toys R Us that were good, too, and don't flatten out. I went to the smaller balls because the big ones made the pan to restricted and I wanted a little more "wiggle to the jiggle". I have cut notches where the 3 motor mount spacers are because, when I first got the rig, they were whacking against the rim of the base and loud as heck. I, also, have TWO springs on each of the 3 metal loops. Originally to try to stop the racket but also because the rig only came with two - again mismatched - springs. I had no idea how big/small the springs should be (they both just looked too wimpy) so I matched the heftier one and doubled them up.
It occurs to me that using bigger or smaller balls or single/multiple springs might be a way to adjust the aggressiveness of the wiggle on these "jiggle pans", ya reckon? c-ya! Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Sept 30, 2011 16:14:51 GMT -5
Thanks, y'all - I'll be giving it a shot this weekend.
Hey, jakesrocks - "...They'll polish on the lap, but won't have the high gloss, glassy look that you get with a polish wheel... '
I'm really bummed to hear this bit. I'd thought that a "jiggle pan" was what was used on the polished agates,t-eggs, and slabs I've bought that are so shiny. I'd been trying to shine stuff up with an Inland 8" spinning lap but there always seemed to be low spots - especially in the center - that I could never seem to even out. And if I did happen to get a slab fairly flat, I almost always seemed to end up with tiny, internal "micro-fractures" I guess from heat? So, I picked this used Lortone and spent a month making it work without breaking or keeping the neighbors up all night in hopes that it would solve ALL of my problems...
You mentioned a wheel - what, like a 6" x 2.5" expanding drum type? I have one that a good friend is letting me use but I don't figure you could polish a really large nodule or an 8-10 inch slab with it. Any suggestions? What's the best grit - 14,000? (yeah - a noooooob! A million questions)
Thanks, Rick
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rykk
spending too much on rocks
Member since September 2011
Posts: 428
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Post by rykk on Sept 28, 2011 9:14:57 GMT -5
Hi! Ok, I've got a 20" Lortone vibratory lap that I bought used and spent almost a month to get working. The old - I think - type. I've been grinding away on a bunch of faced agates and geodes with a few fair-sized, weighted slabs.
I've done 120/220, 220, and 600 grit steps and am looking at taking them to the polish phase with tin oxide. I have a separate pan and a new pad for this.
I'm asking for any tips - other than the usual, "avoid contamination" ones I've already read - as to the best way to do the polish on a "jiggle pan" and what to expect.
The pad they sent is some sort of porous/fibrous looking material and is maybe over 1/4" thick. I looks like this could require a BUNCH of tin oxide powder - does it?
Also, will the rocks rotate around and around the pan like they do in the grit/water phases? Doesn't seem like they'd be able to move as they might stick to or sink into the pad no matter how wet it is.
I've got more questions but will ask them in separate threads - Thanks! Rick
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