10" vibe lap novice questions

[EricD]

I recently procured a 10" RayTech vibe lap and have been running some slabs on/in it.

To my untrained in vibe-lapping self, it seems to take a really long time to remove some seemingly insignificant blade marks from the roughly 2x4" slabs. 3 of them.

I used about 2Tbsp 120/220 SiC to begin with, and after it broke down a bit I added another 2Tbsp. I've had it running for a good 30 hours and the grit seems fine, still large.

Movement is good... the pan moves back and forth and all around a good 1/4 to 1/2 inch, the slabs stay almost stationary but move around the pan slowly, indicating good pan-to-slab movement.

It has new Whamo super balls. Thank you Peruano, found your thread on that

I'm not using weights, yet, but I do plan to cut some out of a 90lb slab of lead I have laying around for no apparent reason.

Could some of you vibe-lapping people out there let me know what your normal method of operation is for your machine? Your recipe, as it were.

I did do some searching around here and found a couple of semi-informative threads, but nothing like anyone's straight up method.

Thank you RTHlings

[AzRockGeek]

Try adding some weight to the top of the slab, probably just floating around. I tried the flat laps multiple times, I found I did not have the patience and polished the slabs on a Poly Arbor with a 8" expandable wheel in a few minutes each.

Good luck.

[Peruano]

I'm no expert but did produce results. I felt like I had to watch it longer than any tumbler so it seemed slow. I've never done slabs by themselves. I have polished flat faces on larger rocks. You could glue flat faced rocks onto your slabs with paper sandwiched between them to facilitate separation later. Having a slight bevel on the edge of the slap could help that grit to get swept underneath the specimen. I know saw marks are difficult to remove.

[HankRocks]

Eric, I have been running a 19 inch Vib Lap for the last 3 or 4 years. As noted by others, slabs or thin end cuts require added weight. In my case it's lead weights. I have tried various caulks to secure the weights. A few problems with caulk or glue, one is waiting for the caulk(or glue) to dry. The other issue is you are running in pan of water that does splash wetting the caulk or glue and that combined with the vibration can cause the weight to come loose. The other issue is taking care not to create any grit traps that might contaminate the later stages. 

The lead weights I use are a combination of flat disks of lead about 1" diameter by 1/2 in in height, and regular fishing weights. The flat disks are usually for the slabs or flat end cuts. The fishing weights are usually used on irregular shaped rocks that require weight. Cutting a rock at the most advantageous plane to maximize the pattern can leave one with an un-balanced rock that does not polish well on the Lap. 

Another issue with using any kind of weight is the time involved with letting the caulk or glue dry. My solution to this is a large queue of rocks waiting to be lapped. I always have a batch glued and drying while another batch is going thru the lap process. The other is cleaning irregular surfaces of caulk or glue residue, soaking in water for a couple of days usually works. 

I use a 4 step process in the Vib Lap for most rocks; 80, 220, 600 and Polish(Tin Oxide). I have found that for certain softer rocks it's better to skip the 80 and go straight to 220. the first stage, 80 SiC is the critical one, you have to get a flat surface which sometimes takes 2 or 3 runs through the 80 stage. I suppose that just like tumbling, they dont move into the next stage until they are ready.

I have some more tips, but I am pressed for time this morning. (never thought retirement would be so busy!!)

[herb]

I've never tried flat lapping a slab, just thundereggs, but like others have said, i think you need to add some weight to your slabs. Otherwise they just kind of bounce around on top of the grit. The other thing to check is whether your pan is flat. Over time the center of the pan wears down more than the sides and it becomes concave. That prevents what you are lapping from coming in full contact with the pan.

For thundereggs, I go in 4 hour cycles. After the cycle is done, I rinse out the pan quickly by using a yogurt cup to splash water onto a pan and into a 5 gallon bucket. I just use the water in the bucket. It doesnt get the pan completely clean, but it doesnt need to be until you move on to the next finer grit. Dont just keep adding more and more new grit to the pan. The broken down finger grit will interfere with the course grit doing its job. I check the thunderegg faces and what needs more work goes back in. It usually takes 3 cycles at each grit so 12 hours. How many cycles of the 1st course are needed depends on how unflat or gouged up the piece is. For me generally between 2 and 4 cycles

[opalpyrexia]

Nov 3, 2020 18:34:20 GMT -5 EricD said:

I recently procured a 10" RayTech vibe lap and have been running some slabs on/in it.

Thanks for starting this thread, Eric. I picked up the same unit on eBay a few months ago, but I haven't used it yet.

[roy]

Nov 3, 2020 18:34:20 GMT -5 EricD said:

I recently procured a 10" RayTech vibe lap and have been running some slabs on/in it.

To my untrained in vibe-lapping self, it seems to take a really long time to remove some seemingly insignificant blade marks from the roughly 2x4" slabs. 3 of them.

I used about 2Tbsp 120/220 SiC to begin with, and after it broke down a bit I added another 2Tbsp. I've had it running for a good 30 hours and the grit seems fine, still large.

Movement is good... the pan moves back and forth and all around a good 1/4 to 1/2 inch, the slabs stay almost stationary but move around the pan slowly, indicating good pan-to-slab movement.

It has new Whamo super balls. Thank you Peruano, found your thread on that

I'm not using weights, yet, but I do plan to cut some out of a 90lb slab of lead I have laying around for no apparent reason.

Could some of you vibe-lapping people out there let me know what your normal method of operation is for your machine? Your recipe, as it were.

I did do some searching around here and found a couple of semi-informative threads, but nothing like anyone's straight up method.

Thank you RTHlings

the slabs have to have weights other wise your slabs will just float on the grit

[pauls]

Agree about the weights, also if you have rock that is heavy on one end getting thinner on the other you need to balance the rock otherwise it will cut a curve instead of flat. ie the heavy end will wear down while the thin end wont.

[taylor]

Thank you EricD for starting this thread. Thank you for the tips, guys. I am also trying to figure out a working process on a vibe lap. I am working on a turritella specimen piece that is too large for my flat lap. Its a thick end cut, perhaps half an inch. The objective is to polish the cut side and keep the rough side as it is...dozens of partially eroded snails. I've got it flat, but polish just isn't happening.

HankRocks would you please provide more details on caulk/glue techniques that work and what to avoid?

herb do you add weight to the thunder eggs?

[herb]

Nov 4, 2020 22:11:33 GMT -5 taylor said:

herb do you add weight to the thunder eggs?

I haven't had to add weights. Eggs down to about 2 in diameter haven't been a problem. Ones that are about 1.5 inches in diameter sometimes take an extra cycle because they are so light. I have a bunch of 1 inch or so wide banded agate nodules that I've halved but not yet tried to polish. I have a feeling I will have to weigh them down somehow

[EricD]

Thank you everyone, for your input.

Think I overdid it on the weights? lol:

[hummingbirdstones]

LOL!  Go big or go home.

[woodman]

I got a 10" lortone vib lap somewhere in shop, bull wheel sander is much better.

[roy]

Nov 11, 2020 20:53:15 GMT -5 woodman said:

I got a 10" lortone vib lap somewhere in shop, bull wheel sander is much better.

yes it is but i prefer to get it flat before i go to the bull

[EricD]

herb I followed your 4 hour suggestion after adding weights, using 4tsp 120/220 SiC each time, and it did indeed remove all saw marks in 3 or less runs.
I find 4tsp grit to work great. It's pretty well broken down after 4 hours, even though there is much more grit waste than tumbling.

4Tbsp that I was reading elsewhere to use did seem like quite a bit too much.

HankRocks on my flat slabs I found super glue works great to glue the lead weight directly to the slab, and sets within 10 minutes. Then just pops off with a screwdriver.

Wouldn't work on anything that isn't flat though, I imagine.

Looks like someone used this pan to shake a paint can... haha:

Otherwise it looked to have never been used before. Nice and flat

[woodman]

Nov 12, 2020 11:32:55 GMT -5 roy said:

Nov 11, 2020 20:53:15 GMT -5 woodman said:

I got a 10" lortone vib lap somewhere in shop, bull wheel sander is much better.

yes it is but i prefer to get it flat before i go to the bull

That is what the rotating 36 inch flat lap is for!, but on thundereggs and agates if the saw marks are not bad, I go straight to the bull wheel.

[herb]

Glad you got a system that works! What I remember reading when I started flat lapping is that for a 10 inch pan it is 2 tablespoons and for a 15 inch pan it is 4 tablespoon. I use a plastic spoon that is probably a little bit bigger than a teaspoon and use 2 or 4 heaping spoonfuls for my 10 and 15 inch pans. Probably works out to a little less than the recommended 2 and 4 tablespoons, but it works for me. With flat laps everything is a balance between time, grit usage, and wear on the pan. You can run longer cycles which will use up the grit more but the tradeoff is it takes longer and you are subjecting the pan to more wear. I've heard some people use a 2 hour cycle which speeds up the grinding action but uses a lot more grit.

Nov 12, 2020 13:37:51 GMT -5 EricD said:

herb I followed your 4 hour suggestion after adding weights, using 4tsp 120/220 SiC each time, and it did indeed remove all saw marks in 3 or less runs.
I find 4tsp grit to work great. It's pretty well broken down after 4 hours, even though there is much more grit waste than tumbling.

4Tbsp that I was reading elsewhere to use did seem like quite a bit too much.

HankRocks on my flat slabs I found super glue works great to glue the lead weight directly to the slab, and sets within 10 minutes. Then just pops off with a screwdriver.

Wouldn't work on anything that isn't flat though, I imagine.

Looks like someone used this pan to shake a paint can... haha:

Otherwise it looked to have never been used before. Nice and flat

[HankRocks]

Nov 13, 2020 9:27:37 GMT -5 herb said:

Glad you got a system that works! What I remember reading when I started flat lapping is that for a 10 inch pan it is 2 tablespoons and for a 15 inch pan it is 4 tablespoon. I use a plastic spoon that is probably a little bit bigger than a teaspoon and use 2 or 4 heaping spoonfuls for my 10 and 15 inch pans. Probably works out to a little less than the recommended 2 and 4 tablespoons, but it works for me. With flat laps everything is a balance between time, grit usage, and wear on the pan. You can run longer cycles which will use up the grit more but the tradeoff is it takes longer and you are subjecting the pan to more wear. I've heard some people use a 2 hour cycle which speeds up the grinding action but uses a lot more grit.

Nov 12, 2020 13:37:51 GMT -5 EricD said:

herb I followed your 4 hour suggestion after adding weights, using 4tsp 120/220 SiC each time, and it did indeed remove all saw marks in 3 or less runs.
I find 4tsp grit to work great. It's pretty well broken down after 4 hours, even though there is much more grit waste than tumbling.

4Tbsp that I was reading elsewhere to use did seem like quite a bit too much.

HankRocks on my flat slabs I found super glue works great to glue the lead weight directly to the slab, and sets within 10 minutes. Then just pops off with a screwdriver.

Wouldn't work on anything that isn't flat though, I imagine.

Looks like someone used this pan to shake a paint can... haha:

Otherwise it looked to have never been used before. Nice and flat

I use 2 to 3 tablespoons(80 SiC) in my 20 inch Lap. After about 6 hours I add another 1.5 tablespoons and let it run for 6 more. Cleanout after this and then sort into "ready to advance" or "repeat coarse". There is usually enough for two loads in the queue so that after two coarse I runs there is usually enough for a full load going forward. 

The difficult part for me is the sorting process and I find that it's easy to miss some of the not quite ready to advance rocks as there will be a spot that I could not see. Have tried the pencil trick and it does not work for me. 

The pan I use is non-grooved. From what I understand the grooves assist in the grinding. Fortunately I was given an old 20 inch Lap with 2 extra pans so I am still working through those. Did convert one of the well worn pans into a polish pan as I figured the un-even surface would not matter with the pad on top. As far as I can tell it hasn't. Also converted one of the polish pans to a normal grind pan.

Contemplating a way to re-furbish worn out pans. Machining seems expensive and as the pan thins out it would only work one or two times. Maybe welding a cutout 1/8 inch plate into the pan. It would make the pan heavier. Not sure what other technical issues would come up. Need to run this by my technical staff. 

Had not thought of using Super Glue to attach the weights. Next time in the hardware store will pick up some for testing on a selected slab. As you mentioned for a non-flat surface it would not be the best solution and will stick with my caulk.

[herb]

Nov 13, 2020 10:19:10 GMT -5 HankRocks said:

Nov 13, 2020 9:27:37 GMT -5 herb said:

I use 2 to 3 tablespoons(80 SiC) in my 20 inch Lap. After about 6 hours I add another 1.5 tablespoons and let it run for 6 more. Cleanout after this and then sort into "ready to advance" or "repeat coarse". There is usually enough for two loads in the queue so that after two coarse I runs there is usually enough for a full load going forward. 

The difficult part for me is the sorting process and I find that it's easy to miss some of the not quite ready to advance rocks as there will be a spot that I could not see. Have tried the pencil trick and it does not work for me. 

The pan I use is non-grooved. From what I understand the grooves assist in the grinding. Fortunately I was given an old 20 inch Lap with 2 extra pans so I am still working through those. Did convert one of the well worn pans into a polish pan as I figured the un-even surface would not matter with the pad on top. As far as I can tell it hasn't. Also converted one of the polish pans to a normal grind pan.

Contemplating a way to re-furbish worn out pans. Machining seems expensive and as the pan thins out it would only work one or two times. Maybe welding a cutout 1/8 inch plate into the pan. It would make the pan heavier. Not sure what other technical issues would come up. Need to run this by my technical staff. 

I process a bunch of geodes at each grit level before moving to the next. I stick a piece of duct tape on top of my geodes and then put a dot of my girlfriends old nail polish on the tape for each 4 hour cycle. Makes it easy to track how long a geode has been grinding for when some take longer than others.

The pencil method for seeing if a stage is done has always worked for me. Perhaps you need more pencil marks on the surface or shorten the time you run after putting the marks on so they dont all get ground off.

I had 2 10 inch and 2 15 inch pans resurfaced for $125. Not cheap, but it's less than new a 15 inch pan would cost. Find a small machine shop. The bigger ones charge more because it is not worth their time for such a small job. Resurfacing doesn't remove all that much material. Nothing in the center and more as you go out to the edge. I can probably resurface the pans another 2 or 3 times before I'd start worrying about it getting too thin. When I get to that point, I was thinking of seeing what it would cost to have a shop make a insert out of 1/4" tempered aluminium. The aluminium itself is less than $30 if I remember. If you have access to a metal bandsaw you could make the disk yourself. The big concern is the flatness of the aluminium plate. From what I remember when I looked a year or so ago, the tolerance specs for flatness of the players stock is kind of alot.

Rather than welding the insert in place, I would make it a bit smaller than needed and put some rubber shelf paper between the pan and insert and then caulk it in place. The plastic bumper tubing would keep the caulk from getting chewed up and it would allow you to pop out the insert when it wears down to either flip it over or to put in a new one

[EricD]

The pencil method has been working for me on the saw marks/low spots as well. I doubt it would work for checking if the last grit's marks have been removed though, but I haven't been there yet. Soon.
Sharpie might work better for that, if you can see the microscopic dots of black that are left.

I'm planning on buying cheap 10" stainless steel thick bottomed cooking/stew pots when I need a new pan, and cut the sides down a bit. Either that or cast iron, but I really love stainless.
I can't believe they made the vibe lap pans out of the softest metal (well, not THE softest) available.

I tried graded 80 grit today, and man does that stuff last compared to the 120/220. Four teaspoons 80 and it's still grinding loudly away 7 hours later. Needed water multiple times of course ( of coarse )

Have any of you tried AO in your vibe lap? 500 grit, etc., after they are flat and have gone through 220 or so?