ladysavvy
starting to shine!
Member since October 2015
Posts: 28 
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Post by ladysavvy on Nov 20, 2015 21:37:25 GMT -5
I am considering investing in a Flat lap pretty soon and have some questions that I hope you guys can answer.
1. how long does it generally take to polish a average size slab (3-4 inches maybe) on a flat lap. I know some rocks are harder than others so let's say agate for example. How long for each stage in general?
2. If I wanted to polish 3-4 inch slabs, what size flat lap would be better, would a 6 inch lap work or would I need an 8 inch lap?
3. I see that Hi tech and Ameritool make fairly affordable flat laps. Are they good brands for the price?
4. I also see that there are regular flat laps and slanted ones. Is either better or worse than the other?
5. Are the laps themselves quick to change out or does it involve alot of work?
Sorry for all the questions but I am new at this and want to make sure my money is well spent before spending it. I figure you guys can probably fill in the blanks for me. Thanks
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Post by Drummond Island Rocks on Nov 20, 2015 22:56:08 GMT -5
The flat laps you described are primarily intended for producing cabochons. I have an 8" flat lap and I do not think it would be a good choice for trying to grind and polish a 4" slab. A vibrating lap is the most common method of polishing slabs. This is an example of a vibrating lap. You basically lay your slabs on the plate with weight on them and add grit and water.  A bull wheel is another method people are using to polish slabs. I have never used this method but others may chime in on its effectiveness.  Chuck |
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Post by jakesrocks on Nov 20, 2015 23:50:09 GMT -5
Gotta agree with Chuck. even an 8" flat lap would be useless for doing 4" slabs. You have to remember that at least an inch is taken up by the center nut & washer, That leaves you 3 - 1/2" of disc to play with. A vibrating lap of at least 10" would be a better choice. And you'll only fit about 3 slabs on a 10" without crowding things.
The closer your slabs are to being perfectly flat when they come off your saw, the better too. If your saw is leaving grooves in your slabs, it can take forever in the course lapping stage to get them all out. And the little nub that's left on a slab at the end of a cut must be ground off before even thinking of putting the slab on the lap.
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ladysavvy
starting to shine!
Member since October 2015
Posts: 28
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Post by ladysavvy on Nov 21, 2015 11:24:12 GMT -5
Good info. It appears that the vibrating laps are cheaper than flat laps as well. How long in general does it take to complete a slab on a vibrating lap?
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Post by roy on Nov 21, 2015 12:21:08 GMT -5
depends on the cut really if your saw is fine tuned you could start off with 220 grit,then 400 ,600 then polish 2 days maybe never us one of the small ones but the lortone 20" is on my radar  that one is for my big stuff |
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Post by woodman on Nov 21, 2015 12:27:49 GMT -5
I have a 10 vibrating flat lap that I never did get to polish anything, it is somewhere in the shop, I think. I use a rotating 30 lap with silicon carbide 180 grit to get the saw marks out and then on to the bull wheel for 3 stages of sanding, 100, 220 and 400 grit. then on to the rotating polish table with cerium oxide polish.
Bull wheel machines get costly but they sure work. I have some poly arbors with diamond wheels that work good for cabs and a arbor set up with a plate and felt for polish. I just need more room for everything!.
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Post by jakesrocks on Nov 21, 2015 15:35:44 GMT -5
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Post by broseph82 on Nov 21, 2015 15:45:26 GMT -5
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Post by jakesrocks on Nov 21, 2015 16:16:04 GMT -5
I'm bidding on one of the old FL 15's right now.
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ladysavvy
starting to shine!
Member since October 2015
Posts: 28
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Post by ladysavvy on Nov 21, 2015 16:27:26 GMT -5
I'm bidding on one of the old FL 15's right now. That may be the same one I was looking at. I am not ready to jump in yet so i doubt i will bid on it but it looks like a good price. Another question, how noisy are vibrating laps? Are they inside the house noisy, leave it in the garage noisy or my spouse may divorce me noisy?  |
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Post by jakesrocks on Nov 21, 2015 17:07:43 GMT -5
Set it up in the garage noisy. They'd drive you insane in the house. Set up on a wooden floor, the sound would resonate throughout the house. They're reasonably quiet on a cement floor.
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ladysavvy
starting to shine!
Member since October 2015
Posts: 28
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Post by ladysavvy on Nov 22, 2015 10:36:19 GMT -5
OK, still researching things and ran across wet belts sanders as an option. Would these work for slabs? I love the idea of a bull wheel but the price is higher than I want to pay right now. Wasn't sure if a vibrating lap or a belt sander would be better for what I want to do. I like the idea of more hands on than the vibratory lap will allow but like I said, I am not ready to plunk down a bunch of money on a Bull wheel yet. I am keeping my eye open for used machines of any type but here on the east coast there doesn't seem to be the demand that there is out west so we are limited in what used machines are available. Thank for all the advice so far
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Post by jakesrocks on Nov 22, 2015 11:28:54 GMT -5
A wet belt sander would certainly do what you want. But if you go that route, get the optional long backing plate. It will give the support you'll need for nice flat surfaces.
It would be a good idea to temporarily glue a block of wood to the back side of the slab, so you have something to hold on to. If you try holding your slabs by the edges, be prepared to shed some blood & loose fingertip flesh & nails. Belts, discs & grinding wheels will certainly remove them. (Been there, done that). And the problem is, your fingers will get cold & numb from cold water. You won't even know you're grinding flesh until the water in your drip tray starts turning red.
Not trying to scare you, and by using proper precautions you can avoid loss of flesh.
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Post by captbob on Nov 22, 2015 11:46:21 GMT -5
woodman, have you posted pictures of your shop here? If so - link? If not. We are waiting!
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Post by woodman on Nov 22, 2015 13:05:46 GMT -5
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Post by captbob on Nov 22, 2015 13:18:35 GMT -5
Well those are cool. thank you. What are the laps (disks) made from?
I assume you use grits on the first one. What is the surface of the 2nd one? What do you use for your polishing compound?
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ladysavvy
starting to shine!
Member since October 2015
Posts: 28
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Post by ladysavvy on Nov 22, 2015 16:09:23 GMT -5
Has anyone tried or heard anything good\bad about this machine? I like that it has the trim saw included and i really love my Lortone tumbler. they seem to make good stuff www.lortone.com/combination.html |
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Post by woodman on Nov 22, 2015 16:11:14 GMT -5
Has anyone tried or heard anything good\bad about this machine? I like that it has the trim saw included and i really love my Lortone tumbler. they seem to make good stuff www.lortone.com/combination.htmlGood machine, I got an older one and had no problems with it. |
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Post by woodman on Nov 22, 2015 16:15:31 GMT -5
Well those are cool. thank you. What are the laps (disks) made from? I assume you use grits on the first one. What is the surface of the 2nd one? What do you use for your polishing compound? The steel lapping plate is a commercial lapping plate. I think it is cast steel but not sure, I use 120 grit and water on it. The polisher has 100% wool carpet with a cerium Oxide polish slurry on it. does a good job. In between the lap plate and the polish wheel, I use a bull wheel, 100, 220, then 400 grit belts. |
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Post by rockpowell on Nov 22, 2015 22:38:30 GMT -5
Has anyone tried or heard anything good\bad about this machine? I like that it has the trim saw included and i really love my Lortone tumbler. they seem to make good stuff www.lortone.com/combination.htmlGood machine, I got an older one and had no problems with it. I picked up one of these Lortone machines a used one for 100.00 and it runs great. Have oil in the trim saw for winter time. use the drum wheel for sanding off glue on cabs. I bet if you looked around you could find one. |
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