sleuthgal
starting to shine!
Member since February 2011
Posts: 46
|
Post by sleuthgal on Mar 7, 2011 0:08:33 GMT -5
Help, I'm all excited about my 8" ameritool flat lap, but seem to be getting a bunch of flat spots on my flat cabs, how do I stop it.
|
|
|
Post by Roller on Mar 7, 2011 0:41:23 GMT -5
I am not sure but I have theories ...1 new wheels... 2 shaking ...3 soft material ..4 I hope someone else chimes in because i really dont know but i was going through alot of flat spots at first that seem to be going away a lil more at a time ..but if i use a soft material i still get them ..
|
|
meta99
has rocks in the head
Ohio Flint Ridge flint
Member since October 2010
Posts: 540
|
Post by meta99 on Mar 7, 2011 6:48:36 GMT -5
I'm using diamond wheels and sanding belts but was getting a ton of flat spots and unintentional faceting on my 25 cabs I'm working on right now. I showed my husband and he said..."Go back to the 220 and use lighter pressure"! Well, it worked. I 'hate it' when he's right! I was pressing too hard and rushing the process. Where did that patience go? (I think it flew off the dopstick!)
Sue
|
|
|
Post by 150FromFundy on Mar 7, 2011 7:36:41 GMT -5
I aslo use an 8" Ameritool and ran into the same problem.
Your sanding disks are flexible. This is ideal for ploishing domed cabs, but a problem for polishing flats. If you try to polish a flat on a flexible disk, the edges tend to polish, but the centre tends to ride above the disk. The more pressure you apply, the more pronouced the problem.
You need to invest in a set of faceting disks. ie - the rigid metal bonded diamond disks. It's expensive, but will also allow you to finish slabs and end cuts.
Darryl.
|
|
stefan
Cave Dweller
Member since January 2005
Posts: 14,095
|
Post by stefan on Mar 7, 2011 11:18:08 GMT -5
Light pressure is key. Flat spots on flat cabs is a real bugger (I'm guessing you mean that the flat surfaces have multiple "flat" spots on them). Lighten up your pressure. Also don't rush the courser stages. If you make a mistake there- it just compounds itself down the line. Don't worry too much as you will get better with practice. I rushed my very first cabs (went from 100 grit to polish in the space of an hour- including belt changes!) The results were terrible. Now i take my time (about an hour per stage for 6 or so cabs). While the results aren't amazing- at least I can get a shine on most things (and the scratches and flat spots are minor).
|
|
sleuthgal
starting to shine!
Member since February 2011
Posts: 46
|
Post by sleuthgal on Mar 7, 2011 13:11:48 GMT -5
Thanks for all the great input, I was definitely rushing through every stage and applying way to much pressure. I was thinking pressure was a good thing, obviously not. I will be back to the grind this evening and will see how it works out with longer time and less pressure.
|
|
dbrealityrocks
fully equipped rock polisher
Member since February 2010
Posts: 1,084
|
Post by dbrealityrocks on Mar 7, 2011 16:05:33 GMT -5
Okay I guess Stefan must have got it right about the flat spots. I read the post and thought gee flat spots on flat cabs? All my flat cabs are flat, you know a big flat spot all across the top. :blush: :blush: :blush:
|
|
Wolfden
fully equipped rock polisher
Member since November 2007
Posts: 1,368
|
Post by Wolfden on Mar 7, 2011 18:03:46 GMT -5
I also have the Ameritool , i use hard disks until my 600 the my 1200 is a soft disk ( i backed it with leather ) .. its all about light pressure and the other key is to keep moving , if you pause there will be a flat spot . i use a rolling movement ( twisting the wrist ) let the disk do the work
Wolf
|
|
|
Post by FrogAndBearCreations on Mar 7, 2011 19:13:48 GMT -5
yep! light pressure and keep twirling and rotating the stone.
I use stubby dop sticks, just long enough to use with my fingers to turn and rotate the cab I'm shaping/polishing. It is hard to keep the stone moving in circular motion and turning at the same time without dopping it, using only your fingers.
|
|