Post by johnjsgems on Apr 24, 2010 21:59:42 GMT -5
I've tumbled a lot of beach rock. They always come out better after at least a short run in 60/90 (several days to a week). Even though they are nicely rounded there are usually some deep scratches. I used to have access to a private beach in Central CA. that was literally all rock. You could fill buckets with good unfractured, unblemished rocks. They still came out better with a 60/90 run.
If you need some quickly (2-3 weeks) polished rocks of average quality for some project you can get away with starting at 120/220 with carefully selected cleaned beach rocks. But as John says it is best to do a 60/90 run first. Steve
God of Multiple Parallel Universes Full of Rocks and Apprentice to THE ONE.
Post by deb193redux on Apr 25, 2010 13:49:56 GMT -5
You should also test hardness and/or smash one to see if there are pits and fractures all the way to the center. Some beach rock is quartzite, and will take a hard polish. Other rock is very altered jasper, and is too soft to take a polish. Too many folks mistakenly believe any rock can be polished.
The fact that these are very rounded suggests that they may be the softer variety. Post a pic and maybe we can give an opinion on whether the rock will polish.
If they are not going to polish, you need to think about clear coatings.