Lapidaryforum.net
Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: Mossagatemac on February 13, 2020, 08:46:29 PM
-
Hi everyone, I've been grinding and polishing cabs for a few months now. I ran in to two pieces I'm having a heck of a time getting to stick to the dop stick. One is a slab of agate and they're both pretty smooth on the side I'm trying to dop. I'm using a dop pot with green wax, and heating up both the stone and wax. I tug on the rock after everything is cool and it feels solid but then I go to the coarse grind and it pops off super easy.
I thought it might be because the rock is smooth, so I roughed it up on the 220 wheel a little but it didn't seem to help much. I could try that some more but didn't want to ruin the smooth side if I didn't have to.
Is there a different dopping technique I should be using?
-
Are the stones super clean? I have some pop off and suspect it's residual cutting oil interfering with adhesion.
-
Try cleaning the stones with denatured alcohol or even acetone. (Good ventilation). Another problem may be in reusing the wax. After a number of heatings it gets brittle or doesn't stick as well. Clean it off and apply new. It should stick okay even to a smooth stone, use only the smallest amount of pressure. I hope this is helpful.
-
Time to change to fresh wax.
-
Washed the stone some more and found some fresh wax. It worked! Will try the other problem stone in a few days.
-
This is a faceting trick, but I use it for dopping my cabs as well:
Dissolve some shellac in a tiny bottle of denatured alcohol (color will be light yellow). Use a small craft paintbrush to paint some of the solution on the back of the cab and let it dry (takes just a minute). Dop as usual. I have never had a cab come off a dop with this method. Sometimes it takes a bit more freezing in the freezer for it to pop off the dop when your done because it really holds!
-
Sounds like a good tip. Have to try that one.