docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Jul 22, 2010 19:48:16 GMT -5
Iwant to pick a few brains about what best to use to fill voids and pits . I am aware of Isinglas (?) or sodium silicate being used to fill the hollow fibers in star stones but I don't think that they would havd much filling power for larger pits and voids. i have heard of using supeglue , too but that's messy and I.m afraid it wouldn't harden in larger pits. i have lots of moss agate and plume agate that would be gorgeous if it weren't for the pits. I even considered using a torch to melt borax into the pits and vugs. i saw some stuff online but it was expensive and I thought it might notwork for anything but tight fissures and cracks. So, what do you guys use?
Mark H.
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spicer m
spending too much on rocks
Member since October 2008
Posts: 337
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Post by spicer m on Jul 22, 2010 22:21:11 GMT -5
I use 330 two part epoxy. works good and drys clear. also used to glue on findings. Mike
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Jul 23, 2010 0:27:14 GMT -5
thanks, Mike. I thought of an epoxy filer, but I wasn't sure it would flow well enough to get into the tiny spots. Anybody elso have ideas? i'm going to try the borax test this weekend on a piece of scrap material. i remember from chemistruy class doing the borax bead test- it melts and fuses into a sort of glass. once again, It might not flow well and the stone could be damaged by the geat (about 800 F). i'll report later. it is a good day for science!
Mark H.
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Post by Woodyrock on Jul 23, 2010 0:28:50 GMT -5
I use waterglass (Sodium silicate, or Potassium silicate) catalyzing it with the acid propylene carbonate. Heating it slowly will harden it making it nearly waterproof. The Sodium silicate catalyzes nearly instantly, whilst the potassium silicate catalyzes more slowly. The waterglass alone if allowed to dry overnight, and then heated will be impervious enough to survive wet fine sanding, and polish. If you are not using diamond sanding, you can dry sand with waterglass filling with good success. Before diamond sanding belts were available this was the usual method the fill cracks, and pits. Woody
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Post by Tony W on Jul 23, 2010 0:42:45 GMT -5
I use super glue and, also, 330 with success. I prefer the super glue for it's east of use, but mix up epoxy on some pits and cracks. I just stand the dopped cab up and load super glue in the hole and let it go overnight. Repeat if necessary. Biggest problem for me comes with matching up the shine of the glue with the shine of the particular stone. Some go easy and I forget where the pit was, but some never seem to fully match up. T
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Post by FrogAndBearCreations on Jul 23, 2010 8:31:14 GMT -5
I do the same as above
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Post by NatureNut on Jul 23, 2010 8:37:52 GMT -5
I was wondering if clear resin would work. The kind you can get at craft stores. It can be used to make pendants by pouring into molds and encasing something inside such as a shell or leaf. Totally clear and no mixing.
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Post by FrogAndBearCreations on Jul 23, 2010 8:43:27 GMT -5
I have never seen a resin that does not need a hardener mixed in, do you have a brand name?
I have used the resin you get at the home depot that is for table tops and have made stuff for jewelry with it. Its grabby when cutting and polishing and tends to get more so when it gets warm. It does work to fill pits as I have used it on some very pitty chrysoprase but is tricky if you don't do it after polish. It rubs out very shiny with holy cow polish.
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Post by jakesrocks on Jul 23, 2010 8:54:51 GMT -5
I use the 330 epoxy with good results. I heat the stones to be treated to 220 degrees in the oven before applying the epoxy. This pre heating serves 2 purposes. #1, it removes any moisture that may be present in any pits and cracks, and #2, it expands pores in the stone and allows the epoxy to penetrate the stone. Don't use this method on heat sensitive stones such as opal. Don
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Post by FrogAndBearCreations on Jul 23, 2010 9:08:04 GMT -5
I have a lamp that I use to preheat stones prior to treating using a 60 watt bulb and it works great. I also set my container of opticon resin under it when I have a batch that needs treating. I leave them heated and soaking for a couple of days, then pull out the stones and put into a baggie with a couple of drops of hardener per stone, rubbing well into all the stones. Let them sit for about 10 -15 minutes at room temp. and clean them up wiping off all and any excess opticon. They go back under the light for another day to cure out. This method works well. Any pits that are needing filled I mix up a little more opticon and fill them at this point and back they go under heat for more curing.
The above method works great too!
I also clean the stuff that is being treated with acetone to get any oils out that may have gotten into the pit or fracture the day before I treat them.
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Post by Tonyterner on Jul 23, 2010 12:53:44 GMT -5
I use epoxy which I have in several different viscosities. There is a company called Starbond out of CA that makes CA glue in 5 different viscosites so you can get the right one for the job. CA always hardens through no matter how large an area you are working. It does tend to shrink so you would need to apply more than one coating on larger areas. I've avoided epoxies and resins because they tend to yellow with time and UV exposure. I also can't get a very good shine from epoxy. I haven't had the issues that TonyW has had with differing degrees of shininess but maybe that's because I never really looked. I've read about water glass and want to try it sometime.
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Jul 24, 2010 0:09:30 GMT -5
great info, folks! Opticon is one of the products I've heard of but assumed it was a sodium silicate/waterglass based material. I wasn't sure if it would be suitable for larger pits or voids. I'm planning to build a "cabbing stove" to preheat stones and melt dop wax. I can use it for the techniques you brought up. i will try the borax filler method for agate this weekend and report back. It hardens up pretty well, but I don't know how it will polsh. It also can't be used with heat sensitive stones. I have some pretty but vuggy graveyard point in mind.
tanks again to all, Mark H.
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docharber
has rocks in the head
Member since October 2008
Posts: 693
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Post by docharber on Jul 24, 2010 21:05:45 GMT -5
So much for the borax. I got a dirty borax bead sitting on top of a piece of waste agate and a cracked piece of stone underneath. I looked it up and Opticon is indeed a resin. I need to find a good source of waterglas.
mark H.
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