Aussie Lapidary Forum
LAPIDARY => Ask a "Silly" Question => Topic started by: tinker on January 28, 2020, 05:40:29 PM
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Hi, has anybody had problems with dopping using sealing wax. I have use wax on my dopping sticks for about 15 years, but over the last twelve months, I don't know whether it is the wax, but the stones seal to the stone, but once I start working on them they drop off the stick. Can anybody suggest what I maybe doing wrong or has anybody got a suggestion on what other median and can use to attach the stone to the dop stick.
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I have hat that problem with Brown faceting wax as well and an stsrting to think it has a use by date
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I have been told it goes off? but I don't know how long we have before it does!
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Hi,
my current hybrid cold-dopping technique using 'brown wax' is to use 100% shellac as the dop material. I melt some shellac flakes onto a clean dop and form it into a cone using a piece of flat steel, and finally my fingers.
I warm the shellaced dop enough to make it soft, but not molten. I then use my transfer block to get an impression of the stone to be cut on the warmed shellac dop, then separate stone from impression.
I then paint the cleaned contact surface of the stone to be cut with a solution of shellac dissolved in alcohol (methylated spirits) using a small artist's brush.
When the alcohol has completely evaporated and the stone is dry, I place a drop of super glue between the two surfaces to be mated, and bring the stone and stone-shaped mold/impression together with my transfer block and wait an hour for the super glue to dry.
A bit of a fuss, but this method is very secure and has a number of advantages.
- The primary bond to the stone is (evaporated) shellac rather than cyanoacrylate, so the stone can be removed much easier when it's time.
- The alcohol-deposited shellac to stone bond is more reliable than a heated shellac to stone bond
- It's inexpensive and the materials are re-usable
- The only heating of the stone is when the impression is made, only for a few seconds, then the stone is easily withdrawn from the impression
I continually re-use the shellaced dops by adding some extra fresh shellac flakes to the warmed end, and then re-shaping by rolling the dop on some cold steel.
I bet your crusty brown wax could be utilised once again using this technique, perhaps by also adding some fresh shellac to the mix, after all, brown setting wax is just shellac with a bit of clay filler added I believe.
RC.
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I've tried using sealing wax before tinker, not for faceting but cabbing. Not good. When it cools and solidifies it is quite brittle and will break off either the stone or dop quite easily. It also has a lower melting point so even if you could keep the stone on the dop, it may melt a little and allow movement in the stone. I've only used wax once or twice, I'm a lot happier with two part epoxy, it holds well and doesn't move. To remove the stone I wrap the stone in a damp cloth and heat the brass dop until it drops off. Using my fingernail I then remove any epoxy still on the stone while it's warm. The bulk of the epoxy seems to remain on the dop and is easily cleaned off while the dop is warm. I haven't used Araldite, just the JB Kwik stuff that Leah and Andrew stock. I've still got some of the old Tite-on as well. Hope this helps.
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Dopping wax of the faceting variety or cabbing variety does go off after a long time, something evaporates out of it and it just goes rubbery and will not melt. I have experimented and as far as I know there is no way to rejuvenate it.
As far as sealing wax goes I guess it's the same, dopping wax is just sealing wax with shellac and a filler. From memory an original recipe from the 1960s was shellac and plaster of paris mixed with the melted sealing wax. POP would be better than clay as it has a low hardness, who knows what the clay minerals hardness is and what it would do if it got onto your polishing lap or pad.
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Thanks guys, I have some shellac, I might try that method.
beers
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Thanks guys,
I'll mix up some shallac for another go. The last lot I tried this with was shellac I had used for my plaited belts. It is a little thinner than shellac for french polishing.
I think I saw some orange flake shellac on my tool cupbpard. If I can't find it, I'll need to buy some more.
Happy faceting
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Yes FlashGP, I have the orange flaked Shellac, so am trying it out today beers
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Assuming tinker is talking about faceting I would go along with what Bucket said.
I never use wax unless the stone is small and I have to central it on the dop after its in the quill. Doing that with a BBQ lighter and the machine dial gauge. I have always used Araldite and never had a problem with it.
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Sorry Faceting Frank, I forgot to say its is for cabbing not faceting.
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Hi tinker,
I use the green wax to dop after putting a couple of drops on the stone, hitting that with a bbq lighter then pressing the formed wax home to it.
After a cuppa and a good yarn it's usually ready to work.
Cheers,
colza
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I dop up with superglue and use 5minute epoxy to transfer(cook it in the oven at 50degreesC for about 15-20minites or so to make sure it's fully cured if wanting quickly) Favorite transfer epoxy is Dextone, which reminds me I need to buy more. JB Quik works but Dextone seem to set harder and sticks better.
Cheers
MB
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Sorry Faceting Frank, I forgot to say its is for cabbing not faceting.
Ah, I was having trouble with brown wax for faceting.
My green wax works fine for cabbing. If I have trouble with it starting to lose its stick I roll a few flakes of orange shellac into it when it is hot enough to be plyable.
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Now that you've mentioned cabbing, Tinker, I had some sealing wax left over from my working days and tried it on wooden dops at the club, it behaved completely different to the wax the club has (currently green, was then a reddish/brown). Again it was brittle and didn't hold the stone particularly well. The best way to describe it is that the cabbing wax seemed to have more 'stick' and while the cabbing wax sets firmly, it also seems to have a little flexibility and doesn't crack as easily, not as brittle.
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Yes my experience too mate, I found the red was more flexible, where green was very brittle but lasted, I threw away the red because it had that flexability, do you think I should have stayed with the red.
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My preference when cabbing is the red/brown but the club is now using the green, which I've found OK, just doesn't seem to stick quite as well as the red/brown.
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If you are having trouble with the stones sticking when dopping mix up a bit of flake shellac with some metho and paint that on the back of your stone before you dop it. You don't need much just a bit in a small vegemite jar and paint it on with a cotton bud.