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#1

Greybeard
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From: Toowoomba, QLD
Joined: 21 September 2016
Posts: 24
Member
16 October 2016 05:03 pm

I have finished cutting and polishing the pavilion of a stone and now need to transfer it.
The first flat dop stick is glued on with super glue.
I glued up a cone dopstick and was trying to take off the first dop stick but it stubbornly stayed in place and the second dop stick came off. I was heating the first with a flame and giving it a slight tap hoping it would give way. But didn't work.
Not sure if I should reglue the cone dop back on and try again.

I have noticed in videos some use V shaped dops instead of cones. It seems like with a cone there is not a lot of glue there. Am I using too much pressure and squeezing the glue out?

Should I try using wax for the second dop?

Would love any suggestions.

1 user likes this post: AtomRat

#2

fossickeract
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Joined: 16 August 2014
Posts: 85
Member
16 October 2016 07:42 pm

My suggestion reglue the cone dop, wrap the cone dop and stone in a wet tissue up to the junction with the flat dop and heat the flat dop again, it should come off without any tap. I use two part epoxy more reliable than superglue.

Last edited by fossickeract (16 October 2016 07:42 pm)

#3

Mr Magoo
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Joined: 04 May 2014
Posts: 144
Member
16 October 2016 10:09 pm

Personally I'm happy to use super glue initially if it's a very flat surface to flat dop, although I'll also use epoxy glue like JB weld. Epoxy's vary alot, some will flex alot as they warm but I find JB to remain fairly solid, stable.
On the transfer I'll use JB weld. Never super glue as the way super glue cures makes it a very poor adhesive if it has to fill gaps.
Others use wax all the way. It's each to their own and each technique has it's pro's and cons.

What are you using on the transfer?

1 user likes this post: AtomRat

#4

Greybeard
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From: Toowoomba, QLD
Joined: 21 September 2016
Posts: 24
Member
20 October 2016 07:56 pm

Mr Magoo wrote:

Personally I'm happy to use super glue initially if it's a very flat surface to flat dop, although I'll also use epoxy glue like JB weld. Epoxy's vary alot, some will flex alot as they warm but I find JB to remain fairly solid, stable.
On the transfer I'll use JB weld. Never super glue as the way super glue cures makes it a very poor adhesive if it has to fill gaps.
Others use wax all the way. It's each to their own and each technique has it's pro's and cons.

What are you using on the transfer?

I was using superglue. However, I changed to epoxy and on my second try it worked fine. I then immersed the dop and stone into Methylene Chloride (paint stripper) and left overnight and it came away easy. Only problem, the culet broke off.

I did read and article on usfacetersguild dot org about 'dopping with adhesives' that explains why that happened and a fix. So that's next to try.

Sorry, I'm not allowed to provide the link yet.

1 user likes this post: AtomRat

#5

Mr Magoo
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Joined: 04 May 2014
Posts: 144
Member
20 October 2016 11:40 pm

Yep! Paint stripper works. A blast on the dop with a blow torch will also work.

Only problem, the culet broke off.

I've heard of that problem but hadn't received it, yet. What I do is put a tiny bit of some sort of grease on the culet. doesn't matter what it is. At the moment I'm using baby butt cream because it's lying around and free and works.
It has to be a smidgen though because as you push the stone into the epoxy, the epoxy will push any excess up the stone reducing the effective bonding area.

Out of curiosity, what kind of stone where you cutting?

Edit. Worked it out - just seen the post. That's gotta suck for first stone.

Last edited by Mr Magoo (20 October 2016 11:43 pm)

1 user likes this post: AtomRat

#6

Dughug
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Joined: 27 January 2013
Posts: 255
Member
21 October 2016 09:42 am

One way to protect the culet from breaking in the dop is to place a small bit of blue-tac into the cone of the dop before using the epoxy - this protects the culet and also helps the gem to be removed when finished.

Take care to avoid overheating your stone when using heat on the dop this can also cause the gem to crack or shatter if it gets to hot. Follow Fossickeract recommendation to use a wet tissue or wrap in a strip of wet rag to reduce the chance of overheating your stone.

#7

Greybeard
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From: Toowoomba, QLD
Joined: 21 September 2016
Posts: 24
Member
21 October 2016 09:06 pm

Thanks guys for your comments. Actually, I am happy with the stone, given that I am a beginner and it was an old machine. It will become a great talking point and some amusement smile

Next stone I will try the Vaseline suggested in that article, or actually I might try the blue-tac. That would be easy to control the amount.

Off to the Toowoomba Gem Fest tomorrow and hope to find some rough to learn with. Will post the next stone.

#8

Mr Magoo
Member
Joined: 04 May 2014
Posts: 144
Member
22 October 2016 09:58 pm

Heating the dop with a blow torch helps to avoid over heating the stone. As the temp increases quickly the bond fails before the heat has time to transfer across to the stone.

#9

Lefty
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Joined: 01 May 2014
Posts: 942
Member
23 October 2016 06:01 am

Mr Magoo wrote:

Heating the dop with a blow torch helps to avoid over heating the stone. As the temp increases quickly the bond fails before the heat has time to transfer across to the stone.

Yep, what MM said. Epoxy in particular is a poor conductor of heat and the glue will nearly always soften and release before any significant amount of heat is transferred across to the stone. You will often find that if you touch the stone immediately it has released in this manner, it is rarely hot (unless you gave it too much), usually it's just barely warm.

#10

Greybeard
Member
From: Toowoomba, QLD
Joined: 21 September 2016
Posts: 24
Member
24 October 2016 09:35 pm

Thanks guys. Will try again with the heat and see how it goes.

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