Denatured alcohol to remove shellac destroys the polish

[HammerTitanGuy]

Hello everyone.
I am facing an extremely peculiar (dare I say a very disturbing) problem. It has already destroyed hours upon hours of work and I cannot figure out in the slightest why that is.

I am doing champlevé in fine silver. I first use a Laser to remove the cells and get basic outline of work (finishing pass is also given). I then manually use my engraver to add the fine lines/etc.

I do not have access to a vice or Thermoloc and import is expensive (due to my country's regulations). So I use jeweller's shellac to hold the piece securely. Unfortunately, some of the shellac almost always makes it through the center hole and pushes above and onto the silver. I do the engraving, and then leave the piece in denatured alcohol. It dissolves the shellac but also dulls the piece. For reference, this is what the piece and engraving (outlined) looks like after its been in the denatured alcohol. All other bright cuts have been added for reference afterward for comparison (that's what they look like before going into the alcohol).

How can I fix this? I can't heat it red hot (destroys polish). Can't leave shellac in (clouds and messes up the enamel). And I can't dip it in denatured alcohol (it is dulling the piece). Is it because of laser? I clean the piece thoroughly prior to engraving.

Any inputs or insights are appreciated. Thank you for your time.

 

[mtlctr]

Did ya try getting back in there with cotton swab & silver polish. Or….get a vise to clamp the work in. You can use scrap leather between the vise jaws & piece you’re working on. Good luck
kent

 

[Leonardo]

Hi!
I cannot understand you very well because you said:
" I do the engraving, and then leave the piece in denatured alcohol."
and then you said:
"And I can't dip it in denatured alcohol (it is dulling the piece)."
Also, what enamel are you talking about?
Anyway, have you rinse the piece very well in a new and clean alcohol? I think that you may have a very thin layer of dissolved shellac still covering your piece. Cleaning it very well with alcohol and a brush can remove any rest of shellac still remaining on the surface.
What do you think about?

 

[HammerTitanGuy]

Did ya try getting back in there with cotton swab & silver polish. Or….get a vise to clamp the work in. You can use scrap leather between the vise jaws & piece you’re working on. Good luck
kent

Hello Kent,

I did not try to do it with a swab. Shall I manually polish the work after it dulls? Won't it take away from the details as polish erodes some material?

 

[HammerTitanGuy]

Hi!
I cannot understand you very well because you said:
" I do the engraving, and then leave the piece in denatured alcohol."
and then you said:
"And I can't dip it in denatured alcohol (it is dulling the piece)."
Also, what enamel are you talking about?
Anyway, have you rinse the piece very well in a new and clean alcohol? I think that you may have a very thin layer of dissolved shellac still covering your piece. Cleaning it very well with alcohol and a brush can remove any rest of shellac still remaining on the surface.
What do you think about?

My apologies Leonardo,

I think I worded it poorly. I am taking about grand feu (vitreous) enamel. I will try to rinse and brush it with a new alcohol and see what happens. This one time I left the piece in for a few hours and it turned the alcohol pinkish. No idea why that is. I'll try to do it with a brush this time. Thank you.

 

[Sinterklaas]

Use clean alcohol again. And repeat until the alcohol stays clean. The alcohol will dissolve the shellac. But after the alcohol evaporates of your piece the dissolved shellac will be left on the piece in a fine layer. Maybe hot water will also wash the layer of shellac off.

What country are you in?

You can try to find polymorph plastic. They come in beads/balls. You can use it instead of thermoloc. And I like it better then the gray thermoloc. Just throw some balls in hot water and it will become a soft blob. Then you can shape the blob to hold almost anything.

polymorph plastic at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[mtlctr]

Hello Kent,

I did not try to do it with a swab. Shall I manually polish the work after it dulls? Won't it take away from the details as polish erodes some material?

Yes, I use denatured alcohol all the time I’ve never re-rinsed pieces just just rub briskly with cotton cloth & a bit of silver polish If needed . For tight areas use a swab. No…..it won’t mar the work surface. No sandpaper, silver polish if needed.

 

[AllenClapp]

Are you using 97% denatured alcohol or 70% denature alcohol. If you are using 70%, can you be seeing tarnish forming due to leaving it in the water/alcohol mix? If so, using a cotton swab to help remove the shellac quickly and limit time in the solution may help.

 

[monk]

fwiw: take some scraps, try different, ideas, and lastly, you may solve yer problem. good luck.

 

[tdelewis]

Don't use shellac. Try hot glue. I cover the back of the item with painter's tape. Then use a heat gun to melt hot glue on to what I am going to attach it to. Usually this is a small block of wood. Then set the item in the hot glue. After you have completed your work remove it with a heat gun.

 

[alastairduncan]

There is a really good book by Phil Barnes called Engraving and Enamelling, the art of champleve. It is available in print and there is also a kindle version. £14.25 in the UK.
There is a chapter, no 6 on Metals and their preparation. Page 62 cleaning fine silver and gold.

Heat the metal and quench in pickle, it should be hot enough to get a good whoosh not phut when quenching. Rinse and then use a brass brush with plenty of soapy water to brighten it.

That's not a direct quote but a summary. I've used this method and it works well.

Alastair

 

[farmer57]

Hello everyone.
I am facing an extremely peculiar (dare I say a very disturbing) problem. It has already destroyed hours upon hours of work and I cannot figure out in the slightest why that is.

I am doing champlevé in fine silver. I first use a Laser to remove the cells and get basic outline of work (finishing pass is also given). I then manually use my engraver to add the fine lines/etc.

I do not have access to a vice or Thermoloc and import is expensive (due to my country's regulations). So I use jeweller's shellac to hold the piece securely. Unfortunately, some of the shellac almost always makes it through the center hole and pushes above and onto the silver. I do the engraving, and then leave the piece in denatured alcohol. It dissolves the shellac but also dulls the piece. For reference, this is what the piece and engraving (outlined) looks like after its been in the denatured alcohol. All other bright cuts have been added for reference afterward for comparison (that's what they look like before going into the alcohol).

How can I fix this? I can't heat it red hot (destroys polish). Can't leave shellac in (clouds and messes up the enamel). And I can't dip it in denatured alcohol (it is dulling the piece). Is it because of laser? I clean the piece thoroughly prior to engraving.

Any inputs or insights are appreciated. Thank you for your time.

You are complicating things. After you are done ALL the work, use brass brush with plenty of dish-washing soap to clean and brighten your cuts. Rinse thoroughly under plenty of running water. Dry with lint free cloth and proceed to enameling.
You can also use Nitric acid to clean your silver, as it has been done for very long time.
If you are having so much trouble with shellac, use something else instead (even hot glue is fine) and either cover your hole or drill it last.
Lastly, (if you don't have it) get a copy of Phil Barnes's book on Champleve engraving/enamelling (The art of Champleve). You are doing a bit of a cheat by lazer removal but that is your deal.
If engraving vise is too much trouble, at least get a peg vise to hold your work. Those are cheap and easily accessible anywhere.
Good luck.

 

[wild willie]

Hello everyone.
I am facing an extremely peculiar (dare I say a very disturbing) problem. It has already destroyed hours upon hours of work and I cannot figure out in the slightest why that is.

I am doing champlevé in fine silver. I first use a Laser to remove the cells and get basic outline of work (finishing pass is also given). I then manually use my engraver to add the fine lines/etc.

I do not have access to a vice or Thermoloc and import is expensive (due to my country's regulations). So I use jeweller's shellac to hold the piece securely. Unfortunately, some of the shellac almost always makes it through the center hole and pushes above and onto the silver. I do the engraving, and then leave the piece in denatured alcohol. It dissolves the shellac but also dulls the piece. For reference, this is what the piece and engraving (outlined) looks like after its been in the denatured alcohol. All other bright cuts have been added for reference afterward for comparison (that's what they look like before going into the alcohol).

How can I fix this? I can't heat it red hot (destroys polish). Can't leave shellac in (clouds and messes up the enamel). And I can't dip it in denatured alcohol (it is dulling the piece). Is it because of laser? I clean the piece thoroughly prior to engraving.

Any inputs or insights are appreciated. Thank you for your time. View attachment 51725

diamond D cement is stronger than shellac , that is a mixture of shellac and bees wax. it comes of quickly in a container suspended in the ultrasonic and its stronger than shellac. steam clean after. or a "boil pot" on heat with dawn dish liquid and water in a slow boil. [ dont let it boil away]. also rinse off the residue shellac with alcohol which might be your problem.

 

[rweigel]

I’d support the hot glue fraction, easy & cheap to get, detaches when soaked in acetone. I use it to glue flat pieces to the support (wood or MDF).

If you stick to shellack (no pun intended), try to soak the piece in Isopropanol, instead of alcohol denat., as you never know what was precisely used for the denaturation. Solvents are not always high purity products, I have seen paint thinner dulling brass parts.

Cheers

Ralf