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Bubbling on reverse glass gold jobs

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Lee Littlewood
Posts: 228
Joined: Thu Apr 15, 2004 2:36 pm
Location: Portland, Oregon
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Bubbling on reverse glass gold jobs

Post by Lee Littlewood »

I started a new thread not because of new info, but to combine some recent threads. If you want to jump back and forth between them, open each in a separate tab and you can feel like the computer nerd hero in a TV show.
.............................

In the last couple of months we have had three posts about this, all a bit different.

1) https://handletteringforum.com/forum ... f=2&t=3803 from Will Lynes
Bubbles appearing in the black outlines of mirror gold but not in the water gild

2) https://handletteringforum.com/forum ... f=2&t=3826 from Dan Seese
Bubbles appearing in matte centers of 2tone letters

3) https://handletteringforum.com/forum ... f=2&t=3836 from Roderick Treese
Bubbles appearing in black background, not in the water gild

and 4) from Bruce Buckley, in the comments to (1), where he referenced an earlier post
https://handletteringforum.com/forum ... 6830#p6830
that discussed blisters in the outlines around mirror gold AND he mentioned, "a few cases of little bubbles appearing in backed up leaf, which looked like shiny little craters from outside the window".

My own contribution was in the comments to (1) where i showed pix of color changes (not bubbles) where a water gild overlapped the back of paint.

My take-away from all this is
A) don't use the new lead-free 1Shot black on glass gilding projects.
B) clean off any excess gold that overlaps a painted area after backing up is completed.

So in Will Lynes' case (1) we have the bubbles in LSS backup black where the gold leaf has an overlap.
With Dan Seese (2) we have bubbles in 16k gold which has been watergilded over.
With Roderick (3) the bubbles are in lead-free 1Shot black-plus-hardener where the watergilding is.
Then there is Chicagold (4) the only place where the watergild itself is developing bubbles.
My example was of paint changing color and staying soft under the watergild - maybe if it were in stronger sun it would have bubbled too.

And now we have Dan's example (in the comments of (2)) showing the LSS back-up black does not hold its color. Fine - Dave Smith (in (4) comments) likes Polyscreen PS, but it has 2 day drying time. Same problem with Noel Weber's Nazdar 59000 series. What's a gilder to do for black outlines and shades???
{wait - maybe there is some hope - Andrew Lawrence posted on March 29 that a 50/50 mix of LSS backup black and Nazdar 59000 seemed quick drying and tough and hopefully colorfast}
where am i? Now, when i need me...
Andrew Lawrence
Posts: 61
Joined: Sat Jun 29, 2013 1:06 pm

Re: Bubbling on reverse glass gold jobs

Post by Andrew Lawrence »

As an update - I talked to a rep at Nazdar, someone with technical know how and he gave me a little insight. I initially asked about the 6100 series, specifically if it was light fast. The answer was that it has a 1 year rating, the 59000 series having a 2+ year rating.

However, the tech I was talking to noted the fact that if it is "sub-surface" ie reverse on glass, then it would receive the benefits that UV coated glass has - he suspected it would have a multiplying effect of 3 or more. He also pointed to the variability of how much UV exposure it gets, whether its north south east or west as well.

I also asked if the 6100 and 59000 series is inter mixable, to which he said yes albeit they have different resins and compounds in them. The 59000 series he said would fully oxidize ie cure, in about 7 days. I believe most all enamels have this type of dry rate.

It feels like a lot of these issues of bubbles in black have to do with paint curing, and if it's covered with gold overlapping then the paint has no where to off gas ie cure or oxidize so it pops and bubbles form.

Robert from Chicagold has a formula he's used to some success albeit I am not a person to give away someone's formula for them.

For me it looks like:
6100 + 59000 + Naptha + Hardener would work (personally haven't tried this, but anecdotally it should work, I know others who use 6100 mix to outline)

OR

LSS Back Up + 59000 + naptha + hardener.
pat mackle
Posts: 162
Joined: Sun Feb 05, 2012 5:35 pm

Re: Bubbling on reverse glass gold jobs

Post by pat mackle »

Without my speaking to a NazDar representative, I have found that I can thin the 59000 series with either lacquer thinner, mineral spirits, or naptha.
It seems to dry fastest when thinned with lacquer thinner and still retains its strong adhesion and glossy film strength qualities.
Would be good to do side by side gold leafed test samples of 59000 thinned with lacquer thinner and naptha to see if the bubbles under the gold appear on each or not.
Andrew Lawrence
Posts: 61
Joined: Sat Jun 29, 2013 1:06 pm

Re: Bubbling on reverse glass gold jobs

Post by Andrew Lawrence »

Agreed Pat - Thing is Lacquer Thinners and VM&P Naptha vary a lot regionally. I know here in California a lot of Lacquer Thinners have been getting diluted and I know that VM&P Naptha is harder to find here. I've always been happy with VM&P Naptha so haven't ventured into the hotter lacquer thinner route, but go for it!

Found this cool little article in the Times too:
http://www.nytimes.com/1996/10/27/nyreg ... vents.html
Andrew Lawrence
Posts: 61
Joined: Sat Jun 29, 2013 1:06 pm

Re: Bubbling on reverse glass gold jobs

Post by Andrew Lawrence »

Just as an update - I used the above mentioned formula successfully on location. Gave it about an hour or two dry time for the outlines, then hit it with steel wool and gilded on top. No issues. Used Shadazzle to clean off the excess which worked well.
Robert Schwieger
Posts: 123
Joined: Wed Feb 07, 2007 12:38 pm
Location: Nebraska

Re: Bubbling on reverse glass gold jobs

Post by Robert Schwieger »

Please give details of the product Shadazzle. I am assuming this is used as Bon Ami is used. Does it leave a residue or does it clean off like Bon Ami. Advantages? Disadvantages? Thanks.
Andrew Lawrence
Posts: 61
Joined: Sat Jun 29, 2013 1:06 pm

Re: Bubbling on reverse glass gold jobs

Post by Andrew Lawrence »

"Please give details of the product Shadazzle. I am assuming this is used as Bon Ami is used."

Same use as Bon Ami for gold removal. Slightly less harsh on paint. Nice Lemony smell.
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