need some help with silvering?

[gabagoo]

I use the term silvering lightly here as I am not really sure what it is. Let me explain what I am doing. A client brought me a sample of an acrylic name plate that is 2" x 10" and 5/8" thick clear and either it was lasered, water jetted or flame polished. I am not sure but they are clean and smooth. I am over the year expected to do 300 of them and the plexi is all supplied. There is copy on the front and a logo on the back reverse. Pretty simple stuff. Now along the bottom edge that would be the 5/8" base there is a piece of blue vinyl which covers it and creates an illusion like all the sides are blue. Seeing that it is only 5/8 x 10" I decided to over size a piece and put it on dry. It went on fine, no bubbles and I trimmed it down. What I did see on certain angles of viewing was a form of silvering between the vinyl and the plexi. Looked like microscopic dots that created this silver ugliness. I left it overnight like a laminate thinking it will be gone in the morning but it is still there. I hit it with heat and still it is there. I ripped it off recleaned and applied the blue (saphire) this time wet, and again it was down perfect with no bubbles. This morning I still see this silvering. OK what is happening and how can I get rid of it. This is just the sample and I cant get it right. I will say that I used..gulp Avery A6 impulse blue. I can try a 3m saphire if anyone thinks it is a vinyl issue. OH I almost forgot to add this. The logo on the reverse side of the plexi that faces out forward was also cut in the impulse blue and is mostly a knockout with a basic square of blue and it is on perfect with no silvering. Can I assume that it could be the plexi edge that was cut by a third party? It is very smooth but maybe it contains micro bubbles from the process? Oh one more thing so you have all the facts here. If you hold the piece up and look from the top down to the bottom it is a perfect blue with no silvering at all. It is only seen on certain angles as light passes through the plexi, usually from the front side looking down at the piece.

 

[Marlene]

could it be the adhesive of the vinyl that you are seeing? do you have any other brand to try to compare the two?

 

[astro8]

Paint the bottom blue...then you can tell for sure if it's the vinyl or the acrylic.

 

[Letterbox Mike]

try a high-performance vinyl, preferably Oracal or 3M. Anytime you apply vinyl reverse to the backside of a clear substrate, be it glass or plastic, you can have this. In theory it will go away with time, I've never had it not and we've done more than a few signs like this. Ideally if you can mount the graphic dry you'll have a lesser chance of it happening, and if you can mount with your laminator, that's even better, but it may be tricky or impractical with such a small sign.

Also, when cleaning the plastic, try using only a mild dishwashing detergent in water, no chemicals like alcohol (really using a solvent that's not approved for acrylic is a no-no anyway, it can really mess up the surface), that will lessen the chance that the surface gets any sort of crazing or haze to it.

 

[gabagoo]

try a high-performance vinyl, preferably Oracal or 3M. Anytime you apply vinyl reverse to the backside of a clear substrate, be it glass or plastic, you can have this. In theory it will go away with time, I've never had it not and we've done more than a few signs like this. Ideally if you can mount the graphic dry you'll have a lesser chance of it happening, and if you can mount with your laminator, that's even better, but it may be tricky or impractical with such a small sign.

Also, when cleaning the plastic, try using only a mild dishwashing detergent in water, no chemicals like alcohol (really using a solvent that's not approved for acrylic is a no-no anyway, it can really mess up the surface), that will lessen the chance that the surface gets any sort of crazing or haze to it.

I will try the 3m. I did the original piece dry and it is perfect, the silvering does not seem to go away with heat or time ( 24 hours anyways) but like I said if you look therough the plexi from the top straight down or even the sides it looks absolutely perfect. It's just certain angles this horrible silver wretch seems to show, and of course my client saw it immediately.

 

[J Hill Designs]

it sounds like its only on the cut edges - my guess would be imperfections in the cut

 

[gabagoo]

it sounds like its only on the cut edges - my guess would be imperfections in the cut

but if that were the case, how am I to remedy it. I have 300 pieces in boxes. This is a large client of mine that I do lots of work for...cant be telling them sorry cant be done. Is there a polish I can try on the edge? I will try the 2ml 3m and see if it goes away

 

[letterman7]

I second the vote for the adhesive layer. There's nothing you can do about it outside of painting the piece as astro suggested. Did you do the forward facing (impulse blue) vinyl, or was it already on there? If it was already there... are you sure it's vinyl and not screen printed?

 

[gabagoo]

I second the vote for the adhesive layer. There's nothing you can do about it outside of painting the piece as astro suggested. Did you do the forward facing (impulse blue) vinyl, or was it already on there? If it was already there... are you sure it's vinyl and not screen printed?

The sample piece is all vinyl. the 2ml does the same thing. Damn!!!

 

[d fleming]

Do you have another piece of the acrylic to try and see if it is maybe the substrate?

 

[Letterbox Mike]

Is it sunny there? If so set it outside for a couple hours to see if it goes away.

 

[gabagoo]

I looked at the sample she gave me and I can see it in there a bit too. I dont know how old it is but I bet its over a year or so. The blue they used was much lighter and probably does not show up as much. I bet it's the plexi and may have to be polished better than it is. LIke I said the logo on the back side is basically a 2" x 2: square and it looks perfect from every angle and that is an untouched (cut / lasered? whatever) side

 

[Doyle]

With some polycarb faces, after pulling off the protective plastic sheet from the surface, the panel needs to outgas for while (overnight I think), otherwise hundreds of tiny bubbles will pop up in your graphics (I learned the hard way). Could this be a similar situation? Are the bubbles showing up on the side that had a clear protective coating that you removed?

Just a thought

 

[gabagoo]

With some polycarb faces, after pulling off the protective plastic sheet from the surface, the panel needs to outgas for while (overnight I think), otherwise hundreds of tiny bubbles will pop up in your graphics (I learned the hard way). Could this be a similar situation? Are the bubbles showing up on the side that had a clear protective coating that you removed?

Just a thought

no its regular acrylic and I am almost positive that it has something to do with the method used to cut it. Although perfectly smooth to the touch and to the eye it may have a multitude of very small continuous punctures and somehow the vinyl just cant recess itself into them wet, dry with heat gun etc. I am no expert in acrylic but I can see no other possibility. It's the way the light refracts through the plexi that caused the effect, but it is obvious.

 

[d fleming]

sand,sand,sand,fire polish, try again

 

[astro8]

It's most likely full of striations from the laser and must be run through a diamond polisher like we get done all the time to get them out or paint the bottom like I already mentioned.

Otherwise you can just keep posting away.....

 

[Steve G.]

I know what you mean... Try applying with rapid tac.. chances are, it won't be there and will look good.
That's what i do on reverse applied to clear acrylic and it works. don't really know why, but it does.