I have to on some Rx's take off more of the backside of poly lenses then I would like to do. This then creates a ring effect after tinting. What can I do to solve this problem? Could I send the lenses back to the lab for them to recoat the backside and the beveled area? Is there a tint that will also dye the poly that is uncoated. Any suggestions would be much appreciated.
Jeff:bbg:
Your best solution is probably to go with polarized lenses or use CR39 and tint it. What you suggest might work in theory, backside coating an edged lens isn't really a good option.
There's one other possible option, and that may be to try a Camouflage pen - go to www.1800optisource.com and search "Camouflage"
-Steve
Originally Posted by snowmonster
Thanks Steve. I'll try the Camouflage pen. I've heard of the pens from Hilco, but not from Optisource. I'll see if they have a grey or black. I don't know if they come off easy where applied.
I was looking for a less expensive alternative to polarized poly for the patients who don't want to pay the higher price. CR39 would work but I was wanting a safer option for motorcycle glasses.
Jeff
In that case, we normally just tell them that it has to be poly polarized, not tinted CR39.
Let us know how it goes.
-Steve
If the pens don't work well, I'll tell them then have to get polarized poly. Transitions work great in wraps because they have a front side coating.
If you have tint bath in office, I just do a "splash" tint to darken the ring. I had to do a pair today (my own!).
I wouldn't recommend polar for a motorcyclist, being able to read the road-surface can be crucial especially when it comes to moisture and puddles.
Those lens pens work great, they've come in handy on those kinds of wrap jobs!
I have a tint bath and I tint the lenses after edging. I think I know what you're talking about tinting over a lens that was pretinted and then edged. The ring effect really stands out when you edge a pretinted lens that is plastic. Poly doesn't tint where it's not coated. The frontside coating does tint some in poly to help take away the ring effect.
I know I've read about poly tint that tints uncoated poly. Maybe I'm wrong. Is there such a thing?:hammer:
Jeff
Last edited by jeffsoptical; 10-23-2009 at 09:43 PM. Reason: needed to correct a mistake
What brand of pens do you use? I've placed an order with Optisource for an opaque black pen. The only other pen that looked like it might work was metallic grey and it was somewhat translucent but too shiny of a grey. I wanted a somewhat translucent black, but the opaque might not look bad. The Optisource pens say they are guaranteed not to chip, peel or wash off.
Jeff
Ok . . . Don't all cringe at the same time, but I use Sharpies on the lens edge.
We used to have Camo pens at LC until Corporate decided to stop purchasing them. Then I ran into trouble when I would have pts bring back their sunglasses b/c they could see the white ring around the edge. So I would go put them in the dye pot to tint the edges, however that did not always work, and I do not have a lab at my store, though I do have access to one at another store. Long story short I tried a black sharpie on my sunglasses and it worked great and didn't come off while washing. It is easily removed with alcohol, All-off etc. Great thing is they have a pack of assorted colors for about $15-$20 and you have your pick of color. I personally like the jumbo black sharpie, one swipe and you're done. Its a quick fix for those rare pts that had Camo from LC but it chipped and they want it reapplied (Yes, I did have this happen, twice! LOL)
Just my 2 cents for the evening.
~Crazy
Tinting poly...........
In order to be tint able, the surface has to contain pores to accept the dye pigments.
The only material that tints easily is un coated CR39.
Poly and Trivex have no pores and you can only tint the hard coat if it is tint able. The more tint able the hard coat is, the less protection it will give, as it is softer the more tint able it is.
If you tint un coated Poly or Trivex it will just adhere to surface temporarily and come off easily after a short time.
Not true Chris. Uncoated Trivex tints faster than almost any material, including CR. It's one of my secrets for creating edge tints on rimless. I've yet to wash off the tint on my samples.
Rough edges .........................
optical24/7.......................Edges are rough and this might well work as you say, I never tried that, we only tested surfaces for a manufacturer and there it was not a permanent solution, neither in a dye pot nor in MicroTints.
..
Last edited by Deleted1234; 10-20-2010 at 06:15 PM.
Hard coat problems
Polycarbonate is so soft that it has to be hard coated or it can be scratched by a finger tip. It is a must to hard coat.
The hardcoat has to chemically link to the polycarbonate surface when curing, either by thermocure or UV cure.
When there is a layer of dye pigments in between the two, you will not get a proper link and the hard coat will peel off.
On CR39 the pigments will go into the pores of the lens.
If you use Trivex and **don't** polish the edges, those edges will take up normal tints quite rapidly - more rapidly than the tintable hardcoat. This gives you a dark edge, the same colour as the tint, which can look quite effective on sports/sun wrap arounds.
I think the Hilco pens are better because about 6 weeks ago I ordered 4 Camouflage pens from optisource and 3 had NO PAINT IN THEM .
These are high gloss polish edges that tint. A high gloss facet will tint only the faceted part also. (another secret weapon).:bbg:
Yes, we've not had any problems getting trivex to take a tint, other than the fact that a tint applied to the surfaces (as opposed to the edges) isn't always taken up very evenly and can lead to spotting or shaded areas. One way to mitigate this is to ensure the lens is scrupulously clean beforehand - or avoid the risk altogether and apply a tintable hardcoat.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks