How To Prevent Polycarbonate Rimless Lenses From Cracking ...........................

[Chris Ryser]

Cold + Colder Weather and Rimless Drill Mounts with Polycarbonate lenses can show star like cracking from their holes.

In Freezing temperatures it can happen as well as when the drill holes have been drilled with a dull drill or too fast with a new one, that heated up and microscopically damaged the drilled hole.

Doing some research into this problem we came up with a solution to cure to this problem. We found a chemical solution that can be applied in less than a minute right before assembling the glasses. It is a highly volatile solvent mix that just about dries instantly after having fused any microscopic rips in the drill holes, that will no more be prone to cracking.

One drop per hole will cure all future problems of cracking holes.

Vision Ease is recommending the use of "Drillseal" in the use of Polycarbonate lenses in drill mount frames, as a big benefit.

See their Technical Tip in: " Polycarbonate Lens Drilling For Rimless Mounts " at:

https://www.visionease.com/wp-conten...echTips916.pdf

[Lelarep]

Certainly sounds interesting. Highly volatile? So, its not really a "seal" as much as it sounds like its basically a chemical "cold weld" that brings the cracks back together.

[Quince]

Or use Trivex...

[Jarhead Daddy]

I recommend spraying the edges (especially the drill holes) with a bit of Windex, and then using a clean cloth to wipe a little acetone around the edges. This will eliminate any waxy residue from the polishing process. ;)

[Browman]

Or use Trivex...

With more and more people having managed care plans and few of those actually offering any substantial (or any) Trivex coverage, we had to keep an emphasis on poly. Waiting for prices to either drop on the supply end or for more MCPs to start actually covering the damn stuff.

[Chris Ryser]

Certainly sounds interesting. Highly volatile? So, its not really a "seal" as much as it sounds like its basically a chemical "cold weld" that brings the cracks back together.

It does not bring cracks together, it actually prevents the lens from cracking, by fusing the rips in the drilled holes back together before assembling the frame.

[Chris Ryser]

^{Or use Trivex...}

The subject of this thread is not the use or sale of an other higher priced product, but to prevent the cracking of Polycarbonate lenses.

[Chris Ryser]

I recommend spraying the edges (especially the drill holes) with a bit of Windex, and then using a clean cloth to wipe a little acetone around the edges. This will eliminate any waxy residue from the polishing process.

Windex contains alcohols, and a little acetone, both of them some of the worst enemies of Polycarbonate.

You are actually preparing your drill holes for early cracking.

How about reading the Vision Ease instructions on the provided link above.

[PRECISIONLAB]

I reviewed the technical tips provided by Vision Ease and feel they should have surveyed or consulted with industry veterans. The "Edging" and "Manual Layout" don't seem to reflect current processes. The "Drilling" and Mounting" sections do provide great tips and I'm curious if labs will take that "extra precautionary step" by using Drillseal.

As noted, minimizing excess tension is key in avoiding cracking. Proper groove width and depth, correct hole size and matching compression sleeve and using appropriate washers for screw mount rimless will greatly extend the life of a pair of poly lenses. Unfortunately not all lab techs practice the aforementioned.

[Chris Ryser]

The "Drilling" and Mounting" sections do provide great tips and I'm curious if labs will take that "extra precautionary step" by using Drillseal.

As noted, minimizing excess tension is key in avoiding cracking. Proper groove width and depth, correct hole size and matching compression sleeve and using appropriate washers for screw mount rimless will greatly extend the life of a pair of poly lenses. Unfortunately not all lab techs practice the aforementioned mentioned.

Actually the largest user lab on this Continent is Walman Optical who seems to be doing every rimless Polycarbonate job with a "Drillseal" protection, over the last few years.

There are a few others in the Essilor Group,

Check it out on my website, at: =========>
http://optochemicals.com/products/info_drillseal.htm

[Jarhead Daddy]

Windex contains alcohols, and a little acetone, both of them some of the worst enemies of Polycarbonate.

You are actually preparing your drill holes for early cracking.

How about reading the Vision Ease instructions on the provided link above.

You forgot the ;) at the end of my statement. lol Gotcha!

[Chris Ryser]

You forgot the ;) at the end of my statement. lol Gotcha!

Yes you Gotcha! me, however you got to forgive me, as not knowing you as a joker and being on OptiBoard, where you can post under the name of the Soviet Republics President, somebody might have believed you.

[DanLiv]

As noted, minimizing excess tension is key in avoiding cracking. Proper groove width and depth, correct hole size and matching compression sleeve and using appropriate washers for screw mount rimless will greatly extend the life of a pair of poly lenses. Unfortunately not all lab techs practice the aforementioned mentioned.

More than anything I think this is it. I drill a lot of poly in house on an ME-1200, primarily Essilor poly but several very inexpensive SOMO stock poly too, and I almost never have drill hole cracking issues. I don't use any drillseal or do special chamforing of the holes, heck I don't even always use a sharp new drill bit (I usually let it go about 50% more than the specs like, with no problems). I only use compression mounts, no nuts and bolts.

[Jarhead Daddy]

Yes you Gotcha! me, however you got to forgive me, as not knowing you as a joker and being on OptiBoard, where you can post under the name of the Soviet Republics President, somebody might have believed you.

True That

[Chris Ryser]

...................and I almost never have drill hole cracking issues. I don't use any drillseal or do special chamforing of the holes, heck I don't even always use a sharp new drill bit (I usually let it go about 50% more than the specs like, with no problems).

.......so you are lucky. However dull drill bits overheat, to much pressure, and other reasons, and do rip the polycarbonate material microscopically, and which then later in the life of the glasses will lead to star like cracking from the holes on outwards.

Drillseal will fuse those microscopic rips instantly and prevent future problems.

If you have never seen or heard of it and it never happened to you, you have the "special optical guardian angel" hovering over your head.

[DanLiv]

.......so you are lucky. However dull drill bits overheat, to much pressure, and other reasons, and do rip the polycarbonate material microscopically, and which then later in the life of the glasses will lead to star like cracking from the holes on outwards.

If you have never seen or heard of it and it never happened to you, you have the "special optical guardian angel" hovering over your head.

I believe I do. I know of all these problems and have seen them at other places I've worked, and I keep waiting for it to become a problem with my stuff now, but it just doesn't seem to be happening. Thank you optical angels!

[Sledzinator]

The subject of this thread is not the use or sale of an other higher priced product, but to prevent the cracking of Polycarbonate lenses.

I thought the subject of this thread was to promote something that you sell.

[Chris Ryser]

I thought the subject of this thread was to promote something that you sell.

I have made a few optical inventions, a few of them patented, and others not.

OptiBoard is only high ranking optical forum on the internet, and one of the only means where you can freely express your opinion, or learn something new, if it is a good idea or not, and respond under a pseudo name.

If I would have to make a living of other OptiBoard posters, I would have ended up in some poor house on the Canadian Prairies a long time ago.