Gluing in 8 Base wrap sunglass lenses?

[jeffsoptical]

Occasionally I edge 8 base lenses for Wiley X and other sunglass brands. Sometimes I don't have any problems with the lenses popping out at the top of the frame. It is far worse for plastic frames to allow the lenses to pop out. I've tried using super glue at top of the bevel in the frame to hold the lenses in well. The main problem is that super glue turns white when is dries. Does anyone know of a good glue that dries like super glue and dries clear? Latex does work fairly good, but the lenses can still pop out.

Jeff

[obxeyeguy]

Occasionally I edge 8 base lenses for Wiley X and other sunglass brands. Sometimes I don't have any problems with the lenses popping out at the top of the frame. It is far worse for plastic frames to allow the lenses to pop out. I've tried using super glue at top of the bevel in the frame to hold the lenses in well. The main problem is that super glue turns white when is dries. Does anyone know of a good glue that dries like super glue and dries clear? Latex does work fairly good, but the lenses can still pop out.

Jeff

Kidding right????

[victor]

If the lenses are popping out the top middle, you can usually (depending on rx) use a 6 base on Wiley-X. If the frame flattens and the temples spread, you need to go back to the 8 base (but then edge it as 7 base). Also, use a special wrap bevel blade. We use a Horizon edger so that the blades are easy to change out. If you don't use the correct blade, you might as well try to whittle the lens with your pocket knife.

Good luck, and stop sniffing the glue!

[HarryChiling]

The bevel is the problem, especially with any sort of significant minus power. Angle of the bevel on the lens does not match the angle of the bevel in the frame, usually you will find that the lens creates pressure on the back side of the frame which causes the frame to flatten out, hence the bevel at the top popping out. Their are five solutions I have found to your problem:

1. Modified Lens Bevel - This was mentioned in the post above by victor.
2. Modify the frame - You could modify the back side of the frame by taking the back side of the bevel down to alleviate some of the pressure. This can be done with a dremel and some polishing compound.
3. Myoter - this is a lens design where the lens is actually surfaced twice once for prescription, then the second time around for, in this case; thinning out the edges. You will find this design done on the spazio lens.
4. Free Form - since it is the form of the lens creating this issue, then the freedom to not be held to any form ;) would be a solution. Look up AWETECH.
5. Hand Work - Old faithfull, when your girlfriedn or wife won't give you none, turn to the hand job. :D You could always apply the bevel by hand and place it on the correct angle.

Just some of the solutions that are available to you, notice how glue is not in the solutions leave the glue to the numb nuts who don't know any better.

[Campellone]

On any 8 base wrap frame you need to make sure the bevel matches the curve of the frame However, even if you have everything correct it's the back of the frame pushing the lens out. So go to your hand stone and give it a very heavy safety bevel until it matches and doesn't push out. I try to put a front bevel on all my 8 base wraps it gives a nice look. On plastic frames when you do the heavy saftey bevel you would think it would look bad but it really does'nt. The frame hides most of it. Hope this helps. OH Stay away from the glue. What do you do when patient wants to put an updated RX back into there glued frame next year. POOR POOR YOU:finger:

[Fezz]

Add to the above helpful posts:


Your "A" measurement on the lens is probably too big or too long. You may want to try to shave a little off of the nasal or temporal edge.

PS. Glue is for grade schoolers and huffing. Do not use anywhere near eyewear!

[Johns]

Glue is for grade schoolers and huffing. Do not use anywhere near eyewear!

Fezz (and the others) are correct!!!

Don't use glue...this is 2007!! Use Velcro!! That way, when the Rx changes, just grip, rip, and put the new Rx in.

No mess, and no fumes.

[TLG]

Fezz and I are together on this one. Many edgers tend to edge the 'a' measurement wide. On lenses where thickness will allow, try as Fezz said to gradually edge away some of the temporal or nasal edge by hand. If you work slowly at it, eventually you will find a point where the lens lays into the groove and stays. Be sure the lens is slightly oversized before you begin hand edging.

-Tony


Glue?

[AWTECH]

jeffsoptical said:

Occasionally I edge 8 base lenses for Wiley X and other sunglass brands. Sometimes I don't have any problems with the lenses popping out at the top of the frame. It is far worse for plastic frames to allow the lenses to pop out. I've tried using super glue at top of the bevel in the frame to hold the lenses in well. The main problem is that super glue turns white when is dries. Does anyone know of a good glue that dries like super glue and dries clear? Latex does work fairly good, but the lenses can still pop out.

The answers to this question so far have not addressed the actual issue. The problem with wrap 8 base lenses is the design of the 3 axis edgers. NONE of these can follow the curve of the frame relative to the radius of the sphere. You need a 4 or 5 axis edger to have the bevel in the proper position to fit frames designed for 8 base wrap around lenses.

The history of prescription eyewear was based on relatively flat lenses and with a flat lens a 3 axis edger works fine. It is not 100% exact on other than a "0" base lenses. The 3 axis works on non wrap eyewear, but wrap around 8 base does not work properly. All 3 axis solutions are a bandaid.

[HarryChiling]

The 3 axis works on non wrap eyewear, but wrap around 8 base does not work properly. All 3 axis solutions are a bandaid.

Agreed, but I am not aware of such a beast as a 5 axis edger. Untill such a animal exists we are stuck with bandaids. The trick is to pick the right band aid for the job. For example if the frame was plastic you could modify the rame slightly and also bevel by hand or use equipment that will bevel special for wraps. If the frame is metal, you could use the myoter technique, free form, or hand work.

[Fezz]

You need a 4 or 5 axis edger to have the bevel in the proper position to fit frames designed for 8 base wrap around lenses

Does such a beast truly exist? I have heard of MEI edgers and understand that they are a 4 axis edger, but I am probably misinformed.

Or, must the existing edgers have to be modified to accomplish the desired goal. This would be easy if someone was coming from a tool and die or machining background. ;)

[Fezz]

Don't use glue...this is 2007!! Use Velcro!!

Jeffsoptical,

Please excuse our pal Johns. He has become wealthy beyond belief from this business and often forgets that the rest of us are just optical peons.

Filthy rich, aristocrat type Opticians= use Velcro

Poor, downtroden, hopeless, filthy slob Opticians= use Rubber Bands (that we steal from the neighbors morning newspaper)

:cheers::D:cheers::D:cheers:

[KStraker]

You might also try to move the bevel more towards the front. I know it can be difficult to move on a wrap, but in my experience it can be helpful.

[Campellone]

Who makes a 4-5 axis edger?

[AWTECH]

I do not know of one that is commercially available for less than $200,000.

[cocoisland58]

Add to the above helpful posts:


Your "A" measurement on the lens is probably too big or too long. You may want to try to shave a little off of the nasal or temporal edge.

PS. Glue is for grade schoolers and huffing. Do not use anywhere near eyewear!

Yep. My lab optician the "old curmudgeon" hates to do these but has accepted the fact that they will turn up in the lab trays anyhow. He touches up the nasal corner by hand and it works great. Just takes a little extra time. There will be no glueing lenses anywhere in this office.

[Campellone]

jeffsoptical said:

The answers to this question so far have not addressed the actual issue. The problem with wrap 8 base lenses is the design of the 3 axis edgers. NONE of these can follow the curve of the frame relative to the radius of the sphere. You need a 4 or 5 axis edger to have the bevel in the proper position to fit frames designed for 8 base wrap around lenses.

The history of prescription eyewear was based on relatively flat lenses and with a flat lens a 3 axis edger works fine. It is not 100% exact on other than a "0" base lenses. The 3 axis works on non wrap eyewear, but wrap around 8 base does not work properly. All 3 axis solutions are a bandaid.

Then why would you offer a solution that is not resonable to the average joe? Do you think anyone would go out and spend 200,000 for an edger if your not a wholesale lab ? Most of us are not. The solution is posted on this thread you just don't want to believe it!

[AWTECH]

Campellone:

Then why would you offer a solution that is not resonable to the average joe? Do you think anyone would go out and spend 200,000 for an edger if your not a wholesale lab ? Most of us are not. The solution is posted on this thread you just don't want to believe it!

Don't take this the wrong way but if there was simple solution we would not have invested what we have in custom edging equipment.

You can use a Bandaid approach on many 8 base wraps. I am saying to do it properly you need a minimum of a 4 axis edger.

As an example, what looks like a simple frame to fit a prescription lens; the Oakley Gascan: Try it with a -4.00 Rx with an 8 base front curve. Let me know how it looks.

[Campellone]

That would be something I would not personally do in my store. I would send it to oakley because they are better equipted to do that then I am. My cut off in minus powers is -2.25 total power anything higher is more then I can handle. I'm not taking this personally ,but just imagine the guy is using glue!!:drop: So I would think he is not going to buy a $200,000 edger.

[HarryChiling]

So I would think he is not going to buy a $200,000 edger

AWTECH just offered a glimpse into the future, that's all. Their may even be a day when free form generators are found in in store labs, I agree it is not a solution that is available to everyone, but it is a solution all the same.

[griffin]

We process wrap frames up to a -6.00, the pop out of the upper eyewire usually indicates that the a dimension is a bit large. A bit of touch off and they fit fine.

[Campellone]

We process wrap frames up to a -6.00, the pop out of the upper eyewire usually indicates that the a dimension is a bit large. A bit of touch off and they fit fine.

Do you order them on an 8 base curve? If so what lens design do you use?

[griffin]

Spazio lenses up to the -6.00 sph, sv up to a -3.00. We have processed sv to the -6.00 limit, but the carrier is always uncosmetically accepted. Progressives upt to a -3.00 that would look acceptable.

[AWTECH]

Spazio lenses up to the -6.00 sph, sv up to a -3.00. We have processed sv to the -6.00 limit, but the carrier is always uncosmetically accepted. Progressives upt to a -3.00 that would look acceptable.

Our ICE-TECH products offer a much better cosmetic solution. The Spazio is traditional double surfaced to get the edge thickness and has an aspheric front surface. The ICE-TECH solution uses an 6 or 8 base spherical front and then matches an a-toric backside design.

[griffin]

You are correct - Spazio is processed similar to a slabbed lens. Interested in your technology. How are they generated atoric???