Defect varnish

Dear ,

some few month, we have a random problem with the coating. We have a small ring on the few lens. It's not a classic "point" with a particule on the center but a distortion varnish. We have this problem on CR39, Rx or Stock lenses, 1.6 and 1.67... I use a same varnish for all material
Sometime front or back

We have changed the pipe DI Water, try to changed the power and time IR in the machin... We see the problem at the machin outlet before the finally oven.
We have same problem with 2 tank varnish, same if the varnish is new.

This defect disappears when I remove the lacquer so it's not in the material.

I have try with a new Mix + Méthanol . I have a old Mix alcool (2015) but same problem with the mix product 2016...

I feel that we are putting lot of Mix+Methanol for to compensated the evaporation but the tank Mix+Methanol is not hermetic
Varnish have 1 month and 10° in the tank

I don't see a bubble in the varnish.

Next month, I will try with my other tank. This tank have clean with detergent , normaly I clean the tank and pipe with the flow Méthanol many time.

I take all idea:help:

Regard

Attachment 13071

Hi ,

I up this post... If Does anyone have a fisa program/recipe for to compare? We have not a stiring SCL.
Do you use US in the city water? Because on my City water tank , we have some bubble with US (water degasing)..

What cleaning process are you using before dip coating? How do you remove the surfacing tape? For me it looks like residue of glue not properly removed. You not see it with naked eye. You have on the missing places another surface tension.
Try Olschner Optimal 22.0 in seperate US Tank put you lenses there for 2-3 minutes, rinse them properly and after this go with the basket in NaoH and make your process.

Thank you Rafael,

The problem is also on Stock lens tinting . After polishing, we remove the tape manualy, use Alcool and paper for the first inspection. Before , the hardcoating; all lens are clean with Acetone and Methanol. I don't think residue of glue because we don't see a glue and same problem with the Stock lens.

I don't know but Fisa machin make "too much" surface tension . How can you check if the surface tension are correct?

I have modified my program machin for add 1 min rincing City and Di water whithout US. Because I see a lot buble on the surface lens during the step City Water.
Maybe , where the buble is ; bad surface tension.

If someone has a program Fisa CC20 for to compared the process; please contact me at: v2i@balbi.fr

Regard

Dear,

Do you any idea of the defect on the lens if the heating group (InfraRed) were not correct after Purewater ? Especialy if the IR is too hot . I measure 95° PTC during my test but I ask me if sometime during the process, we have not a varition too much hot. In the oven after coating (120°) is not problem but it's a hot air. IR can it create a local default on the lens? Actually, I have 4 mn in the oven and 4 min for cooling in the other tank befor varnish
We use a "stick" InfraRed on my machin (I see the red filament).

Regard