Sinn A/R Surgery…

[MDF]

Hello everyone I thought I would share this minor surgery in case anyone else needs to do this sometime. I just purchased a 556A and I knew it had scratches on the A/R so I did some research, saw an article about using a Dremel, was hesitant to do that but in the comments of the article saw a few comments of somebody using Autosol Metal Polish by hand and so I tried it and I’m happy with the results!!!

Before pictures:



Taping it up using the compass to measure an accurate opening for the crystal size in the masking tape.


Results after about half hour of hand polishing, the outer edges were more difficult to polish and took most of the time. I’m happy with the results but based on the last picture may need to polish outer edge for just a few more minutes.





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[hoppyjr]

nicely done. I once used Nevr-Dull wadding polish on Sinn AR and it worked great.

[sierra11b]

it completely removes the AR coating, correct?

i haven't crossed this bridge yet with my u50, but remember it driving me mad with other Sinns.

[dnslater]

I did this years ago on a U1. I just recall it getting a lot worse before it got better and thinking I ruined the crystal.

[MDF]

It just removed the A/R and I was worried doing it but it worked out fine. Most Sinn’s I have and have had are fine but this one was definitely a little messed up and I knew it would bug me I figured worst case would be having to replace the crystal.