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mini disaster



Started polishing at the start of the week and got a good polish up then decided to do some pressing of the lap for good contact.dried everything off and pressed it with about 30kg and left for a few hours.long story short, the lap stuck solid and had to be banged off resulting in a few pieces staying stuck to the mirror.could have been a lot worse and the only bad part was a scratch that was left.the bits cleaned off the mirror ok and after redoing the channels again(the pressing tightened then up) I polished again for a bit.Going to do another hour of polishing to see if the scratch lessens.if not then will do some 600 Ali oxide for a bit to get rid of it then polish again.it's a steep learning curve but I've been lucky with the mistakes I've made.

Hopefully an update mid week


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lesson learned there eh Rich, some times it is the best way to learn, we never forget after that, trust me been

there, done that, usually move things every 30 minutes but have left it lots longer with mesh between for

micro faucetting, but 30 minutes is long enough for things to stick like no tomorrow. and as I said they are

not mistakes they are lessons learned,they make it easier the next time around... hopefully the scratch will

polish out, cheers my friend.


Rick M

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Tbh the contact on my lap is good enough that I don't need to press.I'm using a sub diameter lap and all the squares aredull so won't bother pressing anymore.

Daniel no I didn't think of that tbh :(

Had a look today and have two scratches.will polish tomorrow and check to see if the scratches are lessening and then decide if I need to go back to 600.or not.

You live you learn :)

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Bad luck Rich. I had that happen with mine too. I tried the warmth bath method, worked well, but then mine was a lot smaller than yours. Don't suppose you got lucky with the scratch being in the shadow of the secondary?

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The scratch is shallow enough that my finger nail won't pick it up but after doing an hour today I'm not 100% sure it's lessened or not but will have a look in the light tomorrow.

The scratches won't effect performance or the coatings but I will know they are there!!

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I picked up a couple of scratches in the final stages too. The Devil in me made me ignore them as the lap was working so well. Make no difference whatsoever, but as you say, I know they are there.

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Have polished for 4 1/2 hours now and a few more fine scratches are evident now probably just because it's easier to see them now.I can't get them to show up in photos so obviously they are pretty fine.spoke to John Nichol who saidits hard to get it perfect so going to keep polishing for now then have him look when we test it at the mirror making seminar in two weeks.if they are too big I will go back to 600.I have loads of time so its no buggy I just want to make sure it will coat ok

Did a 15min wet press today which went much better so will do that in future if needed :)

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The only time I ever pressed a lap dry I used a fine dusting of acid washed talc over the mirror. That was OK but I usually pressed with a thin wash of CeO and taped the edges to stop it drying out

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I am going to go back to my original 2" overhang stroke instead of the 1/3 through centre as I didn't get scratches doing the initial stroke and still had good contact and even polish

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