MIMF

Ive gotten to the spiriting off step in french polishing my arch top all went well . its been curing 4 weeks now Yesterday I was fitting the pick guard bracket and scratched the surface thru a couple layers of shellac.Its a small screatch about 1-2 mm length How do I repair this scratch?
Also on the back I found a swirl left from the spiriting off step I missed. How do I fix it ?

I would use a very small artist's brush to slowly fill the scratch and build a few thous above with multiple applications of 1lb shellac. Then follow Dan Earlywine's instruction here: https://www.youtube.com/watch?v=rTVScFJoe24 except use Naptha as a lubricant instead of water.
As far as swirl marks use a swirl remover polish.

This is french polish. That's how you 'fix' it. Your swirls on the back are due to too much stuff in your pad, which should be nearly dry at the end of the process. Certainly not wet enough to leave streaks and swirl marks.

If you let it all dry for a few days you can sand off the swirl marks with 1200 grit wet/dry paper, then put down your final application of french polish to fill in the haze of tiny scratches the fine grit leaves. You shouldn't need anything else but the french polish. If you want a high gloss then practice the process until you get the result you want. I prefer a softer appearance, shiny but not super glossy.

Isn't swirl remover polish for lacquer? I hadn't heard of it used for french polish.

Thank you for the input . I've done lacquer finishes all my life , this is my first french polish. The swirls were in one spot only and they came out with 1200 grit wet sanded with naphtha. The scratch was from my long thumb nail, it didn't go down to white wood, so I was able to sand lightly and filled the scratch with shellac, waited a couple hours and frenched polished (mostly alcohol and a drop of oil),pretty dry. I did this about six times over a 2 day period. luckily my nail went with the grain,mostly, it is filling in nicely .When i'm done it should be invisible to everyone except me.

I have decided to go more satin than gloss.

"This is french polish. That's how you 'fix' it." I guess you ment the french polishing procedures done correctly, mend themselves. Nothing else is necessary. I like that. Thanks I get it now.

Michael Lewis wrote:This is french polish. That's how you 'fix' it.
Isn't swirl remover polish for lacquer? I hadn't heard of it used for french polish.

It works great on shellac that has had time to set up for a week or longer. It's much faster and harder to mess up if you're not very experienced with french polishing.