Acoustic Guitar Construction

I put a ding in the side of one of luthier made classicals.
I called him and he said he uses nitro cellulose lacquer.

I went and bought a spray can of Behlen for Stringed Instruments.
Lighly sanded the ding level, cleaned it (just with a rag), masked and sprayed (just lightly)

Lacquer is not adhering to the spot.
Any suggestions?

Is there a possibility a polish containing silicone has been used in the instrument's life since original finishing?

I use Dunlap 65 Guitar polish cleaner. Have to research its content for silicone.
But why would it just not adhere on the sanded spot. The lacquer adheres outside the spot.
Could the sand paper contain silicone?

Do you think I should seal the spot first. I do have a spray can of Behlen vinyl sealer.

Renee Labordus wrote:I use Dunlap 65 Guitar polish cleaner. Have to research its content for silicone.
But why would it just not adhere on the sanded spot. The lacquer adheres outside the spot.
Could the sand paper contain silicone?

Do you think I should seal the spot first. I do have a spray can of Behlen vinyl sealer.

Get a silicone free sandpaper (3M Fre-cut 220 grit) to sand the area, after sanding clean the area with naptha and allow to dry a couple minutes, then spray with your sealer followed by the nitro.

Thank you...I will try that procedure.