oil finish still sticky after several days

[Jean-Philippe Regnard]

Hi,
i used an oil finish on my guitar and the three first coats goes well. I let dry several days between each coats.
But since the fourth coat, after 15 days, the surface of the guitar stay sticky. I'm even be able to mark the finish just with little taps with the flat of my nails!!!
Do I have to wait longer for drying (the last few weeks have been very wet), reapply oil and wipe off immediately (reactivate the solvent) or sand everything and start again?
Thank you for your help!!!
Best regards,

[Barry Daniels]

Need some details: What kind of oil? Brand name? What kind of wood is the guitar made from?

[Jean-Philippe Regnard]

it's the "penetrating oil finish" made by Crimson Guitars.
It's on a swamp ash guitar body.

[Barry Daniels]

I am not familiar with their finish, but if it is advertised as a "penetrating" oil then it may not be a "drying" type of oil finish. I think what may have happened is that you got the wood saturated with the oil on the first 3 coats and then the last coat is just sitting on top and not drying. You should not expect a penetrating oil to be capable of creating a film on top of the surface.

Since you have waited 15 days after the last coat, you can assume that it may never dry hard. I would take a rag and dampen it with a bit of thinner (mineral spirits, turpentine, paint thinner, etc.) and wipe the surface until it looks clean.

[Alain Lambert]

From the manufacturer/seller web site:

Apply the initial coat to finely sanded wood, at least, 240 grit. Apply with a brush, soft cloth or rub in with 1200 grit wet and dry paper. Leave to cure for 5 to 10 minutes, or until sticky. Rub off the excess with a clean cloth and leave to cure completely before applying the next coat.

I find that the best result is achieved rubbing the oil in with 1200 grit wet and dry paper and then wiping away all the excess until you have a finish that is dry to the touch. A few coats like this followed by, if you fancy, some wax. I like heating up the cloth I apply wax with so it goes easier. You shouldn't need to key the surface before applying more coats but if you want to just rub back a little bit with more 1200 grit wet and dry using a little of the oil as a lubricant. - Ben Crowe

I think your wood is saturated, I would whipe the sticky excess may be by sanding with 1200 wet/dry with a little more oil, then whipe dry. Let cure for a few days then apply some wax as recommended.
Disclaimer: I have not experience with that particular oil!