How long till I can sand/level shellac pre tru oil?

[deepestend]

24 hours ended up being plenty of time. I used some 400 grit sandpaper and kept it plenty wet (with a drop of soap), and sanded lightly with the paper wrapped around a pink eraser for a sanding block. I need to do the neck next.

Question: how smooth does it need to be to get the tru oil totally smooth? The shellac feels very smooth to the touch in places but doesn't look totally smooth in the light? Will I be able to get a totally smooth finish with the tru oil if the shellac isn't 100 visually smooth? I'm happy to put in more elbow grease, I just don't want to sand through at all.

 

[Manton Customs]

You shouldn't wet sand shellac, it is not particularly water proof, so if you didn't get cloudy patches then you're lucky! If it's just the scratches from the 400 you can see then you should be fine to move on, if you want to check wet the surface with naphtha, if the scratches disseaper when wet then they will once oiled.

 

[deepestend]

I'm getting cloudy patches, but I think that it's just scratches. When I wet it down they disappear.

I'll hit it with some naptha and see what happens.

 

[Lonnybass]

I'm getting cloudy patches, but I think that it's just scratches. When I wet it down they disappear.

I'll hit it with some naptha and see what happens.

Cloudy patches sound like witness lines. They'll go away as you build up a hard film.

 

[PDX Rich]

Cloudy patches sound like witness lines. They'll go away as you build up a hard film.

^ This

Luckily, it likely will not take many coats for it to clear up. Just be very careful buffing, as those thin Tru Oil coats can't take much heat buildup before burning though. Also, make sure to let it cure for 3-4 weeks prior to buffing. Some folks will say that you can buff quicker than that, but it is nice to be on the safe side!

 

[deepestend]

Are you guys saying that I should do more passes of shellac? Or can I move in to tru oil?

 

[deepestend]

Are you guys saying that I should do more passes of shellac? Or can I move in to tru oil?

Just went ahead and rubbed in a layer of tru oil after finishing the light sanding of the body. Took away all of the cloudiness and seemed to even out the pebbliness of the shellac. So far, so good!

 

[Means2nEnd]

de waxed shellac is an excellent sealer before any finish. I am doing a bass right now and first step after finish sanding was a heavy coat of shellac and I will sand this weekend and start applying Tru-oil. I have had on a few occasions with swirly burly redwood, claro walnut and maple in places where poly rub and Tru-oil had spots where there was eyes in the wood where the finish would stay gummy and not cure or adhere to the those spots. It was suggested to me by a 30+ year woodworker to seal the wood with a half and half de waxed Shellac alcohol mixture first then sand back and finish as normal to seal the tannins around the burly knotty stuff and adhesion would not be an issue.

I skipped this step a few times and most times I had no issues and three times I had to sand all the way down to bare wood and start over doing what I was told and then it went smoothly. But that's my life in a nutshell. Ask someone who I trust and admire how to do something I know nothing about and they are masters then do the complete opposite and then get pissed off when it goes south. I guess it's not something you have to do and can get away without it most times but for the one time it doesn't you might wish you did just my 2C.