how long to leave shellac to cure?

[thetyreman]

just wondering how long you should leave it to fully cure before wet/dry sanding, I have read that 7 days is minimum, I have noticed it needs to fully cure or it gums up the paper, so I'm on layer 4 at the moment, it's almost looking filled into the grain, on a pine bookcase, should I use washing up liquid with the water when wet sanding? luckily I have time on my hands as this one is for myself, it doesn't matter how long it takes.

 

[profchris]

I leave 7 days before wet sanding. This is for ukulele finishing, so the shellac is very thin indeed - I might leave a thick coat longer. Humid weather seems to slow curing.

My test is to scrape a less conspicuous area gently with a razor blade - if it's cured enough to sand it feels "crisp" under the blade.

I wet sand using White Spirit as a lubricant - with water there's a risk of making the shellac cloudy.

 

[ED65]

As this is just a pine bookcase can I ask why you're intending to wet-sand it? That's a high-end finishing technique (hence it's use on nice musical instruments). Just for yer average piece of furniture two or three coats brushed on followed by a bit of pad work if you really want to will give you a lovely finish with no abrasion needed.

Orrrr you could use wiping varnish instead for the same look with less effort

 

[Tetsuaiga]

I think it probably depends on the thickness, thicker it is the longer it will need. I usually just pad mine on.

 

[thetyreman]

I think it probably depends on the thickness, thicker it is the longer it will need. I usually just pad mine on.

thanks, I waited 7 full days, and 7 full nights, and it came out great, sanded to 600g wet/dry, it came out great. Next time I will try padding it, or using a water based varnish.