How long does BLO outgas?

[®smpr_fi_mac®]

I have a two boxes in my shop that I applied three coats of BLO to in mid December.  They *still* stink of BLO.  That's with the lids off to allow for air movement.  How long should this last?  I'm aware that BLO should be fully cured in a few days, so I'm confused.

If I put a sealing coat of shellac over them, will that stop the outgassing?

[FS7]

I've had this happen before when I was a little too aggressive with the application. It's happened with spar varnish as well as danish oil. 

I don't know exactly what is happening, but I think when I apply another coat I'm doing it (intentionally or not) before the surface is ready. This retards drying or curing of the underlying coat. This means it can only dry through additional layers of finish (whatever it is) or through the wood, which is the problem. In my case it was tacky for weeks and smelled for months. One of them, actually, was a spar varnish finish on an outdoor box, and it still smells a bit three months later.

[BaileyNo5]

I have a two boxes in my shop that I applied three coats of BLO to in mid December.  They *still* stink of BLO.  That's with the lids off to allow for air movement.  How long should this last?  I'm aware that BLO should be fully cured in a few days, so I'm confused.

If I put a sealing coat of shellac over them, will that stop the outgassing?

I have a rule of thumb - never put any kind of finish inside a box.  It's almost impossible to get the smell out.  If it's a box for the shop, it's not a big deal.  But if it's a piece of furniture, and it stays closed a lot, you will likely smell the finish for years.

Occasionally I will bend this rule and put a single coat of shellac inside a box.  But not often.

[Stwood_]

I have a rule of thumb - never put any kind of finish inside a box.  It's almost impossible to get the smell out. 

+1

I use it mostly for tool handles and such. Never anything that's enclosed like a box.

[giradman]

I have a rule of thumb - never put any kind of finish inside a box.  It's almost impossible to get the smell out.  If it's a box for the shop, it's not a big deal.  But if it's a piece of furniture, and it stays closed a lot, you will likely smell the finish for years.

Occasionally I will bend this rule and put a single coat of shellac inside a box.  But not often.

Agree w/ previous posters - i.e. never use an oil finish nor BLO (or similar drying oils) inside a box, especially one that may contain clothes - your options are: 1) No finish at all; 2) Shellac; or 3) Waterborne finish - another option in a few projects that I've made is to line the insides w/ bare cedar - Dave

[®smpr_fi_mac®]

Ah. I've learned something new today. From now on, a waterborne finish inside, oil outside.

[fredhargis]

Shellac and maybe even NC lacquer works on the interior as well. But if using any oil based finish on the interior, it will smell for a very long time. Worse, if the box contains clothes or food they may well pick up that smell.

[Admiral]

Ah.  I've learned something new today.  From now on, a waterborne finish inside, oil outside.

I made the same mistake 25 years ago.  Shellac is you friend here, get yourself some flakes, a cheap digital kitchen scale from Walmart and DNA and you can make small batches as needed.  Mixed shellac goes bad after 60-90 days or so, which is why I haven't gone with Zinnzer in decades.  Great finish and great sealer.

[joespehar]

I made the same mistake 25 years ago.  Shellac is you friend here, get yourself some flakes, a cheap digital kitchen scale from Walmart and DNA and you can make small batches as needed.  Mixed shellac goes bad after 60-90 days or so, which is why I haven't gone with Zinnzer in decades.  Great finish and great sealer.

That special Zinnser unwaxed shellac that's supposed to last for at least a year:  it really does.

[Ed in NC]

To add a short note...do not use any type of oil finish on ANY part of the interior of furniture. It will be as bad as if you just put it on a drawer. Don't ask how I know....one of my first disasters with finishing years ago.