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+-- Thread: Do finishes go bad? (/showthread.php?tid=7104156)
Do finishes go bad? - bubba - 09-23-2015
Hey all,
I have a question about some finishes that I have had for a while. I used to work very close to the Rockler outlet store. Every summer they used to have a clearance sale to get rid of all of their returns, 2nd's, overstock, etc. The short of it is that I picked up a LOT of finishes for pennies on the dollar. Deft laquer for 80 cents per quart, tons of General and Watco stains and top coat quarts for even less, 2 lb jars of shellac flakes for a buck. You get the idea.
Problem is, I am just a weekend warrior when it comes to woodworking, and not a particularly productive one at that. So I have a lot of containers of finish that are around 8 years old. Some are open, some not. None of the containers have any 'use by' date that I could see.
I am in the middle of a project where I want to apply General Danish Oil followed by a satin poly. I have been experimenting with finish combinations, and this combination gives me the protection that I want and it closely matches some existing cabinetry.
So, I have been using these finishes for shop projects and other small items, but I want to make sure that the Danish Oil and wipe-on satin poly are ok to use on this project.
What say you all? Are these finishes ok to use? Is there a way to test that the finish is ok?
Thanks in advance for any help.
Re: Do finishes go bad? - daveferg - 09-23-2015
I've only had problems with old finishes that have been opened. If the lid seal is tight, might be worth trying out on some scrap wood first----biggest problem in my experience are finishes that never seem to dry----horrible if it's on a piece you've worked long and hard on---hence testing on scrap.
Re: Do finishes go bad? - JR1 - 09-23-2015
Shellac flake is pretty much forever so long as it dissolves (flake should leave little residue) and dry in ~30min at room temp if it is good. Waterbornes are forever if they have not evaporated.
In any case test it1
Re: Do finishes go bad? - Dennis Puskar - 09-23-2015
Finishes that I opened 6 months don't apply as well as a fresh one, so yes I would say they go bad.
( I have heard other people say they have to go out and buy a fresh can of finish.)
Re: Do finishes go bad? - fredhargis - 09-24-2015
Jewitt wrote an article that I think was in FWW about shelf life of finishes. He didn't mention solvent lacquer (as I recall) but pretty much said that oil based finishes left unopened had an almost indefinite life. My experience with solvent lacquer seems to suggest it's also very long. He did say that waterbornes started to go bad after 2 years, regardless of the whether they've been opened or not. That's not what I've seen, but he knows a lot more about this than I, and I take him at his word. Once opened, oil based finishes (all of them) start to react with O2 and their life is ending. So the once opened items you may want to be very careful when using and prove them good first (test piece). The shellac flakes keep a very long time, and refrigeration helps a lot. I also refrigerate mixed shellac, and opened cans of varnish to get a little more life out of them. Lastly, there is a new product I've been wanting to try that may save finishes, but haven't yet. I have the bags, just haven't used any oil based varnish recently, but the reviews seem to be positive.
Re: Do finishes go bad? - Howard Acheson - 09-24-2015
>>>> What say you all? Are these finishes ok to use?
Only way to know is to test it on some scrap from your project. See if it dries/cures in the expected time.
It's foolish to take chances on old finish. After all, the finish is what folks see, not the joinery.
Re: Do finishes go bad? - bubba - 09-24-2015
Howard Acheson said:
>>>> What say you all? Are these finishes ok to use?
Only way to know is to test it on some scrap from your project. See if it dries/cures in the expected time.
It's foolish to take chances on old finish. After all, the finish is what folks see, not the joinery.
So as long as the finish dries or cures normally, I shouldn't be in for any surprises a year or 5 or 10 down the road?
The test pieces that I have done seem to be fine. I was mostly worried about failures down the line...
Re: Do finishes go bad? - woodsman83192 - 09-24-2015
You say refrigeration helps for shellac flakes to keep their shelf-life. Would that work for opened oil based and waterborne finishes as well?? Have a shop fridge that's empty, maybe a good place for poly? Just an idea...
Jake
Re: Do finishes go bad? - fredhargis - 09-24-2015
That's what I do, but I can't gauge what the effect is. Right now I have a can of varnish I opened on 12-1-14 in our fridge and it's still good. But that can is about 80% full. It seem s like the lower the level in the can, the shorter the time it keeps. It's a fairly imprecise process. I do date all the cans the day I open them with a Sharpie, but I don't keep records of how long they last.
Re: Do finishes go bad? - woodsman83192 - 09-24-2015
fredhargis;
Anecdotal's are good enough for me. I'll have to move them to the fridge. Wish I could use up the cans more quickly!!