do finishes expire? and refrigerating glue?

[Matthew N. Masail]

does finishing oil and wax go bad? I got some birthday cash and was thinking of stocking up on some new finishes. I've never tried tung oil, danish oil, finishing oil. I also need some wax and sanding sealer.

I live in a warm climate, during the day in summer my workshop can be around 80-90F and more. would I benefit from keeping glue in the fridge? I'm only concerned about it for plane making. are there any side effect?

Thanks a lot,
Matthew

[Andrae Covington]

does finishing oil and wax go bad? I got some birthday cash and was thinking of stocking up on some new finishes. I've never tried tung oil, danish oil, finishing oil. I also need some wax and sanding sealer.

I live in a warm climate, during the day in summer my workshop can be around 80-90F and more. would I benefit from keeping glue in the fridge? I'm only concerned about it for plane making. are there any side effect?

Thanks a lot,
Matthew

The short answer is yes.

Varnishes and oils are affected by contact with oxygen. They will develop a skin on the surface and/or eventually the entire contents will turn into a solid gel. If it's still at just the skin phase, you can strain that off and get to the liquid underneath. Collapsible bottles (http://www.leevalley.com/US/wood/page.aspx?p=20052&cat=1,190,44133) and argon gas (http://www.leevalley.com/US/wood/page.aspx?p=30268&cat=1,190,44133&ap=1) can extend the shelf life.

Most glue manufacturers state a shelf life of one to two years at "room temperature" in sealed containers. PVA glues like Elmers or Titebond II eventually become thick and stringy or gel-like. Polyurethane glues like Gorilla react with moisture and start to solidify. Liquid hide glue looses its holding strength over time, but there's no visible clue as it sits in the bottle, so either test with scraps or adhere to the expiration date. The other glues can last longer than the stated expiration; if they still look ok, they probably are. As far as I know you can store all the standard glues in the fridge.

[glenn bradley]

After a few throw-out sessions I realized that I save money overall by buying the more expensive smaller containers as needed. DNA and mineral spirits I use a lot and buy gallons. Other use lacquer thinner and BLO the same way. Analyze your consumption and adjust for that ;-)

[John Coloccia]

Lacquer and epoxy last forever, as far as I can tell. Refrigerate or freeze hot hide glue. Refrigerate super glue if you must. Buy/mix everything else in small quantities as needed, and toss them when they get old. I've been burned numerous times with bad glue and bad finishes. It's just not worth it for the small quantities most of us are using. Just my opinion.

[Matthew N. Masail]

how long should the oils last? a year, two, five? ...

[Jim Belair]

In my experience BLO is good for many years, like 10+.

With varnish and polyurethane, I displace oxygen using propane. Stick the head of the propane torch in the part can and use the lid to partially block the opening. Open the propane valve for several seconds , then shut off. Propane is slightly heavier than air so will sink into the can. I then put a sticker on the lid indicating that it contain propane. Obvious precautions- don't over do it and don't do near a pilot light or sparking device.

[Matthew N. Masail]

please excuse my “newbebness”, but what is BLO?

Thanks for the propane tip! if I understand correctly oil will only go bad if it contacts oxygen, so a sealed container should last many years?

[Sam Takeuchi]

Boiled linseed oil. There are chemically treated BLO and naturally boiled (or heated) linseed oil. They are not exactly the same thing, but called the same. I would assume they react differently over storage duration.

[Rick Fisher]

I have had a can of wipe on poly go bad.. I think it had been opened about 1-1/2 years before I used it again.. Sigh..

I would not stock up on finishes.. I would stock up on wood..