Tung Oil Question?

[Ross Lowry]

Will tung oil yellow over time?
Thanks

[Spencer Hochstetler]

I haven't found tung oil to yellow. You do need to make sure you use neat tung oil, not a polyurethane/tung oil mix. Seems like in my past research I remember many tung oils today are sold as a tung oil/poly mix. Polyurethane will, of course, yellow with age.

[Ross Lowry]

Hello Spencer.
I always thought that varnish would yellow over time, but I didn't think that polyurethane would. Maybe I am wrong?
Thank you for your reply.

[Howard Acheson]

There is always an issue about what is meant by "tung oil". There is pure, 100% real tung oil. Like linseed oil, it's a drying oil. Pure tung oil will yellow very little over time but it takes a long time to dry and it is not a protective finish.

There are many "tung oil finishes" which are a faux tung oil. Minwax Tung Oil Finish is one of the more popular. It is an oil/varnish mixture and contains no real tung oil at all. The oil used is linseed oil. Linseed oil is more yellow initially than pure tung oil and will yellow more over time.

To clear up a point, polyurethane is varnish. It's just a varnish made with some or of its resin being urethane. Like all varnishes, poly varnishes are made with a resin and a drying oil. If the oil used in making the poly is linseed oil--and almost all poly varnishes are made with linseed oil--it will yellow over time. The least yellowing varnish is one made with alkyd resin and soya oil. This will be an almost water clear varnish.

[David Epperson]

The least yellowing varnish is one made with alkyd resin and soya oil. This will be an almost water clear varnish.
Is there a brand name to look for to get this?

[Jim Becker]

Is there a brand name to look for to get this?

Pratt and Lamber #38 is a soya based varnish...and very nice. I believe Varathane also has at least one soya based varnish now, too.

[Bonnie Campbell]

Thanks Jim! I'm going to look for some. Always hated putting a 'yellow' coat on a bright white wood.

[Ross Lowry]

Thanks you all for clearing that up for me!