Oil over varnish?

[stuartpaul]

As I approach something like the seventh day ( ) and the varnish on the teak box still hasn't dried properly I'm left wondering what to do next?

I think I will wait until it's dry, - will obviously take a few more days (if not then out comes the nitromors!!). Don't fancy trying to sand down tacky varnish!! :shock:

When it is dry I want to put some additional protection on it and am wondering if it's possible to use any form of oil over the varnish? A bit of me says don't be daft, - no chance and the other bit says at least ask!!

So, - can I?!! and if so what?

As I type I also wonder if the first coat does dry will that act as a 'sealer' and subsequent coats will dry normally?

The main learning point here is don't varnish teak unless you have at least 2 weeks to wait for it to dry.

 

[Chris Knight]

You could try wiping on some Japan driers - available from decorators' stores and the like. These help speed up drying times of paints, varnishes, oils etc. They are normally added in small amounts to the finish before applying it but they might work as suggested - try an unobtrusive bit first though!

 

[Sgian Dubh]

One possible problem Stuart is the fact that you varnished over teak, and I'm assuming you used an oil based varnish rather than a water based varnish. Teak is an oily wood and those natural oils can detrimentally affect curing of oil based varnish, and with water based varnish the oils can sometimes prevent the varnish adhering properly water based varnishes being particularly sensitive to impurities underneath them.

It's possible that you may have to end up stripping the varnish and starting again, but one trick you might try is to place the varnished item in a warm and dry environment to see if this will let the stuff properly cure. I suggest this because another cause of problems in curing can be high humidity which slows down the evaporation of solvents thus preventing a proper cure.

If the stuff just won't cure properly and remains soft, and you have to strip here's a technique that should work.

Thin the first coat of varnish by as much as 40-50% and apply a light covering. This puts a lot of solvent on the wood surface which will help drive the natural oils of the wood into the wood thus allowing the first wash coat to cure. Thin a second coat by perhaps 20-30% and apply again. After this has cured you've now created a barrier between the wood and the subsequent coats, and from this point apply and build up film thickness as required.

The above isn't the only method for getting a varnish finish on teak, but it should work.

As to your second question about applying oil over varnish, the answer is that it doesn't work. Pure oils like linseed and tung oil are wood penetrative finishes and don't cure hard. They will not penetrate a cured film finish and just tend to sit on the top forming a gummy mess. Slainte.