I believe the WATCO has a small amount of cobalt drier added. You
could speed curing time by adding more drier, such as 1 part in 10 of
Japan drier. I wouldn't add it to the entire container, but to some of
the WATCO in a jar.
That's a lot more drier than normally used. I'd try that on some scrap
first. Also, you can test whether the current coat is cured by sanding
with some 400 grit. If it sands to powder, it is ready for another
coat. If it sands to balls of gunk, then it needs more time.
[...snip...]
There is no "teak oil" in teak oil.
If you can find something called 100% pure teak oil, then you have the
real teak oil. But for your project, that isn't what you want for this
application, unless it is part of a mix you make. See below.
Like almost all wipe on products
(I say all... I personally don't know of an exception) it is just some
type of resin that has been thinned to nothing. Just in case you are
really interested:
http://apps.risd.edu/envirohealth_ms...tcoTeakOil.pdf
Note the MINUSCULE amount of solids in the product. Essentially, it
is a hyper-thinned bottle of BLO with some metallic driers to make
sure it eventually dries. The reason this product offers so little
protection for hard use surfaces is in its own ingredients,
specifically its use of an inferior resin.
[...snip...]
I was curious, so I followed the link. The ingredients listed total to
about 50%.
Hydrotreated distilate, light 21-30%
Solvent naphtha (petroleum) medium aliphatic 1-10%
Linseed Oil, Acid Refined 1-10%
Cobalt Compounds 1%
The actual resin products are not listed, anyway. So I assume they are
within that remaining 50%. Not sure how much of the 50% is varnish,
however. I ver much doubt it is all of the 50%.
But that didn't match the Teak Oil MSDS that is listed at the
Rustoleum web site. There the link to "Teak Oil" provides this entry
(which is titled WATCO Exterior Oil once you follow the link):
Mineral Spirits 8052 -41-3 50.0%
VM&P Naphtha 64742-89 -8 40.0%
So that shows 90% thinner. There are no varnish, oil, or driers listed
at all, just the mixture of thinners.
Here's what Rustoleum lists for natural Danish Oil:
Mineral Spirits 60.0 %
aromatic petroleum distillates 5.0%
Dipropylene Glycol Monomethyl Ether 5.0%
Stoddard Solvent 5.0%
That totals 75%. No varnish, oil or driers listed for this, either,
but from other sources I understand there is linseed oil and some
varnish in the mix. I don't know the ratio.
So from that I'd say WATCO is fairly expensive bottle of thinner with
a little oil and varnish added.
In traditional homebrew oil-varnish mixes the ratio of
thinner-oil-varnish is usually 1-1-1.
If you want an oil-varnish finish that wipes on easy and dries fast, a
Fine Woodworking article has a formula of:
10 parts Pratt & Lambert No. 38 alkyd varnish,
10 parts pure tung oil,
2 parts Japan drier,
2 to 3 parts turpentine as thinner, no more than 5 parts.
Alkyd varnish is getting a bit harder for me to find, most local
sources just sell poly. The rest I can get at local hardware/paint
stores.
That's a lot of drier for the volume. The article says because of the
extra drier, the mix hardens in the container in a few weeks, and that
rags are at high risk of igniting if not dried properly. But is
water/alcohol proof and can be buffed to a gloss or something softer
as desired. Just mix what you need.