Woke up and couldn't fall back to sleep this morning so I decided to get up
early and try painting again. I was impatient to try the "linseed oil"
idea. But I don't have any linseed oil in the house and nothing's open here
at 3 AM. So on a whim I used some food-grade MTC
(medium-chain-triglyceride) oil I happened to have lying around (from my
days if experimenting with fad body-building food supplements). MTC oil is
a very light oil. But one advantage the MTC oil happens to offer as paint
additive is that it is completely colourless. OTOH linseed oil being yellow,
whilst my paint being white... well you can see where I'm going. Anyway, I
just finished putting up a coat of Varathane, after thinning it with this
MTC oil. And man, what a difference! Although a little on the runny side
for my liking, the problem with the bubbles has now been completely
resolved! By delaying the Varathane setup, and thereby increasing my time
to work with it, I am now able to painstakingly tease out all the bubbles
with my brush before leaving the project to dry. (Also, as a bonus, brush
marks now less prominent. I'll see later if they don't have enough time to
disappear completely on their own before the paint does finally begin to
set.)

Thanks again,
Ken


"Stephen Hull" wrote in message
...
In message fKOif.648108$tl2.646851@pd7tw3no
"Ken Moiarty" wrote:

"Stephen Hull" wrote
[...]
Air bubbles can sometimes be avoided by not over brushing and should be
eliminated completely by adding a little raw linseed oil to ease off
the faster drying properties associated with polyurathane finishing.

Steve.


Hmmm... Raw linseed oil to delay drying, eh... I'll be giving this a
try. I didn't know I could delay the drying time of Varathane,

[snip]

Most people would automatically add turpentine or white spirit into
paint in an attempt to retard the drying process when experiencing
drying problems but these are also classed as driers and although
they'll ease application it doesn't always decrease drying times.

There's a product called Owatrol that will also retard the drying
process.
Unfortunately Polyurethane is proven to set-up too quickly and sometimes
needs a hand to slow it down.

An alternative method would be to use a recognised slower synthetic
thinner perhaps 10% and if possible paint on a cooler day.

Steve.


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