Varnish not drying properly

[Doug Hortvet]

All,

Continuing the project of varnishing the exterior face of a mahogany entry door.

Is going well - better than I would have expected, certainly the result of all the helpful
guidance from members of the group - with special thanks to DadiOH.

The first coat of Flagship varnish was thinned 10% (per manufacturer's instructions) with
their T120 brushing thinner and went on well for my first time applying varnish and to a
vertical surface.

The product tech bulletin states time to dry hard is 8-12 hrs @ 90 F.

Four days after application there were areas where the varnish had accumulated that were
still very gummy / tacky - note our max. temps have been in the mid to upper 90's. The
accumulation was approx. 1/32 +/- thick.

Thinned to the max. recommended - do not understand why this would be the case.

Any ideas?

Should remaining coats be similarly thinned or applied with no thinner - although may need
some considering the temperature.

Best time is late afternoon when the humidity is below 50% - of course that is when the
temp is at or near max. for the day.

Thanks again for all the great advice!

Regards,

Doug

[Doug Miller]

Doug Hortvet <dhor...@pdq.net> wrote in
news:stcq189mfhfv7j1s8...@4ax.com:
[...]

> The first coat of Flagship varnish was thinned 10% (per
> manufacturer's instructions) with their T120 brushing thinner
> and went on well for my first time applying varnish and to a
> vertical surface.
>
> The product tech bulletin states time to dry hard is 8-12 hrs @
> 90 F.
>
> Four days after application there were areas where the varnish
> had accumulated that were still very gummy / tacky

Too heavy a coat, or old varnish.

> - note our
> max. temps have been in the mid to upper 90's. The accumulation
> was approx. 1/32 +/- thick.

Too heavy.
[...]

> Should remaining coats be similarly thinned or applied with no
> thinner - although may need some considering the temperature.

Thin it. And don't brush it on nearly so heavy.

[Leon]

So would "Flagship" varnish possibly be a marine type Spar varnish???

If so keep in mind that Spar varnishes never really harden, they will
always remain some what sticky and not harden so that they can flex.

[dadiOH]

Marine, yes; spar, no. I have never had spar (or any other) varnish stay
sticky.

--

dadiOH
____________________________

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[Leon]

You might have that backwards, Spar always remains sticky, so much so
that I will no longer use it for around the house.
When the spar flexes the spar varnish needs to flex with it.

[dadiOH]

Just because it flexes more than non-spar doesn't mean it has to stay
sticky. I kept a foremast, mizzen mast, main boom, main gaff, mizzen boom,
jib boom and yard varnished with spar varnish for close to 20 years. They
were never sticky.

[Stuart Wheaton]

Did you use Epoxy on the door? I have had issues like this going over
epoxy. You have to give the epoxy time for a full cure, and then wash
the amine blush off completely or it will interfere with varnish curing.

Stuart

[Leon]

That simply has not been my results and perhaps the OP's results either.

[Doug Hortvet]

Thanks to all for their comments.

Epoxy was not used - just the varnish on bare wood.

Is clear the first coat was too thick, which allowed the accumulation to form.

Although the accumulation was not all that thick - I would have thought it would have
dried hard after 4 days with max. daytime temps in the mid 90's.

A better description would be gummy instead of sticky - kind of balled up when sanding.

Was going to apply the next coat this afternoon - and it is now raining.

No complaints on the rain - it is sorely needed.

Drier days are sure to come shortly.

Regards,

Doug

[dadiOH]

Doug Hortvet wrote:

> A better description would be gummy instead of sticky - kind of
> balled up when sanding.

Did you stir the varnish well before using? Remember, varnish is resin +
oil + thinner. If the oil wasn't mixed in well that might be your problem
as oil stays sort of gummy even when cured. Stir well, don't shake, don't
make bubbles.

[Doug Hortvet]

Will make certain to sufficiently stir before the next application.

All surfaces were dry and sanded nicely except where the varnish had accumulated - the
result of being applied too heavily.

Thanks again!

Regards,

Doug