wood rib varnish?

[Kurt Colvin]

What are the options for varnish on wood ribs? I thought I read that you
need a 2-part epoxy varnish, but looking in Aircraft Spruce, I see only
Alkyd-type spar varnish and Urethane varnish.

Looking in the "metal" section of the catalog, I see some epoxy primers, but
they don't mention anything about application to wood.

I'm interested in maximum protection for the ribs, what are my options?

thx, Kurt

kco...@calpoly.edu

[Richard Lamb]

three coats of good spar varnish.

--
Richard Lamb
--
http://www.flash.net/~lamb01

[John]

Stitts covering info states that it will dissolve 1 part varnishs and
recommends their own 2 part epoxy varnish (in Aircraft Spruce with
coverings). I that what you are referring to?

Kurt Colvin wrote in message <8ipmlc$p8t$1...@cscnews.csc.calpoly.edu>...

[Charles K. Scott]

In article <8ipmlc$p8t$1...@cscnews.csc.calpoly.edu>
"Kurt Colvin" <kco...@calpoly.edu> writes:

> What are the options for varnish on wood ribs? I thought I read that you
> need a 2-part epoxy varnish, but looking in Aircraft Spruce, I see only
> Alkyd-type spar varnish and Urethane varnish.
>
> Looking in the "metal" section of the catalog, I see some epoxy primers, but
> they don't mention anything about application to wood.
>
> I'm interested in maximum protection for the ribs, what are my options?
>
> thx, Kurt
>
> kco...@calpoly.edu

Polyfiber says that their fabric glue is incompatible with standard
Urethane varnishes, they say it dissolves them. I asked them if you
could apply the two part varnish they recommend over standard varnish,
they replied yes.

So you really only need to coat the surface that will be taking the
glue, not every single item requiring varnish weather protection. This
at least will allow you to keep costs lower.

Corky Scott

[Dreidjax]

>Polyfiber says that their fabric glue is incompatible with standard
>Urethane varnishes, they say it dissolves them.

<snip>
Hi Corky...
This is the one thing that "bugs" me about the "Poly Fiber System". I've also
heard not to use anything without their label (and price tag) on it.

I think the Poly Fiber system is excellent...and in no way am I "beating up" on
it...but...their epoxy spar varnish, for instant...is VERY expensive...and so
is their primers...not to mention having to buy their
"reducers...thinners...retarders
..hardners..etc. Then UPS has to get their "cut" to ship the stuff to ya' with
the HAZMAT "stickup"....I mean "sticker" on it.

Seems to me...as fast as the Poly Tak dries...it wouldnt have time to soften,
much less dissolve a good quality urethane varnish. Of course...the bonding
strength could be affected I suppose. I dont know.

I've always used a good urethane varnish in the past...thinned 50/50 first
couple of coats...then a couple more full strenght. Once cured...for a week or
so...I havnt found a common solvent yet (yet) that would attack it. Even
nitrate and butyrate dopes and their thinners/reducers didnt hurt it.
(no...I didnt try paint stripper, I'am a little crazy...but not stoopid).

It is my suspicion's that Poly Tak's "Base component" is probably Nitrate
cellulose with added compounds to reduce volitility and enhance adhesion and
drying. Maybe these "added" compounds is what attacks urethane varnish. I dont
know...

I think I'll run some tests...or if anyone has some of this stuff on hand and
wants to test it, I would sure be interested in what happens to Poly Tak over a
good grade of urethane varnish, properly applied.

To me...a "good grade" of varnish is a marine quality, U/V blocking type
varnish. Not the "Homer Simpson (or is it Formby?) do it yourself furniture
varnish" that you use to cover "Aunt Matilda's" coffee table.

Just my thoughts,
Dave(supports the local economy, and my wallet loves me for it)Reid

[Ron Natalie]

Dreidjax wrote:
>
> I think the Poly Fiber system is excellent...and in no way am I "beating up" on
> it...but...their epoxy spar varnish, for instant...is VERY expensive...and so
> is their primers...not to mention having to buy their
> "reducers...thinners...retarders
> ..hardners..etc. Then UPS has to get their "cut" to ship the stuff to ya' with
> the HAZMAT "stickup"....I mean "sticker" on it.

They don't insist you use their varnish. They say any two-part epoxy is fine.
You can pick it up from a local marine store, no UPS or other charges.

[Charles K. Scott]

In article <20000621110347...@ng-cj1.aol.com>
drei...@aol.com (Dreidjax) writes:

> It is my suspicion's that Poly Tak's "Base component" is probably Nitrate
> cellulose with added compounds to reduce volitility and enhance adhesion and
> drying. Maybe these "added" compounds is what attacks urethane varnish. I dont
> know...
>
> I think I'll run some tests...or if anyone has some of this stuff on hand and
> wants to test it, I would sure be interested in what happens to Poly Tak over a
> good grade of urethane varnish, properly applied.

Sounds like a good idea. Let us know what you discover.

Corky Scott

[Eddie6870]

Aircraft Finishings Systems uses a water carrier covering system. All of their
products including the reccomended wood sealant are water carrier products that
dont require the hazmat sticker. Their prices are about the same as everyone
elses but suposedly they go farther. Im going to try their practice kit and I
will post what I think. Anyone who has had experience with this system I would
love to hear from. Their website is www.aircraftfinishing.com

[Dreidjax]

>They don't insist you use their varnish. They say any two-part epoxy is
>fine.

<snip>

Well...this is true too...I suppose.

I'am lucky to live in a costal area...with several well stocked marine stores
in the area. I think i'll hit a few and see what they have to offer.

Just because it is a "Two part" varnish...or any other "finishing
system"...doesnt mean it is epoxy. I've read the label on a few, two part
"Epoxy" cans...and they say..."Clean up with mineral spirits". Epoxy???... I
dont think so.

I wonder if a good "Two Part" urethane would standup as well...Well..only one
way to find out...I'll put it to the test.

...and let ya'll know the result.

Dave

[Scrappman]

I've seen a few guys use poly brush for the varnish. It seals well,
builds well, and the glue loves it. Cut the first coat 50/50, then lay it on.
A little goes along way when varnishing wood.
Scrappman

John wrote:

> Stitts covering info states that it will dissolve 1 part varnishs and
> recommends their own 2 part epoxy varnish (in Aircraft Spruce with
> coverings). I that what you are referring to?
>
> Kurt Colvin wrote in message <8ipmlc$p8t$1...@cscnews.csc.calpoly.edu>...

[Richard Lamb]

I used "Defthane" on my wood. It seems to be pretty good
stuff. Kinda pricy, but I didn't need that much.
Beautiful finish.

[Gary]

I, for one, would be interested in knowing your results using urethane varnish.
Thanks
Gary

[la...@larryville.com]

After much discussion about this in other forums, the truth seems to
be that some 1-part varnishes resist the MEK in the Poly-Tak and some
don't. I used a high-quality spar varnish and the Poly-Tak lifted it
right off the wood. I had to back up and go over all of the fabric
contact areas with the Stits 2-part epoxy varnish and that made the
problem go away for good.

Some people swear by certain brands, but I'll only say that you should
TEST your proposed varnish with Poly-Tak and/or MEK before you invest
time and money in any 1-part varnish. I still have epoxy varnish left
over from my last wing, so I'm just gonna play it safe on my current
project and cover the fabric contact areas with it.

Doug
TEAM Tandem AirBike
http://www.larryville.com/dcd/tandem

Dreidjax wrote:
>
> >Polyfiber says that their fabric glue is incompatible with standard
> >Urethane varnishes, they say it dissolves them.
> <snip>
> Hi Corky...
> This is the one thing that "bugs" me about the "Poly Fiber System". I've also
> heard not to use anything without their label (and price tag) on it.
>

> I think the Poly Fiber system is excellent...and in no way am I "beating up" on
> it...but...their epoxy spar varnish, for instant...is VERY expensive...and so
> is their primers...not to mention having to buy their
> "reducers...thinners...retarders
> ..hardners..etc. Then UPS has to get their "cut" to ship the stuff to ya' with
> the HAZMAT "stickup"....I mean "sticker" on it.
>

> Seems to me...as fast as the Poly Tak dries...it wouldnt have time to soften,
> much less dissolve a good quality urethane varnish. Of course...the bonding
> strength could be affected I suppose. I dont know.
>
> I've always used a good urethane varnish in the past...thinned 50/50 first
> couple of coats...then a couple more full strenght. Once cured...for a week or
> so...I havnt found a common solvent yet (yet) that would attack it. Even
> nitrate and butyrate dopes and their thinners/reducers didnt hurt it.
> (no...I didnt try paint stripper, I'am a little crazy...but not stoopid).
>

> It is my suspicion's that Poly Tak's "Base component" is probably Nitrate
> cellulose with added compounds to reduce volitility and enhance adhesion and
> drying. Maybe these "added" compounds is what attacks urethane varnish. I dont
> know...
>
> I think I'll run some tests...or if anyone has some of this stuff on hand and
> wants to test it, I would sure be interested in what happens to Poly Tak over a
> good grade of urethane varnish, properly applied.
>