Author: "Knox Tool & Die" <knoxtool@...> Time: Thu Dec 20, 2001 7:00 am PST Link
I'm new to the list and just getting started on my tailfeathers. I would like to know if anyone has any advice on what primer to use or not use.
Thanks,
Phil Knox
[Non-text portions of this message have been removed]
Author: "rp10294648" <rpflanze2@...> Time: Thu Dec 20, 2001 7:20 am PST Link
Sure, I love a new primer war.
Don't use one at all. It is a waste of time, expensive, slows down
the building process and doesn't offer squat in terms of corrosion
protection unless you do the entire prep, etch, alodine, and prime
route. What a waste. And the two-part epoxy primers are toxic and
heavy.
Just look inside the wing of a 40 year-old Cessna. Know what you'll
see? That's right, bare Alcad aluminum. (and no corrosion). And
that's from an airplane that has been sitting on the ramp out in the
weather. If you're like me, your RV will get babied in a hangar,
every spec of bug do-do and moisture carefully removed.
For the parts that aren't Alcad, I use a spray can of etching primer
from Sherwin-Williams. Go to one of their "auto" paint stores.
Randy Pflanzer ("Kill the Primer myth")
RV-6 (Sold)
RV-7A (Empennage)
--- In RV7and7A@y..., "Knox Tool & Die" <knoxtool@d...> wrote:
> I'm new to the list and just getting started on my tailfeathers. I
would like to know if anyone has any advice on what primer to use or
not use.
> Thanks,
> Phil Knox
> [Non-text portions of this message have been removed]
Author: "dimplemaster" <johnsiebold@...> Time: Thu Dec 20, 2001 8:23 am PST Link
--- In RV7and7A@y..., "Knox Tool & Die" <knoxtool@d...> wrote:
> I'm new to the list and just getting started on my tailfeathers. I
would like to know if anyone has any advice on what primer to use or
not use.
> Thanks,
> Phil Knox
> [Non-text portions of this message have been removed]
Whooppee!! Dog Pile on Primer Wars!
Hi, Phil! Welcome. I'm new here, too, and jam packed with opinion.
I started construction, with convenience and health in mind,
using a self-etching rattle can primer (Sherwin-Wms 988) then topping
with enamel (Rustoleum Hardhat in rattle cans). I'm switching to
Akzo for big surfaces/components that can be done in large batches in
a booth with proper spray gear. This is not to advocate priming,
surprisingly. With the exception of unalclad Al alloys and steel
(which is powder coated by Van's anyway), priming is not necessarily
necessary, but might be desirable, depending on circumstances and
personal standards.
Right now, popular thought is to prime that sucker until it gasps
for air. I'm priming because I'm paying real strict attention to
deburring, and part of my process is to scrub and smooth all rivet
lines and edges with Scotch-Brite after deburring with a twist
drill. That ruins the alclad, so priming is required for me.
Serendipitously, I get improved overall corrosion control. But
priming adds a huge amount of labor and not trivial cost. If your
beauty will be hangered in a dry climate, priming just isn't
necessary. Besides, to do it right, how are you going to prime all
those shop heads in closed spaces? Dipping the rivet won't do
because cracks will form with upset. That has to keep perfectionists
lying awake at night.
Also, I'm priming for resale purposes in line with popular
thought. BUT... ten years from now popular thought might be "What
fool would unnecessarily prime and add all that weight?". Who's to
say?
If you prime, the chemicals used must seal out moisture and air.
That's basically how corrosion is controlled. I noted in a recent
issue of Sport Aviation that the Boeing 307 was in excellent shape
having used lacquer over primer. No exotic epoxies then. The key is
sealing the metal. Primers like SW 988 are porous by design,
intended to receive a sealing top coat. A primer alone will let
moisture and oxygen migrate to the metal, albeit slowed down. That's
why epoxies are attractive. One coat does it all and they are very
hard.
There have been many moments when I question my sanity for having
started priming (if only I did not Scotch-Brite!) In sum, it's
because of my particular process, a bit of best quality, (popular
thought, again), and other than probably 5 pounds useful lost and
whole bunches of time, I do have improved corrosion control when all
is said and done.
So There! Who's next?
John Siebold
7 wings
Author: Clifford Dow <cdowjr@...> Time: Thu Dec 20, 2001 8:31 am PST Link
December 20, 2001
I'm very opinionated on this topic. I ran out and
spent about $200 on a two-part primer and metal etch
and then read about Tempo brand self etching primers –
in a can! I called Vans and they said this stuff was
fine. It’s normally used for outboard motor lower
units. Part #5606 – about $10/spray can - I found it
at West Marine – but any marine shop should be able to
get it. Also, check out website
www.tempoproducts.com. The two part primers are
extremely hazardous to your health.
There are many ways to make a project very
complicated. I’m quite confident that your typical
RV would last a couple of decades if it were NOT
primed. If it’s primed with Tempo paint it would
likely last at least 4 decades and maybe 5 decades if
primed with some complicated two-part primer.
However, the fumes from the two part primers might
shorten your life a bit. I’m 37 now and I’d rather
concentrate on getting my RV flying NOW and not worry
about what its corrosion state might be when I’m age
77!
The priming discussions I have heard were way too
in-depth – a bit like someone writing a 100 page book
on how to set a basic mouse trap! And then consider
that Vans on the quick build kit just sprays it with
some water-based Sherwin Williams primer – nothing
even close to the quality of the Tempo primers or the
two part primers – so what’s the point in getting so
nit picky with the tail?
Suppose in a couple of decades the tail were corroded,
rebuild it – it might make nice winter project and you
might do a better job the second time around – not a
huge deal here.
To prime the parts for my VS, I just set them on the
ground out front of my garage and sprayed them down –
then brought them in the garage and let them dry next
to the wood stove – very simple – no mess no fuss.
Want to use the two part method? First we put on the
rubber gloves, etch the parts, probably get etch all
over our hands anyway. Let that dry, mix up the
primer, hope the cans don’t get knocked over
accidentally, get out the sprayer and hook it up to
the compressor – make a huge mess and then have to
clean up things – never did like cleaning a spray gun
out. Fun, Fun, Fun, - I’ll leave this method for
those who prefer building to flying.
And for those who might intend to jump all over me for
these thoughts as a finishing note I would point out
again that Vans said the Tempo process was fine.
Sincerely,
Cliff Dow Jr,
Cdowjr@y...
P.S. anyone want to buy my two-part primer? I lost the
receipt - $50 and it’s yours!
--- Knox Tool & Die <knoxtool@d...> wrote:
> I'm new to the list and just getting started on my
> tailfeathers. I would like to know if anyone has any
> advice on what primer to use or not use.
> Thanks,
> Phil Knox
> [Non-text portions of this message have been
> removed]
__________________________________________________
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Author: Clifford Dow <cdowjr@...> Time: Thu Dec 20, 2001 8:35 am PST Link
I'm with you.
However, the Tempo primer process mentioned in my
previous e-mail is so easy to do, I cannot imagine why
one would not do it. Perhaps think about resale
value - I would think the $30 it might cost for three
spray cans and the extra hour it might take to spray
the entire tail kit might be worth it.
cliff jr
cdowjr@y...
--- rp10294648 <rpflanze2@h...> wrote:
> Sure, I love a new primer war.
>
> Don't use one at all. It is a waste of time,
> expensive, slows down
> the building process and doesn't offer squat in
> terms of corrosion
> protection unless you do the entire prep, etch,
> alodine, and prime
> route. What a waste. And the two-part epoxy
> primers are toxic and
> heavy.
>
> Just look inside the wing of a 40 year-old Cessna.
> Know what you'll
> see? That's right, bare Alcad aluminum. (and no
> corrosion). And
> that's from an airplane that has been sitting on the
> ramp out in the
> weather. If you're like me, your RV will get babied
> in a hangar,
> every spec of bug do-do and moisture carefully
> removed.
>
> For the parts that aren't Alcad, I use a spray can
> of etching primer
> from Sherwin-Williams. Go to one of their "auto"
> paint stores.
>
> Randy Pflanzer ("Kill the Primer myth")
> RV-6 (Sold)
> RV-7A (Empennage)
> --- In RV7and7A@y..., "Knox Tool & Die"
> <knoxtool@d...> wrote:
> > I'm new to the list and just getting started on my
> tailfeathers. I
> would like to know if anyone has any advice on what
> primer to use or
> not use.
> > Thanks,
> > Phil Knox
> > [Non-text portions of this message have been
> removed]
__________________________________________________
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Check out Yahoo! Shopping and Yahoo! Auctions for all of
your unique holiday gifts! Buy at http://shopping.yahoo.com
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Author: "Gary Powers" <gpowers14@...> Time: Thu Dec 20, 2001 8:39 am PST Link
Got to agree, Randy! I've got a '64 Mooney and there is no corrosion at all on the alclad parts (or anywhere else for that matter!).
Gary Powers
-7A N317LG (reserved)
----- Original Message -----
From: rp10294648
To: RV7and7A@yahoogroups.com
Sent: Thursday, December 20, 2001 9:20 AM
Subject: [RV7and7A] Re: Aluminum Primer
Sure, I love a new primer war.
Don't use one at all. It is a waste of time, expensive, slows down
[Non-text portions of this message have been removed]
Author: "Daniel Masys, M.D." <dmasys@...> Time: Thu Dec 20, 2001 8:59 am PST Link
At 10:32 AM 12/20/2001 -0600, you wrote:
>Got to agree, Randy! I've got a '64 Mooney and there is no corrosion at
>all on the alclad parts (or anywhere else for that matter!).
>
>Gary Powers
But just to add a little fuel to the fire, I owned a 1973 Cessna 182 for
five years during which it did develop some surface corrosion inside the
wings, a fact I knew well from opening and closing the bird for
owner-assisted annuals every year. It was something of a special case,
living in a hangar about 100 yards from the water on Kent Island in the
Chesapeake Bay, so it was exposed to salt air. But corrosion really does
happen, even to Alclad surfaces.
This problem was stopped in its tracks by a fogging with ACF-50,
however. So my current approach to building is to prime all non-Alclad
surfaces with rattle can primer (NAPA 7220 self etching primer; scuff with
Scotchbrite first or it doesn't stick very well even to clean aluminum),
and to prime any surface that will be closed and not available for
inspection, such as the inside of elevators and HS. For inspectable areas
such as the wings, I am priming the ribs and leaving the skins bare.
Just one approach, not necessarily better or worse than any other.
-Dan Masys
-7A wings
Author: "manlosangeles" <manlosangeles@...> Time: Thu Dec 20, 2001 9:30 am PST Link
Here's what I (don't) know so far about priming:
- You're better off priming, right? Without it, you *might* not get
corrosion; with it you *won't* get any.
- Resale is enhanced if you prime.
- Van's wash primer used on QB wing skins ain't doin' jack to stop
corrosion, according to the primer's manufacturer. Van's uses it cuz
it's cheap. (what someone said Van's said when they asked them about
it).
- Epoxies are best but they do add weight. Paint guns are easy to
clean up if you use something called a PLASTIC BAG in the reservoir!
- Alclad is destroyed during some operations like deburring, etc.
so...why not prime?
- I saw a 50 year old Beechcraft kept 1-3 miles from the ocean all
it's life with no corrosion at all. But RVs use 2024 and it's not as
corrosion resistant as 6061. Don't know what the Beechcraft was made
with. I did see some 15-20 year old raw 2024 Alclad sheeting that
was in very sad shape from just sitting around a hangar (near that
old Beechcraft)...
- so if I end up building an RV3, to save weight I'll probably prime
judiciously, without epoxies. But if it's an RV7A (which looks like
it's gonna be), I'm going with epoxy. UNLESS OF COURSE I CHANGE MY
MIND AFTER READING MORE OF THESE GREAT POSTS ABOUT PRIMERS...WHICH
WILL PROBABLY HAPPEN SO DISREGARD EVERYTYING I'VE JUST WRITTEN.
G
--- In RV7and7A@y..., "Knox Tool & Die" <knoxtool@d...> wrote:
> I'm new to the list and just getting started on my tailfeathers. I
would like to know if anyone has any advice on what primer to use or
not use.
> Thanks,
> Phil Knox
> [Non-text portions of this message have been removed]
Author: "rp10294648" <rpflanze2@...> Time: Thu Dec 20, 2001 9:54 am PST Link
The two reasons are weight and effectiveness. One poster said that
he thought the weight gain was 5 pounds. Not likely. A good
exterior paint job weighs 10 to 15 pounds conservatively. I look at
all the parts I coated with primer on my RV-6 and cringe at the
weight gain. Others have said it before, keep it light and it will
keep you happy.
That aside, just how effective is priming considering the offsetting
weight gain? As it turns out, not very. The place you are likely to
get corrosion is under rivets. This happens to be the very place you
probably don't have any primer. The rivet isn't primered and the
edges of the hole in which the rivet sits is not primered. So all
that expanse of primer on perfectly Alcad aluminum provides you with
a weight gain for little or no benefit.
But hey, if it makes you sleep better at night, go for it. It's your
bird.
BTW, the impact on resale is insignificant. If someone likes your
airplane, it won't matter one hoot whether it is primered inside or
not. I content that you can hide a lot of aluminum abuse under a
coat of primer.
Randy Pflanzer
RV-6 (Sold)
RV-7A (Empennage)
--- In RV7and7A@y..., Clifford Dow <cdowjr@y...> wrote:
> I'm with you.
> However, the Tempo primer process mentioned in my
> previous e-mail is so easy to do, I cannot imagine why
> one would not do it. Perhaps think about resale
> value - I would think the $30 it might cost for three
> spray cans and the extra hour it might take to spray
> the entire tail kit might be worth it.
> cliff jr
> cdowjr@y...
Author: Tom Caruthers <tomcaruthers@...> Time: Thu Dec 20, 2001 1:27 pm PST Link
OK. I'll pile on with everyone else.
Use Sherwin Williams 988 on the bare aluminum only.
If a person really wanted to worry about corrosion,
that person would worry about the aluminum rivets that
hold the steel parts like the hinge brackets to the
spars. There should be galvanic corrosion between the
steel and aluminum. Ever seen a house where someone
used steel gutters along with aluminum gutters? It's
not pretty.
Oh well. If I worried about all of this, I wouln't
get anything done.
Tom
--- Knox Tool & Die <knoxtool@d...> wrote:
> I'm new to the list and just getting started on my
> tailfeathers. I would like to know if anyone has any
> advice on what primer to use or not use.
> Thanks,
> Phil Knox
> [Non-text portions of this message have been
> removed]
__________________________________________________
Do You Yahoo!?
Check out Yahoo! Shopping and Yahoo! Auctions for all of
your unique holiday gifts! Buy at http://shopping.yahoo.com
or bid at http://auctions.yahoo.com
Author: "dimplemaster" <johnsiebold@...> Time: Thu Dec 20, 2001 3:07 pm PST Link
I'm baaack. Don't you just love primer wars.
Rivets really bother me. It's one of the weak links in pro-primer
arguments. I asked Van's about rivet and hole corrosion. Their
answer, which jives with my metallurgical understanding, is that a
properly formed rivet creates an air-tight seal about all interfaces
in/around the joint, ergo, no corrosion. It's the same idea behind
why crimped electrical connections are so reliable - no air gets to
the interface.
As far as where corrosion starts, my 27 year old 172 has a bit of the
stuff, just about everywhere: panels, ribs, rivets. It hasn't
started under rivets. The worst area is above the cabin headliner
where moisture tends to accumulate on the sheets.
And with that, I have a splendid (I think) suggestion. Don't mess
with priming. If corrosion worries you, then fog with Corrosion-X
occasionally. That's what I did with the 172 after acquisition and
corrosion stopped dead in its tracks. It certainly will act as a
preventative. The post-application leakage is not all that big a
deal. And your controls are oh so smooth!
John Siebold
Author: "Bev Sinkbeil" <bevandjim@...> Time: Thu Dec 20, 2001 9:15 pm PST Link
NAPA self-etching for 5.40 a can works great.
-----Original Message-----
From: Clifford Dow <cdowjr@y...>
To: RV7and7A@yahoogroups.com <RV7and7A@yahoogroups.com>
Date: Thursday, December 20, 2001 8:31 AM
Subject: Re: [RV7and7A] Aluminum Primer
>December 20, 2001
>
>I'm very opinionated on this topic. I ran out and
>spent about $200 on a two-part primer and metal etch
>and then read about Tempo brand self etching primers –
>in a can! I called Vans and they said this stuff was
>fine. It’s normally used for outboard motor lower
>units. Part #5606 – about $10/spray can - I found it
>at West Marine – but any marine shop should be able to
>get it. Also, check out website
>www.tempoproducts.com. The two part primers are
>extremely hazardous to your health.
>
>There are many ways to make a project very
>complicated. I’m quite confident that your typical
>RV would last a couple of decades if it were NOT
>primed. If it’s primed with Tempo paint it would
>likely last at least 4 decades and maybe 5 decades if
>primed with some complicated two-part primer.
>However, the fumes from the two part primers might
>shorten your life a bit. I’m 37 now and I’d rather
>concentrate on getting my RV flying NOW and not worry
>about what its corrosion state might be when I’m age
>77!
>
>The priming discussions I have heard were way too
>in-depth – a bit like someone writing a 100 page book
>on how to set a basic mouse trap! And then consider
>that Vans on the quick build kit just sprays it with
>some water-based Sherwin Williams primer – nothing
>even close to the quality of the Tempo primers or the
>two part primers – so what’s the point in getting so
>nit picky with the tail?
>
>Suppose in a couple of decades the tail were corroded,
>rebuild it – it might make nice winter project and you
>might do a better job the second time around – not a
>huge deal here.
>
>To prime the parts for my VS, I just set them on the
>ground out front of my garage and sprayed them down –
>then brought them in the garage and let them dry next
>to the wood stove – very simple – no mess no fuss.
>
>Want to use the two part method? First we put on the
>rubber gloves, etch the parts, probably get etch all
>over our hands anyway. Let that dry, mix up the
>primer, hope the cans don’t get knocked over
>accidentally, get out the sprayer and hook it up to
>the compressor – make a huge mess and then have to
>clean up things – never did like cleaning a spray gun
>out. Fun, Fun, Fun, - I’ll leave this method for
>those who prefer building to flying.
>
>And for those who might intend to jump all over me for
>these thoughts as a finishing note I would point out
>again that Vans said the Tempo process was fine.
>
>Sincerely,
>Cliff Dow Jr,
>Cdowjr@y...
>P.S. anyone want to buy my two-part primer? I lost the
>receipt - $50 and it’s yours!
>
>--- Knox Tool & Die <knoxtool@d...> wrote:
>> I'm new to the list and just getting started on my
>> tailfeathers. I would like to know if anyone has any
>> advice on what primer to use or not use.
>> Thanks,
>> Phil Knox
>> [Non-text portions of this message have been
>> removed]
>__________________________________________________
>Do You Yahoo!?
>Check out Yahoo! Shopping and Yahoo! Auctions for all of
>your unique holiday gifts! Buy at http://shopping.yahoo.com
>or bid at http://auctions.yahoo.com
>Van's Air Force - World Wide Wing
>www.vansaircraft.net
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Author: "rp10294648" <rpflanze2@...> Time: Fri Dec 21, 2001 6:09 am PST Link
John, I think you've offered an excellent suggestion.
My perspective on the primer war thing, and why I'm a little bit over
the top, is to make a simple point. The way that "most" builders
apply primer, they are doing very little in the way of effective
corrosion protection. They will religiously prime parts using way
too much primer, but will scratch the part during final assembly.
Alcad surfaces will receive a great coat of primer but unprotected
edges will receive little or no primer at all. It's all the little
things that add up. Rivet holes will be unprotected especially the
back side of dimpled holes.
You can (and some do) unnecessarily obsess over the whole primer
issue. Use that energy to get your project completed and forget the
whole primer argument. Besides, you'll have plenty of opportunity to
obsess over other aspects of the project like the canopy, wiring,
paint, avionics, firewall forward, fiberglass finishing, and the like.
Randy Pflanzer
RV-6 (Sold)
RV-7A (Empennage)
--- In RV7and7A@y..., "dimplemaster" <johnsiebold@a...> wrote:
> I'm baaack. Don't you just love primer wars.
>
> Rivets really bother me. It's one of the weak links in pro-primer
> arguments. I asked Van's about rivet and hole corrosion. Their
> answer, which jives with my metallurgical understanding, is that a
> properly formed rivet creates an air-tight seal about all
interfaces
> in/around the joint, ergo, no corrosion. It's the same idea behind
> why crimped electrical connections are so reliable - no air gets to
> the interface.
>
> As far as where corrosion starts, my 27 year old 172 has a bit of
the
> stuff, just about everywhere: panels, ribs, rivets. It hasn't
> started under rivets. The worst area is above the cabin headliner
> where moisture tends to accumulate on the sheets.
>
> And with that, I have a splendid (I think) suggestion. Don't mess
> with priming. If corrosion worries you, then fog with Corrosion-X
> occasionally. That's what I did with the 172 after acquisition and
> corrosion stopped dead in its tracks. It certainly will act as a
> preventative. The post-application leakage is not all that big a
> deal. And your controls are oh so smooth!
>
> John Siebold