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Forgive a Canadian primer inquiry!

S

swixtt

Well Known Member
:eek:hello... i'm just starting out on my 9a and i've read and read about the 'primer wars' and certainly don't want to start anything here.
i feel a little more confused than i originally did. i wasn't really planning on doing any primer cover for the parts as most of the parts are coated from factory already. i realize that Van's has suggested treating the extruded pieces but where do one draw the line. those pieces that will be primed have holes in them, all be it they will be riveted, but that won't stop corrosion will it?
a lot of people say they are going to prime the pieces that are touching. i think there seems to be a lot of areas where pieces are touching. ribs to spar, ribs to skin,etc.

what have other canadian builders done for sources of the primer? rattle cans seem sketchy as i've NEVER seen a autobody guy use them. they even say some contain moisture in them.:rolleyes:
 
As Vans states throughout the manuals "prime if desired". If the aircraft spends its life inland in a dry environment and is hangared, you are possibly wasting your time priming any alclad parts. Prime the non-cladded parts as Vans says to like pushrod tubes and possibly some brackets.

If you are near the coast or in the humid/ rainy part of BC, priming makes more sense and if the aircraft is not hangared, you should probably prime everything with good 2 part primer.

I see many RV builders agonizing over priming, setting up booths, cleaning up and worrying about how to dispose of paint, etching and alodining products. Only a small proportion of builders put 500 hours on in the first 5 years. You have to ask yourself if priming is worth it for you and your climate.

"Prime if desired" really means, most people don't have to IMO. It has become the norm with RV builders though. Looks nice, adds weight and expense, may add resale value. As with all things, there are compromises but we are not building seaplanes here- unless you plan to fit floats.
 
I agree

Another data point..I built a Zenair Zodiac which is made entirely from 6061-T6..I.e the same non alcad stuff that Vans says to prime.

On the Zodiac I primed the mating surfaces only. The airplane was hangered in Western oregon which is WET but not salty wet. After 7 years of regular use i didn't find a hint of corrosion.

On the RV I used the NAPA self etching primer on the mating surfaces only. The NAPA primer seemed to be tougher than the zinc Chromate i used on the Zodiac.

Cheers

Frank
RV7a IO360
 
primer inquiry

ok, not a builder, but just did the 2nd annual on my -9a......here's my 2 bits worth...
inside the rear fuselage, there are tell-tale streaks and stains where condensation ran down the sides and settled in the seams ( mating surfaces)
this is in the desert-like interior ( Penticton)....but lots of temperature variation, not high humidity will do this!
If I were building I'd be tempted to prime all mating surfaces as suggested by those in the know, and perhaps all the lower skins, and ensure there are drain holes at all the low points. (the rattle-can primer is better than NOT doing it, 'cause you didn't want to clean a spray-gun.)
there sure is a lot of dust, oil and **** that accumulates in the corners etc. in just 80 hours!
.....where does it come from...in a 'sealed' metal box??? :)
 
Corrosion X..

......treatment is all you really need. Ask around at some FBO's and you'll more than likely find who fogs it in your airplane and the cost.

I have had my ag airplanes done since we get a lot of chemical drift on them and sometimes in them. The military just recently passed Corrosion X with flying colors on all their tests.

It'll wick between skins at the overlaps and wont add any noticeable weight, plus it's a lot cheaper to get done every three years or so.

Regards,
 
Nice idea!

I like it Pierre,

I assume you can buy it in a spray can and do it yourself at an annual?

Frank
 
thanks guys for all the info and not getting cranky about a newbie asking it.:D

we will be riveting soon and obvoiusly need to make the decision soon about it.
 
Fellow Canadian

Hi Fellow Canadian,

I started out using rattle can primer on the mating parts and soon found it much easier to buy a gallon of two part epoxy primer, an inexpensive HVLP gun and prime most of the bits going into the aircraft. Not a heavy coat but just enough to seal it. Tough as nails once done.

I live in Toronto and although not salty and it will be hangared it will see its share of moisture. Nice not to have to worry about bits you can no longer see.

Getting to grips with the HVLP gun has paid dividends when it came time to paint the interior bits.

Worth the time and effort
 
Yes......

frankh said:
I like it Pierre,

I assume you can buy it in a spray can and do it yourself at an annual?

Frank
Click to expand...

....you can buy a spray nozzle at auto parts stores and stick the suction hose into the bottle of Corrosion X. You do need around 150 psi, though, in order to create a fog. They insert the nozzle through the elevator tips and wingtips and inspection plates. You end up with a thin film of this oily stuff.

Be sure and have the airplane painted before you do this or you'll come to grief with fisheyes.

Regards,
 
Primer

I live in the Deep South.....hot, humid near the Gulf. Evey builder here that I spoke to about this topic suggested Dupont Vari-Prime. I used it inside and out on my tail kit. The entire Assembly came it at 58 pounds and took 2 activated quarts total. I made one pass using 50% overlap......

The peace of mind I have knowing there is primer on the inside is well worth the minimal extra weight.
 
Corrosion-X works!

If I had it to do again, I would not prime except the extruded parts and maybe overlaps. I would fly the plane for a year to get the bugs worked out and painted then FOG that sucker.
 
well i've looked high and low for some primer around here. the napa 7220 isn't something the local Napa guys know about??? is that a US number?
i did find a self-etching primer from Duplicolour(which is distributed by napa and sherwin williams) a slight green in colour... but that is all i can find so far.

we are planning on leaving all of the 2024 alclad alone and only doing the non-alclad pieces.
any north of the boarder with any part numbers from a local supplier?

so far we've match drilled the horizontal stab and now i'm deburring and dimpling soon. :D
 
It is labeled "TECnique Self Etching Primer 7220" and also carries the NAPA & Martin Senour Paints Logos. The number 7220 is also on the front label. For unknown reasons, it is frequently stocked in the "back" of the NAPA store, not in the front with the other primers, even though there are usually other self-etching primers on the front shelves. It often takes a good deal of searching by the sales clerk to find a can. Best bet is a personal visit - sometimes they will let you rummage the stock. The color is definitely gray.
 
I talked to a friend of mine who is an automotive painter and has painted commercial aircraft but now works for General Paint in Vancouver. He gave me a contact for their Industrial and Chemical Coatings Department here in Vancouver. His name is Joshua at 604-940-9868 he should be able to help you make a decision and find suitable coatings.

Bob Parry
 
thanks for that.

today i found a product from ProForm. It is Self-Etching Primer (Grey in colour) PF654.
this comes in a spray can as well as PF652 in 1 gallon cans.

it indicates it is for bare aluminum and metal specifically.

anyone ever heard of this?

similar to Marhyde?
 
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