Recommended "Rattle Can" Primer - Page 2

jcoloccia · #11 07-06-2007, 02:26 PM

The best I've found is Tempo 20420 Zinc Chromate (5606 from Redden marine supply). This is the YELLOW one. The Green Zinc Chromate is garbage...the yellow goes on very nicely. After a couple of days, it is hard as a rock.

Only my opinion but I'm very satisfied.

wingtime · #12 07-06-2007, 02:29 PM

I've had good luck with the NAPA or the Sherwin Williams self etching stuff. I have used the SEM and I like the way it looks. However even in thin coats it's adheasion is rather poor for a self etching primer in my opinion. Oh and it's really pricy!

I've even gone as far as putting on a light coat of the SW stuff and then top coating it with some zinc chromate.

N62XS · #13 07-06-2007, 03:21 PM

Several questions come to mind while viewing this thread.

Does anyone make a self-etching epoxy rattle can primer?

I've been using Alumiprep33/Alodine 1201/PPG DP40, spraying the two-part DP40 with a Preval sprayer. This is expensive.

Do the other primers listed provide the same "encapsulation" allegedly provided by epoxy?

I've read and been told that applied Zinc Chromate has a life cycle and actually repels corrosion by some type molecular exfoliation.

What would you use if your bird were to be based less than two miles from the Atlantic Ocean?

I've been told that the only way to protect the metal from the salt environment is to "encapsulate" in epoxy primer.

I plan to prime every interior inch of the 8 and the 10 now under construction and your constructive views/ideas/concerns are valued and appreciated.

captainron · #14 07-06-2007, 03:48 PM

http://www.sjdiscounttools.com/sem39683.html

jcoloccia · #15 07-06-2007, 04:25 PM

Quote:

Originally Posted by Hard Knox

What would you use if your bird were to be based less than two miles from the Atlantic Ocean?

Akzo-Nobel epoxy. The stuff ACS sells. They call it a "primer" but it's really a fluid resistant sealer designed to seal out...well...everything. My opinion is this stuff is as good as anything else you'll find and goes on easier than anything else I've tried. It's tough as nails and lasts forever as far as I can tell. If you're really paranoid, you can Alodine underneath but I don't think it's nescessary for full protection.

The datasheet tells all but I don't have it in front of me.

LettersFromFlyoverCountry · #16 07-06-2007, 04:39 PM

A primer thread. What are odds?

Captain Avgas · #17 07-07-2007, 05:18 AM

Quote:

Originally Posted by Hard Knox

I've been using Alumiprep33/Alodine 1201/PPG DP40, spraying the two-part DP40 with a Preval sprayer. This is expensive.

What would you use if your bird were to be based less than two miles from the Atlantic Ocean?

I would upgrade from DP40 to a Boeing spec BMS10-11 product (Akzo have one). The BMS10-11 spec is a product which is a final coating in itself and is extremely resistant to corrosive environments and is also quite inert to solvents, fuels, and brake fluids. DP40 on the other hand was not designed to be a stand-alone coating....it REALLY is a primer and is recommended only where a top coat will be used.

All of the certificated spam cans (Cessna, Piper etc) now feature BMS10-11 'primers' as a standard protection.

As for the rattle can products.....they're all complete junk by comparison. You just don't get the developed cross linking of the long chain molecules in the single pack paints that you get from the two pack epoxies.

Rick6a · #18 07-07-2007, 05:53 AM

Quote:

Originally Posted by Captain Avgas

.....I would upgrade from DP40 to a Boeing spec BMS10-11 product (Akzo have one)..........

Akzo is truly tough stuff. I like it because you can shoot a part and in less than an hour, the part is dry enough to work with. Here's something no rattle can primer can claim. When Akzo is fully cured, you can wipe it down with MEK over and over and over and the most you will do is lighten it. I have never found any rattle can primer that can hold up to a thorough and periodic wipe down with MEK, which the floor of my 6A can attest too.

Using the little spray gun fitted with a 35mm film canister, I shot the entire -8 fuselage interior....sometimes as few as one or two pieces at a time using Akzo. It is very easy to mix a small amount, frequently I mix less than 4 oz. at a time using small dixie cups as disposable measuring devices and waste is kept to a minimum.

My idea of surface prep is nothing more than a wash in mild soapy water using a scotchbrite pad for light scrubbing, then rinse and dry. Larger parts were done in the bathtub. Really large parts are done outside with a bucket of soapy water and a garden hose. Prior to applying the primer, I wipe down the part surface with MEK which as you know evaporates almost immediately.

The stuff dries like porcelain.

jcoloccia · #19 07-07-2007, 07:28 AM

The BMS10-11 spec and the DMS 1786 spec (the one Spruce sells) look to be similar in performance (DMS 1786 perhaps a little better). BMS10-11 looks like the low VOC version, it goes on a little thinner, and takes FOREVER to dry (tack free in 2 hours). The Spruce one is tack free pretty much as soon as you spray it....within 5 or 10 minutes on a reasonably warm day.

cnpeters · #20 07-07-2007, 08:13 AM

Another nod toward NAPA 7220. Inexpensive, easy to apply, durable. Doesn't scratch off easily. Sharpie will show through. I first wipe with MEK or acetone, replace any markings immediately so I don't forget, then spray.