I can't respond to that question, BUT, this product supposedly compares to Rustoleum primer.   https://www.harborfreight.com/10-oz-iron-armor-gray-sandable-primer-spray-paint-60789.html

I bought some for a different project, (motorhome repair) and noticed it smelled just like the NAPA stuff that was all the rage.  I tried it under some butyrate dope and it worked just fine.  I have used up the whole can with no issues.

I noticed in the ad that Harbor Freight has a disclaimer that the comparison could be  for the price.  I do know, if it works, then it does.  With the 20% discounts that always show up it is a pretty good deal. 

My disclaimer:  I don't suggest everyone go out and use this stuff, it just worked for me.  If you don't like it, don't use it.  But then I use cheap Lowe's thinner in my dope too.

Maybe I'll try the Rustoleum just for drill.

Gentlemen,


Just used my last can of NAPA COLORLINE  grey primer.

Has any one had additional experience with the Harbor Freight Iron Armor grey sandable primer?

T Michael Jennings
Knoxville, TN

I'm glad to hear it works. I have a Scientific P-40 with plastic turtle-deck looking to get primered. So I'm thinking if using this stuff as an undercoat on plastic so the dope sticks. I guess it is time to buy a can and see how well it adheres to a plastic Dixie Cup.
Hopefully I can get the plane finished soon. I checked a timestamp on the build log at CEF...two years. Good grief! At this rate I'll be dead and planted before I get the first crash on it!

Having had many, many instances of incompatible materials causing issues, I always advise, do what the manufacturer says. But, as Mike pointed out, I've tried some pretty weird combinations and it worked fine, at least once. You pays your money and you takes your chances.