Iron Armor primer - has anyone used it?

[stinkybritches]

I was in Harbor Freight and found 10oz cans of Iron Armor primer for $4.00 a can. They have a filler version and a sandable version. I bought one of each. I was wondering if anyone here has tried them. The only thing I've been able to do is prime a couple of plastic spoons. It seems to cover well but it feels a little grainy; not rough, but not smooth. I haven't had the chance to put any paint over it yet but I have a practice body that I hope to test it out on soon. Do any of you have any experience with this product? 

[Oldcarfan27]

For primers, grainy is not a bad thing, as long as it blocks and provides attachment for the paint.

Sandable primers are supposed to be block sanded before applying color coat finishes.

If you've ever seen a paint job applied over an unprepped primer, the color usually takes on the look of cottage cheese. Block sanding smooths out the foundation for the final finish.

Does the primer dry hard and sandable after curing? Does it craze the plastic? Does it provide protection of the paint to the plastic?

Practice on unpainted plastic and let us know. I'd like to find out if it's a good replacement for the bad primers we currently have available. 

[peteski]

Sanding? Yuck!  Why make my modeling more difficult that it has to be? If I had to do all the sanding and polishing you guys all do to get a decent surface finish, I would quit the hobby.  I skip the primer altogether whenever I can.  If I can sand the body smooth, and use plastic compatible paints (like Testors), I shoot it directly on plastic.  No polishing afterwards either.

If I do have to use primer, I would never use grainy primer.  Tamiya Fine Surface primer is nice and smooth. I seem to recall that Alclad also has a smooth primer).  Then I shoot the color over unmolested primer for a nice smooth surface finish. 

[bisc63]

I had recently purchased some Iron Armor primer at Harbor Freight just because the price was so appealing for a sandable filler primer. I just got around to doing a quick test, because I'm as curious as anyone if it's worth trying! A few points: First; it does have a VERY fine graininess, but nothing unusual for a primer with higher solids content for filling. You have to feel it, you can't see it, even in a WET coat. Second; it sprays with a good pattern, and covers very well. Third; I was unable to make it craze a model car body or even one of those cheap plastic Wal-Mart spoons, and in my experience, plastic spoons craze easily. (I sprayed 2 heavy wet coats on each, no holding back for testing purposes) Fourth; I like the smell! Seriously, it reminds me of the smell of Kylon Sandable from 10 years ago, a primer I really liked for modeling. BONUS points; the model pictured is an old glue bomb Monogram 66 Chevelle street machine I will be restoring, molded in RED, and it ain't bleeding through! Sprayed day before yesterday. The primer is a very light gray color, the handle of the (white) spoon was not sprayed at all.

[Straightliner59]

That looks very promising!

[stinkybritches]

5 hours ago, bisc63 said:

I had recently purchased some Iron Armor primer at Harbor Freight just because the price was so appealing for a sandable filler primer. I just got around to doing a quick test, because I'm as curious as anyone if it's worth trying! A few points: First; it does have a VERY fine graininess, but nothing unusual for a primer with higher solids content for filling. You have to feel it, you can't see it, even in a WET coat. Second; it sprays with a good pattern, and covers very well. Third; I was unable to make it craze a model car body or even one of those cheap plastic Wal-Mart spoons, and in my experience, plastic spoons craze easily. (I sprayed 2 heavy wet coats on each, no holding back for testing purposes) Fourth; I like the smell! Seriously, it reminds me of the smell of Kylon Sandable from 10 years ago, a primer I really liked for modeling. BONUS points; the model pictured is an old glue bomb Monogram 66 Chevelle street machine I will be restoring, molded in RED, and it ain't bleeding through! Sprayed day before yesterday. The primer is a very light gray color, the handle of the (white) spoon was not sprayed at all.

 

Thanks for giving this a test. I was able to spray a test body last night and I liked what I saw. Covered extremely well, but I haven't had a chance to check it over today. Definitely looks promising.

[Oldcarfan27]

17 hours ago, bisc63 said:

I see no pink at all! This is looking good.

I gotta get me some and try it.

Hopefully the formulation isn't different for California. 

[bisc63]

5 hours ago, Oldcarfan27 said:

Hopefully the formulation isn't different for California.

Everything's different for California, I learnt that on the TV!

Edited May 21, 2021 by bisc63
typo

[TransAmMike]

Well this could turn out to be an interesting thread, no so much for the HF Primer but Peter said.....no primer at all.

[DiscoRover007]

Might have to give this a shot. Looks like with some light sanding you could get a smooth surface for painting quite easily.

[peteski]

 

On 5/21/2021 at 2:36 PM, TransAmMike said:

Well this could turn out to be an interesting thread, no so much for the HF Primer but Peter said.....no primer at all.

 

No primer on any of these models. Paints are Testors (airbrushed).  These have clear coat (no sanding, no polishing, no wax).

 

 

Same as above but no clear coat.

 

This is a very old model (built in the late '80s. I don't own it anymore (sold it).  I was fairly inexperienced at that time.  On this one I did use primer, but only on certain parts.  Most of the body parts were white - no primer needed.  But the fender flares and, IIRC some front spoiler parts were molded in black. I sprayed white primer on those before gluing them to the body, then it all got spray painted Testors red.  It was all from spray cans (before I owned an airbrush).

 

I do use primer/barrier when I use hot paints, but as I said, I skip primer whenever I can. IMO, the thinner the paint layers are, the more realistic the model will look.  I also very seldom modify the model bodies, or use putties. If I did, I would have to use primer too, because of the dissimilar materials having slightly different surface texture.

Edited May 22, 2021 by peteski

[bisc63]

Exactly my reason for using primer, I enjoy modifying and custom work, so a variety of fillers and their unique properties necessitate something to provide a uniform surface for the topcoats. It's all about intent and purpose.

[Bills72sj]

On 5/17/2021 at 5:39 PM, peteski said:

Sanding? Yuck!  Why make my modeling more difficult that it has to be? If I had to do all the sanding and polishing you guys all do to get a decent surface finish, I would quit the hobby.  I skip the primer altogether whenever I can.  If I can sand the body smooth, and use plastic compatible paints (like Testors), I shoot it directly on plastic.  No polishing afterwards either.

If I do have to use primer, I would never use grainy primer.  Tamiya Fine Surface primer is nice and smooth. I seem to recall that Alclad also has a smooth primer).  Then I shoot the color over unmolested primer for a nice smooth surface finish. 

I am with you brother! I avoid sanding as I always make things worse not better. I can accept some orange peel much more than sand-through and repaint.

I have had pretty good results on paint directly on plastic. Molded plastic is about as smooth as it gets. It is only a bummer if there are sink holes.

[TransAmMike]

Not having to spray primer is appealing (for smoothness) but I assume since I use craft acrylic, it would be needed for the paint to adhere What ya say??

[peteski]

2 hours ago, TransAmMike said:

Not having to spray primer is appealing (for smoothness) but I assume since I use craft acrylic, it would be needed for the paint to adhere What ya say??

Except for some very minor brush-on application and washes I have no experience with water-based enamels, but reading info on this forum, I believe that you should use a primer under those paints to maximize their adhesion to plastic.

[TransAmMike]

54 minutes ago, peteski said:

Except for some very minor brush-on application and washes I have no experience with water-based enamels, but reading info on this forum, I believe that you should use a primer under those paints to maximize their adhesion to plastic.

Thanks Peter, it's what I thought too.

[gejettest]

I love those blue "fan spray nozzles" adjustable and very easy on the trigger finger.

All cans should come with those!