On Platicote's website, there are primers galore:

* Etching Primer
* Flexible Spot Filler & Primer
* Paint & Primer Sealer
* Plastic Primer
* Sandable Primer
* Spot Filler & Primer
* Zinc Rich Primer

I take it is the Sandable Primer that I want, correct? Also, is it lacquer?


Here's a snip from the MSDS:

...Wt.%.|.Chemical.Name
35.-.40.|.Acetone
10.-.15.|.Propane
.5.-.10.|.Butane
.5.-.10.|.Talc.(Mg3H2(SiO3)4)
.5.-.10.|.Xylenes.(o-,.m-,.p-.isomers)
.1.-..5.|.Titanium.dioxide

Greg

You want the Spot Filler and Primer- #466
I found the regular sandable Plasti-kote primer at Tractor Supply...they carry the Plasti-kote brand, but the 466 Filler Primer is not a stock item for them. I asked two managers at two different locations if they could order it in, but I was told they are not allowed that SKU # through their inventory channels. Shame, since TS would be very convenient for me since both locations are close by.

I agree with foose, you want the spot filler/primer, if you can get it. After that, the sandable primer.

The plastic primer is interesting.

I'm curious what the fliexible primer is. I wonder if it's flexible in its application, or if it's physically pliable as needed on an automtive bumper for example.

Doug

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From the PK website:


Flexible Spot Filler & Primer

* 'High build' primer with excellent adhesion for semi-rigid and flexible plastics
* All the same characteristics of SPOT FILLER with the addition of being flexible
* Preparation is easy because no excessive sanding or scraping is required
* Successive applications build up quickly to the desired level

Here's what's listed on RustOleum's Stops Rust automotive primer:
Liquefied Petroleum Gas 30%
Xylene 25
Magnesium Silicate 20
Toluene 15
Ethylbenzene 10
Titanium Dioxide 5
Zinc Phosphate 5
Basic Zinc Molybdate 5

We need GH to chime in here - he can address the chemical content tradeoffs better than I. But you see more Magnesium Silicate (Talc) in the RustOleum implying a higher solids content, I think.

In both cases, you see lots of hot solvents (aromatics?) - acetone, xylene, toluene, ethylbenzene. These evaporate quickly thus giving these primers their fast-drying feature.

We tend to call fast-drying paints lacquers because lacquers dry fast, but I think that's a morph of the term - I don't think there's any lacquer in these primers. Nevertheless, that's the term I use.

Doug

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YORF member #11

Ask and ye shall receive

Thanks, Craig.

Doug

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Typically those primers loaded heavy with hot Aromatic solvents (Toluene, Xylene, Acetone, Ethyl Acetate, MEK, MIBK) capable of softening plastics if not careful are called "Lacquer based" and those with slow drying Aliphatic solvents that cannot be recoated anytime are called "Enamel" primers.
The higher the MgSi (Talc) content, the better they tend to fill.

Zinc Molybdate would give the primer a dark color (Is this a dark grey "hot rod black" primer ?).
Titanium Dioxide is straight white pigment that was first used years ago as a safe replacement for white lead.
Have no clue why Zinc Phosphate is in there.

As far as the percentages of the Aromatic Solvents, the higher the Acetone content and the lower the Toluene content the faster it will dry due to the evaporation points of the solvents.
Ethylbenzene (next slowest), Xylene, MEK and MIBK (next fastest) are all in between Toluene and Acetone as far as evaporarion rates.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

Lot's of good information here, so thanks to all the contributors.

This has become a real "primer" on primer.

Greg

Plastikote Spot Filler and Primer. Grey. The Red Oxide I have found tends to clog within the first use.

I've tried Duplicolor's product and it will do, better than any other, but Plastikote is the way to go.

My current finishing regimen:

Shoot one coat of SF&P.
lightly sand off the roughness.
Apply watered-down Elmer's Carpenters Wood Filler (or Fill'n'Finish if you've got some), to fill in the deepest valleys, dry, sand lightly.
Shoot successive coats of SF&P, sanding lightly between each one, until satisfied. Use a strong light and look along the surfaces toward the light to see remaining imperfections.

You *can* skip the wood filler step, and just use the SF&P. I just find it accellerates the process, and doing it AFTER the first coat of SF&P removes the threat of warping fins and such.

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Roy
nar12605

My favorite primer is Duplicolor. On a summer day in dry Colorado, you can be sanding almost immediately!

I used to get it in the Automotive Dept. at Walmart, but our stores seemed to have dropped paints in Automotive. Seems they now just carry the typical/standard brands of paints like Krylon and Rustoleum in their Paint/Hardware Dept Looks like I'll have to go to the automotive supply shops now.

__________________
Lee Reep
NAR 55948

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