Rustoleum Primers: Rustoleum 2X vs Rustoleum Filler & Sandable vs Rustoleum Primer Sealer

[lakeroadster]

This is a recap of my experiences using Rustoleum Primers on my P-40 Warhawk Oddroc. The subject of these primers comes up here on TRF quite often, I thought it worth documenting this for future reference, and thought others might benefit from the synopsis.

Rustoleum 2X Primer

I sprayed a paper and wood constructed motor mount / spool with Rustoleum 2X Primer and 4 days later it is still kind of tacky and gooey? Its finish is smooth, more like a paint than a primer. It's an ok product, but IMO the following products are much better.​

Rustoleum 2 in 1 Filler & Sandable

At that same time that I sprayed the above spool, I also sprayed a paper and wood constructed rocket with Rustoleum Filler Sandable. This is a high fill primer that dries with a rough texture, as it is meant to be sanded. I sanded that rocket 3 days later and applied the finish primer coat of Rustoleum Primer Sealer.​

Rustoleum Primer Sealer

This product is not the same as the 2 in 1 Filler & Sandable.​

The Primer Sealer should be used as the last primer coat.​

• It doesn't fill or sand as well as the 2 in 1 Filler & Sandable.
• It dries smooth, unlike the 2 in 1 Filler Sandable which dries with a rougher texture, as it is meant to be sanded.

1st Primer Coat: Applied 09-27-2022


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2nd (Final) Primer Coat: Applied 09-30-2022

 

[Back_at_it]

The sandable filler primer is an OK product if you have days to wait for it to cure. It does an pretty good job of filling balsa and some spirals. I don't care for the gummy outer layer. I also don't personally have patients to wait for it to cure so I switched over SEM high Build. Typically dries in 30-45 mins. and is cured in a day.

 

[neil_w]

The esteemed @John Brohm recommended Rusto Automotive Primer to me a while back. Because I am stupid I have not heeded his advice and tried it yet.

If only there were more different primers to choose from!

 

[tsmith1315]

Rusto Automotive Primer

Try it!

No complaints here. It dries quickly, that's non-negotiable for me. I prefer to shoot a couple of coats and sand in between to see how the surface is looking.

 

[lakeroadster]

The esteemed @John Brohm recommended Rusto Automotive Primer to me a while back. Because I am stupid I have not heeded his advice and tried it yet.

If only there were more different primers to choose from!

Wait... I thought Saturday you said you always start with the 2 in 1 sandable? I'm confused again.

 

[neil_w]

Wait... I thought Saturday you said you always start with the 2 in 1 sandable? I'm confused again.

That remains true. The automotive primer is a different product.

 

[teepot]

I stopped using the grey 2x because it never seems to dry and clogs the sandpaper even after days of sitting. I like the automotive primer. Trouble is Home Depot here hasn't had any for a month or two. So, I'm using the white 2x which does dry. It leaves a lot to be desired though.

 

[lakeroadster]

That remains true. The automotive primer is a different product.

ABOUT 2 IN 1 FILLER AND SANDABLE PRIMER​

Rust-Oleum® 2 in 1 Primer provides a tough, rust inhibitive base for most brands of Automotive lacquers and enamels.

 

[neil_w]

 

[lakeroadster]

View attachment 540370

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Rustoleum Filler & Sandable, as well as Rustoleum Primer Sealer are both automotive primers and are found on the Rustoleum website under https://www.rustoleum.com/product-catalog/consumer-brands/auto/primers

I guess it's always been obvious to me because when I first started buying these cans of primer they were located in the automotive department at Walmart, right next to the Bondo body filler, plastic putty applicators, etc.

 

[Philip Tiberius D.]

For the SEM or Rustoleum can you use either Acrylic or Enamel spray paint and not get alligator skin ? I’ve had that issue spring up a few times and have resolved it by using Dupli-Color primer and paint.

 

[rharshberger]

For the SEM or Rustoleum can you use either Acrylic or Enamel spray paint and not get alligator skin ? I’ve had that issue spring up a few times and have resolved it by using Dupli-Color primer and paint.

Duplicolor primer is a high solids lacquer, I believe both the SEM and the Rusto 2 in 1 Filler primers are as well. The only solvent that should attack a lacquer is lacquer thinner. Let any of the three primers listed dry for a couple of days before color coating and you can cover with pretty much any type paint.

 

[Back_at_it]

For the SEM or Rustoleum can you use either Acrylic or Enamel spray paint and not get alligator skin ? I’ve had that issue spring up a few times and have resolved it by using Dupli-Color primer and paint.

I have never had an issue going over SEM or Duplicolor with any paint brand or type. I've tried Rustoleum, Krylon, Ace, Duplicolor, dollar store brands, junk I've found in my garage etc. Nothing has affected either of them.

Rustoleum primers are a different story. I've had them react badly to their own rustoleum brand paint even after letting it cure for days or weeks. I can tell you that Krylon over Rustoleum primer works fine.

 

[zog139]

I have never had an issue going over SEM or Duplicolor with any paint brand or type. I've tried Rustoleum, Krylon, Ace, Duplicolor, dollar store brands, junk I've found in my garage etc. Nothing has affected either of them.

Rustoleum primers are a different story. I've had them react badly to their own rustoleum brand paint even after letting it cure for days or weeks. I can tell you that Krylon over Rustoleum primer works fine.

Do you buy SEM primer from Amazon or from a local retailer and if so which one ?

 

[caveduck]

I appreciate the test data posting!! We need way more of that.

Some SEM products are available OTC at O'Reilly's. They are really in a different quality league from any of the Rustoleum products. I've had the same experiences with the Rusto primers randomly deciding to cure slowly or not at all with permanent gummy texture. I won't risk an important project on them anymore, and I don't want to wait 2-3 days for it to get dry enough to sand. The SEM high build primer/surfacer 42003 is spec'd to cure in 1 hour and comes in 5 colors, but you definitely have to pay for that capability. I can also vouch for the SEM self-etching primer for metal parts.

The other really great rattle can primers are Tamiya and Mr. Surfacer. They are very fine grained and are intended for smaller plastic models, but they are fantastic for doing no-holds-barred scale rockets. Unfortunately they only come in very small cans.

 

[DaHabes]

The sandable filler primer is an OK product if you have days to wait for it to cure. It does an pretty good job of filling balsa and some spirals. I don't care for the gummy outer layer. I also don't personally have patients to wait for it to cure so I switched over SEM high Build. Typically dries in 30-45 mins. and is cured in a day.

I've never had an issue with the filler-primer. It can be wet sanded after 2 hours, per the can, and I always wet sand it with 320 grit. It sands down to a very smooth surface. If I prep carefully, I can get a perfect top coat with 2 light coats of Rustoleum 2x.

I never use it it fill spirals or balsa, though. For spirals I always use Bondo, thinned with acetone. I paint it on with a foam brush, multiple coats to fill in the low spots; it dries so fast you can recoat in 2 minutes. Sand that down, then primer-filler, then wet sand, then bondo again for any remaining divots. At that point I'll either do a light gray primer coat (non-filler) or just top coat with 2X color.

For balsa (or basswood, balsa is impossible to find), I use sanding sealer first, then the above prep as needed (unless I paper the fins).

For balsa nose cones, I found this prep from another poster. I coat the nose cone with CA (thin or thick, doesn't matter), then sand it down smooth. Then bondo any irregularities and sand it smooth. Primer and paint. The nose cones are much tougher with almost no weight added and can survive rough landings.

 

[techrat]

But just think of the advantages! The automotive primer STOPS RUST. This is critically important in your wood and cardboard rocket! You don't want that thing rusting away after a few flights. SpaceX uses it. That's why those boosters have been reused 20 times already, even after landing in salt water on some little barge anchored off the coast of Bermuda.

 

[lakeroadster]

As a heads up, the marketing folks at Rustoleum have again changed the look of the spray cans. I bought the one on the left at Walmart 10-06-2022 in the automotive department. I'm so used to looking at the old can design I looked right past it until my wife said "Is that it"?

 

[goose_in_co]

View attachment 540370

+1

I have started using this primer, found at the Blue Home store, with much better results than the 2x primer. I have stopped using any spray product that has 2x in the name.