# Is Rustoleum an enamel?

### Help Support The Rocketry Forum:

#### watheyak

##### Barnstormer
TRF Supporter
Hey there,

Is Rustoleum an enamel or a lacquer? Or neither?

Or more specifically, can I put Krylon Fusion over Rustoleum Primer? There seems to be a spray paint shortage of all brands, and the only primer I could find was Rustoleum Automotive, and the only brand that had the correct colors was the Krylon Fusion. The Ace employee assured me all would be fine, but now I'm not so sure.

I'm definitely going to do a test piece, but I wanted to see if anyone here had some insight.

Thanks

#### Scott_650

##### Well-Known Member
Rusto is an enamel as is Krylon Fusion - I’ve used both brands of primer pretty much interchangeably with either brands of paint - drying/cure times and technique seem to be a bigger factor than brand. I typically sand primer down to a very thin coat, filling imperfections more than using it as a base layer and I always stick to the recoat times on the cans (treating the max recoat as a minimum isn’t a bad idea).

Test pieces are a must! I keep a stash of toilet paper and kitchen wrap tubes just for testing.

#### jderimig

Almost anything can go over a lacquer primer. Go to an auto body supply shop and get the cheapest 1k lacquer primer you can. Universal primer.

##### Well-Known Member
Lacquer off-gasses so quickly (a day or so) so you can put anything over it. The reverse isn't true since enamel takes weeks to fully off-gas.

Dry to touch, dry to sand and fully cured are vastly different times and when switching types, you need to wait until the previous layer is fully cured.

To be safe, stick with the same type and brand and you shouldn't have issues if you follow the instructions for that paint.

#### tsmith1315

##### Well-Known Member
To be safe, stick with the same type and brand
Trouble is, that's not easy to do right now. I lucked out today and found yellow and orange Rustoleum. I've been looking for both for 2 weeks.

#### teepot

##### Well-Known Member
TRF Supporter
I finally gave up and bought some Krylon on Amazon. $3.95 for 2 in 1 primer. I got 3 cans. But$12 to $15 dollars for the other 5 cans each. Dropped$85. The good news is our Home Depot has restocked a lot of the Rusto.

#### MidOH

##### Well-Known Member
Mine is. If you spray black over paint, lay down a super thin layer of primer first. Rusto black seems very thin.

Smooth primer, not the buildable fuzzy kind.

#### DES

##### Well-Known Member
Hey there,

Is Rustoleum an enamel or a lacquer? Or neither?

Or more specifically, can I put Krylon Fusion over Rustoleum Primer? There seems to be a spray paint shortage of all brands, and the only primer I could find was Rustoleum Automotive, and the only brand that had the correct colors was the Krylon Fusion. The Ace employee assured me all would be fine, but now I'm not so sure.

I'm definitely going to do a test piece, but I wanted to see if anyone here had some insight.

Thanks
Rustoleum automotive primer is lacquer based. The "stops rust" and "industrial" primers are oil based and dry slowly.

Rustoleum "Stops Rust" is basically an alkyd enamel (oil based paint), stays a little soft so it resists chipping on metal surfaces. Topcoats do not adhere well.

Rustoleum 2x and Krylon are acrylic enamels. But some of the clears are lacquer or seems to have a hotter, more lacquer like solvent, so you do need to read the TDS, and unfortunately, you do need to test compatibility.

#### Funkworks

##### Low Earth Orbit, obstructing Earth's view of Venus
I still don't quite understand the difference between "enamel" and "lacquer". Definitions I found so far have been inconsistent and confusing. I always expect something like "one is oil-based and the other is water-based", but I don't think it's that simple.

#### jderimig

L
I still don't quite understand the difference between "enamel" and "lacquer". Definitions I found so far have been inconsistent and confusing. I always expect something like "one is oil-based and the other is water-based", but I don't think it's that simple.
Lacquer is thinned with lacquer thinner. Enamel is thinned with enamel thinner.

##### Well-Known Member
L
Lacquer is thinned with lacquer thinner. Enamel is thinned with enamel thinner.
In most cases, lacquer thinner == mostly toluene (but they can't just call it that....for reasons)

#### DES

##### Well-Known Member
I still don't quite understand the difference between "enamel" and "lacquer". Definitions I found so far have been inconsistent and confusing. I always expect something like "one is oil-based and the other is water-based", but I don't think it's that simple.
It has gotten more and more difficult and confusing in recent years due to constantly changing formulations.

In general, lacquer is a cellulous or acetate resin dissolved in lacquer thinners, which are mostly acetone and some alcohols. They cure by drying - evaporation of the solvent. A lacquer can be re-dissolved by adding solvent. That is the defining characteristic of a lacquer.

Enamels were originally smooth, hard oil-based paints that cure by polymerization of the the oil once the carrier solvent evaporates. Now we have acrylic enamels, which cure by polymerization of the acrylic resin. Both types are typically dissolved in "paint thinners", which are mostly mineral spirts, naphtha, and similar solvents. But to confuse things, especially in spray paint, frequently some acetone, toluene, or other fast evaporating solvent is blended in to make it dry faster. So an enamel first dries (the solvent evaporates) then the film cures - hardens and stabilizes as the resin polymerizes and cross links. An enamel will not usually re-dissolve in the original solvent once cured. But a strong solvent - such as acetone, will attack and swell the enamel resins, which is why you cannot use lacquer over the top of enamel.

Water based paints are an entirely different animal. They are complicated emulsions of paint droplets in water with voodoo chemistry.

Last edited:

#### watheyak

##### Barnstormer
TRF Supporter
Thanks for the insight everyone.

So far, so good. The Rust-oleum primer was sanded after about 24 hours. Now the Krylon fusion is going on with out any issues so far.

I've been using a Klass Kote epoxy paint primer, but ran out. I think the last time I used Rusto it was a different formulation and a different nozzle. Once I got my technique corrected things went a little smoother.

#### caveduck

##### semi old rocketeer
I've used Klass Kote 2K primer for a long time and love it. Predictable cure time, sands perfectly, and you can put anything over it. Last time I tried Rusto spray primer it took 2-3 days to be sandable and was still a bit rubbery...not going there again.

#### watheyak

##### Barnstormer
TRF Supporter
For the record, Krylon Fusion is compatible with Rusto Automotive Primer.

I'm also pretty terrible at getting a good, even coat of paint on with the tips on either can. Many light coats followed by one final heavy coat didn't work in this situation. Still many rough spots from overspray.

#### G_T

##### Well-Known Member
Perhaps use clear coat to get the final surface.

#### boomtube-mk2

##### Well-Known Member
There seems to be a spray paint shortage of all brands,
There is somewhere around 90 container ships sitting off the California coast awaiting berth times at the LA or Long Beach ports so as to be unloaded.
So it's not surprising there's a dearth of available spray paints, the surprising thing is we can still buy shoes, tools and small appliances.

#### icyclops

##### Well-Known Member
There is somewhere around 90 container ships sitting off the California coast awaiting berth times at the LA or Long Beach ports so as to be unloaded.
So it's not surprising there's a dearth of available spray paints, the surprising thing is we can still buy shoes, tools and small appliances.
Hmmmm….last time I was at Home Depot and Michaels there was plenty of spray paint still on the shelves….but I live in the Bay Area CA. Alameda long shore men are back to work so those container ships you speak of are slowly coming into port for unloading….last time I was in the SF city I counted about 8, but couldn’t see all the way down the bay or out past the golden gate…so not 100% sure on that count.
The problem now with this state is it is a welfare state (both good and bad in certain cases)….pays too much in unemployment so people are not going back to work as fast as they can. There are plenty of service jobs available, people just are not moving as they are getting unemployment benefits and Covid non-eviction rent….and the state is about to pay for another 2-3 months of rent relief. After all that runs out, the people in this state who are unemployed will then have to do something (Get a job or leave). They would be wiser to go to work now while the job selection and demand is high….if its a COVID safe environment at work…but the Bay Area has one of the highest vaccination rates….my county is over 75%. I think you will see things start to move faster in the next month or so (just my opinion).

#### boomtube-mk2

##### Well-Known Member
Compared to the ports of Los Angeles and Long Beach the Bay Area ports are small potatoes with regards to the loading and unloading of container ships.
The fastest growing west coast container port is Prince Rupert in British Columbia Canada.
As weird as it may sound, containers unloaded at Prince Rupert can reach Chicago nearly a day ahead of containers unloaded at any port on the U.S. west coast.

#### Nathan

##### ☢
TRF Supporter
Lacquer off-gasses so quickly (a day or so) so you can put anything over it. The reverse isn't true since enamel takes weeks to fully off-gas.

Dry to touch, dry to sand and fully cured are vastly different times and when switching types, you need to wait until the previous layer is fully cured.

To be safe, stick with the same type and brand and you shouldn't have issues if you follow the instructions for that paint.
The problem with enamel isn't that it takes a long time for the solvents to off-gas, it's that enamel doesn't fully hardened until it is done curing which is the process of polymerization and that can take weeks. Heat can be used to speed up the process. Some kinds of enamel will never fully cure unless they are heated at high temperature, like for example caliper paint.

#### Scott_650

##### Well-Known Member
The problem with enamel isn't that it takes a long time for the solvents to off-gas, it's that enamel doesn't fully hardened until it is done curing which is the process of polymerization and that can take weeks. Heat can be used to speed up the process. Some kinds of enamel will never fully cure unless they are heated at high temperature, like for example caliper paint.
Exactly. Until your acrylic enamel paint is fully cured - the polymer chains are formed from the surface to the substrate - the carrier solvent from an additional layer of paint on top can reactivate the original paint and it will wrinkle. All the other anecdotal data, suppositions and folklore isn’t a factor compared to whether your paint is fully cured, partly cured or just dry. Follow the recoat time on the can, use light layers (no matter how much you might want it to, paint isn’t very good at filling in imperfections - that’s a part of preparation, not painting) and never forget that sometimes it just doesn’t work right no matter what you do - who doesn’t love sanding?

#### Grant_Edwards

##### Well-Known Member
Paint (noun)

A liquid applied to a project to permanently highlight defects in workmanship.

#### boomtube-mk2

##### Well-Known Member
Paint (noun)

A liquid applied to a project to permanently highlight defects in workmanship.
That's odd, because I always heard it as; Bash to shape. File to fit. Paint to hide.

#### DES

##### Well-Known Member
Depends on your trade. Typical machine shop practice - measure with a micrometer; cut with an axe; beat to fit; and paint to match.

#### msjohnso

##### Well-Known Member
...or maybe it's "Force to fit; file to hide; paint to cover."

#### Grant_Edwards

##### Well-Known Member
Maybe it's just me, but when doing woodworking it seems like I always think all the joints are nice and flush and the sanding and planing turned out nicely and that wood doesn't really need filler. Then I put on the paint, varnish, urethane, whatever — and all sorts of little defects that weren't noticeable before are suddenly very obvious. The glossier the finish, the worse the effect.

#### neil_w

TRF Supporter
The glossier the finish, the worse the effect.
Gloss paint is the premier revealer of surface defects. There's a reason why we paint our ceilings with flat paint.

#### Grant_Edwards

##### Well-Known Member
Gloss paint is the premier revealer of surface defects. There's a reason why we paint our ceilings with flat paint.
And for drywall installers who can't manage something good enough for flat paint, there's the "popcorn" finish. It's amazing what that stuff will hide.

Though I bet it's really high drag.

OTOH, many of us would have guessed that putting dimples on a golf ball would decrease distance, but it actually helps by creating a turbulent boundary layer which makes it easier for the air to close in behind the ball, resulting in less overall drag. My vague understand of aerodynamics would lead me to guess that the boundary layer drag goes up some, but the base drag goes down by more. Or something like that.

#### watheyak

##### Barnstormer
TRF Supporter
And for drywall installers who can't manage something good enough for flat paint, there's the "popcorn" finish. It's amazing what that stuff will hide.

Though I bet it's really high drag.

OTOH, many of us would have guessed that putting dimples on a golf ball would decrease distance, but it actually helps by creating a turbulent boundary layer which makes it easier for the air to close in behind the ball, resulting in less overall drag. My vague understand of aerodynamics would lead me to guess that the boundary layer drag goes up some, but the base drag goes down by more. Or something like that.
A popcorn rocket would be cool! Reminds me of a Deb Kolom rocket a while back that was furry.

Also I think Myth Busters proved that the dimples only helped on spherical shapes.

#### Grant_Edwards

##### Well-Known Member
A popcorn rocket would be cool!
I was thinking that too.
Also I think Myth Busters proved that the dimples only helped on spherical shapes.
Ah, so it would work for cows.

I'm pretty sure I've seen something similar on airplane wing surfaces (which were not spherical), which was supposed to reduce total drag and delay boundary layer separation (which delays the point at which a stall occurs).