Priming before painting

[geodehunter]

Do you guy's prime your rockets before you paint them with your final color? TIA

[MClark]

yes

[JAL3]

We need an "open can of worms" smiley!

The short answer is, generally, "yes".

As to the preferred method, it varies from person to person and they all tend to be rather passionate.

[LW Bercini]

Yes. You should do so searches for "paint" and "primer" and read the plethora of opinions. Then give some of the options a try for yourself and decide what works best for you.

[Barracuda]

yep

[Rocketbuilder]

I'm too lazy to prime my rockets before I paint them. Plus I'm cheap, and primer costs just as much as paint.
I know I probably should use primer, but so far I've never had any problems getting an even coat, or with paint not sticking to the rocket.

[CPUTommy]

Build, Sand high spots down
Prime with filler primer (to see the areas needing work)
Sand (the areas you found with primer)
Prime with filler primer again (to see if all areas were fixed)
Sand (usually with 320 or higher to smooth the surface that the base is going to be applied to)
Spray base coat ( White ) (sometimes 2 coats)
Spray Final Coat, Two coats..
Clear

[McKailas Dad]

If you want to have it look good at apogee, at 700 to 1000 feet away, then don't prime it.

If you want it to be a glossy, mirror-like finish, then fill the sprials, prime-sand-220 grit, prime-sand-320, prime-sand-400, prime-sand-600...

Then you can start wet sanding with 600, then 800 grit. 1200 if you really want to get crazy...and that's just the primer.

It all depends on how you want the final finish to look like.

[luke strawwalker]

If you want the best finish you can get, yes... If you just want to give it some color and don't particularly care how it looks, then just shooting paint on it is okay...

Fill the fins with carpenter's wood filler (or equivalent) or better yet paper them for additional strength and to cover the wood grain, fill the spirals in the tube with Bondo Auto Body Spot Putty, fill and sand the nosecone (balsa) and then prime the rocket with 2 coats or so of good primer (Walmart colorplace 99 cent a can stuff works great!)

Sand with 220 grit followed by 400 grit wet/dry, inspect, re-prime any imperfections or low spots, and resand. If it looks acceptable after the 400 grit sanding, your good to go. If you want a REALLY slick/smooth looking finish, dip the 400 grit wet/dry paper in a bowl of water, shake off the excess, and sand the rocket again with the damp paper, in small overlapping circles as you gently turn the rocket in your hand... wipe down with damp paper towel to remove the "sanding mud" and wipe again with dry paper towel. Hold the rocket up to a light in the background or sunlit window, and site down the length of it, or over its fin and nosecone surfaces, gently turning it... any defects will be readily visible in the 'glint' or reflection from the primered rocket. If there are any defects, fix them now, with more sanding or some more primer if necessary... any defects you can see WILL be visible through the final coat of paint... paint COVERS, NOT FILLS... it MAGNIFIES imperfections, it doesn't cover them up. That's what filler and primer are for!

Once you've got the prep work as good as you want the final coat to be, then shoot it with the final color coat(s) as necessary. Be careful, put it on smooth in several LIGHT coats to prevent runs, drips, sags, etc. that will ruin your finish.

Mask and put second/third colors as desired, decal, then clearcoat if desired... Later! OL JR

[hornet driver]

With out a doubt--prime then paint ---if it ain't flyin, it's on display for all to see !!! Besides, slick is good --rough is bad---my current build not withstanding !

[Sparkytfl]

Will bondo work ok after some primer has already been applied? I'm building a Bull Pup and didnt manage to fill all the line between the body and the tail cone.

What kind of sanding sealer are you supposed to use? All I saw at the hardware store was quart cans for 10 or 15 dollars that I dont know if they're even the right kind to paint over. They looked like they were for floors.

[Marc_G]

Will bondo work ok after some primer has already been applied? I'm building a Bull Pup and didnt manage to fill all the line between the body and the tail cone.

What kind of sanding sealer are you supposed to use? All I saw at the hardware store was quart cans for 10 or 15 dollars that I dont know if they're even the right kind to paint over. They looked like they were for floors.

On balsa, I rub thin CA on with a q-tip, let cure/dry, then go with either carpenter's wood filler (NOT the kind listed as superior staining... this matters!), or 3m/Bondo spot/glazing putty. Then Rustoleum auto filler primer.

Basswood: I go straight to the filler primer.

[DavidQ]

Do you guy's prime your rockets before you paint them with your final color?

Sometimes, I simply build my rockets out of primer. It saves time that way.

Well, it seems like that - the cardboard and balsa is just there to hold the primer, which is there to shape the smidge of paint.

[o1d_dude]

There are some who don't bother with primer or paint.

Whatever makes you happy.

Me, I like to make my birds shiny so I use a couple of coats of primer followed by a couple of coats of color. Most times I follow that up with a clear coat or three.

To each his own.

[geodehunter]

Thanks for the reply's gentlemen I greatly appreciate it. I will be heading to town tomorrow for spot putty and sandpaper.

[JPVegh]

Sometimes I don't even bother with the paint.

Some rockets just cry out to be nicely finished. If you put a lot of time into building a level 4 or 5 rocket you want to spend more than ten minutes finishing it. Those rockets get the works, sanding, filling, sanding, sealing, sanding, priming, sanding, painting, sanding, clearcoat... I really hate sanding.

I'm not above slapping a rocket together and just hitting it with a coat or two of color then launching it the same day. Some of my favorite rockets were built that way. I have one ugly Big Bertha that has been launched dozens of times, it flies great.

Do what makes you happy.

[jd2cylman]

With out a doubt--prime then paint ---if it ain't flyin, it's on display for all to see !!! Besides, slick is good --rough is bad---my current build not withstanding !

My next rocket build, I am tempted to use Rustoleum Hammered finish or even the Textured finish. Just because.......

Adrian

[GRIFFIN]

Build, Sand high spots down
Prime with filler primer (to see the areas needing work)
Sand (the areas you found with primer)
Prime with filler primer again (to see if all areas were fixed)
Sand (usually with 320 or higher to smooth the surface that the base is going to be applied to)
Spray base coat ( White ) (sometimes 2 coats)
Spray Final Coat, Two coats..
Clear

Fly
Crash
Repeat
Repeat

[luke strawwalker]

Will bondo work ok after some primer has already been applied? I'm building a Bull Pup and didnt manage to fill all the line between the body and the tail cone.

What kind of sanding sealer are you supposed to use? All I saw at the hardware store was quart cans for 10 or 15 dollars that I dont know if they're even the right kind to paint over. They looked like they were for floors.

There's a difference between "Bondo" (body filler) and Bondo Glazing and Spot Putty... the spot putty comes in a tube... that's the stuff you want.

It uses lacquer thinner as a carrier, so you have to be careful putting it on over primer... enamel primer can dissolve and come off... but it's not a big deal, since you have to sand the spot putty down and reprime anyway... I HAVE put it on successfully over something that had primer already applied, but you have to be careful and don't use too much... put it on VERY THIN so that there's not enough lacquer thinner there to really hurt the enamel primer... If it does do something wonky, well, like I said, you have to sand the spot putty down and really should reprime over it anyway to get an even finish...

As for "sanding sealer"... I don't recommend the stuff... Yeah, there are a lot of guys who LOVE to use the old-style model airplane sanding sealers, but they're expensive and they smell, and they're not water soluble... and it takes a BUNCH of coat-and-sand-and-recoat-and-resand cycles to really fill the balsa and seal the wood. Elmer's Carpenters Wood Filler will fill the grain, usually in one application, it's water soluble and in fact, works even better if you thin it with water and brush it on the fins... (put about a teaspoon of the stuff in an old baby food jar (or equivalent) and add a squirt of water-- not much... maybe 1/4 teaspoon to start... you can always add more, but you can't take it away! A few drop is a good start (say 6-8). Use a 1 inch wide paintbrush to work the water and filler together... add water as necessary to get it about the consistency of yellow hot dog mustard. Brush it on the fins/balsa nosecone/transition, and let it dry. Sand with 220 grit, follow up with 400 grit, and you should be ready to prime... Better yet paper the fins-- they're stronger and smoother and it's easier to do as well... there's a thread around here about papering fins, complete with pics...

Later and good luck! OL JR

[luke strawwalker]

Thanks for the reply's gentlemen I greatly appreciate it. I will be heading to town tomorrow for spot putty and sandpaper.

When it comes to sandpaper, get good stuff... it doesn't cost much more, but it's WAY WAY better than the 'el cheapo" stuff... and well worth the money...

I've bought about probably 20 different grits, but I find that 98% of the time, I only need two different grits... 220 grit to start with and take the outside layers off to get it down smooth and level, and then 400 grit wet/dry paper to really get it slick, smooth, and pretty... and don't be scared to use a LITTLE water... it's amazing what a little lube (water) can accomplish. It also makes your paper last nearly forever, because when it starts clogging, a quick dip in water and running your thumb or thumbnail across the paper facing a few times will release the stuck paint and make the paper just like new again). Shake off the excess water, and then sand the rocket with the damp paper... as you sand, what would ordinarily be sanding DUST will mix with the water and form sanding MUD... this will thicken as you work and liberate more material from sanding... wipe it off periodically with a barely damp paper towel, or if you're really making good headway sanding, you can just drop a single drop of water off the tip of your finger to keep the paper lubed and sanding mud flowing so it doesn't gum up the paper. The tiny amounts of water we're talking about here won't hurt the rocket, so long as you don't just SOAK the rocket with water... and frankly it's not necessary-- just a drop of water is enough to do the job...

Some will scream to high heaven that wet sanding primer is a huge mistake... not so... they make primers that are specifically labeled for "wet sanding". If you want a terrific finish, "damp" sanding is at least a necessity... (damp versus soaking wet... true 'wet sanding" like you'd do on a classic car, say, is done with a garden hose pretty much constantly dribbling a steady supply of fresh water on the area... of course you can't do a rocket this way... it's not necessary and cardboard is far more susceptible to water than steel car bodies...

Let the rocket dry overnight (at least) before applying color coats or supplemental primer coats over the top. This will give any moisture absorbed into the primer layer time to evaporate out.

I've had EXCELLENT results using these methods, so I KNOW they work... but everybody's different, so you may have to do some experimenting to find what works well for you and that you like...

HOW you sand is more important that WHAT you sand with... remember to sand in a small circular motion, and keep the rocket or paper moving at all times... DO NOT sand in one spot continuously... this makes flat spots in the primer and makes sanding scratches. Don't sand in a straight line motion if at all possible (you usually have to around fin roots, but try to keep it as small as possible by sanding up to the part in small circular motions. Straight line sanding results in sanding scratches...

I generally paper fins, CA harden (lightly soaking the outer layer of balsa nosecones and transitions with a layer of rubbed on CA ultra-thin glue, done outdoors to prevent from being overpowered by the fumes, until the wood will no longer "drink in" any more CA), and then fill the tube spirals and any dings with Bondo Spot Putty... sometimes I fill the fins with CWF (carpenter's wood filler) and sand that smooth and level with 220 grit. Then give it several nice coats of primer, starting rather thin layers and making it a little thicker as you go... usually shoot it 3-4 times with about 30 minutes between "coats". Then I sand with 220 grit, taking MOST of the primer off. If I sand through working down the high spots, I reshoot with a little primer in these spots,and resand with 220 until everything's pretty well level and smooth. Any dings or anything can be filled with more primer, or with spot putty used carefully, and resanded with 220. THEN hit it with the 400 grit, sanding dry... see how it looks... if there's any sand-thru's of the primer, it's best to hit those spots again... then resand with 220 and then 400. Sometimes you get high spots that just end up getting sanded through no matter what you do... but it's best if you can get an even primer coat sanded glassy smooth. Once you can't see, or better FEEL with your fingertips lightly gliding over the parts, any more imperfections, your ready to damp sand, as previously described.

Once you've damp sanded and cleaned the thing off with a damp paper towel followed by a dry paper towel, hold it up to a sunlit window or a bright light source across the room (ceiling lights, whatever) and inspect the rocket's surface... don't look at the light source directly, and don't really look at the surface itself... look at the GLINT of light, the reflected light, off the tube from the light source... the reflection will give you a perfect image of the surface it's reflecting off of. The reflection should be smooth, straight, and unbroken... if you can see ANY imperfections, waves, spots, dips, high spots, etc, you'll either want to sand them out with a little more damp sanding, or if necessary due to depth or whatever, decide if you can live with it or if you want to use a bit of primer on that spot or even spot putty... it's more work, so it's up to you how much you want to do and what you can live with when it comes to imperfections.

After damp sanding with 400 grit, the rocket, even in just primer, will literally have a slight gloss to it from the smoothness of the primer... don't worry-- it still has enough "tooth" to hold onto the color coats that go over it. Let it dry overnight, run a clean paper towel (or better a tack cloth) over it to remove any residual sanding dust, then you're ready for your first color coat. Start by shooting it lightly and build the coats up with more applications about every 30 minutes. If you did the prep work right, the color coat will be smooth and flawless and look fantastic. Balsa parts will look like plastic they'll be so smooth. I've never had a need to sand the color coats if they're put on right.

Color coats cover NOTHING when it comes to poor prep work... if you can see defects in the prep work, the color coats will MAGNIFY them, not cover them. If you do the prep work beautifully, you CAN get a gorgeous finish-- if you don't screw up the color coat application... just go slow and be careful and you'll do fine and have a GORGEOUS rocket to show for it.

Then just pray it doesn't find the tallest tree, or end up rotting on a power line, or fail to eject the chute and lawn-dart... BUT a beautiful finish is, IMHO, its own reward... Plus it's cool at the field when other club guys go "how did you do THAT!??"

later! OL JR

[Sparkytfl]

Thanks luke, thats a ton of good info. I'll have to try thedamp sanding too. My paper gets clogged pretty quickly and I'd been using my thumbnail to clean it.

[LaunchPad]

I'm too lazy to prime my rockets before I paint them. Plus I'm cheap, and primer costs just as much as paint.
I know I probably should use primer, but so far I've never had any problems getting an even coat, or with paint not sticking to the rocket.

Yup. Same here. Not only lazy but impatient.
And I use latex/acrylic paint that I brush on.
I don't care to go through the expense or hassle of buying a bunch of spray paint when I already have so many colors in liquid form which is more eco-friendly as well.
Even though my rockets won't end up in a museum and I'm pretty much the only one that sees them, it doesn't matter to me to have something professional looking. I do try to make it look nice though.

[Barracuda]

My next rocket build, I am tempted to use Rustoleum Hammered finish or even the Textured finish. Just because.......

Adrian

Yea me too I've had some "stone "paint my wife used on the fireplace..it's been really tempting but so far no

[GDJ]

I use Rustoleum Plastic Primer on everything. It seems to stick quite well to the Glassine coating on Bodytubes, then paint.

[BABAR]

Do you guy's prime your rockets before you paint them with your final color? TIA

Usually. When I tried priming a rocket AFTER the final color it just didn't look right.