spray painting advice?

[jimboshop99]

Hey everyone,

I just got back into rocketry this year and have built several kits so far (Shuttle Express, High Flier XL, Deltie B, Black Brant III, Crossfire, Crossbow) and they turned out ok, a few flew very well. The thing I'm having a hard time with is the spray painting. The first rocket I painted had significant crackling afterward, some drips. So I tried sanding it down after it dried, finally said "screw it" and launched it anyway. I did a little research, found out more about temperature and applying all the coats (2?) within 1 hour or waiting 48 hrs between, applying thin coats and long strokes. So this time I've held the rocket body by the engine hook in one hand, paint can in the other as I rotate the rocket while I spray in long (hopefully) even coats, and I'm stilling getting drips, which I might try to sand down and repaint in a few days. I'm using the Rustoleum 2 in 1 from Home Depot, seems to cover pretty well.

For my next rocket, I'm thinking about putting the body tube part of the rocket upside down on an old turntable, rotating it during painting, spraying SLOWLY at least 1 foot away.

Any ideas to make this easier and reduce the drips? How much time do you wait between coats? Do you sand between coats? How many coats total? I saw that someone on the forum said not to spend too much time finishing since I'll eventually lose it... Thanks again for any and all help.

Jim

 

[Funkworks]

Many thin coats are better than few thick ones, so it's up to you to find a balance you can live with. At first, I would do about 4 coats. Now (after 15-20 rockets), I sand in between, still doing about 2-3 primer coats and 3-4 color coats. I'm never in a rush and enjoy the sanding part though, but that's me. Also, instead of holding the rocket by the engine hook, I would find the right size dowel and have a solid grip. It'd helpful for drying too.

 

[neil_w]

Runs and drips typically mean you’re too close and/or moving too slowly. Adjust accordingly.

Holding the rocket horizontally is usually the recommended way to avoid drops and runs, if you’re able. Sticking a dowel into the engine mount and holding the dowel is a common technique. For larger rockets, some sort of stand to hold the rocket is beneficial.

With Rusto 2x, I usually aim for 3 coats, 2 light and then one heavy, 10-15 minutes apart. Then give several days to dry before the next steps.

 

[Ronz Rocketz]

I use dowels to insert into the motor tube: 3/8, 1/2 or 3/4". The goal is to hold the rocket as horizontal as you can and the spray can as vertical as you can. Everyone has their own technique but figure out what works for you, should only take a couple dozen rockets (mostly kidding).

Different paints react differently depending on type, brand, temperature, etc. so some crackling and splattering happens unless you can control all variables. Some people get frustrated and buy a spray booth and paint sprayer.

For technique, I spray twice with primer to cover up the mistakes with 220 grit between coats. Next is thin coat then sand with 400 grit. Next is wet coat and light brushing with ultra fine steel wool. Allow as much time as you can stand between coats.

Lately, I've been using the Pledge floor gloss after the paint has dried for two days. I'm really liking how easy it is to apply and the results.

 

[Adam3836]

Runs and drips typically mean you’re too close and/or moving too slowly. Adjust accordingly.

Holding the rocket horizontally is usually the recommended way to avoid drops and runs, if you’re able. Sticking a dowel into the engine mount and holding the dowel is a common technique. For larger rockets, some sort of stand to hold the rocket is beneficial.

With Rusty 2x, I usually aim for 3 coats, 2 light and then one heavy, 10-15 minutes apart. Then give several days to dry before the next steps.

I will second forsure when using rustoleum 2x
2 light coats then A 3rd heavier and be patient inbetween coats 10-15 min is Perfect I have rushed it to more like 5 mins inbetween coats and that didn’t work out to well

 

[o1d_dude]

I always paint horizontally.

A length of metal tubing and a combination of pvc pipe and fittings. They don’t even need to be cemented together.

Adjustable to the length of your spindle pipe.

 

[David Schwantz]

All this is good advice, but color also matters. Much easier to cover with just a couple coats and a dark color, black, red, blue. A lighter color such as yellow takes many coats to cover.

 

[JohnCoker]

Here's a video that might be helpful:

 

[Spitfire222]

When I come across discussion about spray painting problems, a common theme I've noticed is that the user is simply not following the instructions on the can. You should not really have needed to do research, the directions are literally printed there in your hand. I've found that when I began considering those directions as things to do, and not merely suggestions, my results improved. Actually shake the can for 1-2 minutes, not just for 5 seconds before you paint. Actually wait the recommended recoat times (sometime as little as one minute). Actually hold the can away the distance the instructions say.

Like others have mentioned here, I generally get good results with 3-4 coats: the first few going on lightly and waiting a minute between, and then a final slightly heavier coat for good final coverage (which varies based on the specific color and brand being used). It does take practice to find the correct speed for the distance you're spraying from. Regarding your plan, slowly isn't necessarily better, and over one foot away might lead to less than satisfactory results as the paint particles might actually dry on their way to your model and you will end up with a less than ideal finish (of course, unless that is what the instructions recommend). Good luck, and don't get discouraged, it takes practice!

 

[neil_w]

Regarding your plan, slowly isn't necessarily better, and over one foot away might lead to less than satisfactory results as the paint particles might actually dry on their way to your model and you will end up with a less than ideal finish (of course, unless that is what the instructions recommend).

Wanted to reemphasize this, since I just noticed in the original post that you were talking about moving a foot away. That's pushing it.

Follow recommended distance on the can, and adjust speed as needed to get desired coverage without runs.

 

[gna]

I take old engines, 18mm, 24mm, and 29mm, and push them onto dowels. That way the engine hook can clip over and hold the rocket in place. I have used rolled up newspaper, too, as a handle. I hold horizontally when possible, and rotate the rocket. Light coats, keep the can moving. I usually wait 30 mins between coats, but maybe I can shorten it to 15 after reading this thread. 2 light coats then a final coat is enough.

I have used future to protect decals. It seems to work well either airbrushed or brushed on.

 

[neil_w]

I usually wait 30 mins between coats, but maybe I can shorten it to 15 after reading this thread. 2 light coats then a final coat is enough.

Yes, you definitely do not need to wait 30 minutes, and that pushes the third coat into the danger zone of the 1 hour recoat window. 10-15 minutes is fine, and frankly I don't think there's any problem with 5 minutes when you're covering light coats.

 

[gna]

Yes, you definitely do not need to wait 30 minutes, and that pushes the third coat into the danger zone of the 1 hour recoat window. 10-15 minutes is fine, and frankly I don't think there's any problem with 5 minutes when you're covering light coats.

I took the advice on the can to mean recoat within an hour, so up to an hour between coats. I reread my Rusto 2x, and it said something like "apply second coat within an hour", so not clear about third coat. Half hour seemed to work, but I like 15 mins better.

I just painted a rocket on my lunch break, and 15 mins between coats worked just fine.

 

[neil_w]

I took the advice on the can to mean recoat within an hour, so up to an hour between coats. I reread my Rusto 2x, and it said something like "apply second coat within an hour", so not clear about third coat.

What it means is finish painting within one hour from when you start. Past the hour mark, wait another 47 (I always wait at least another day or two on top of that).

When I spoke to them on the phone once, I could not get them to give me a *minimum* recoat time. 10-15 minutes "feels" about right to me, although I have pushed it shorter on a couple of occasions when I was in a rush.

 

[gna]

I imagine if it's cool out (40-50 F) one should wait a bit longer.

 

[neil_w]

If it's 40-50 F you shouldn't be painting.

(at least not with Rusto 2x)

 

[gna]

If it's 40-50 F you shouldn't be painting.

(at least not with Rusto 2x)

Hey, I live in Minnesota. One do what one can.

 

[David Schwantz]

Im also in MN, I paint when it 43 below

 

[PXR5]

I paint outside under a covered porch, so there are lots of sticks of various diameters lying around
Grab one and stick it up where the engine goes
Then I carry stick/rocket inside where an old vase holds the assembly

When I was a kid I got in trouble with Mom, because I put the rocket in a very expressive vase!

I still think of her when I do this

 

[Angel_of_the_Skies]

Many thin coats are better than few thick ones, so it's up to you to find a balance you can live with. At first, I would do about 4 coats. Now (after 15-20 rockets), I sand in between, still doing about 2-3 primer coats and 3-4 color coats. I'm never in a rush and enjoy the sanding part though, but that's me. Also, instead of holding the rocket by the engine hook, I would find the right size dowel and have a solid grip. It'd helpful for drying too.

You’re sanding in between every coat ? Doesn’t that take a gazillion years ? (I hope you’re talking about after ALL your coats are done drying

 

[Donnager]

You’re sanding in between every coat ? Doesn’t that take a gazillion years ? (I hope you’re talking about after ALL your coats are done drying

Gazillion, no. 3, Yes.

I tend to buff all my precoats with either 330 grit paper or scotch brite,. You can get a nice finish this way and the paint will find a nice home and lay flat and smooth.

Clear coat is a different animal.

 

[Hobie1dog]

Runs and drips typically mean you’re too close and/or moving too slowly. Adjust accordingly.

Holding the rocket horizontally is usually the recommended way to avoid drops and runs, if you’re able. Sticking a dowel into the engine mount and holding the dowel is a common technique. For larger rockets, some sort of stand to hold the rocket is beneficial.

There's a prominent YouTube person who was spraying a rocket vertically and his rattle can naturally had a vertical pattern, and he was wondering why he was getting so many runs. It didn't occur to him that he was putting a vertical line of paint on ,which was going to run down.

 

[SolarYellow]

I learned when I was a kid that moving the can across the tube makes it much easier to prevent runs. I mount the rocket with the airframe vertical and move the can side to side, making multiple passes up the side. Move around the tube, repeat. This prevents putting down a long stretch of paint that can build up and get heavy, leading to a run. Probably a little less efficient on use of paint, but it works well for me.

Also, never start or stop spraying on the rocket. Start the flow of paint and the motion with the can pointed off the side of the surface to be sprayed, so you get a consistent pattern of paint flow rate vs. speed of movement at all times that paint is hitting the surface. If you try to start the paint flow while it's pointed at the rocket, then start moving, you'll leave a pile of paint where the can was pointed when the flow started. This will run. Same with stopping.

 

[Angel_of_the_Skies]

I learned when I was a kid that moving the can across the tube makes it much easier to prevent runs. I mount the rocket with the airframe vertical and move the can side to side, making multiple passes up the side. Move around the tube, repeat. This prevents putting down a long stretch of paint that can build up and get heavy, leading to a run. Probably a little less efficient on use of paint, but it works well for me.

Also, never start or stop spraying on the rocket. Start the flow of paint and the motion with the can pointed off the side of the surface to be sprayed, so you get a consistent pattern of paint flow rate vs. speed of movement at all times that paint is hitting the surface. If you try to start the paint flow while it's pointed at the rocket, then start moving, you'll leave a pile of paint where the can was pointed when the flow started. This will run. Same with stopping.

This is key, else paint doesn’t smooth out or come out smooth. Also, starting on the surface could cause splatter of paint on your surface as once you press down on the nozzle, the first few streams of paint are not atomized properly