Related Finishing Questions

[RocketDad]

I have a couple of questions related to another thread here in relation to what we are doing.

As a result of reading a number of threads here my daughter and I are finishing our cardboard and balsa rockets with Duplicolor grey or maroon filler/primer, then two different colors of the Duplicolor Auto Spray Touch Up Paints: Silver and a Teal (like) Green.

The body tubes will be the green with a thin (1/2") silver stripe and the fins will be the matching silver.

Questions:

1. The green is a clear coat, but the silver is not. Is that a problem?
2. Which should be painted first? The silver (not clear coat) or the Green (clear coat)?
3. If the green should be done first, do I clear coat it before I masking tape it to spray the silver?
4. If I do the silver first, do I need to tape the body tubes first so that silver paint won't get on the area where the green is supposed to go? Or can I just spray the silver, and then mask the silver stripe and just spray the green over the extra silver paint on the body tubes? If I do the latter, will it create a "bump" where the green overlies the silver?
5. How many coats of paint should be sprayed? I did about three to four coats of filler/primer with sanding to remove the spiral grooves and such. I need to do the final sanding of the filler/primer, and I plan to use 320 dry for that sanding.
6. Can you clear coat a paint that isn't clear coat?
7. Assuming I clear coat it, is there another finishing product that will make the surface as smooth as possible? (Car wax or something)?

Thanks in advance.

Rocket Dad

 

[NjCo]

7. Assuming I clear coat it, is there another finishing product that will make the surface as smooth as possible? (Car wax or something)?

Not sure about all your paint questions since I haven't used that type of paint.

But if you are looking for a clear smooth finish I would recommend Future acrylic floor wax. I believe the product is called 'Pledge with Future shine' and is available from WalMart.

This is a wax free acrylic liquid that you can brush on your rocket. I used this on a rocket this summer as a test to see how it would improve the finish on an old rocket. It was very simple to apply and the end result turned out great. It looks a lot better than most of the rockets that I've applied a clear coat to. And you don't have to worry about all the finicky problems that can crop up when using rattle can spray paints.

I just applied the product with a soft 1" brush. The liquid flows over the rocket surface nicely. Unlike a paint product you don't have to worry about brush lines or runs and drips. If too much of the liquid gets on an area and it starts to bead up or run you can just dab off the excess with the corner of a paper towel. You have about 5 to 10 minutes of working time before the product begins to set so there's plenty of time to work over your finish. The only thing you have to watch out for is bubbles but those are pretty easy to remove with the corner of a paper towel. The drying time is 20-30 minutes and the end result is a smooth, shiny finish. I was very happy with my test and plan on applying Future to a number of other rockets.

 

[kjohnson]

If I understand the question right, and you want to celarcoat the green but not the silver, I'd suggest patinting the green, then celarcoating, then masking that and doing the silver.

kj

 

[rocketsmith]

Make sure you remove all dust with a tack rag before base coat. Paint the whole rocket silver,allow dry time, then spray on a suitable clear intercoat (same brand of clear). Allow to dry for at least 3 days (I wait a week) then mask all areas you want to remain silver. Make sure the green is compatible with the base coat, it should say on the can. Spray light coats of green over the silver until you get the desired color. Allow to dry for 2-4 hours then carefully peel away the masking. Allow to dry the appropriate amount of time and clear coat or use Future to protect surface. The ridges you get are somewhat unavoidable without following a multistage regiment of clears and color coats. Good luck.

 

[mkadams001]

Questions:

1. The green is a clear coat, but the silver is not. Is that a problem?
2. Which should be painted first? The silver (not clear coat) or the Green (clear coat)?
3. If the green should be done first, do I clear coat it before I masking tape it to spray the silver?
4. If I do the silver first, do I need to tape the body tubes first so that silver paint won't get on the area where the green is supposed to go? Or can I just spray the silver, and then mask the silver stripe and just spray the green over the extra silver paint on the body tubes? If I do the latter, will it create a "bump" where the green overlies the silver?
5. How many coats of paint should be sprayed? I did about three to four coats of filler/primer with sanding to remove the spiral grooves and such. I need to do the final sanding of the filler/primer, and I plan to use 320 dry for that sanding.
6. Can you clear coat a paint that isn't clear coat?
7. Assuming I clear coat it, is there another finishing product that will make the surface as smooth as possible? (Car wax or something)?

Thanks in advance.

Rocket Dad

Here are the answers that I have to offer...
1) That should not be a problem
2) I would paint the rocket silver first
3) If you did the green first you shouldn't need to clear coat the green.
4) No, paint the the entire rocket silver. You will get a bump. There are methods to reduce the bump or eliminate it altogether. Pulling the masking tape while the paint is almost tack free should reduce the bump.
5) The number of coats is determined on how well the paint covers the substrate
6) Yes, if the paints are compatible
7) Some people like the Future method. I have never tried this method, I normally just do a spray clear coat

The best route to go is to make a test board using the finishing methods that you want to use. Do everything the same as you did prepping the rocket then do the finishing techniques. This will give you an indication of what will work and if you are getting the desired results before doing the actual thing.

Good luck with your paint job.

 

[MarkII]

Doesn't clear coat lift metallics and make them look muddy? (I'm not sure if Future does this, though.) The standard rule that I have always heard is that you apply the metallic paint LAST. I would be very reluctant to put masking tape in a metallic color, because it is very likely to lift some or all of it. At the very least, it will mar the metallic sheen.

MarkII

 

[mkadams001]

Doesn't clear coat lift metallics and make them look muddy? (I'm not sure if Future does this, though.) The standard rule that I have always heard is that you apply the metallic paint LAST. I would be very reluctant to put masking tape in a metallic color, because it is very likely to lift some or all of it. At the very least, it will mar the metallic sheen.

MarkII

Since they are planning on using Duplicolor auto paints I don't think that there will be a problem. I would do the test board to make sure.

I personally have not had problems with metallics. However, I don't use the chrome type paints which behave differently than automotive type metallics.

 

[rokitflite]

If I understand the question right, and you want to celarcoat the green but not the silver, I'd suggest patinting the green, then celarcoating, then masking that and doing the silver.

kj

What he said...

 

[RocketDad]

I don't mind clear coating the green, but when we purchased the two paints, I didn't realize the silver was not labled clear coat, but the green one was.

Some of the questions above were more intended to find out if I can use the two side by side and if I do, what specificly I need to do to have it finish right.

What I've gathered (and please tell me if I'm wrong) is that you can clear coat a paint that is not labled clear coat, but you must clear coat a paint that is labled clear coat.

 

[luke strawwalker]

I don't mind clear coating the green, but when we purchased the two paints, I didn't realize the silver was not labled clear coat, but the green one was.

Some of the questions above were more intended to find out if I can use the two side by side and if I do, what specificly I need to do to have it finish right.

What I've gathered (and please tell me if I'm wrong) is that you can clear coat a paint that is not labled clear coat, but you must clear coat a paint that is labled clear coat.

Hmmmm... not sure on that one... that might be 'backwards'...

I'd tend to think you CAN (if you choose to) clearcoat paints labeled 'clearcoat', but you SHOULD NOT clearcoat paints NOT labeled clear coat. If in doubt, read the can instructions or ask the paint seller, if they know what they're talking about...

If the paint is REALLY chalky and powdery looking (not just 'flat' finish) and labeled 'clear coat' then yeah, you SHOULD clear coat those, because the paint is actually porous and NEEDS a clearcoat to seal it, and will be very soft and easily damaged without it.

I don't know of any rattle can paints that MUST be clearcoated. The silver will probably turn a dull gray if it's clearcoated, which is why it's recommended not to, but I don't know that for a FACT (do a paint test on scrap materials if in doubt). I did a clearcoat test on some Rustoleum "chrome" spray paint awhile back and it turned it to a really dull-looking almost transparent (could see sanding scratches underneath the paint, though the paint was smooth and 'shiny') gray metallic-y looking color. It was just a test on scrap tube, but it DEFINITELY would have wiped out a "chrome" rattle can finish. Silver paints in general don't seem to respond well to clearcoats, at least rattle-can formulations... if you get into urethane automotive finishes then you're in a whole other ballpark, but you need a compressor and spray gun to shoot them, so unless your painting a 15 foot tall HPR rocket, that's probably not a realistic option...

If in doubt, build a little cheap rocket like a mosquito or something and give it the same kind of paintjob you're planning to use on your 'nice' rocket... and see what works and what doesn't. Just make sure you remember (or better document) what you're doing, what you're applying over what, etc. and then repeat it on the bigger rocket when you like your results...

Good luck! OL JR

 

[NjCo]

What I've gathered (and please tell me if I'm wrong) is that you can clear coat a paint that is not labled clear coat, but you must clear coat a paint that is labled clear coat.

I think the part we are having problems with is most of us are probably not familiar with a paint that must be clear coated. I have four different types of spray paint on my shelf and only one of them even mentions a clear coat. That is the Testors Model Masters lacquer system which is designed to mimic automotive paint. To give your model a 'automotive' finish you would clear coat over these paints but it's certainly not necessary.

Maybe that is also the case with the paint you are using. You have chosen an automotive paint and these are normally applied with a clear coat finish over them. Now whether that clear coat is necessary for your nonautomotive application appears to be anyones guess. I'd say just try a test application on a piece of cardboard and see what happens.

 

[RocketDad]

OK. I think I solved this problem.

I returned the green clear coat paint for a green that is not labled clear coat and is very close to the original green we wanted.

So my plan now is to paint the rocket with the silver paint, masking tape with the blue masking tape the fins and the strip on the body, and paint the body tubes with the green on top of the silver.

Does this sound like a good plan?

also

When I masking tape the sliver area, how do I file down the ridge that will develop along the transition from the silver to the green? Can I use a buffing felt wheel on a Dremmel drill? Yes? No?

 

[NjCo]

When I masking tape the sliver area, how do I file down the ridge that will develop along the transition from the silver to the green? Can I use a buffing felt wheel on a Dremmel drill? Yes? No?

I have never messed with that little ridge. Seems like it would be a major pain in the butt to fix such a minor issue. I generally just try to use the thinest tape I can and that has worked well so far. I'm sure the buffing wheel would do something. You might try it with a test and see what happens.

 

[rockets2000]

When I masking tape the sliver area, how do I file down the ridge that will develop along the transition from the silver to the green? Can I use a buffing felt wheel on a Dremmel drill? Yes? No?

Unless you're putting more than 3 separate coats on, I don't think your ridge will be so bad that you would notice during flight. If you're after good looks, try the Future method. That should easily fill the ridges and make it shiny.

 

[hardinlw]

The best masking tape I've ever used is a Tamiya tape which will be found with the plastic models. It leaves a clean edge and does not lift paint. 3M makes a green masking tape that is better than the blue for rockets because it is not quite as sticky and is less prone to lifting paint.

To get a clean paint line, spray a light coat of clear after masking to seal the edge of the tape. If any of the clear bleeds under the tape, you'll never see it. I generally wet sand with 400 or 600 paper to get rid of the ridge left by the masking tape and then spray on clear to get the gloss back.

 

[Gillard]

The best masking tape I've ever used is a Tamiya tapeQUOTE]

Got to agree.
i've gone through every type of masking tape there is and had alot of leaks, bleeds and paint lifts. now i only use Tamiya and i have never had a problem since.

 

[rocketsmith]

When shooting automotive paint, an interstage clear coat helps prevent sanding into the base coat when trying to get rid of that ridge. I always shoot clear in between coats for this reason, then wet sand with 600 grit to provide some "tooth" for the top coat to adhere to. It helps with masking off , you tend to get tighter lines and it is less likely to pull away when removing tape. I then clear over the top of the second coat then sand down the ridge then more clear. Do the test board to get the hang of it first. However, the projects I am doing tend to be large, so I don't know how much time you want to spend on a smaller project. By the way, the clear green was probably a candy type paint that is designed to go over a silver base coat. Once you have seen these types of paint it's hard not to use them every time. The colors are just amazing. Good luck, be patient and I'm sure it will turn out great.

 

[RocketDad]

OK. As it turns out, we finished the rockets by painting the silver first, waiting three days, taping with the blue 3M tape (couldn't find the green tape), painting the green layers 2-3 coats, waiting a day and then removing the tape.

They came out nice, but there were a couple of problems.
1. The blue tape took off small spots of silver paint like everyone said it would. They were real small (< 1mm) but noticable.
2. We didn't have time to use the Pledge with Future Shine, so we didn't sand down the ridge created at the border between the silver and green paints.
3. The second can of green Dupli-color paint (identical to the first one) had a dull finish to it. It wasn't completely dull, but it didn't have the luster that the silver and the other green can had. We used this second can immediately after the first one was empty, so there was no change in atmosphere or technique. I went to purchase another can, but the local stores were out of that color.

As it turns out, we attempted to launch these rockets last Saturday. We got only 3 of 6 launches off and only got one good launch for data usage. It was way too windy, and it was a launch site we were unfamiliar with. It was an abandoned real estate development with knee deep grass and lots of streets for our rockets to unsafely land on. And that they did. We lost a nose cone on the payload tube and an $80 altimeter. Note to self: Never use a friction fit to secure the nose cone-- especially when an $80 altimeter is in it.

So we got them back-- sans one altimeter and nose cone, made repairs and resanded them. The finish is now silver body tube with fins, green payload and silver nose cone. No tape, no stripe.

We will use the Pledge with Future Shine to smooth them out for Saturday's launch, but our questions for that is in another thread.

Thanks for your help, guys! We learned a lot from this thread.

Oh... BTW: The project is testing the difference in apogees of two identical rockets, but one with a smooth finish and one with a very rough finish. The rough finished rockets (two of each finish in case one crashes) are painted with Rustoleum American Accents Stone paint. It is real rough with at least 1mm indentations all over the rocket.

Hopefully I can report some good results next week.

 

[hardinlw]

One of the standard boundary layer trips in wind tunnel testing is to mask off the model leaving the area you want to be rough exposed, spray with clear, and dust with sand of some appropriate grit. It's almost black magic and as people shift to computer modeling, few people still know how to do it. I'm not one of those, but I've seen it done. I would assume that you could use a similar trick but maybe use Elmers glue for the adhesive so you could remove one grit and replace with another so that a single rocket (or at least a small number of rockets) allows you to do all your testing. For our TARC rocket, we wrapped a layer of Top Flite Monokote trim sheet around the end of the payload section (that's to keep the body tube from being damaged when attaching and removing the nose cone) and then used 3/4" wide strips of Monokote trim to tape on the nose cone.