Let's Talk About Painting the LOC 4' Goblin

[mtnmanak]

Let's Talk About Painting the LOC 4' Goblin​

A 4 foot diameter Goblin? That is going to take a LOT of paint!

 

[ShadowSpire48]

I would never build a rocket without at least rounding the leading and trailing edges. Leaving them square just looks like heck to me, like someone couldn't even be bothered. If you're not going to round them, maybe don't even bother painting at all because it's a disposable rocket. Tips should be left square, as it's generally aerodynamically more efficient.

Another Acryli-Quik user here. I get mine from zoro.com. Set up/sign into an account, put it in your cart and wait for them to email you discount coupons.

I have found a significant difference in brightness of lighter (red and orange) top coats when going over white vs. grey primer. Yellow will be even more so. I use the AQ white primer under most any color coat.

I've used Rusto filler-primer, but don't like how it sands. @hcmbanjo has repeatedly posted his finishing techniques and uses Dupli-Color FP101 filler-primer, available online and at auto parts stores. Says it sands much better. My next build will use it.

Asterisk to all that is, I like the Rusto Golden Sunset color on the Goblin, and will be using it on the ones I build (different sizes). I've sworn off Rusto, except for that color. It's an enamel, so the AQ black likely won't play nice with it. I have a can of Ace brand gloss black to go with the GS. I should try the Ace white primer, too, since it's considerably cheaper and easier to get than the AQ white primer.

Certain rockets look good with different fin edges. The Goblin and Der Red Max look best with squared fins, they're not designed for altitude competitions.

 

[SolarYellow]

Certain rockets look good with different fin edges. The Goblin and Der Red Max look best with squared fins, they're not designed for altitude competitions.

Red Max is BT-60 with an 18mm motor mount, so I'm with you there. On the other hand, the Goblin is a fairly small rocket with a motor mount made to take the largest certified motor Estes had available at the time it was designed. So, although it's not an optimized design for maximum apogee performance, much of the love that there is for the Goblin is due to its flight performance.

 

[Stargeezer]

A 4 foot diameter Goblin? That is going to take a LOT of paint!

Ok ok it was a typo lol. Although that would be awesome.

 

[Stargeezer]

Instead of "adhesion promotor" I hit my cone with a propane torch like someone suggested in a prior post. It was scary but I did it and the filler primer stuck like a charm so I'm not disappointed.

 

[mtnmanak]

Ok ok it was a typo lol. Although that would be awesome.

Def too bad - would love to see a 4ft Goblin!!

 

[Wrightme43]

Instead of "adhesion promotor" I hit my cone with a propane torch like someone suggested in a prior post. It was scary but I did it and the filler primer stuck like a charm so I'm not disappointed.

Thank you, I will try this next time.

 

[John Kemker]

Instead of "adhesion promotor" I hit my cone with a propane torch like someone suggested in a prior post. It was scary but I did it and the filler primer stuck like a charm so I'm not disappointed.

And there's some very good science behind this. I read about it once, but can't honestly repeat it accurately, so I'll just say, "Yep! It works and it's supposed to, because, SCIENCE." LOL

http://roboticpaint.com/flame-treatment-in-plastic-painting/
I learned about it originally when making a SPAD: Simple Plastic Airplane Design. You made the wings out of corrugated plastic with the spars made out of wooden yardsticks. In order to get the plastic to adhere to anything, you had to hit it with a propane torch. Not enough to melt, but just pass over the plastic where you want the CA or epoxy to stick.

 

[ep29030]

In all my years of building I only had one nose cone adhesion issue (a Dynastar kit). All I ever did was wet sand the nosecone in the kitchen sink with 400 grit paper, dry it and use my normal Dupli-color Sandable Primer--same as I use on the airframe.

 

[RobertH3]

Sand plastic to 800-1000 grit.
Clean plastic nose cone thoroughly with 91%+ Alcohol. IMPORTANT.
Use Dupli-Color adhesion promoter from the auto store.
Per instructions, time the application of filler primer.
I had a some trouble with the plastic they use (PET I think) and this fixed it.
I waited too long after applying the adhesion promoter to prime the nose cone of Minie-Magg #1.
When building anything with PET plastic, follow the above.

Cheers / Robert

 

[SolarYellow]

And there's some very good science behind this. I read about it once, but can't honestly repeat it accurately, so I'll just say, "Yep! It works and it's supposed to, because, SCIENCE." LOL

http://roboticpaint.com/flame-treatment-in-plastic-painting/
I learned about it originally when making a SPAD: Simple Plastic Airplane Design. You made the wings out of corrugated plastic with the spars made out of wooden yardsticks. In order to get the plastic to adhere to anything, you had to hit it with a propane torch. Not enough to melt, but just pass over the plastic where you want the CA or epoxy to stick.

https://en.wikipedia.org/wiki/Flame_treatment

 

[Hobie1dog]

Instead of "adhesion promotor" I hit my cone with a propane torch like someone suggested in a prior post. It was scary but I did it and the filler primer stuck like a charm so I'm not disappointed.

And that is exactly what the adhesion promoter does. It softens the plastic.

 

[Stargeezer]

And that is exactly what the adhesion promoter does. It softens the plastic.

Propane torch was free though lol.

Anyway…rocket is coming along! Waiting on the blue glow spraypaint still. Won’t be here until next week. Then decals, motor comes Monday…then final weight and sims in OR.

Nosecone is not tucked into body as everything was drying in front of the fire. Will post a final photo once it’s all said and done. Thanks to everyone for their amazing help and advice. This is truly a special community of people.

 

[Hobie1dog]

With that being the same color as the sky, I hope you have a fluorescent orange parachute

 

[Wrightme43]

I think he is going glow in the dark blue from Kustom Canz. They say that stuff will glow for a couple day when charged in the sun. I have been wanting to try it too.

 

[Stargeezer]

With that being the same color as the sky, I hope you have a fluorescent orange parachute

YES my parachute is flourescent. And I considered the color but decided to stick with my chosen theme. I think all will be okay. And yes Wrightme43, I am using the Kustom Canz though I'm worried it will compete with the color I've chosen. I'm uncertain if that stuff sprays out clear or a shade of blue all its own. I'll find out next week!

 

[tsmith1315]

I think he is going glow in the dark blue from Kustom Canz.

Stargeezer is actually a she, as stated in another thread. An assumption we probably all made, especially after hearing about the torch! I imagine it would get tiresome correcting everyone.

 

[Wrightme43]

If I understand correctly it is clear, and best used over white basecoat. It shows blue glow, in the dark.

It should work over blue too.

Also my apologies @Stargeezer,
I didn't pay attention to detail.

 

[Stargeezer]

If I understand correctly it is clear, and best used over white basecoat. It shows blue glow, in the dark.

It should work over blue too.

Also my apologies @Stargeezer,
I didn't pay attention to detail.

No worries.

You think I should spray the Kustom Canz under or over the clearcoat?

 

[Hobie1dog]

No worries.

You think I should spray the Kustom Canz under or over the clearcoat?

The Kustom Cans coat is laid down first, the clear coat goes on top of the color

 

[Stargeezer]

I used the Custom Kanz Blue that was suggested and just wanted to update that this rocket glows extremely bright! This was held under my shop light for just 10 seconds if that. I’m excited to see what the sun will do. So neat! It’s not evenly glowing and looks a little splotchy due to uneven charging. This spray is powerful though for sure!

 

[Stargeezer]

It’s done. Now to assemble recovery, get a final weight and sim…drill motor and ready to go! The “Quantum” rocket lol.

 

[bjphoenix]

In all my years of building I only had one nose cone adhesion issue (a Dynastar kit). All I ever did was wet sand the nosecone in the kitchen sink with 400 grit paper, dry it and use my normal Dupli-color Sandable Primer--same as I use on the airframe.

I've not had any problems either. I might sand with 320 grit and then spray, or I might prime and then spray. I have an old rocket that I sprayed color directly on the nose cone and body tube without primer. Over time some paint has come off of the body tube but not the nose cone.
Of course YMMV and other people could have trouble that I didn't have.

 

[mcderek]

Congratulations stargeezer on your level one certification flight today! It was a beautiful flight. Good job!