To fill those spirals or not fill those spirals…THAT IS THE QUESTION!

[JoeFilgas]

So there’s this question out in the model rocket community (LPR and MPR mostly)…..to fill those spirals or not to fill those spirals…that is the question? I’m not here to say yay or nay to either, but for myself and myself only I fillem’ up! For me it’s a challenge to make them disappear! I know full well most people won’t even notice, but I will. I’ll never say a word as someone else’s preference is just that…a preference. It may differ from mine, but who really cares? There’s no wrong answer here I’m just curious what everyone thinks. I’ve built these 11 rockets so far this year. Not bad for my first year of model rocketry I guess. Being forcefully retired due to a bad back I just feel blessed to be able to dabble a bit with numerous hobbies and I find model rocketry especially gratifying. Just wondering what you all think either way. Call it an informal and unscientific poll if you will. I do hope you’ll chime in with what you think!

 

[cls]

Beautiful!

 

[David Schwantz]

I hate to tell you this, but in the Mercury and the Saturn, I can still see the spirals.

 

[David Schwantz]

Ahh, just kiddin, your work looks really great. You have done a fine job at hiding them. What did you use? How did it apply?
I also like to fill them.

 

[prfesser]

I don't really hate filling spirals...but I do dislike it. A lot of work and time even with the one-part Bondo putty that dries to sand in an hour (gotta pick up some more, I'm almost out). But the results make it worth it, at least to me. The rocket looks less like a paper tube with fins, more like a "real rocket".

The main reason I was so upset when the dog "retrieved" my Interceptor E last launch was because of the time I put into finishing it, more than any rocket I've build so far. Lots of filling and sanding, then primer, only to find that a few spots were still visible, so fill again, prime, paint, coat again, and again, decals, and clearcoat.

If I put all the time, money, and energy into a good paint job I figure I might as well put the extra time into filling spirals and making it look solid. But that's just me.

 

[JoeFilgas]

Beautiful!

Thanks so much!

 

[JoeFilgas]

I hate to tell you this, but in the Mercury and the Saturn, I can still see the spirals.

You made me blink LOL!

 

[JoeFilgas]

Ahh, just kiddin, your work looks really great. You have done a fine job at hiding them. What did you use? How did it apply?
I also like to fill them.

LOL thanks so much! The larger rockets usually get the glazing putty treatment with a razor blade to press into the spirals followed by automotive filler primer (Iron Armor) from Harbor Freight. The smaller rockets I just use the same filler primer concentrating on the spirals and sanding until they’re gone.

 

[JoeFilgas]

I don't really hate filling spirals...but I do dislike it. A lot of work and time even with the one-part Bondo putty that dries to sand in an hour (gotta pick up some more, I'm almost out). But the results make it worth it, at least to me. The rocket looks less like a paper tube with fins, more like a "real rocket".

The main reason I was so upset when the dog "retrieved" my Interceptor E last launch was because of the time I put into finishing it, more than any rocket I've build so far. Lots of filling and sanding, then primer, only to find that a few spots were still visible, so fill again, prime, paint, coat again, and again, decals, and clearcoat.

If I put all the time, money, and energy into a good paint job I figure I might as well put the extra time into filling spirals and making it look solid. But that's just me.

I wholeheartedly agree with you and well said. Thanks for chiming in sir!

 

[RocketTree]

Some great looking rockets you got there!

I fill spirals on maybe half of the builds, depending what it is, but find myself doing it more often these days.

Tried some different methods:

-Tape off the spiral and brush on filler primer until built up, remove tape, sand.

-Spray filler primer, sand, filler primer, sand, filler primer, sand....

-Tape off the spiral and apply carpenters wood filler (mixed with few drops of water), remove tape, sand.

Now, I apply carpenters wood filler with a small paint brush (mixed with a few drops of water). Scrape it smooth with a credit card, reapply if needed. Sand.
Elmers wood filler seemed to be the easiest to apply and sand with quick drying time.

 

[les]

I hate to think the number of hours I've spent filling spirals, but I do it. Typically using Elmer's Fill and Finish

 

[Rocket86]

Fill them, always. It's not fun, but it's worth it IMO.

 

[JoeFilgas]

Some great looking rockets you got there!

I fill spirals on maybe half of the builds, depending what it is, but find myself doing it more often these days.

Tried some different methods:

-Tape off the spiral and brush on filler primer until built up, remove tape, sand.

-Spray filler primer, sand, filler primer, sand, filler primer, sand....

-Tape off the spiral and apply carpenters wood filler (mixed with few drops of water), remove tape, sand.

Now, I apply carpenters wood filler with a small paint brush (mixed with a few drops of water). Scrape it smooth with a credit card, reapply if needed. Sand.
Elmers wood filler seemed to be the easiest to apply and sand with quick drying time.

View attachment 617767

Thank you! And thanks for chiming in!

 

[teepot]

Some I fill, most I don't. If the rocket is supposed to look like it's made of metal I fill the spirals.

 

[bad_idea]

Fiberglass sleeves solve spirals for me, but they don't allow me to escape from any number of other cosmetic failings of my ham-fisted finishing.

 

[Dotini]

If I'm making a series of models for comparative data collection testing different HSR configurations, etc., I won't bother to fill the spirals. If they are stand-alone models for the permanent collection and appearance matters more than weight, I dutifully fill the spirals.

 

[SolarYellow]

Just do a HCMBanjo-style CWF or whatever you prefer on the tube before you even start building. That way, the fins don't get in the way.

 

[Capt. Eric]

Really nice job on those rockets. Fun and creative too. (I don't think there are a lot of Devo rockets out there!) I have a few of those kits too, but don't think I did quite as good a job.

If I need to get something together quick for a Club event or holiday, I may not fill the spirals. If I am trying to get a project to look as nice as yours, I take the time, using Minwax filler (the stuff in a tube that's about the consistency of toothpaste). I do the balsa fins too to get rid of the grain. Then 1 or 2 coats of filler primer.

 

[Greg Furtman]

 

[Promod117]

So, along the same lines, (pun intended!) what about the secondary spiral that is convex to the tube? I've noticed this on a couple 4" kits I'm working on.

 

[mtnmanak]

When I do fill in the spirals on LPRs, I like the thinned wood filler technique using an xacto blade that Chris Michielssen talks about on his site:

https://modelrocketbuilding.blogspot.com/
The Elmer's Carpenter's Wood Filler is great stuff, but this stuff from Australia blows it out of the water. Best wood filler I have ever found for use on rockets:

https://www.amazon.com/gp/product/B001NV7GRA
For anything with a 24mm motor mount and above, I usually just "paint" the rocket with a thin coat of laminating epoxy. It does add some weight (which is why I usually don't do it for 18mm and below), but it can leave your tubes and fins glass smooth like an FG rocket. Often, I also paint epoxy on the balsa fins of smaller LPRs - just makes it easier to get them smooth and stiffens them up a bit.

The trick is, painting a thing coat. Sometimes I paint all the epoxy on, then smooth and thin the coat using a felt covered squeegee.

 

[DerRedMax]

I don't do paper tubes anymore. Just go with Mac Performance Phenolic Canvas or any of the fiberglass rockets. No spirals to fill. Spend your time on finishing the quality fillets.

 

[SolarYellow]

So, along the same lines, (pun intended!) what about the secondary spiral that is convex to the tube? I've noticed this on a couple 4" kits I'm working on.

This has been an issue for me, too. There appears to be a void under it, so there's really no way to make a solid surface without cutting it out.

 

[Wild Bill emeritus]

So there’s this question out in the model rocket community (LPR and MPR mostly)…..to fill those spirals or not to fill those spirals…that is the question? I’m not here to say yay or nay to either, but for myself and myself only I fillem’ up! For me it’s a challenge to make them disappear! I know full well most people won’t even notice, but I will. I’ll never say a word as someone else’s preference is just that…a preference. It may differ from mine, but who really cares? There’s no wrong answer here I’m just curious what everyone thinks. I’ve built these 11 rockets so far this year. Not bad for my first year of model rocketry I guess. Being forcefully retired due to a bad back I just feel blessed to be able to dabble a bit with numerous hobbies and I find model rocketry especially gratifying. Just wondering what you all think either way. Call it an informal and unscientific poll if you will. I do hope you’ll chime in with what you think!

I have been covering my rockets, for the last 30 years, with TOP Flite Monokote.
It can be a problem covering round surfaces, but with a lot of practice the finish will be great, with no spirals.
https://www.rc-airplanes-simplified.com/monokote.htmlgood luck

 

[SolarYellow]

I've done three rockets with Monokote. At this point, I have to consider it less than successful. Without putting a bunch of fillers under it to smooth out the cardboard tube, it shows up all the roughness of the cardboard tube. Worse, it can't take the heat of ejection charges on the other side of the cardboard. The two more successful rockets are always recovered with the covering bubbling and wrinkled. On the good side, they take getting dinged and scraped very, very well and don't show the abuse of lakebed service that much. The other really nice thing, and what drove me down the Monokote path in the first place, is that they are quite light. The Monokote adds a lot less weight than I was getting with paint.

The completely unsuccessful rocket (tiny BT-20 with an A8-5) actually had the Monokote at the top of the airframe melted and shrunk away from the top of the tube due to the flame of the ejection charge wrapping outside the tube. I've had a slight darkening and loss of brightness when bright spray paint colors are used on similar rockets, but nothing like the failures of Monokote. I might use it again on hardwood-skinned or plywood fins in the future, but not likely on body tubes, especially thin ones (0.021-wall and thinner).

Rockets that are prepped and painted well look much better than rockets covered with Monokote, IMO. The challenge I have set for myself is in keeping them light and finding ways to make them more durable, so they don't show rash as quickly. I'll be playing with things like hardwood fin tips and CA soaking the perimeters of fins, for example.

It's surprising how easy it is to add an astonishing amount of weight to a rocket with paint. I've had a 9-gram body tube end up weighing 19 grams after it was painted. It was more than half paint by weight. That's when I tried Monokote, which was indeed much lighter. I'm going to be working on my process and technique to try to minimize paint weight while making the rocket meet my appearance standards.

I'm all about functional machines, but what kind of loser wants to fly a rocket that looks like they didn't even try to make it look good?

 

[Jmhepworth]

I have never filled spirals. I don’t believe I ever will.

 

[bjphoenix]

Some I fill, most I don't. If the rocket is supposed to look like it's made of metal I fill the spirals.

Estes and LOC tubes I don't worry about spirals. Somewhere years ago I got a piece of 2.6" phenolic tube with very big spiral grooves so I filled those with some leftover JBweld epoxy putty that I had, tedious and took a lot of time.

 

[tsmith1315]

So, along the same lines, (pun intended!) what about the secondary spiral that is convex to the tube? I've noticed this on a couple 4" kits I'm working on.

What brand of tube?

 

[Old School Doug]

My preference has been to fill the spirals every time. LPR/MPR gets the thinned CWF. LOC stuff gets Bondo spot putty. I typically spend a decent amount of time trying to get a good looking finished product. It's always rewarding to hear "damn you do nice work" when at club launches, knowing that the time put gets recognized (although I do it for my own satisfaction and not to impress anyone).

 

[suborbital]

So there’s this question out in the model rocket community (LPR and MPR mostly)…..to fill those spirals or not to fill those spirals…that is the question? I’m not here to say yay or nay to either, but for myself and myself only I fillem’ up! For me it’s a challenge to make them disappear! I know full well most people won’t even notice, but I will. I’ll never say a word as someone else’s preference is just that…a preference. It may differ from mine, but who really cares? There’s no wrong answer here I’m just curious what everyone thinks. I’ve built these 11 rockets so far this year. Not bad for my first year of model rocketry I guess. Being forcefully retired due to a bad back I just feel blessed to be able to dabble a bit with numerous hobbies and I find model rocketry especially gratifying. Just wondering what you all think either way. Call it an informal and unscientific poll if you will. I do hope you’ll chime in with what you think!

It looks like you are going for one-a-month rocket builds! And as a child of 50's and 60's cartoons, I got a real rise out of the "ACME" rocket, pardon the pun!
I also had back problems with a blown out L4-L5 disk, but I was extremely lucky to find a surgeon that was able to fix the problem for me, but you have my heart-felt sympathy for your suffering. It is good to see that you can still function, and even enjoy life with that.
On the spiral issue, I am in the "fill all spirals" camp. I personally enjoy seeing rockets that could pass for high art (I hope someday to achieve the finishes some of the masters on this site accomplish.) My wife accuses me of being a perfectionist, I believe the term she uses most often is "anal", whatever that means.