The Path to Level 1: Acquisition, Build, Test, and Certification Attempt Thread

[SolarYellow]

Read here until you're tired of reading:

http://modelrocketbuilding.blogspot.com/search?q=spirals
I used this my first time filling spirals without any problem:
https://www.lowes.com/pd/3M-Patch-Plus-Primer-8-fl-oz-White-Patching-Compound/3851673
Just had to get the water mix right. Estes tubing.

 

[Doug Rocket]

https://cdn.imagearchive.com/rocket...6/476738-5ce6a28bb02ffab76aa48db1db1d5c80.mp4. Video

 

[rdrown]

^^^ This.

I use Duplicolor FILLER primer. Put it on heavy, sand smooth. Might have to do an additional coat if the spirals are real deep. I just finished up 2 rockets using it, and you can't see any evidence of the spirals at all. In addition, I put it on very heavy at body tube joints, and sand smooth.

It typically dries to the point of being sandable in under an hour.

Hans.

I have found a product called Kilz. It comes in a 13 ounce spray can and fills spirals great. It’s also about 5 bucks at my hardware store. Get the original, not the water based. Dries in about an hour and sands sooo easy. Also any paint I have tried sticks well and will not ”acne” on you.
Just my $.02 worth.
edit: changed 16 to 13.

 

[4regt4]

I have found a product called Kilz. It comes in a 16 ounce spray can and fills spirals great. It’s also about 5 bucks at my hardware store. Get the original, not the water based. Dries in about an hour and sands sooo easy. Also any paint I have tried sticks well and will not ”acne” on you.
Just my $.02 worth.

Never heard of it. (Image of me doing a deep dive into Google....)

Home Depot? Lowes? Ace?

Gotta try it.

Hans.

 

[rdrown]

Never heard of it. (Image of me doing a deep dive into Google....)

Home Depot? Lowes? Ace?

Gotta try it.

Hans.

I got mine at True Value hardware. Google shows 13 ounce spray can is $6.00.

 

[tsmith1315]

Home Depot? Lowes? Ace?

Any hardware store. May be with the canned primers, not spray paints. It’s made for home use- it “Kilz” mold & mildew.

 

[mikec]

Some people love Kilz. I mentioned it upthread. FWIW, my experiences were far from positive and I'll never try it again -- goes on way too thick, requires way too much sanding.

 

[smstachwick]

I sprayed on primer this afternoon. I’m hoping that sanding, priming again, and sanding once more will get this build and the thread back on track.

 

[Initiator001]

Some people love Kilz. I mentioned it upthread. FWIW, my experiences were far from positive and I'll never try it again -- goes on way too thick, requires way too much sanding.

That was my experience with Kilz. Lots of sanding plus lots of dust.

Went back to Krylon primer.

 

[Initiator001]

I sprayed on primer this afternoon. I’m hoping that sanding, priming again, and sanding once more. will get this build and the thread back on track.

View attachment 561883

You should apply some thin CA adhesive on the ends of the body tubes.

This will keep the paper from fraying and being sanded off leaving an obvious cosmetic issue.

 

[smstachwick]

You should apply some thin CA adhesive on the ends of the body tubes.

This will keep the paper from fraying and being sanded off leaving an obvious cosmetic issue.

Probably will end up doing that at some point. I wouldn’t want the ends to weaken a ton before I get it ready to fly.

I don’t suppose you would have had a specific recommendation for a filling method (everyone seems to have one)? Or are you more of a “whatever works” kind of guy?

 

[smstachwick]

Well, I sanded down the tubes,



made a dusty mess,



and I’m happy with the result. The finish seems pretty smooth, although I don’t really know if that’s because of the thin layer of primer dust or if 400 grit is really that good. I’ll probably clean the tubes off and start another another priming/sanding cycle over the weekend.

There are a few places where the spiral isn’t quite filled but for the most part it’s difficult to distinguish between the one that was printed on the tube and the one that was indented on it. One more round should do it, I think. I might even be able to just spot spray the areas that aren’t filled.

I’m also realizing that my technique of spinning the tube in my hand and sanding along the spiral was probably causing the putty to fall off, and sanding along the length of the tube may have been better. Oh well, something to try next time.

 

[smstachwick]

I took a slightly damp rag and wiped all the primer dust off, then dried the tubes with a microfiber. No immediately visible difference, but the texture indicates it’s almost completely clean. I wish I had thought to get a picture of the rag before I rinsed it clean.



I’m going to leave until at least tomorrow before I put on another coat of primer. I don’t need water or vapor interfering with the adhesion.

 

[4regt4]

I took a slightly damp rag and wiped all the primer dust off, then dried the tubes with a microfiber. No immediately visible difference, but the texture indicates it’s almost completely clean. I wish I had thought to get a picture of the rag before I rinsed it clean.

View attachment 562943

I’m going to leave until at least tomorrow before I put on another coat of primer. I don’t need water or vapor interfering with the adhesion.

You don't need to scrub all the primer off. I just sand until spots of the tube appear. In other words, it's almost totally grey, specks of white. Not the other way around. Then final coat of primer and paint!

From 1st application of primer until finish coat is just a few hours. Done.

Hans.

 

[smstachwick]

You don't need to scrub all the primer off. I just sand until spots of the tube appear. In other words, it's almost totally grey, specks of white. Not the other way around. Then final coat of primer and paint!

From 1st application of primer until finish coat is just a few hours. Done.

Hans.

Maybe I’ll do the next coat like that. On this one, the spiral had been giving me so much crap that I felt a strong need to bring down the high spots as much as possible.

 

[4regt4]

Maybe I’ll do the next coat like that. On this one, the spiral had been giving me so much crap that I felt a strong need to bring down the high spots as much as possible.

Just spray it on thick, sand. Done. Spirals are gone. I can post close up pics of a couple of my most recent builds if you want. You can't see any spirals. I spent maybe an hour total doing prep and primer.

Hans.

 

[smstachwick]

Just spray it on thick, sand. Done. Spirals are gone. I can post close up pics of a couple of my most recent builds if you want. You can't see any spirals. I spent maybe an hour total doing prep and primer.

Hans.

That’d be nice. That way I’d have a better idea what I’m shooting for on the next coat.

 

[4regt4]

That’d be nice. That way I’d have a better idea what I’m shooting for on the next coat.

Here's the fin can of a recently finished Leviathan. And a shot of the whole rocket in primer, and one of the forward body tube after the finish coat. This is the extent that I sanded the one and only coat of filler primer. After fillets done, I shot it with a thin coat of regular primer, then the black finish coat. No spirals at all. Hans.

 

[smstachwick]

Here's the fin can of a recently finished Leviathan. And a shot of the whole rocket in primer, and one of the forward body tube after the finish coat. This is the extent that I sanded the one and only coat of filler primer. After fillets done, I shot it with a thin coat of regular primer, then the black finish coat. No spirals at all. Hans. View attachment 562950





View attachment 562951


View attachment 562948View attachment 562949

Impressive. Thanks for sharing! I’ll give that a try and see how it goes. Lord knows I’ve got plenty of sandpaper…

 

[4regt4]

Impressive. Thanks for sharing! I’ll give that a try and see how it goes. Lord knows I’ve got plenty of sandpaper…

Was able to scrape some of the paint off of it on a landing in gravel yesterday...

Hans.

 

[4regt4]

Impressive. Thanks for sharing! I’ll give that a try and see how it goes. Lord knows I’ve got plenty of sandpaper…

Actually, you don't need loads of sandpaper. I've done everything on the last 4 rockets with a single 3 X 8 piece of 320 grit.

It's really that simple....

Hans.

 

[Zbench]

It’s not traditional but to whoever said to seal the tube first and then fill is on the right track. I’ve found the best thing to use for that is plain old shellac. Being as I use quite a bit of if for woodworking, I mix it up fresh from flakes but you can buy it premixed for cheap at Lowe’s. (That’s the active ingredient in kilz btw)

I brush on a coat and it’s dry before I finish as it’s dissolved in alcohol. I wait until it’s dry, maybe 30 min and then sand with 320 as it does raise the paper fibers a little. I then apply a second coat and sand again. When done, the spirals are nearly filled. All that might take an hour.

At this point I top coat with sandable primer and sand smooth and done. The advantage of the shellac is that it is extremely cheap and very durable. I haven’t found any process which is faster, but again it’s not a finish that is typically used for rocketry. As an added bonus it’s great for sealing fins as well. It’s a very versatile finish and is what all furniture was finished with before 1900.

 

[4regt4]

It’s not traditional but to whoever said to seal the tube first and then fill is on the right track. I’ve found the best thing to use for that is plain old shellac. Being as I use quite a bit of if for woodworking, I mix it up fresh from flakes but you can buy it premixed for cheap at Lowe’s. (That’s the active ingredient in kilz btw)

I brush on a coat and it’s dry before I finish as it’s dissolved in alcohol. I wait until it’s dry, maybe 30 min and then sand with 320 as it does raise the paper fibers a little. I then apply a second coat and sand again. When done, the spirals are nearly filled. All that might take an hour.

At this point I top coat with sandable primer and sand smooth and done. The advantage of the shellac is that it is extremely cheap and very durable. I haven’t found any process which is faster, but again it’s not a finish that is typically used for rocketry. As an added bonus it’s great for sealing fins as well. It’s a very versatile finish and is what all furniture was finished with before 1900.

Why not just hit it with a single thick coat of filler, sand, paint? It's absolutely glassy smooth. And it takes an hour, including drying time of the primers. It's incredibly simple. (Finish coat has to sit for a while...)

I just don't get why anyone wants to over complicate.

Hans.

 

[thzero]

Why not just hit it with a single thick coat of filler, sand, paint? It's absolutely glassy smooth. And it takes an hour, including drying time of the primers. It's incredibly simple. (Finish coat has to sit for a while...)

I just don't get why anyone wants to over complicate.

Hans.

You do it your way, other people do it their way.

 

[Handeman]

I didn't go through this whole OP thread, but it looks like another L1 build of a large MPR rocket. An Estes Leviathan MPR to be used as a L1 cert rocket.

It seem to me like you are spending way too much time and effort on building a large MPR rocket to use as a L1 cert and then you won't have any rocket to actually fly L1 motors on. What would you put a I161W or I284W into and how high would the rocket fly.

I just don't understand why you would you would build a L1 cert rocket that would limit you to baby H motors. Why not build something that you could explore the full range of L1 motors with?

Just my way of looking at the world. Do what is good for you.

 

[Zbench]

Why not just hit it with a single thick coat of filler, sand, paint? It's absolutely glassy smooth. And it takes an hour, including drying time of the primers. It's incredibly simple. (Finish coat has to sit for a while...)

I just don't get why anyone wants to over complicate.

Hans.

Because in my experience a single coat doesn’t completely fill the spirals, or even 2. Also because shellac flakes are extremely cheap and sandable spray primer is very expensive by comparison. Since both have volatile solvents that flash off at about the same rate, I like to apply a few coats of shellac first and then apply a coat of spray primer last to even it all out.

Either method is infinitely faster than the OPs method of attempting to laboriously apply and fill the spiral only.

 

[4regt4]

I didn't go through this whole OP thread, but it looks like another L1 build of a large MPR rocket. An Estes Leviathan MPR to be used as a L1 cert rocket.

It seem to me like you are spending way too much time and effort on building a large MPR rocket to use as a L1 cert and then you won't have any rocket to actually fly L1 motors on. What would you put a I161W or I284W into and how high would the rocket fly.

I just don't understand why you would you would build a L1 cert rocket that would limit you to baby H motors. Why not build something that you could explore the full range of L1 motors with?

Just my way of looking at the world. Do what is good for you.

Errr, NO.

The OP was about building an Astrobee D for L1. I posted pics of my Leviathan just to show painting techniques.

No relation at all. Your post does not pertain the discussion of filling spirals.

Hans.

 

[4regt4]

Because in my experience a single coat doesn’t completely fill the spirals, or even 2. Also because shellac flakes are extremely cheap and sandable spray primer is very expensive by comparison. Since both have volatile solvents that flash off at about the same rate, I like to apply a few coats of shellac first and then apply a coat of spray primer last to even it all out.

Either method is infinitely faster than the OPs method of attempting to laboriously apply and fill the spiral only.

A single *thick* coat of *FILLER* will fill the spirals. Regular primer won't. Take another look at the pic of the finished upper body tube I just posted and tell me again how a single coat of FILLER doesn't do the job.

Hans.

 

[Zbench]

A single *thick* coat of *FILLER* will fill the spirals. Regular primer won't. Take another look at the pic of the finished upper body tube I just posted and tell me again how a single coat of FILLER doesn't do the job.

Hans.

Hans,

Good for you! You seems to miss the point about cost. 20 years ago I bought 20# of blond shellac flakes for about $20. I still have about 15# left. I have enough to last several lifetimes and my initial investment was less than two cans of high end filler primer.

I’m happy your method works for you. My method works for me and is much, much cheaper.

 

[smstachwick]

I’m going to request that if there are more arguments to be shared, that they be put elsewhere. It’s great that we’ve all got our own approaches and I’ve been more than open to suggestions thus far, but I’ve made my decision regarding how to proceed. Thanks for your help guys, it has not gone unnoticed.

I see no reason for difference of style or preference to become a tension point in what started as a very personal thread.

Regarding my kit selection, I admit that I selected it with only L1 certification in mind. It might be a shelf queen after the certification flight, it might not. That said, there is absolutely nothing to stop me from, say, picking up an Apogee Zephyr or throwing together a scratch build that can take full advantage of what the L1 range has to offer. I do plan to push into the L2 range once I feel ready.