What is used to fill the spirals on a body tube

[ac2fv]

I'm starting a Loc Warlock build soon, and want to fill in the spirals on the body tube. What is a common/good filler to use for that purpose?
Thanks!
Scott
AC2FV

 

[Spitfire222]

Wood putty, carpenter's wood filler (CWF), or Bondo Spot Glazing putty all work.

 

[neil_w]

Welcome to the forum.

Such questions should be directed to the "Techniques" subforum, or perhaps the HPR subforum since that's a high-powered rocket. This forum is for meta-discussion of the forum itself.

As for spiral-filling techniques, @Spitfire222 covered it but there have been many, many, many threads about this topic, so a bit of searching should find you lots of good info.

 

[Titan II]

filling rocket tube spirals - Google Search

 

[hcmbanjo]

Here's a bunch of seam filling posts from my blog.

Model Rocket Building

modelrocketbuilding.blogspot.com

After the one pass of CWF (Elmer's Carpenter's Wood Filler) and sanding,
then a moderate spray of Duplicolor Filler/Primer (FP101) and sanding follows.
Two steps. Fill balsa grain, tube seams and even launch lug seams.

 

[neil_w]

Here's a bunch of seam filling posts from my blog.

Model Rocket Building

modelrocketbuilding.blogspot.com

After the one pass of CWF (Elmer's Carpenter's Wood Filler) and sanding,
then a moderate spray of Duplicolor Filler/Primer (FP101) and sanding follows.
Two steps. Fill balsa grain, tube seams and even launch lug seams.

FWIW this is where I started (thanks to Chris’s blog) and it worked excellently for me.

 

[samb]

Yes, water thinned CWF is what I use as well. Run, don't walk, to Chris Michielssen's blog for his detailed tutorial.
Avoid any Elmer's filler product with Pro or Max in the title, anything with real wood fiber in the ingredients.
FWIW, Elmer's CWF has disappeared from the Home Depots in my neck of the woods.

 

[fyrwrxz]

I really wanted to chime in with some sage advice from an old school rocketeer, hey, look! A squirrel!

 

[samb]

"Spirals? We don't fill no stinkin' spirals! ", said the old school rocketeer.

 

[Sooner Boomer]

It helps if you mask off the body tube, leaving only the spiral, plus a little on each side. That is, unless you *really like* sanding!

 

[hobie1dog]

It helps if you mask off the body tube, leaving only the spiral, plus a little on each side. That is, unless you *really like* sanding!

+1

 

[jahall4]

I'm starting a Loc Warlock build soon, and want to fill in the spirals on the body tube. What is a common/good filler to use for that purpose?
Thanks!
Scott
AC2FV

If you are going to make the effort, why stop at the spirals? ;-) Just filling spirals will not give you the glass like finish you see on part of the rocket below. Interested in what will?

 

[ac2fv]

Thanks to all for the advice. Smash ahead!
Scott
AC2FV

 

[John Kemker]

Funny you should mention that, as I just put a LOT of Bondo Glazing and Spot Putty on my LOC 4" Goblin. Thankfully, my 4" AMW Der FiberMax won't need spirals filled. [whew!]

 

[Back_at_it]

When I did mine I shot on three or four good coats of high build primer which took care of a bunch of the spirals. Once that was cured I used DAP brand wood filler and literally covered the entire body tube. Mine had an unusual amount of waves and bumps that needed to be addressed so covering the entire tube was the right thing for that rocket.

Good news is the DAP stuff sands extremely easy so a couple of quick passes with 100 grit knocked off the high spots then 220 and I believe 400 grit. If I had to do it again I would primer and fill the tube before building as handling a rocket that big with the fins attached wasn't easy.

Here are a couple of pics from that point of the build. You can see where there were low spots as there is still visible filler on the rocket.

 

[Lee]

If you are going to make the effort, why stop at the spirals? ;-) Just filling spirals will not give you the glass like finish you see on part of the rocket below. Interested in what will?

Okl - what will?

 

[jahall4]

Okl - what will?

All it takes are a few coats of filler primer sanding radial between each coat (depending of course on the surface of the tube and depth of spirals) Light coats sanded back to the high points. Will look something like the picture below. Resist the temptation of spraying thicker coats between sanding. All that will do is increase the amount of time you spending sanding. This technique works regardless of substrate and with glass you can wet sand. Always cradle the tube in something like a Macklin Jig. It Supports the tube and makes the sanding go faster, allows you to use 2 hands. I use Duplicolor Filler primer. Typically lay down a first coat in Red so I can see when I have sanded back to the base (https://www.duplicolor.com/product/filler-primer/)

 

[hobie1dog]

Thanks to all for the advice. Smash ahead!
Scott
AC2FV

After all the replies, what method are you going with?

 

[Angel_of_the_Skies]

All it takes are a few coats of filler primer sanding radial between each coat (depending of course on the surface of the tube and depth of spirals) Light coats sanded back to the high points. Will look something like the picture below. Resist the temptation of spraying thicker coats between sanding. All that will do is increase the amount of time you spending sanding. This technique works regardless of substrate and with glass you can wet sand. Always cradle the tube in something like a Macklin Jig. It Supports the tube and makes the sanding go faster, allows you to use 2 hands. I use Duplicolor Filler primer. Typically lay down a first coat in Red so I can see when I have sanded back to the base (https://www.duplicolor.com/product/filler-primer/)

Im always confused as to how much to sand off and when to reprime and sand again. Just finished my first MPR with ok results. Do you mind elaborating your process please ?

 

[jahall4]

Im always confused as to how much to sand off and when to reprime and sand again. Just finished my first MPR with ok results. Do you mind elaborating your process please ?

All the way back to the substrate as shown in the pics. You may have to do it multiple times, but every time is all the way back until the low spots aren't low anymore.

 

[hobie1dog]

since this 7-month-old rebirth it probably needs repeated that you can get the best results if you get a hard foam black Dura-Block made for sanding auto body panels and if you wrap some 320 paper around the bottom and just use the bottom perpendicular to the tube it will give you the best results.... as if you try using your fingers on sandpaper, and if you look at it in detail, it will actually be removing the filler material because of the pressure on your hands going down in between the spirals

 

[fyrwrxz]

I see nobody believed me about the squirrel...
(I'm filling playa rash on a half dozen birds and feel your pain. Just smile and keep on sanding...

 

[Angel_of_the_Skies]

All the way back to the substrate as shown in the pics. You may have to do it multiple times, but every time is all the way back until the low spots aren't low anymore.

Okay makes sense. I finished a rocket recently and I couldn’t tell how the low spots look like, do you have any prime examples ?

 

[jahall4]

Okay makes sense. I finished a rocket recently and I couldn’t tell how the low spots look like, do you have any prime examples ?

No pics I don't think, but I usually just use a spot light directly over the tube. Low and high spots become obvious. Mark lightly w/pencil as if you were shading a sketch.

 

[Angel_of_the_Skies]

No pics I don't think, but I usually just use a spot light directly over the tube. Low and high spots become obvious. Mark lightly w/pencil as if you were shading a sketch.

Okay makes sense, after my first coat, I did not notice any low or high spots, maybe I’m not looking hard enough, or perhaps this tube came out quite well from factory

 

[jahall4]

Okay makes sense, after my first coat, I did not notice any low or high spots, maybe I’m not looking hard enough, or perhaps this tube came out quite well from factory

If you sanded all the way back to the substrate you may not have had any. All depends on the substrate.