What is everyone using to fill body tube grooves?

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My choices:

Evercoat Formula 27 General Purpose Filler. You mix it with some kicker and it goes on like peanut butter...sets in 5 minutes, sands like a dream into a no-buildup powder. Sticks to everything. Downside is it has only 5 minutes of work time.

Available at your better boating and automotive stores.

Elmers General Purpose Filler in the white toothpaste tube is my backup...comes out thick, but if you dip your squegee in water, it is just enough to thin it out and it will fill pinholes well this way.

Available anywhere.

sand, primer, sand, primer, sand, primer, sand, and then paint.
Although I should say that I use Elmer's Fill-N-Finish, I am usually too lazy for that.....

Mostly it is cheapo Wal-mart primer, sanded, primed, sanded, etc, until they are gone.

Most of the time I use light drywall spakling paste. About 3 bucks for a quart tub.
I shoot primer via an airbrush in a stripe that follows the groove. When the primer (thinned latex house paint primer) sets, usually within 5 minutes, I shoot another coat just like the first, primarly following the spiral. Usually two coats gives enough build to fill the spiral, although at that point it won't *look* like it's filled. That is because the primer is "telegraphing" the groove to the paint surface. I let it dry - usually an hour - and then sand it smooth so mostly what's left is just the primer that's filled the groove, just slightly feathering out to the main BT surface. Now it's ready for final prime and/or paint.
What is everyone using to fill body tube grooves?

Huh??? You guys fill body tube grooves?? :confused:

You have way too much free time on your hands. ;)
Here's what I do, and yes, I may have too much time on my hands:

I lay a strip of tape on both sides of the spiral, apply the Fill-n-Finish just to the spiral, remove the tape and sand the narrow band of filler. Takes very little time to lay the tape and saves time by not having to sand a wide band of filler.

I've tried to fill the spirals with just primer, even high build primers like Duplicolor and several coats, but the spiral is always visable and I wind up filling them anyway.

I've got to try that. Sounds so easy why hadn't I thought of that before. Even with shallow spirals, primer just doesn't seem to get it all covered. Stop holding back and share some more of your building secrets with your old friend.
Huh??? You guys fill body tube grooves?? :confused:

You have way too much free time on your hands. ;)

Lame attempt at a joke :rolleyes:

Just because I sometimes only finish a rocket "good enough" doesn't mean that you shouldn't try for the perfect finish.
Originally posted by BobH48
Huh??? You guys fill body tube grooves??

You have way too much free time on your hands.

Joking or not, I agree. Many of the rockets I build are pre-destined to never make it into my 'permanent' fleet. When I build for school launches or other demos, or the cheapo kits where a can of primer would cost more than the rocket, or experimental rockets where I don't know if it's even going to make one complete flight, I skip the fillers.

Hey, live dangerously once in a while.
Bondo spot putty in the tube .. drys fast,sands very easy

I've used fill n finish but I seem to sand alot more of the tube away in the process, compared to the putty.
Have those of you who use spackle had any problems with it absorbing water and bubbling up when you hit it with a latex paint? This happened to me last year when I was painting the basement despite letting the spackle dry for 24 hours. I had to go back and sand all the spots down, cover with oil based primer, and paint the whole blasted wall again. Needless to say I *wasn't* happy.
Thanks for all the feedback! Went out to buy some light weight spackle after the guys at Home Depot and Lowes didn't have a clue what Fill n' Finish was. I did see some Bondo Car Filler but decided to try something a little cheaper first.
Thanks again.
You may notice with lightweight spakle that it is a bit too thick out of the tub. I add a small amount of water in a plastic cup and thin it out a little. It fills better.
You can even thin it to a soupy consitancy and use it to fill balsa grain, works great:D
Originally posted by rocketsonly
What is everyone using to fill body tube grooves?

I use the same Deft lacquer sanding sealer I use on the wood. After sanding the first coat and recoating (just like the fins), it's competely filled in.

If I hadn't discovered this, then like powderburner says, I wouldn't bother most of the time because it's not worth the effort considering the intended outcome.