How do I fill seams on the body tube?

Hey guys,

real noob question here. I am building a TLP 2.6 Phoenix currently and have the body built. Before I begin with the fins, I want to seal all the wrap seams and the seams from the two body tubes coming together.

What can I use to seal these up while keeping the weight down?

Thanks

paul.nortness said:

Hey guys,

real noob question here. I am building a TLP 2.6 Phoenix currently and have the body built. Before I begin with the fins, I want to seal all the wrap seams and the seams from the two body tubes coming together.

What can I use to seal these up while keeping the weight down?

Thanks

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Elmers Carpenter Wood Filler. It's very light and sands easily to a very smooth finish. I use a sculpting tool and my finger to apply the CWF after it's thinned down with a bit of water. You could use a small brush. I cut up matching sized body tubes and use them as conformal sanding blocks. CWF does wonders on a balsa nose cone and fins also.

I use super lite or ultra lite or or whatever the maker calls their light spackeling. you can tell if it's the right stuff if the container feels almost empty. I wonder if the Elmer's is the same stuff or if it's heavier. I know it's sold in hobby shops and costs 3 times what it does at Ace or Home Depot. I thin it with water and brush it over the spirals. Stuff's real strange, sands very easy but let a little chunk dry then try to snap it apart. Very tough that way. And it does make good filler for balsa. Multi coat if you need to but I really like the lite spackeling for the job. Absorbs epoxies, primers and paint without reaction, too

dave carver said:

I use super lite or ultra lite or or whatever the maker calls their light spackeling. you can tell if it's the right stuff if the container feels almost empty. I wonder if the Elmer's is the same stuff or if it's heavier. I know it's sold in hobby shops and costs 3 times what it does at Ace or Home Depot. I thin it with water and brush it over the spirals. Stuff's real strange, sands very easy but let a little chunk dry then try to snap it apart. Very tough that way. And it does make good filler for balsa. Multi coat if you need to but I really like the lite spackeling for the job. Absorbs epoxies, primers and paint without reaction, too

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That's a great endorsment for whatever it is by whoever makes it. :wink:

So it's called super ultra lite spackeling? Got it! :wink:

Jokes aside, I actually think I know just the stuff and might have some on the shelf.

Thanks for the tips guys

Really depends on your family tolerance for smell & cleanup.

Elmers Wood Filler (or Fill n Finish) whatever it's being called this week. works wonderfully after thinning as bradycros posted.

Light weight wall and Ceiling Spackle works also but has it bit more crumbly. can also be thinned slightly with a few drops of water.

Midwest Balsa Filler.. Not Sanding sealer can also be used to fill seams and grain.

Adding Talc baby powder to Clear dope also works, as does chalk as a filler soild but that does add some weight.

Personally I haven't use a bit of filler material on any Model or LMR in more the decade, preferring to use Cheapy...less then a dollar cheap...Rattlecan auto primer to take care of all but the WORST body seams and balsa grain.
Spray 3 coats of primer letting each coat tac up about 5 minutes between coats, let dry completely (read the lable) and sand. repeat if necessary. Using thinner cheapy primers it usually takes a second set of 2 or 3 coats to completely fill normal depth balsa and glassine body tube seams. Since we sand almost all the primer off anyway the added mass of the primer is generally not an issue. the Drawback to this is the overspray and sanding dust. You'll have sanding dust with all but the overspray and perhaps the spraypaint smell may bother other in your house. I'm lucky enough to have a couple spray booths in the basement so these problems don't come up

I prefer to use Bondo spot putty to fill gaps and seams (but does have a stong smell).

dixontj93060 said:

I prefer to use Bondo spot putty to fill gaps and seams (but does have a stong smell).

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X2 and because of the MEK base,it works well for plastic nosecones as well as fiberglass & all woods.

Paul T

I use that Bondo for filling seams on scale aircraft models. Didn't even think about using it on a rocket.

Thanks

paul.nortness said:

I use that Bondo for filling seams on scale aircraft models. Didn't even think about using it on a rocket.

Thanks

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Tamiya putty is great for all styrene nosecones ,as in TLP kits.

Paul t

bradycros said:

That's a great endorsment for whatever it is by whoever makes it. :wink:

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Oh, absolutely. It's the same product under many names. Red Devil called it Super Lite. Ace calls it Ultra Lite. Light weight spackeling is not the same, it's much heavier. Like I said, if the container feels empty you have the right stuff.

Paul,

Couple of topics down has a great discussion as well:

https://www.rocketryforum.com/showthread.php?t=20835

Personally, I've been using Elmers Wood Filler since I've been a BAR. I've noticed for tubes, one good coat is enough...balsa requires 2 coats, both with a single good primer paint job afterward (using a standard spray can). I like Elmers mainly because it dries pretty quickly, it's easy to sand, and non-toxic...makes it TSA friendly (well, okay, it's an eye irritant - but so's a 300 pound woman with 'Juicy' written on her spandex pants...).

FC

I agree I think that Elmer's FnF is the way to go, but I did come across this stuff on Hobbylinc's website. I never used it, but thought I would post it....

Has anyone used this before?

https://www.hobbylinc.com/htm/hca/hcahcar3401.htm

pokerace721 said:

I agree I think that Elmer's FnF is the way to go, but I did come across this stuff on Hobbylinc's website. I never used it, but thought I would post it....

Has anyone used this before?

https://www.hobbylinc.com/htm/hca/hcahcar3401.htm

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That was the first stuff I got for filling spirals and balsa. It's light and comes more like a paste and wasn't real easy to work with. But adding water to thin it out so I could brush it on and it works pretty well. The only other techniques I've used is bondo and just multiple coats of primer and sanding.

MrGneissGuy said:

That was the first stuff I got for filling spirals and balsa. It's light and comes more like a paste and wasn't real easy to work with. But adding water to thin it out so I could brush it on and it works pretty well. The only other techniques I've used is bondo and just multiple coats of primer and sanding.

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So it's pretty much like FnF, but harder to work with?

pokerace721 said:

So it's pretty much like FnF, but harder to work with?

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Haven't used FnF, but from what I've read here on TRF, it sounds like pretty much the same stuff. It was much easier to work with once I added water to it to thin it out.

But it has taken multiple coats to fill the spirals and balsa, and part of me thinks it's easier to do multiple coats of primer with sanding between each coat. Bondo, for me anyway, has been the best. Typically with one coat of Bondo sanded, and then one coat of primer lightly sanded, I get a pretty good finish.