Damaged body tube - repair?

[danielhv]

Completed my L1 yesterday at AirFest! My Zephyr flew great (compared to what little experience I have), and now I'm already planning for the next thing. I'm either going to setup the Zephyr for dual deploy, or build something new w/DD for my L2 in the future. The zephyr as some of you know, has fins that extend beyond the engine mount. Unfortunately when it hit the ground on landing, it looks like it transferred a bit of that energy through the fin and into the body tube which caused a little damage.
I'm looking for feedback on if I should attempt to repair this and move forward with dual deploy and more launches, or if I should just make this the H - I motor rocket and build something else for the L2 stuff... while I could sand and smooth this out, my concern is the integrity of the body tube, and since this is down below the front bulkhead of the motor mount, I can't get behind it to reinforce it.

 

[rcktnut]

Congratulations on the L1
I think you need a bigger chute! As far as rockets go, you just can't have one. As far as repairing if you sand it down wicking some CA into the "wound" might do the trick.

 

[kjhambrick]

Congrats on your Level 1 @danielhv !

Is the crimp located at the forward motor mount centering ring ?

That makes it tough to cut the tube, install a coupler and screw or glue it back together ( I try to use a single wood screw to reattach the fin can if possible ).

You know your rocket better than I. Is there a way to get a coupler in there ?

If not, I've got a Lil Nuke that landed hrd with a tangled chute in a bad place in Ocotillo and it crimped right at the fwd MMT Ring.

To repair it, I sanded it ; straightened it ; clamped it and then applied a fiberglass bandaide with epoxy

Someone in the TRASD Prefect suggested that I paint the bandaide in flesh-tone paint but I never did that -- It just didn't sound right with my yellow and black bumblebee motif

Anyhow, I was able to fly it many times more on 29mm H motors.

That one might still be in my rocket loft ... I'll have to look for it.

I am with @rcktnut -- maybe you need a bigger chute and more rockets ?

-- kjh

 

[mtnmanak]

Sand the area, "paint" some laminating epoxy around the area, sand, paint. Should be fine.

If you are really worried about it, get a cheap 5.5" coupler from LOC (https://locprecision.com/collections/rocket-components/products/tube-coupler?variant=39778656387263), cut it down to length so it would just cover the area above the fins and make a cuff that you can glue into place (sand the body tube, glue in place with wood glue). If the coupler tube is too big in diameter, cut it lengthwise and trim until the cuff wraps around the BT perfectly. you can fillet the forward edge if you want it to look like a seamless transition. Paint, done.

As noted above, get a different parachute. The 36" nylon parachute Apogee supplies with the kit is woefully inadequate. A 36" Fruity Chute Iris is way more expensive, but it has 3x the Cd of the Apogee chute and will bring your Zephyr down safely. Use attach points in your rockets that allow you to switch parachutes from one rocket to another and you can invest in good para's that will serve you for years on many rockets.

 

[danielhv]

Yea I looked at the Fruity Chutes at one point, big pill to swallow, but after this incident it seems I don't have much of a choice.

 

[danielhv]

As far as repair, I decided to cut the body tube as the damage is high enough that I can put a coupler in there to reinforce the tube, and I'll sand it all down, fill the joint, and repaint. As far as the decals, I guess they are all getting painted over or something. Kinda regretting clear coating them in!!

 

[Pinetree]

I think just about everyone clear coats over their decals.. if all else fails you can just chalk it up to experience, and build another rocket.

As far as the chute goes, it's an investment... assuming you don't lose the rocket you can use that parachute on any other rockets you may have in the future..

 

[Handeman]

It just hit me looking at @danielhv pic. The recommended coupler length is the shoulder should be equal to the caliber of the BT. That sound great for slip couplers. What about ones glued in place to do repairs. Do you really need 1 caliber length or is a 1/4 caliber, or even shorter, sufficient for a glued up repair?

 

[kjhambrick]

It just hit me looking at @danielhv pic. The recommended coupler length is the shoulder should be equal to the caliber of the BT. That sound great for slip couplers. What about ones glued in place to do repairs. Do you really need 1 caliber length or is a 1/4 caliber, or even shorter, sufficient for a glued up repair?

Good Q, Jeff.

I cheated on my Vulcanite where I couldn't get a full caliber of coupler length below the cut because of the location of the top C-Ring.

The short aft end of the standard 54mm LOC coupler is epoxied in.

That repair with a single wood screw above the break is still holding firm without any wiggle for 25 years now.

Note that the forward end with the screw actually has more than a caliber of coupler length ...

Awaithing opinions from the group !

Thanks for asking a Q that I forgot about @Handeman !

-- kjh

 

[jmasterj]

Yea I looked at the Fruity Chutes at one point, big pill to swallow, but after this incident it seems I don't have much of a choice.

You can buy much less expensive chutes that will work fine. You just need a bigger one. Try top flight or rocketman.

 

[troj]

As far as repair, I decided to cut the body tube as the damage is high enough that I can put a coupler in there to reinforce the tube, and I'll sand it all down, fill the joint, and repaint. As far as the decals, I guess they are all getting painted over or something. Kinda regretting clear coating them in!!

When you go to install that coupler, put a thin coat of glue on the body tube where the coupler will be in contact, as well as on the coupler itself - put that thin coat on everything. Do it quickly, slide the coupler in, then slide the upper body on.

The reason I say this is that I've peeled apart rockets that have had the glue applied to just one surface and been slid in - you end up with dry spots.

Cutting it like you have and installing a coupler, that'll be nice and solid.

-Kevin

 

[kjhambrick]

You can buy much less expensive chutes that will work fine. You just need a bigger one. Try top flight or rocketman.

@jmasterj --

Yes, I like the Top Flight bang for the buck ratio (*).

Or if you're so inclined, there are great threads here on TRF documenting do-it-yourself chutes.

-- kjh

(*) -- is it OK to use the bang-word when discussing parachutes ?

 

[kjhambrick]

When you go to install that coupler, put a thin coat of glue on the body tube where the coupler will be in contact, as well as on the coupler itself - put that thin coat on everything. Do it quickly, slide the coupler in, then slide the upper body on.

The reason I say this is that I've peeled apart rockets that have had the glue applied to just one surface and been slid in - you end up with dry spots.

Cutting it like you have and installing a coupler, that'll be nice and solid.

-Kevin

Thin coats of Wood Glue or Elmer's on couplers is a method I have avoided ever since I got one stuck where it did not belong.

Is there a trick to it @troj ?

Or did you mean Epoxy glue ?

Thanks.

-- kjh

 

[troj]

Thin coats of Wood Glue or Elmer's on couplers is a method I have avoided ever since I got one stuck where it did not belong.

Is there a trick to it @troj ?

Or did you mean Epoxy glue ?

You can use wood glue or Elmer's.....but you need to move quickly. Or, as you've discovered, they get stuck.

Epoxy is the easiest. What I like to do is dribble some in place, the use a popsicle stick on its side to squeegee it into a thin layer. Epoxy gives you more working time, making this easier - use 20 minute or longer working time epoxy.

-Kevin