Paper shroud technique!

[Tramper Al]

I've probably built more than 50 rockets at this point, but my paper shroud skills are seriously lacking. I made a couple Camroc Carriers that came out OK, but it took a few tries. I have several exotic Centuri clones at the front of the build pile (Laser-X, Quasar, etc.) and most of them have a paper shroud to build. Yesterday I kind of botched the shroud for my Semroc Orion - the kit called for either white glue (lent to neighbors, not returned) or CA. So you can guess how that went.

Here is my question. One of these kits, in the original Centuri instructions / template, has a second tab on the shroud to help with assembly. They all have basically a full width tab on one end that you place under/over then other end for gluing, right? This one had a second narrower tab on the other end, and then you slice out a gap in the middle of the other tab (fold line) to receive it. Think of the way a cereal box top closes. Anyone have better success with this approach?

Anyway, I was thinking of trying this (second smaller tab) on my next couple of shroud attempts - if only to help with proper alignment before my adhesive gets me into trouble. I'd like to at least get my shroud skills to the point where I can consider CA brushing and/or seam filling for a better final result.

 

[Incongruent]

Here's a resource: https://www.apogeerockets.com/education/downloads/Newsletter349.pdf

 

[Tramper Al]

Here's a resource: https://www.apogeerockets.com/education/downloads/Newsletter349.pdf

Good ideas in there, thanks. And something to do with my imperfect first attempts.

Do you guys like white glue for this? I find the alignment to be tricky, so could use a few seconds of sliding/adjusting, and I invariable put some glue fingerprints down on the outside, over the flap.

 

[Trident]

I prefer to have a full length, separate tab backing the shroud seam. Basically I roll a shroud over a pencil or dowel to get the shroud to curve, then glue the separate tab onto the inside edge of one side of the seam, covering just half the tab. Then apply glue to the other half, and press the other edge of the shroud onto the tab, so that the edges align and form a smooth seam. The old method of having a tab as part of the shroud always produced an unsightly bulge for me.

 

[Tramper Al]

I prefer to have a full length, separate tab backing the shroud seam.

I will try this as well. I don't think I've seen it in a kit's instructions, surprisingly. It appeals to me in part because it will give me a very visible alignment to see on the outside, and as you say may leave less of a defect to try to mask later.

 

[Gary Byrum]

Al, here's my solution. Use white glue because Titebond grips too quickly. Second, my "old" method was to putty fill (Bondo) the edge of the tab overlay as seen in figure 1 below. This left an annoying bump in the shroud. In figure #2, this is the same exaggerated rear view of the tab overlay, but the shroud has been treated with multiple coats of CA. Once this hardens, you can sand that annoying bump off like the one produced in figure one. The end result is usually a smooth surface, You may still need a smidgen of Bondo, but the bump is gone.

 

[gpoehlein]

Check out my Project Paper thread in which I present a number of paper versions of classic Estes components (body tubes, noses and fins) to build several of the classic models. Also there is a set of instructions for how to build these parts. Although I haven't gotten to transitions yet, most noses are built from a series of transitions terminated by a cone.

https://www.rocketryforum.com/showthread.php?26616-Project-Paper&highlight=Project+paper

One other tip for building tubes and transitions is to use a covering iron. White glue can thermoset, and if you coat both the glue tab and the inside of the part with white glue (NOT school glue) and let dry, you can then seal the parts together with the iron. This works best if you cut the glue tab off and glue it inside both sides of the seam.

 

[K'Tesh]

More on Transitions...

[video=youtube;L6G34z5daHE]https://www.youtube.com/watch?v=L6G34z5daHE[/video]

And something from Transition:

[video=youtube;2XTBwvi0h2E]https://www.youtube.com/watch?v=2XTBwvi0h2E[/video]

 

[Micromeister]

2nd Trident's method for most paper, cardstock, 1/64" & 3/64" 3-ply Aircraft plywood transitions. This method creates a much tighter seam totally eliminating Gery's annoying bulge.

Full backed Glue tabs can also be pre-curled to fit the ID of the transition making full glue adhesion a bit easier. White Elemer's or White or Clear Aleen's Tacky glue do a great job on paper and Cardstock transitions.

 

[TangoJuliet]

Would someone kindly explain the difference between White Glue and "School" Glue? I thought they were one and the same. :confused2:

 

[rharshberger]

Would someone kindly explain the difference between White Glue and "School" Glue? I thought they were one and the same. :confused2:

Elmers School Glue is more water soluable than Elmers Glue All (current name of Elmers gp white glue), both are similar otherwise, the school glue just washes out better from kids hands and clothes.

 

[Tramper Al]

Elmers School Glue is more water soluable than Elmers Glue All (current name of Elmers gp white glue), both are similar otherwise, the school glue just washes out better from kids hands and clothes.

Maybe my best strategy is to start with the most benign and forgiving glue to get things lined up well with minimal mess and crimping. Then go back later and secure a little bit more with a soak-thru or inside fillet. Or the whole CA thing.

 

[K'Tesh]

I should have suggested that you make photocopies of the transitions with cardstock, then use those for practice, and possibly even as the shroud you actually use.

 

[TangoJuliet]

Elmers School Glue is more water soluable than Elmers Glue All (current name of Elmers gp white glue), both are similar otherwise, the school glue just washes out better from kids hands and clothes.

Thanks Rich.

 

[hcmbanjo]

I should have suggested that you make photocopies of the transitions with cardstock, then use those for practice, and possibly even as the shroud you actually use.

Ditto on this!
I usually make three of the same shroud then pick the best one to go on the model.
It's takes very little glue to hold a shroud together.
I've had good results using a glue stick, it allows for repositioning before the glue dries.

 

[Blades]

One of my favorite tools is the Template Widget by Matt Stum. Available here: https://archive.rocketreviews.com/tool_template_widget.shtml . Not only will it print any transitions, but it will also do fin guides and mitre guides as well. Terribly useful little program, particularly for scratch building.

 

[gpoehlein]

Maybe my best strategy is to start with the most benign and forgiving glue to get things lined up well with minimal mess and crimping. Then go back later and secure a little bit more with a soak-thru or inside fillet. Or the whole CA thing.

If you mean starting with school glue - don't. There IS. A difference between the two as far as joint strength goes. And regular Elmer's white glue will wash out of clothes just fine and cleans up with water. And don't forget the double glue bond with white glue (which, in my experience, is not as strong with school glue) where you coat both parts, let dry and then glue the parts together with a bit more glue. The joint will be stronger than the materials you are gluing together. Just keep the glue thin - more is not better with white glue. And you will be surprised how fast a double glue joint will grab and set up.

 

[bill_s]

I just did a 19" long, 5.5" to 2.2" shroud/transition/airframe from premium poster board. Total job took over 10 hours to lay out, cut, form, multiple glue stages including clamping the seam between a table and pipe, reinforcing rings, WEST painted outside and rear inside, attaching to the inner structure. Should have put a fiberglass cone inside the rear where the fin cuts will go, ended up painting a chopped fiberglass ring on the outside, hopefully it won't pucker too much when I start cutting. Haven't started fairing the seam. This thing's basically the entire rocket except for the NC.