Using CA to stiffen transitions and nosecones

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Marlin523

Well-Known Member
Joined
Jul 25, 2009
Messages
728
Reaction score
2
Can someone tell me how this is done? I've never built transitions and have never used CA. Thanks
 
using CA -thin stuff if possible, just coat whatever you want to harden up.
becareful not to over coat as the CA will run and you'll glue yourself, rocket, table together - best to have some debonder close to hand.
work in a ventilated area, CA gives off eye watering fumes.
 
There's some LokTite CA you can get that comes with a brush. Sniff around some local hardware type stores and you may find some. Experiment accordingly on scrap paper or cardboard until you get the hang of it.

As mentioned earlier, the thinner the better to help permiate the surface of whatever material you are trying to harden.

Learn some dextarity with surgical/nitrile gloves if you can, if not, keep some acetone or nail polish remover handy in case you end up instantly adheared to something you don't wish to be adheared to. Final note, keep some acetone/nail polish remover around anyway.

Not as hard as it sounds, just think ahead and be smart with CA. You'll be an "expert" the 3rd time you open the container.
 
When you need to do the hardening thing on larger surfaces you can thin epoxy with laquer thinner. The thinner stops the epoxy process until it evaporates off then the epoxy can harden. Thin the epoxy to where it "just" becomes watery then brush it on, it will soak in fairly deep, deeper that the CA will.

I make my fins on large projects this way and use Luan aka door skins to make fins from. The wood is Phillipean Mahogany and although it's a hard wood it's very permiable and accepts the epoxy with no troubles, well, except maybe it will take more epoxy that you think possible and the results are very tough. Phenolic is epoxy soaked paper so you can imagine how strong these fins can be.
 
Building paper transitions will take a little practice, but hardening them with CA is pretty easy. Like as was suggested above use water thin CA, use it sparingly and try not to glue any of your bits together.
 
I make paper transitions as hard as wood by using a second layer of paper over the initial cone glued on with brushed on epoxy. The second layer of paper is cut smaller than the first by omitting the overlap area and gluing it on either side of it. After it is dry I smear on thin CA using a plastic grocery bag over my hand(ink side in), the CA doesn't stick to the plastic. When it is cured it's hard enough for filler and sanding.
To achieve a rounder cone remove the overlap tab where it joins the tube/centering ring. This prevents the bump caused by the double layer of paper. Ted

kids and rockets 145.jpg
 
Go to apogeerockets.com/rocketry_video_tips.asp and watch Transition Section Construction parts 1,2,3 &4
 
Last edited:
OR, you can make them out of thin Styrene like I do and forget the CA for hardening. .010 works great on small projects.

Andrew
Dark Lord Of The Scratch Builders
 
Then go to rocketreviews.com and select the "Resources" box on left side of page. Select "Tool's and Calculators". Open "Body Tube Transitions Creator". Enter your measurments for desired size transition. Print out and practice, it's free!
 
OR, you can make them out of thin Styrene like I do and forget the CA for hardening. .010 works great on small projects.

Andrew
Dark Lord Of The Scratch Builders
Styrene is cheap but cardstock is MUCH cheaper. Plus you can print out the transition pattern onto the cardstock with your printer. I don't believe you can do that with styrene. Cardstock is also easier to glue together. If this sounds like I am down on styrene, don't worry; I'm not. I use it occasionally in my builds and would not want to be without it. I just think that cardstock has a number of advantages over styrene for transitions.

After the water-thin (Instant) CA cures, it usually produces a coarse white crust on the surface of the material. Although this is easy to sand off, it makes sense to apply the CA on the inside surface of the transition, if you can. (It isn't always possible to access the inside of the shroud, though.)

If you want to make incredibly tough, hard hollow transitions, you can also try using 0.011" thick G-10, a k a waferglass (thin fiberglass sheet).

MarkII
 
I agree with MarkII,
"Although this is easy to sand off, it makes sense to apply the CA on the inside surface of the transition, if you can."

It's easier and makes for a smoother outside surface - no cleaning up sanding afterwards.
 
Yep, card stock is cheaper, and yes you can print on it, BUT, it ain't no where near as easy to get a good transition from as styrene is.

What I do is print out the transition, tape it to the styrene and cut it out.

Another plus is, NO CA, very little sanding, smoother finish.

BUT, on the other hand card stock is great also. Just not my cup of tea.

Andrew
The Dark Lord Of The Scratch Builders.
 
Yep, card stock is cheaper, and yes you can print on it, BUT, it ain't no where near as easy to get a good transition from as styrene is.

What I do is print out the transition, tape it to the styrene and cut it out.

Another plus is, NO CA, very little sanding, smoother finish.

BUT, on the other hand card stock is great also. Just not my cup of tea.

Andrew
The Dark Lord Of The Scratch Builders.
BTW, what do you use to bond the styrene? A variety of materials can be used to make shrouds and transitions. Styrene is one of them.

Forming a nice, even cone from cardstock takes a little bit of practice, but it's not hard to do. And stiffening it with CA is really easy, even if you do have to sand it afterward. (Sanding it is really easy, too.) Even if your shroud comes out a little bit oval, sliding the tube through the top and inserting a centering ring in the bottom will make it round. It's easier if you do that installation before you stiffen it with CA. That is why I mentioned that it is not always possible to access the inside of the shroud in order to coat it with CA.

MarkII

P.S.: "Dark Lord?" I didn't know that there had even been a coronation. :dark: What happened to my invitation? :( :D
 
Last edited:
If you remember, I tried and tried to make transitions out of card stock with no luck, I then turned to styrene and have been making great looking transitions using Testors cement with great success. I say it's because of my little fat fingers that keeps me from doing well with card stock.

The tag line is my son's doing.

Andrew
Dark Lord Of The Scratch Builders
 
Cardstock Transitions are the easiest and cheapest way to consturct adaptors of any size AC. it does take just a little practice but having built more then I like to remember from all sorts of materials I have to second what Mark has already written.

.010" styrene is ok for some things but it's just not the ticket for most LPR or even MPR models. Cardboard or cardstock are far easier to roll, join and finish.

I have to differ slightly in the CA application. I've found it also added to the ease of application to use medium CA. I use Zap med CA but most any med should work just as well using a folded paper towel as a mop to spread and even layer all around the transition, into the seams and joints and even slightly onto the BT connection. Once you've got your even application set the part aside to air dry, do not use accelerator. Second and third coats can be added if necessary for strength or smoothing.
 
I have to differ slightly in the CA application. I've found it also added to the ease of application to use medium CA. I use Zap med CA but most any med should work just as well using a folded paper towel as a mop to spread and even layer all around the transition, into the seams and joints and even slightly onto the BT connection. Once you've got your even application set the part aside to air dry, do not use accelerator. Second and third coats can be added if necessary for strength or smoothing.
Never thought of that. I'll have to try it next time.

MarkII
 
Back
Top