CA Reinforcement

I have read several times about using CA to strengthen balsa and fill in the grain. I even tried this on one occasion but my results were mediocre.

It seemed like thin CA was the way to go but it set up too quickly. The resulting fins were light and strong but the finish had lots of CA "warts" which were difficult to sand. I thought there must surely be a better way.

I remember being happy with the rocket until it had an unfortuante encounter with a truck on US 87. I'd like to revisit this option but am still in the dark as to the best way to apply the CA. Should I just drible it on?
Apply it with a sacrificed brush and hope it doesn't stick? Dip it in a CA bath?

How is this supposed to be done?

John, I've used both thin and medium CA, and I just put a few drops on the surface and "brush" it around with a piece of paper, cardstock, or even paper towel. For the edges of fins, I run the tip of the bottle along the edge and soak the edge. Whatever runs down the side of the fin I brush on as above.

Thin CA is probably preferable, since it soaks into the balsa better.

As for sanding, I just lay a piece of sandpaper on the table and slide the fin over it, which is pretty much the same way I sand plain balsa, too. My results have been pretty good, but I'm not extremely concerned with getting a glass-smooth finish on my rockets anyway.

Use thin CA and spread liberally with your bare fingers.

Seriously, I've never used it for grain filling, but I have used it to strengthen fins. For that, I just let thin CA wick in and sand the rough spots a little when it dries good.

If/when I use CA to harden, I do as JRThro says...run the tip of the bottle along the fin but I use the side of the bottle tip to spread. It works wonders on balsa nosecones too!!!

If you may be concerned with CA on your fingers, wear some rubber gloves while applying as you can get the gloves off easier than you can pull your fingers apart.

bigone5500 said:

If/when I use CA to harden, I do as JRThro says...run the tip of the bottle along the fin but I use the side of the bottle tip to spread. It works wonders on balsa nosecones too!!!

If you may be concerned with CA on your fingers, wear some rubber gloves while applying as you can get the gloves off easier than you can pull your fingers apart.

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Or if you hate gloves, keep some acetone handy. If your wife has regular fingernail polish remover, it has enough acetone to dissolve CA also. Just make sure she's not using the kind without acetone.

tbzep said:

Or if you hate gloves, keep some acetone handy. If your wife has regular fingernail polish remover, it has enough acetone to dissolve CA also. Just make sure she's not using the kind without acetone.

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^^^ what he said...

You can get it at wally world for around a buck...

I thank you all for the advice so far. Let me add to the questioning.

If I'm trying to slick the stuff around with a 3x5 or somesuch, wouldn't it make sense to do this before the piece is removed from the balsa sheet (assuming precut). that would give a bit more surface to hold on to and reduce, minimally, the danger of getting stuck on myself.

I do have gloves I use sometimes but when I use them, my already high clumsy coefficient goes way up.

Now I've gone and made a mess of it!!!!!!!!!!!!

After reading the previous posts, I got back to tonight's building. The 2 in process just needed another spray of paint and that left me with some time on my hands. I decided to open the Squirrel Works Space Ranger and get started on it. (Beautiful materials!)

One of the first things I notices was how thin and fragile the fins are. The balsa is good but delicate because of the thinness. I also noticed that the instructions say to round all but the root edges. Those poor things would never survive my aggressive assault so I decided to strengthen them with CA.

I thought I had read somewhere that it is a good idea to do this over wax paper because the fins would not stilck to that. I put out the paper. I then set the balsa sheet on it, gathered my carstock spreader and drizzled the CA on. I swished it about a bit and then tried to turn it over.

Look at the first sentence of the previous paragraph. WRONG!
Wax definitely adheres to CA. As I tried to clean up the mess, I also relearned that CA and wax and balsa and the placemat also adhere to me!

It appears that Gracie does not use nail polish but I remembered that my stepdaughter is always sneaking some in. I ransacked her bathroom and noticed that the wax hinders the setting of the CA just enough for the drawer knob to adhere to me as well. I didn't really notice this until i let go, removed my hand and had my hand refuse to be removed. THe drawer came crashing out and the 12 year old girl went running off to mom screaming about burglars. Now Gracie is awake, I am in more trouble and worst of all, my fins have little star shaped tattoos all over them. (It was CHristmas wax paper)

:cry::cry::cry::cry::cry::cry::cry::cry::cry::cry:

Do y'all know how hard it is to type with your finger tips sanded off?

If I harden fins with CA, I like to do it with the fin removed from the finstock sheet. This allows for application to the edge of the fin where the grain edge is thus allowing for maximum wicking effect.

bigone5500 said:

If I harden fins with CA, I like to do it with the fin removed from the finstock sheet. This allows for application to the edge of the fin where the grain edge is thus allowing for maximum wicking effect.

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Agreed, I like to run thin CA into the fin tips and let it soak the grain real good. As for using it as a filler, well it gets kinda messy. I have used it to fill/strengthen balsa nosecones like the big one on the Fliskits Deuce. Helps to keep it from getting all dented up.

Fins these days are cut with a laser. But older Estes kits used to use the "crush-dies" to mfg the fins...here is where thin CA wicked into the grains is really needed in my opinion, as the fins are pre-damaged from the factory.

Johnnie

JAL3 said:

Now I've gone and made a mess of it!!!!!!!!!!!!

After reading the previous posts, I got back to tonight's building. The 2 in process just needed another spray of paint and that left me with some time on my hands. I decided to open the Squirrel Works Space Ranger and get started on it. (Beautiful materials!)

One of the first things I notices was how thin and fragile the fins are. The balsa is good but delicate because of the thinness. I also noticed that the instructions say to round all but the root edges. Those poor things would never survive my aggressive assault so I decided to strengthen them with CA.

I thought I had read somewhere that it is a good idea to do this over wax paper because the fins would not stilck to that. I put out the paper. I then set the balsa sheet on it, gathered my carstock spreader and drizzled the CA on. I swished it about a bit and then tried to turn it over.

Look at the first sentence of the previous paragraph. WRONG!
Wax definitely adheres to CA. As I tried to clean up the mess, I also relearned that CA and wax and balsa and the placemat also adhere to me!

It appears that Gracie does not use nail polish but I remembered that my stepdaughter is always sneaking some in. I ransacked her bathroom and noticed that the wax hinders the setting of the CA just enough for the drawer knob to adhere to me as well. I didn't really notice this until i let go, removed my hand and had my hand refuse to be removed. THe drawer came crashing out and the 12 year old girl went running off to mom screaming about burglars. Now Gracie is awake, I am in more trouble and worst of all, my fins have little star shaped tattoos all over them. (It was CHristmas wax paper)


Do y'all know how hard it is to type with your finger tips sanded off?

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Oh man, that's rough!..I have 'hardened' a few fins using the CA method in the past-not great results so I have only done it twice..I didn't have a problem with it sticking to wax paper..I think you nay have used what I call a 'phantom' product- one which is labeled as wax paper but really isn't..I use the type of wax paper used in cooking!To be precise: Reynolds Cut-Rite Wax Paper..Lately if I want to strengthen the fin stock I paper it using the peel and stick shelf liner paper and have gotten good results from that..

I use a an old expired credit card to spread thin CA. I have tried a 3x5 index card before, but I get much better results from the stiffer and more sturdy plastic card.

I have never had a problem with it sticking to wax paper, just everything else. :argh:

SlingShot said:

I use a an old expired credit card to spread thin CA.

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My daughter gets Itunes gift cards all the time and redeems them on line. I use the old cards for "glue spreaders" and when it's all "gunked up", I just toss it and get a new one from her. An endless supply and much better than cardstock for spreading glue.

I have used a brush-on CA glue for many tasks but not (yet) for strengthening fins. Maybe it would meet your needs.

https://www.krazyglue.com/products/product_detail.asp?pc=KG988&g=3

I've seen it for sale in many supermarkets and home improvement stores.

JAL3 said:

If I'm trying to slick the stuff around with a 3x5 or somesuch, wouldn't it make sense to do this before the piece is removed from the balsa sheet (assuming precut). that would give a bit more surface to hold on to and reduce, minimally, the danger of getting stuck on myself.

Click to expand...

I usually add CA to balsa after the fin has been attached to the rocket, so I have lots of other stuff to grab onto. I use thin, and apply right from the bottle, working from tip to root across the cord of the fin. I usually tilt the fin so that the CA flows across the surface as it soaks in, to minimize the high spots. Then sand and paint as normal.

kj

Tom Swift said:

I have used a brush-on CA glue for many tasks but not (yet) for strengthening fins. Maybe it would meet your needs.

https://www.krazyglue.com/products/product_detail.asp?pc=KG988&g=3

I've seen it for sale in many supermarkets and home improvement stores.

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Bingo!!!!!!

THanks,

For brush on CA I have used Loctite brand. I find it sands easier and the fumes aren't as bad.
It can be found at Wal-Mart and Lowe's.

tonypv said:

For brush on CA I have used Loctite brand. I find it sands easier and the fumes aren't as bad.
It can be found at Wal-Mart and Lowe's.

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That helps too! Thanks

I have only used CA to harden edges, not flat areas, of cardboard tubes, balsa and plywood. Always after shaping and assembly. Applied directly from nozzle of bottle and quickly wiped off with paper towel, in a well ventilated area.

Had good luck with a - thin - layer of white glue and paper to harden sides of balsa fins. Press flat while drying. Makes the balsa stronger and easier to finish. No fumes.

For hardening, thin Epoxy works also very nicely, like West Systems slow (206). Gives you plenty of time to work it. Paint on balsa NC or anything else and sand. Re-apply and sand again. Now hard and ready to prime. Gloves and ventilation required.

John L., I say this with all due respect, your CA adventure tale above should win a TRF award for the funniest story of the month.

boris katan said:

I have only used CA to harden edges, not flat areas, of cardboard tubes, balsa and plywood. Always after shaping and assembly. Applied directly from nozzle of bottle and quickly wiped off with paper towel, in a well ventilated area.

Had good luck with a - thin - layer of white glue and paper to harden sides of balsa fins. Press flat while drying. Makes the balsa stronger and easier to finish. No fumes.

For hardening, thin Epoxy works also very nicely, like West Systems slow (206). Gives you plenty of time to work it. Paint on balsa NC or anything else and sand. Re-apply and sand again. Now hard and ready to prime. Gloves and ventilation required.

John L., I say this with all due respect, your CA adventure tale above should win a TRF award for the funniest story of the month.

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As I am sure you will appreciate, these things are a lot funnier when you read about them happening to other people.:rotflol: When they happen to me personally, we are talking about tradgedies that would put shakespeare to shame. Besides, his are much more believable.:surprised:

I do appreciate the tips. I just wish that either I liked the finishing process more or finishing were less time comsuming/easier. That way, however, lies the EX2 and RTF...