"Diluting" CA for 'painting'...

Forgive me if this is too basic, but I've never run into this before.


The instructions on my rocket kit tells to paint the inside of the body tube after gluing in the motor mount. It instructs to use weak or thin CA, to 'fireproof' the portion that will be below the exhaust of the motor when fired.

I have only one bottle of 'Thick CA' that was purchased by another at a distant Hobby Lobby, and then given to me. (We have no Hobby Lobby in this area. But there is a Crafts 2000 45 miles east in the city in which I work. Would Joann's Fabrics stock 'thin' CA?)

Is it possible or advisable to "dillute" CA? How about stroking or 'painting' CA? Is there any method of cleaning a brush after doing this?

Just go get the Thin CA. You know they have it at your Hobby Store.

TopRamen said:

Just go get the Thin CA. You know they have it at your Hobby Store.

Click to expand...

+1!

Ditto on just getting thin CA... Or, I used epoxy around the bottom of my Estes Phoenix, just smeared it pretty thin using a Popsicle stick.

And if you go with Epoxy, get the Thin 20 Minute Finishing Type.

Kirk G said:

Forgive me if this is too basic, but I've never run into this before.

The instructions on my rocket kit tells to paint the inside of the body tube after gluing in the motor mount. It instructs to use weak or thin CA, to 'fireproof' the portion that will be below the exhaust of the motor when fired.

I have only one bottle of 'Thick CA' that was purchased by another at Hobby Lobby, and then given to me.

Is it possible or advisable to "dillute" CA? How about stroking or 'painting' CA? Is there any method of cleaning a brush after doing this?

Click to expand...

Sorry no! as previously stated go to the hobby shop and purchase a bottle of Water thin CA. Over time it will thicken if not sealed against air actually the moisture in the air which causes it to thicken.
I've started keeping all my CA's in zip-lok baggies which helps prevent or delay this process.

Also so you better understand the kit proposed process: Your actually not "Flame Proofing" your sort of creating a Phenolic plasitc out of the cardboard and CA. If you have medium CA it will do the same thing it just takes a bit longer to soak into the cardboard fibers.

I recommend foam safe thin CA. It has less fumes and is lo easier on the eyes and sinuses.

They'll have thin CA at your local hardware store


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wfcook said:

They'll have thin CA at your local hardware store


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Click to expand...

Upon re-reading it, I guess they said "A thin film of CA" which I mis-interpreted.
Of course, I could go to Lowes and get a small tube of "Crazy glue" or "Super Glue" to accomplish this.
Thanks for the nudge in the right direction.

I get the four-packs of super glue for a buck at Wal-Mart for this type of thing. Anything that's just using the glue as a strengthener or non-structural is fine, same ingredients as more expensive name brand stuff.

kyle said:

I get the four-packs of super glue for a buck at Wal-Mart for this type of thing. Anything that's just using the glue as a strengthener or non-structural is fine, same ingredients as more expensive name brand stuff.

Click to expand...

+1 It's the same no matter the label. 4 tubes for a dollar at the Dollar Store of your choice. You can use the gel type if you glove or I will use a plastic bag over a finger and work it into the paper, same with epoxy. This works really good on the top of the tube, too. Makes where the string passes over the edge a lot tougher.

Here's my take, everybody has their own methods.

I get the medium Super Glue small bottles at the Dollar Tree store, two for $1.00.
Squeeze out a drop onto some scrap thick paper or cardboard.
Dip a cotton Q-tip in the CA drop and use the Q-tip as a "brush" to spread on the CA.



While holding onto the Q-tip you can use the side of your finger as a depth guide against the body tube edge.
Don't use a regular brush, the Q-tips work fine and are thrown away after one use.
In the picture I'm just coating about 3/16" in, on the sides of your recessed engine mount your coverage should be deeper.
In this application, don't apply right out of the bottle and expect to spread it out. The thin stuff dries to quick.
The medium CA gives you a few more seconds to spread or brush it around.

Regarding thin CA -
It lasts a LONG time if you keep it in the refrigerator!
Be sure to block it in place. You don't want it to tip over and drip over everything.

UPDATE: The wife announced she was going to Joann Fabrics (we have a NEW one in town, after 5-10 years after the old one closed down!) and so I asked her to look for a SMALL bottle of "super glue" or "CA" (which I explained was the actual chemical name). She said she'd look if she could find it.

About two hours later she returned with a bunch of HER things, and announced that they had LOTS of various glues, including Elmers' and everything else that I could want. My heart sunk. But since I had asked her for a SMALL bottle, she got me the smallest bottle of Lock-Tight possible, with a long narrow neck for application. She said that was a better value than the $9 bottle, considering how little I needed at the moment. I agreed. I asked how much she paid, and she said it was about a $4 tiny bottle, but she had a 50% coupon for her entire purchases, and so it was something like $2.00 for the tiny squeeze bottle of an ounce or two.

I was delighted, read off the ingredients and assured her that the "Cyronacri....whatever" was the "CA" that we were looking for. I opened the package, twisted off the cap with no problem and immediately applied a drop or two right from the long thin nose to the inside of the body tube. It immediately soaked in and darkened the brown craft paper tube. I snatched up a cue-tip, as advised above, and "brushed it around" coating about a quarter of the way around the tube. I repeated this time and again, and found I hadn't used even half the tiny bottle and one cue-tip to do the entire surface of the bottom end of the tube, inside. I noticed also that the yellow fillet of Elmer's glue that I had used to secure the rear centering ring, clearly rejected the CA and remained firm... though I thought I detected a little yellow dissolving and staining my cue-tip.

Taking a tip from above, I also did a band around the top of the tube, but thinner and narrower... I realized the balsa nose-cone had to slide in and out easily...and didn't know if the additional layer was going to create a problem. So I stopped.

I set the rocket down to dry, capped the bottle easily and put it back in the package. After five minutes, I realized I was going to have a difficult time getting the Elmer's glue down between the body tube and a flat stablizer fin, but that I might be able to drip CA into the seam and strengthen it. So that's what I did.

And boy, did the fumes ever kick up. So I recapped it all, set the rocket aside to dry and let any drips evaporate.

Next step: Priming the exterior of all surfaces with White Valspar spray primer! (So, I'm on schedule for this project this weekend!)

Thanks for all the advice guys! It worked!

Kirk G said:

Forgive me if this is too basic, but I've never run into this before.
View attachment 187058

The instructions on my rocket kit tells to paint the inside of the body tube after gluing in the motor mount. It instructs to use weak or thin CA, to 'fireproof' the portion that will be below the exhaust of the motor when fired.

I have only one bottle of 'Thick CA' that was purchased by another at a distant Hobby Lobby, and then given to me. (We have no Hobby Lobby in this area. But there is a Crafts 2000 45 miles east in the city in which I work. Would Joann's Fabrics stock 'thin' CA?)

Is it possible or advisable to "dillute" CA? How about stroking or 'painting' CA? Is there any method of cleaning a brush after doing this?

Click to expand...

Micromeister said:

Sorry no! as previously stated go to the hobby shop and purchase a bottle of Water thin CA. Over time it will thicken if not sealed against air actually the moisture in the air which causes it to thicken.
I've started keeping all my CA's in zip-lok baggies which helps prevent or delay this process.

Also so you better understand the kit proposed process: Your actually not "Flame Proofing" your sort of creating a Phenolic plasitc out of the cardboard and CA. If you have medium CA it will do the same thing it just takes a bit longer to soak into the cardboard fibers.

Click to expand...

As most everyone knows, fire needs fuel (the cardboard body tube), oxygen (the air around us or is in the fuel) and heat to sustain its self.

The heat from an ejection charge is mostly blown out of the body tube when the nose cone is ejected.

The CA will almost completely prevent the card board body from being used as fuel as the momentary heat blast from the ejection charge blows by the CA saturated portion of the body tube.

Since the fuel source has been made fire retardant and the heat source is momentary, the chances of a fire are nil, You couldn't say the rocket is "fire proof" but you could say it's 100% fire retardant.