Let's talk about acrylic coatings.

CA vs Acrylic Nail Polish:

I see you guys painting CA on everything, tube ends, fin edges, even entire nose cones. And I've been trying it.

It's very difficult to work with. It's thin, it drips everywhere, it gets on mu hands, sometimes I'm gluing my fingers to the part. The fumes burn my eyes. It goes on rough, and needs sanding (and then you're probably sanding most of it off anyway). Then I remembered that I used to use clear nail polish for that when I was a kid.

So I got some. It seems to be just as hard, it goes on smooth (it *was* formulated to be a coating,) the balsa sucks it up just like CA. If you get it on your fingers, you can just wipe it up. it even comes with an applicator brush!

Is there any reason you guys aren't using this stuff?
Do you know something I don't? (or do I know something you don't)

And about the Floor Polish:
I ordered the exact right stuff online. (couldn't find it locally) but I'm afraid to use it!

The last step of my usual construction process, involves several coats of Rustolium clear enamel, to seal in the decals. That gives me a really nice finish. Am I supposed to use the floor polish on top of that? Instead of that?? or- does my use of the enamel make the floor polish obsolete?

I will say this about CA, it gets brittle.
I personally use titebond on everything, even if I paper the fins.
Especially balsa nose cones it gives it a nice shell.
I have never personally used floor polish, but some here swear by it.
I prefer clear coating and if you want to slip through the air with a little less drag and keep the dust off...
Nothing works better than auto paste wax.
I imagine if you put floor polish on before your clear, you will have a major fish eye problem and a horrible mess.
(I did custom auto painting for 15 years, nothing sucks worse than wax or oil on any surface your painting)

Post your findings. I have used several balsa fillers and coats and find each to have their weaknesses and strengths.

Future floor polish would typically be instead of a sprayed-on clear coat, although there's nothing saying you can't use both. Future, being very gentle, can be applied over pretty much anything. I have good luck with it, and use it whenever I want a gloss finish. For matte, I'll use Krylon UV-resistant clear.

Many clear nail polishes are nitrocellulose. Just a heads up, check the label and maybe the flammability of a piece of scrap.

For those who use CA glue, and especially for filling, due to the quantity used, this outfit sells very good CA glue at excellent prices. I have used this stuff for years.

Specifically for (grain) filling, I use a paper towel (Bounty works well, and yes, there is some difference in behavior between brands) fold it into little squares, and wipe away, trying to be clean. I know people in the stringed instrument industry who use it for grain fill under nitro lacquer, and it works well. I use it sometimes for this purpose, but generally use a catalyzed polyester for grain filling.

I think the EM-150 is a medium thickness that a lot of luthier folks use for grain filling. Personally, I like the thinner stuff, and wipe on thinner, more manageable coats. The thinner stuff will penetrate more, and it is thin like water.

https://www.starbond.com/

Nitrocellulose lacquer is a great finish. If you are set up with a gun, it can be tinted with automotive 'candies', with Trans-Tint dyes, with industrial tints (not the stuff that tints latex and oil paint!) Clear Nitro can be tinted to give about any color, transparent to opaque. It can be used as a carrier for flake, pearls, and color changing powder. It sands easy, sprays easy, and wipes off with acetone if you mess it up. It does stink a bit, so some planning ahead of time is a good idea, as well as a good cartridge respirator and a clean-ish spray area. Also, it dries fast. In the long run, it is way, way better than rattle can paints.

I'm pretty sure that nitrocellulose lacquer can no longer be used as an automotive finish legally anywhere in the U.S., although it is still used on furniture.

Nitrocellulose lacquer is not an automotive finish, it never has been. I am not sure of the chemistry of what the automotive 'lacquers' are, but nitro is a completely different animal. I believe that automotive lacquers are also, still available, except not legal for professional use in some states due to VOC regulations, but we are not talking about that stuff. House of Kolor would be the source for automotive lacquers, as well as a source for numerous other killer (professional) finishes. By professional, I mean that it requires a spray gun and some experience in spraying, mixing, reducing. Automotive urethanes, catalyzed polyeaster, and some other finishes contain polyisocyanates, and those really are 'Professional only' as they Require the use of an air supplied respirator system, And some sort of spray booth system. Nitro is available everywhere.

Nitro could be used as a finish to do what you have done on your rocket, Nathan, and I think there is a chance that it may be the carrier of what you used. You mentioned it elsewhere, but I do not recall. I recall it beaing a lacquer based system? With nitro, I could do what you have done with that finish, with only the carrier, some candies (color), a base,
and some flake.

A few quick thoughts from my perspective:

CA: Love the stuff. But not as a glue. I use it to harden body tube edges as described in the OP. I use it as part of my fin papering technique (I use computer paper, lightly tacked with spray adhesive, trip paper onto fin, then soak with CA... when it cures it will be hard, sandable-to-gloss-without-fuzzies, and paintable by any method). I brush it onto balsa nosecones as a first step in getting the grain filled: the hardened balsa is much easier to sand after applying actual filler without fear of oversanding the balsa. I could go on and on. It's amazing stuff. But, used as a glue, it will get brittle. I never use it for structural bonding. Comes in many thicknesses, one just right for any application. Get it on fingers? That's what nitrile gloves are for. Burning eyes? That's what ventilation is for.

"Future" style acrylic polish: Also love the stuff. I sometimes use it in place of a clear coat. Sometimes for extra gloss on top of a clear coat. It DOES NOT cause clear sprayed on top of it to fisheye. I've tested this, because I sometimes use Future to help with decal application, followed by clear coating with either lacquer or enamel clears.

Nail polish: Yes, I've used these on occasion, but the formulations / solvents vary quite a bit out there, so one would need to be very specific about the brand and such. The great thing is you can get them in so many colors you can touch up dinged rockets easily. But no clear nail polish I've tried, soaked into balsa, is anywhere near as hard as CA soaked into balsa.

Happy finishing!

Chris_H said:

Nitrocellulose lacquer is not an automotive finish, it never has been. . .

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Well that's certainly not true. Just about every car made from the 1920's to the 1950's had a nitrocellulose lacquer paint job. See A Brief History Of Automotive Coatings Technology from the American Coatings Association.

Nathan said:

Well that's certainly not true. Just about every car made from the 1920's to the 1950's had a nitrocellulose lacquer paint job. See A Brief History Of Automotive Coatings Technology from the American Coatings Association.

Click to expand...

I stand corrected. I was thinking of acrylic automotive lacquer. The nitro that is commonly available now is mainly designed for finishing wood. I have sprayed upwards of a couple of thousand gallons of the stuff.

Marc_G said:

A few quick thoughts from my perspective:

CA: Love the stuff. But not as a glue. I use it to harden body tube edges as described in the OP. I use it as part of my fin papering technique (I use computer paper, lightly tacked with spray adhesive, trip paper onto fin, then soak with CA... when it cures it will be hard, sandable-to-gloss-without-fuzzies, and paintable by any method).
Happy finishing!

Click to expand...

Would you elaborate a bit on your papering method? What kind of brush works with CA? What kind of tacking adhesive? Do you think this technique would work with a 2-piece bass wood fin that are very thin and need to be reinforced since the are butt-glued?
Thanks

WFWalby said:

Would you elaborate a bit on your papering method? What kind of brush works with CA? What kind of tacking adhesive? Do you think this technique would work with a 2-piece bass wood fin that are very thin and need to be reinforced since the are butt-glued?
Thanks

Click to expand...

I use a couple variations. Sometimes I start with the fins already glued to the body tube, sometimes I paper them prior to attachment to the body tube. "It depends" is something of a mantra to me.

Let me start by saying my method works fine for multi-part fins, but I wouldn't paper basswood. Since the grain is so fine, and the wood so much harder than balsa, for basswood I just spray a few coats of high-build primer, sand down, and start spraying paint. If the two part fins (butt-jointed) have part of both fin-parts glued to the body tube, that adds a lot of strength and I don't think you have to worry or need to reinforce them.

But here's my method:

Take a piece of standard computer printer paper ("20 lb bond"). Spray it LIGHTLY with something like 3M Super 77 spray adhesive. Just enough that it gets some tack, to hold it to the fin material. DON'T SPRAY INSIDE. The overspray gets on everything.

Lay the fin on the paper, leaving 1-2mm of the fin along the root edge exposed. In other words, don't paper right up to the root edge, leave some space. Press the fin down to make sure it sticks well to the tacky paper. Trace the edges of the fin with an exacto knife, so that you release the papered fin from the remainder of the sheet of paper. Flip the fin, repeat the process. Now you have a fin that is papered both sides. Some folks prefer to wrap the paper around the fin, instead of the one side/flip/other side method, so that you have paper going around the leading edge. I like this, but it doesn't work for complex fin shapes.

Now, use wood glue and coat the root edge and the exposed 1-2 mm along the root mentioned above. Let the wood glue soak into the balsa, and leave it to dry completely before proceeding. This glue soaked edge will be attaching the body tube a bit later.

Go somewhere where there is good ventilation, and lay out some parchment paper or other CA-impervious layer to work on. Wear gloves, eye protection, and make sure the fumes won't be blown back at you. Put the fin on the parchment paper, and dribble Thin CA onto the papered part of the fin. You'll see it soak right through the paper and into the wood. Make sure to get the leading/trailing/outer edges saturated too. I use q-tips rather than brushes. Throw away the q-tip after each fin side, as the CA starts setting quickly on the q-tip. Once the fin is saturated, set it aside (on the parchment paper) to set. Work on other fins now. If it's at all humid, within 15 minutes the CA will have set and you can flip the fins and do the other sides.

Once the fins are fully cured (I usually leave them overnight), you can sand them smooth. The CA/paper/balsa is now a composite material you can sand without fear of fuzzies, including the fin edges where paper meets exposed balsa. If the CA soaked in correctly, you can round the edges just fine and there will be no sharp edge, if you wish to round them.

After you are done, lightly scuff sand the wood-glued root edge; it often will have a coating of CA over the wood glue. Now, proceed to double-glue-joint attach the fin to the body tube (which should have a dried layer of wood glue where the fin root will make contact). Put a thin layer of wood glue on the fin edge, press it into place onto the dried glue on the body tube, and hold for 30 seconds. It should grab.

I hope this helps; I'll be happy to answer any questions. Like I said, I wouldn't bother with this for basswood but it would work; I have done it once or twice.

Marc