Painting papered fins

Lately I've read...and watched...a lot of tutorials about papering fins but none have explained about painting. Do I apply a clear coat over the fins before painting or do I just go ahead and paint the paper?

Put on a light coat of spray primer to seal the paper first.

ballistic_trep said:

Lately I've read...and watched...a lot of tutorials about papering fins but none have explained about painting. Do I apply a clear coat over the fins before painting or do I just go ahead and paint the paper?

Click to expand...

I just primer and paint normally... works for me.

As an aside, I use regular printer paper folded over the leading edge and held on with a super-thin coat of white glue. Works like a champ. Have yet to have one come loose...

I use mostly regular enamel primers (mostly the cheap Walmart Colorplace (which works just fine for me despite some of the dire warnings given here by some on the forum) and Rustoleum primers) and enamel paints (again, WM Colorplace and Rusto for the most part).

Later and good luck! OL JR

ballistic_trep said:

Lately I've read...and watched...a lot of tutorials about papering fins but none have explained about painting. Do I apply a clear coat over the fins before painting or do I just go ahead and paint the paper?

Click to expand...

Just my personal opinion, but I think your decision should be, or at least mine was, based on color uniformity. I've done several rockets with papered fins, both in #20 and #110 bond. The only ones I primered were ones where color uniformity was really important. One recent build, a 7-cluster Fat Boy, was painted semi-gloss black, and I did no additional prep before painting. Another, a modified Storm Caster, was sprayed with white primer, then a red-to-fade nose and a blue-to-fade tail (red/white/blue color scheme).

I just primer over them like I do the rest of the rocket, then after allowing it to dry, I sand them, re-prime/sand as needed, then paint.

I did have one fin that (using my method) bubbled when it was primed, but after letting it dry for a few days, it laid back down, and now I can't tell where the problem spot was.

why should papered fins be any different than a (craft)paper body tube , just don't sand into the paper when sanding your primer.
Rex

Rex R said:

why should papered fins be any different than a (craft)paper body tube , just don't sand into the paper when sanding your primer.
Rex

Click to expand...

Valid point, Rex!

Rex R said:

why should papered fins be any different than a (craft)paper body tube , just don't sand into the paper when sanding your primer.
Rex

Click to expand...

One potential difference, is that the kraft paper body tube has a glassine coating. Glassine is a type of paper that is resistant (but not impervious) to water. If you are using water soluble paint systems, papered fins can act less than stable dimensionally... you might get uneven swelling depending on the amount of glue that has soaked into the paper, causing a rough surface with swell-spots. The glassine coated body tubes are generally not hurt by using aqueous paint, unless the glassine is messed up. Since I paint with acrylic (water-based) paints, this is a potential issue. I've switched to the "Paper/saturate with CA" technique so don't have to worry about it.

on plain typewriter paper, two coats of primer - 400 grit sandpaper after the first and a Scotchbrite pad after the 2nd.

I also had one bubble that I used an Avery label on. Just put a couple LIGHT coats of primer or paint on them before you start laying the color coats on.

I use Avery full page labels, slap down the fins, cut around to size and CA the ends. Never had any problem priming or sanding.

The other material I use that I am now tending to sway to using more than Avery is a generic pack of matte photo paper. A little more work as I have to glue them but the end finish is nicer. I lightly glue the photo paper down with regular wood glue, squeegee out any excess glue, and put under some weight to dry. Prime, sand, prime, scuff with pad, and paint to a glass finish.

I put the fin on the label and then cut a fin thickness tab around each fin and fold it over. Then I use thin CA to seal them together.

Like others I just use spray primer and paint as I normally would. I use 20 pound stationery paper, which does show a surface texture when viewed close-up, but the strength and weight are so good, I don't worry about it.

I decided to try out a few of the methods I learned on this forum with an Alpha kit. I papered the fins with Avery label paper and they turned out really nice. But I noticed that after I applied the fillets there was some slight wrinkling of the paper....hardly noticeable but I'm doubtful it will sand out. Three out of the six fillets had some wrinkling just above the fillet. I want to stress that there was no wrinkling at all on the fins after they were glued to the BT and left to dry. I applied the fillets just as I have in the past and used my finger to smooth and remove excess glue. The glue I'm using is Gorilla white glue. Can anyone shine some light on how to avoid the wrinkling and why only half the fillets were affected?

Gorilla glue uses water to cure. Remember "Damp it"? That may have something to do with the problem you're having ballistic_trep.

You're using this:



not this:



right, ballistic ?

I don't paper alot but isn't one of the steps to seal the edges with thin CA ? Anyway I would probably just start the prime/sand cycle and see how it looks.

Yes, samb, I'm using the top one....the white wood glue. I sealed the outer and trailing edges with CA....I didn't try to overlap the paper on the trailing edge of the fins. But the attaching surface I left bare.....I wasn't sure if I should seal with CA or just simply glue it to the BT (which I did)...expecting the wood glue to act as a sealant.

K'tesh, aren't all white wood glues water based? If I had used an epoxy...would that have had a better result?