Papering fins, adhesive label paper vs glued on paper

[Bill S]

I'm giving some consideration to papering the fins on my Estes Executioner, and wanted some advice. The kit comes with 1/8" balsa fins, and I'm a bit concerned that the fin tips will take damage upon landing. I am considering papering the fins, but I'm not sure which way I want to go with it.

It seems to me that using adhesive label paper and using CA on the edges would be easier, but I seem to recall reading here that using white glue, while much messier/trickier to do, is stronger.

Lastly, are my concerns about damaging the fin tips justified or not warranted?

 

[K'Tesh]

I'll just drop this here...

https://www.rocketryforum.com/threads/papering-balsa-ply-fins-a-foolproof-method.65628/

 

[lakeroadster]

I'm giving some consideration to papering the fins on my Estes Executioner, and wanted some advice. The kit comes with 1/8" balsa fins, and I'm a bit concerned that the fin tips will take damage upon landing. I am considering papering the fins, but I'm not sure which way I want to go with it.

It seems to me that using adhesive label paper and using CA on the edges would be easier, but I seem to recall reading here that using white glue, while much messier/trickier to do, is stronger.

Lastly, are my concerns about damaging the fin tips justified or not warranted?

White glue will bond the paper fibers to the fin fibers.

Adhesive paper is only as good as whatever the adhesive is.

Here's a link to how I papered the fins on my Hammerhead Shark... It's really easy to do. Hope that helps.

Papering Fins

 

[Daddyisabar]

Lable paper is quite sticky. A good seal on the edge with CA and I nave never had any problem through mid power.

 

[o1d_dude]

My personal experience with label paper was less than satisfactory. During hot weather, the label paper “bubbles” up on the fins.

I’ve tried piercing the bubbles with pin holes but no joy. The bubbles simply pop up somewhere else.

The fins that were papered with glue and bond paper were far more durable and remained “stuck”.

YMMV.

 

[afadeev]

White glue will bond the paper fibers to the fin fibers.
Adhesive paper is only as good as whatever the adhesive is.

Gluing for strength and durability.
Adhesive labels for ease of handling, and speed of application.

I use TiteBond II to glue all my (printer) paper skins to balsa fins. Sometimes, I print a design onto that paper, then glue it to the balsa fin cores, for both strength and looks.
In the past, I had tried adhesive labels as well, but found them to be thicker and trickier to blend with the edges of balsa fins.

Both paper layer types get CA treatment to seal all exposed edges.
If you need really strong fins, you can CA seal the entire surface of the papered skin. But that requires much more sanding afterwards (CA is hard to sand).

YMMV,

 

[Ronz Rocketz]

My personal experience with label paper was less than satisfactory. During hot weather, the label paper “bubbles” up on the fins.

I’ve tried piercing the bubbles with pin holes but no joy. The bubbles simply pop up somewhere else.

The fins that were papered with glue and bond paper were far more durable and remained “stuck”.

YMMV.

I’ve used label paper on about 8 rockets. The first four had no bubbles and recent had. With 2 layers primer and 2 layers paint, it’s hardly noticeable. I wondered if there was something to treat the balsa but then, might as well glue paper. It might have to do with the humidity lately. Summer’s ending so we’ll see.

The thin CA is great because it leaves a better finish than just the primer on bare balsa edge. It often smokes as it runs along the edge, so good ventilation...

 

[heada]

70 lbs Kraft paper saturated with universal wallpaper paste and then the grain broken by crumpling up. When spread over balsa and applied to both sides it gives the strength of plywood but the weight of balsa. I also apply it as tip to tip with thin CA on the edges of the balsa for rockets going near trans-sonic.

 

[Lugnut56]

I've papered the fins on about a half dozen rockets, and for the most part have been happy with the results. On most of them, I've rounded the leading edge and wrapped the paper over the leading edge. I use TB II (use too much and the paper will wrinkle , use too little and the edges will lift). After applying the paper, I'll run over the surface with a round object (a king size sharpie works perfect) to work out any bubbles or wrinkles. Then put under some weight to try and prevent warping. On fins without rounded leading edges, pretty much the same procedure except I apply glue to the one side of all the fins and place on a sheet of printer paper. Then apply glue to the exposed side and place a sheet of paper on top . Burnish the fins with something round and place under some weight, then cut out with a sharp knife. I have had good luck doing this without using CA on the edges, but like using hair restoration products, results may vary.

 

[OZRoc]

Label paper all fins w/ overlap on the edges (paper wider than fin) (Use a hard roller to ensure bond) Trim paper back to fin.
Do not paper TTW roots
NOTE: Special care needed on large areas (wings, etc)
Sand edges as desired.
Wick CA to all faired edges with Q-tip.
Sand all faired edges (320G)
Repeat as necessary.
Job's right.
Cheers,
Mark

 

[Bill Heath]

Adhesive label paper is pressure sensitive. Clamp the papered fins between 2 boards for 24 hours. No bubbles, no lifting. No problems.

 

[Ronz Rocketz]

Adhesive label paper is pressure sensitive. Clamp the papered fins between 2 boards for 24 hours. No bubbles, no lifting. No problems.

Some reasons I thought of why bubbles formed under the label paper.
1. Not enough clamp pressure.
2. humidity
3. I initially was using the NCR airfoil sanding blocks and had no bubbles. I then stopped using them and used a sheet of sandpaper with bubbles forming but this could be a coincidence.
4. The bubbles might form after I thin CA the edges which would be a shame because I really like the finish of the CA.

I just papered the large fins on the Odyssey and will let you know how it goes. I could glue the paper with TBII but that just seems messy.

 

[BABAR]

Couple things.
For strength, white glue papering is very, very good. Adhesive label paper does little if anything for strength, but is great cosmetically.

Other options. Going outside the box, this would be a beautiful bird to do rear ejection.

Other options, basswood, plywood, or create your own plywood, sort of like “papering” but using 1/16 or 1/32 balsa, in an orthogonal grain direction, with wood glue.

Whether you paper with white glue or balsa ply with yellow glue, stick it in wax paper and put it in an old book to make sure it stays flat.

 

[Ronz Rocketz]

So far, no bubbles with using the NCR airfoil block and using an old book.

I agree using glue is stinger because it absorbs into the balsa. I’ve been using sanding sealer on the small parts because not as messy.

 

[OZRoc]

.......
For strength, white glue papering is very, very good. Adhesive label paper does little if anything for strength, but is great cosmetically.
.......

Sorry mate. I believe any lamination improves strength greatly. Laminate a piece of 1/16 balsa with label paper and compare it with the same size original. 50-100% stronger IMHO. Yes, white glue papering may be stronger (more glue into the grain) but is a lot messy(i)er.
Cheers,
Mark

 

[Bill Heath]

Couple things.
For strength, white glue papering is very, very good. Adhesive label paper does little if anything for strength, but is great cosmetically.

Other options. Going outside the box, this would be a beautiful bird to do rear ejection.

Other options, basswood, plywood, or create your own plywood, sort of like “papering” but using 1/16 or 1/32 balsa, in an orthogonal grain direction, with wood glue.

Whether you paper with white glue or balsa ply with yellow glue, stick it in wax paper and put it in an old book to make sure it stays flat.

I beg to differ. Label paper increases fin strength by a huge amount. Test it.

 

[neil_w]

Label paper definitely increases fin stiffness, by a lot, although I have had a label-papered fin break on landing. Glued paper seems to be stronger, but I usually don't need that extra strength. Glued paper is certainly more effort.

At this point I've label-papered a lot of fins on a lot of rockets; I've had not a single bubble, although all my rockets are stored in my basement which is reasonably well climate-controlled. I don't know if it's luck or if it's my anal-retentive process, but I've had 100% success. My process is:
1) Sand fin surface smooth (just a few quick passes is sufficient)
2) *Thoroughly* remove dust from surface:
a) quick brush off with a soft paint brush until clouds of dust no longer rise from the surface.
b) Press some blue painter's tape to the surfaces and lift, to remove any remaining surface dust
3) Apply label. I don't do anything particularly special here, just lay it flat and press it down, then give it a good rub-down with my fingers.
4) Sand off excess from edges with 400 grit paper
5) thin CA or TBII to seal edges.

Seems like a lot but the whole thing is still very quick.

 

[icyclops]

I have been papering my fins since the 1980s. I simply use 3M Spraymount 77 spray adhesive and then trim off the excess. So easy and depending on the paper you use (I use a coated card stock) it really strengthens the balsa and provides a smooth surface for the primer. using white glue on balsa to laminate paper can cause the fins to warp and placing heavy objects on them to prevent this Doesn’t always work. I only use white glue to seal and smooth the fin edges...making sure to bead it up on the leading fin edge touching the paper on both sides of the fin. This not only makes a strong edge seal, but also gives the edge a rounded effect and is strong. Any crash on the fin i have had doing lamination this way has been minimal and very easy to fix...but I am talking low power hear A-E.

 

[prfesser]

I should have papered all the fins/wings of my build:
https://www.rocketryforum.com/threads/build-thread-johnny-star-commander.161421/#post-2042411
Finally gave up, left some unfilled grain. Those who have purchased this kit........you have been warned.

 

[Bill S]

I should have papered all the fins/wings of my build:
https://www.rocketryforum.com/threads/build-thread-johnny-star-commander.161421/#post-2042411
Finally gave up, left some unfilled grain. Those who have purchased this kit........you have been warned.

I'm guessing you had a hard time puttying up that thing as well? Really a TON of work.

 

[Bill S]

I did up a practice fin, using 65lb cardstock and 30-minute expoxy. Despite my best efforts, too much epoxy got applied to the fin/cardstock and some of the epoxy squeezed out the edges and hardened. Naturally some got on my gloves and transferred to the outside, though I was able to remove most of it with 800-grit sandpaper. Next time I'll custom fit each cardstock piece and not leave any protruding past the balsa - its a real pain to sand flush.

I'm glad I did a practice fin; I'd be annoyed to mess up an original fin. But the resulting fin is STRONG to say the least.

Lessons learned:
Apply less epoxy; I need to come up with a different squeegie (smaller).
Trim closer to the edge of the cardstock to eliminate extra material.
Consider epoxying one side at a time (glue one side, wait an hour and do the other side).


Any other tips for me?

 

[Scott_650]

I did up a practice fin, using 65lb cardstock and 30-minute expoxy. Despite my best efforts, too much epoxy got applied to the fin/cardstock and some of the epoxy squeezed out the edges and hardened. Naturally some got on my gloves and transferred to the outside, though I was able to remove most of it with 800-grit sandpaper. Next time I'll custom fit each cardstock piece and not leave any protruding past the balsa - its a real pain to sand flush.

I'm glad I did a practice fin; I'd be annoyed to mess up an original fin. But the resulting fin is STRONG to say the least.

Lessons learned:
Apply less epoxy; I need to come up with a different squeegie (smaller).
Trim closer to the edge of the cardstock to eliminate extra material.
Consider epoxying one side at a time (glue one side, wait an hour and do the other side).


Any other tips for me?

Article in Apogee’s Peak of Flight newsletter shows how to gin up a press from cheapo cutting boards for pressing epoxied fins: https://www.apogeerockets.com/Peak-of-Flight/Newsletter509. Could be helpful even for glue/paper/labels...

 

[neil_w]

I did up a practice fin, using 65lb cardstock and 30-minute expoxy. Despite my best efforts, too much epoxy got applied to the fin/cardstock and some of the epoxy squeezed out the edges and hardened. Naturally some got on my gloves and transferred to the outside, though I was able to remove most of it with 800-grit sandpaper. Next time I'll custom fit each cardstock piece and not leave any protruding past the balsa - its a real pain to sand flush.

I'm glad I did a practice fin; I'd be annoyed to mess up an original fin. But the resulting fin is STRONG to say the least.

Lessons learned:
Apply less epoxy; I need to come up with a different squeegie (smaller).
Trim closer to the edge of the cardstock to eliminate extra material.
Consider epoxying one side at a time (glue one side, wait an hour and do the other side).


Any other tips for me?

Why are you using epoxy rather than white or yellow glue?

 

[Scott_650]

Why are you using epoxy rather than white or yellow glue?

I’m not an “epoxy guy” - if PVA glue will work it’s my first choice - however I have used epoxy for general building and I’ve used it to harden paper tubes (an experiment to flame-proof the aft end inner body tube that worked well). I’ve not done epoxy coated fins but I gotta figure they’d be harder and stiffer even more so than glue/paper/labels. I’d be interested to see the weight difference between glue/paper and epoxy/paper laminate balsa fins - my guess is the epoxy is going to be heavier...

 

[Bill S]

Why are you using epoxy rather than white or yellow glue?

Because my experiences with water-based glues haven't been great. My Super Big Bertha fins all warped, despite being weighed down, and I don't want to have problems with the new fins. In retrospect, I probably didn't use enough heavy books. I did let the fins sit a couple days to dry.

 

[neil_w]

I’ve not done epoxy coated fins but I gotta figure they’d be harder and stiffer even more so than glue/paper/labels.

At some point it would be reasonable to ask exactly how stiff do you need the fins to be. We're talking balsa here.

Because my experiences with water-based glues haven't been great. My Super Big Bertha fins all warped, despite being weighed down, and I don't want to have problems with the new fins. In retrospect, I probably didn't use enough heavy books. I did let the fins sit a couple days to dry.

Hmm. Epoxy-papering sounds like a mess to me, and epoxy + cardstock is going to be very heavy (albeit very strong no doubt). Is it your goal to have a good smooth finish or ultimate strength?

My own personal opinion (take it for what it's worth) is that the combination of balsa + epoxy + cardstock suggests a wrong turn has been taken. Feel free to disagree, and of course it is ultimately up to you to choose whatever technique gets you the results you want.

 

[Bill S]

I decided to weigh my practice fin to see what the weight increase was.
Bare fin (moderate density balsa?): .14oz
Bare fin+cardstock: .27oz
Epoxied fin: .43 oz
Big difference.

I decided to try a practice fin with printer paper and yellow glue (all I have on hand).
Bare fin: .14oz
Bare fin+paper .19oz
Finished fin: to be determined.

At some point it would be reasonable to ask exactly how stiff do you need the fins to be. We're talking balsa here.

Hmm. Epoxy-papering sounds like a mess to me, and epoxy + cardstock is going to be very heavy (albeit very strong no doubt). Is it your goal to have a good smooth finish or ultimate strength?

I was looking for a combination of less puttying/surface finishing, but also wanted to strengthen up the fin. As this is a new technique to me, I'm going to try using yellow glue + printer paper, despite my misgivings. At worst, I expend some balsa and time, at best it works better than I thought.

 

[neil_w]

Hey, I'm all about experimenting with techniques like that. It's the only way to know if you're doing things the best way *for you*. Papering is very inexpensive to experiment with.

One of my favorite aspects of label papering lack of warpage, no pressing. Just adhere the paper on and then go. The biggest downside is that the surface is fairly sensitive to sandpaper, and once scuffed it never un-scuffs. I've concluded never to let any sandpaper coarser than 800 grit touch it (that seems to be safe), and when applying filler/primer I try to leave a coating of primer, and not sand down to the white.

 

[Bill S]

I already discovered that I have to apply the yellow glue to the balsa, not the paper, lest it start to wrinkle/get soggy immediately. And once pressed on to the balsa, that paper isn't going anywhere - even using a roller to smooth it out is dicey. Probably due to the learning curve, as expected.

How long should I let the fin dry before removing from under the stack of books. I was thinking a day or two.

 

[neil_w]

I can’t imagine you’d ever need more than a day.