Delamination problem with paper over balsa

Not sure if anyone here can help, but I have to ask just the same.
I have used standard printer/copier paper, card stock and even poster board card stock using TiteBond II. Once trimmed, I usually give 3 coats of thinned TBII to seal it in and be able to sand it flat and smooth. (this is where I think I'm the only one that does this)
I use 120, 180 and 220 grits, going slow with little to no presure reduce heat from friction and gumming and keeping the sandpaper clean.
Every time, no mater what paper product I use, it seams to delaminate leaving a film of paper on the balsa, and the rest bubbling off.
I've even tried using Elmers wood putty over the paper, with the same results.
Sould I dip the paper in more thinned glue before applying to completely saturate the paper?
Abondon the papering technique all together?
I've always extremely good results just using TBII without paper products and never a problem splitting fins on hard landings.
Anyone one else have delamination problems?

I use elmers white glue and cover the complete fin and let them dry AFTER the fins are mounted on the rocket. I use the overlap to make my rivets and acually overlap one paper from one fin to the other. (one seam to hide versus two)

after cured I then sand the endges with 220 and feather them past my leading edges, I then prime, sand and base coat. After the base coat the leading edges are blended and there is no trace of the paper.

Final coat seals up everything and havent had a problem with delmaniation.

One of my papered rockets got run over by a car and the paper stayed on the fins even though I needed a broom to pick up the reminents across the travel lane.

USE THE WHITE GLUE AND DONT SKIMP ON IT. LET IT DRY THEN SAND with 220..

Thats about all I can add to your problem/issue.. Good luck..

Tom

I use Scotch brand "Quick Dry" adhesive for gluing paper over balsa fins. You can find it in the "scrap bookers" aisle in crafts stores. I never had a problem with this stuff.

Edited to add: I just follow the directions on the bottle. It glues down paper quickly. I sand the fins smooth with maybe 220-320 grit before gluing down the paper. I don't have a delamination problem.

I papered my fins on my Rascal clone (old model). White glue, 2 very thick, very smooth boards, 2 big c-clamps, and I didn't sand afterwards. Painted them with 3 coats of Epoxy white gloss and they were plenty smooth enough.

But yes on the white glue. My favourite glue is Gorilla Wood Glue, but it's too thick for this job.

I'm glad and thankful for all the methods you guys use.
Looking more for the cause of the delamination.
Am I using the wrong paper/cardstock?
To me, this problem shouldn't exist.
Regular old printer paper is laminated, so why is it delaminating?
It's just boggles my mind, ya know?

Woody's Workshop said:

I'm glad and thankful for all the methods you guys use.
Looking more for the cause of the delamination.
Am I using the wrong paper/cardstock?
To me, this problem shouldn't exist.
Regular old printer paper is laminated, so why is it delaminating?
It's just boggles my mind, ya know?

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Maybe too little glue, as it's not penetrating the paper enough?

Just a shot in the dark. I know I had lots to make the paper fairly moist.

Woody's Workshop said:

Am I using the wrong paper/cardstock?

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I think it's the glue. Paper gets wet, top slayer sloughs off. All this slathering on of glue, sanding, more glue, c-clamps... c'mon guys...all we're doing is gluing paper to wood!

Sven Knudsen has this on his website: Fin Finishing Technique. I tried that, and it works. I don't know if Rollataq adhesive is still around, but the scrap bookers have glues that are designed for gluing paper to stuff. And it works. Go figure....

astronwolf said:

I think it's the glue. Paper gets wet, top slayer sloughs off. All this slathering on of glue, sanding, more glue....

Click to expand...

Woody, your three outer layers of additional glue are (IMHO) not necessary. I have not had much problem with laminating paper onto balsa, but I don't use as much glue as you do. I start with watered-down (thinned) glue, and I generally use the cheapo school glue stuff. I brush a quick coat on the balsa, I wipe a quick coat on the inside of the paper, I mist with water (as req'd) to keep them moist, and get them assembled as quickly as possible. Sandwich between waxed paper, place under books or magazines, leave alone for a few days.

To apply external finish I just spray on some rattlecan primer and sand, spray and sand, until I am happy with the smoothness. I would point out here that the spray stuff does not use a water-based solvent. I think your repeated applications of water-based glues to the outside could easily be soaking through the paper and loosening it.

I am also a little surprised that you are able to get any sort of decent paint job out of your process. My experience has usually been that spraying much of any base coat or color coat over a heavily glued area (with water-based glue) results in crazing in the paint.

You guys ever use "silkspan" and dope? Or .2-.5 carbon veil and dope? that's what we use to apply to the surfaces of our controline stunt model airplanes because strength stiffness and weight were all factors.

A little heat treatment with an iron on low. Reflows the glue more into the papert and balsa. Justb a thought

I've had this happen decades ago... I was using thin paper and overcoating it with glue and additional layers of paper. It wrinkled horribly and delaminated, separated, etc...

Your using too much glue. Glue in and of itself (excepting epoxy which is actually a catalyzed resin) imparts virtually NO strength in and of itself. The additional layers of glue are practically worthless strengthwise. The strongest bonds actually come from the THINNEST layers of glue.

Apply a THIN layer of white glue over the ENTIRE surface of the fin, and glue the paper to it. Let that dry COMPLETELY (overnight) and you're done. If you REALLY insist on giving the thing ANOTHER coat of some kind, apply a THIN layer of CA directly the paper layer... but it's really not necessary. Even that MAY give you delamination problems. Using water-based products IMHO is just asking for the kinds of problems you're encountering... because the paper is porous and the water (solvent) in the additional layers of glue are going to soak down into the paper itself and the lower layer of glue holding it on and 'redissolve' it. CA at least has the benefit of being a different glue formulation and actually cures from contact with moisture.

I really think you're overthinking this and making things a LOT more difficult than they need to be. There's a lot to be said for the KISS principle... that's the main reason for using paper on fins-- eliminating a bunch of extra applications of fillers and sanding... I do papered fins quite a bit and a thin layer of white glue overlaid with printer paper is enough to fill 99% of the grain and get you ready for primer and paint... and 2 coats of primer sanded with 220 and followed by 400 grit is enough to make fins look like plastic... and at least double the strength of bare balsa...

Later and good luck! OL JR

'strawwalker, I've read your technique for papering (on YORF or here, I forget) and decided to try it.

I used light weight (20 lb.) printer paper. Spread Elmer's Wood Glue on the fin, laid the paper on top and used an expired credit card to squeegee it down. That's it. The paper never got soaked through with glue and most of it got squeegeed out anyway. I let 'em dry under a fat book.

When it had dried, (I forgot to sand the fins) it dried so hard the paper got sucked down into the grain of the balsa! That glue really pulls things together. I just went ahead and painted the rocket as usual. You can't tell if the fins were papered or not by their appearance. They turned out great—and much stronger.

Thanks for the "how-to." https://i233.photobucket.com/albums/ee215/Savaje/Rockets/Acacius-2.jpg

+1 on what JR said about THIN layers of glue. One thing he didn't mention, though - if you use too much glue, it will not only wrinkle the paper and potentially cause delamination, but it can also warp the fins. I like to apply a squiggle of glue on the part I'm gluing and use an old gift card (I have lots of used iTunes cards! ) as a squeegee to spread the white glue really thin. You might want to put on a really thin layer and let that dry, then put on a second really thin layer before applying the paper - the first layer of glue tends to soak in really fast and may dry before you can get the paper on. YMMV.