I used regular wood sealers in the past on balsa ; "Last & Last" ,Minwax, Varnises and Poly sealers... thats what Dad had around the house. Some took along time to dry and some not so long. But they did SEAL very well. I agree with your info on Water based filler, I got me some Elmers FnF and I have had issues with the cell ends of the NC and edges of fins blistering. I would get a nice wet coat of paint on the NC and would watch as little pin head size blisters would pop out. Only thing I could make of it is a dif in temp when painting. I been takeing the parts out on to my sun-porch that may be only 40-50 deg ,shooting them, let set some and takem back in house. I guess its "gas/air" coming out on the balsa cell ends.I know if I had used a TRUE WOOD sealer this would not happen.Anywhoo-I ve had it with the mess and softness of the FnFs. Im going to get me some Aero Gloss Products. I have used Aero Gloss Products in the past. I built alot of balsa/tissue paper airplanes. Mostly rubber band man powered. Hm, I might just pick me up a simple airplane kit when Im at the LHS getting the Aero Gloss.

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Scotty Dog
NAR 90998

Back in the day Elmers school glue and a can of half dried up Rustoleum swiped from the neighbor's garage was about as sophisticated as we got....

But as a recent BAR I am trying to do better. I have adopted GHRocketman's method of Aerogloss Balsa Fillercoat then Aerogloss Sanding Sealer. Simple with great results. Good point about STIRING the Fillercoat, I learned that the hard way. You can shake the bottle until your blue in the face, still won't mix right. I have been waiting 3 days between the last coat of Sanding Sealer and primer as recommended on the bottle.

Problem is so far I have been buying 1 oz bottles on ebay for about 5 bucks a crack. I am trying to get a little smarter about this and I found the 3.5 oz six packs on Hobbylink but they are out of stock until sometime in March.

Is 3.5 oz the largest size for Aerogloss and does anyone sell it in bulk?

ehobby.com and ACSupply both sell 3.5 oz. jars of Aerogloss by the 6 pack. ehobby is where I get mine.

I don't know why Aerogloss doesn't come in pint cans (like SIG does).

Jeff

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Never trust an atom. They make up everything.

4 out of 3 people struggle with math.

Chemically, alcohol IS a solution.

NAR# 94042
SAM# 0078

I Have Quarts and Pints of original Pactra Aero Gloss Balsa Fillercoat and Sanding Sealer from the 70's, 80's and 90's that I have stockpiled from old hobby shop closeouts in person and on ebay.

Other than from Sig or Brodak, Pints/Quarts have not been available since the early 90's (at least for Aero Gloss).
Brodak's dope is actually re-packaged Full-Scale Aircraft Randolph Dope. It is available in 3 times the colors that the Aero Gloss line was in it's highest point and is every bit as good.

Brodak's Sanding Sealer is almost exactly the same as the Aero Gloss product; the Sig stuff is usable, but only if you cut it about 60/40 Sealer to thinner; otherwise the Sig is far too thick and will form hideous outgassing bubbles.

As far as Balsa Fillercoat goes, I think the only source now is in small (3.5oz largest) bottles from Midwest under the Aero Gloss label. Fortunately, making your own Balsa Fillercoat is a snap. Take a pint or half-pint of Clear BUTYRATE (NOT Nitrate) Dope in a brand of your choice and dissolve a couple tablespoons plain unscented Talcum Powder and a teaspoon of "Plastic Wood" into a half-pint or double those amounts of solids into a pint of Clear dope. That IS Balsa Fillercoat.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

Bill:

By "plastic wood," do you mean that grainy brown putty stuff from Red Deveil, or its equivalent?

Another vote for using laminating epoxy on balsa nose cones. For anything smaller than BT-50 I use it exclusively. For BT-55 to ST-18 (1.84") I first soak the wood as best I can with Minwax Wood Hardener. Wood Hardener seals but does not fill the grain but as the name indicates, it toughens up the wood. I let the hardener in the outer layers of wood cure for a couple of days, then lightly sand it and apply another treatment of MWH. After that, I hang it up for up to a couple of weeks to allow the hardener to fully cure inside and out. (The surface can feel dry and hard while the inner layers of wood are still uncured and soft.) I sand it again to get the roughness out after it cures, and then coat the cone with laminating epoxy as before. For large balsa cones, (2" and up) I usually just use Wood Hardener alone. The larger the cone, the longer it can take to cure, so I set it aside for awhile. I don't build fast, so this isn't a problem for me.

Large balsa cones tend to be quite smooth, at least the ones that I get typically are. Sanding the fully-cured hardened wood takes care of nearly all of the raised grain. Large cones can take up to a month, sometimes longer, to fully cure after a couple of treatments with wood hardener, but the result is worth the wait. Factor that into your timeline for completing the project. I apply some Delta Ceramcoat All-Purpose Sealer to fill in little pores or remaining grain. This sealer works well but isn't quite as hard as epoxy. It is easier than mixing up a bucket full of epoxy, though and the MWH has already done a very good job of making the wood dent-resistant.

If there are any problem areas on the bigger cones, I apply Aeropoxy Lightweight Filler to them. This is a two-part epoxy-based wood filler. It can be sanded fairly easily after it cures, but it fills the gaps or holes with very tough material, the hardest wood filler that I have ever used (including Dap Plastic Wood). For smaller nose cones, I fix any remaining problem areas with either Carpenter's Wood Filler or Bondo Spot and Glazing Putty. I may also use the aforementioned plastic wood for this, too, on small cones, but otherwise I reserve my plastic wood for repairing nicks, cuts and sanding errors in the edges of balsa fins. It is truly superb for that particular job.

For fins, I use either of two methods that have already been mentioned. Especially with small-pattern fins, I fill and seal them with Aerogloss products in the same manner that ghrocketman described. With larger, broader fins, I paper the balsa. I have had excellent results with using Reynold Freezer Paper for this. The paper resembles white butcher paper, but it has a thin and very smooth coating of plastic on one side. I use a craft stick or a plastic (Bondo) putty spreader to apply a thin, even coating of white glue to the uncoated side of the paper and then bond it to the fin. As soon as I do one side, I follow up as quickly as possible by papering the other side in order to minimize warping. I lay all of the fins on a sheet of wax paper on my smooth Formica counter or on a smooth table, cover them with another sheet of wax paper, and then pile a stack of smooth textured hardcover books on them. Since there's not much air circulation under the books, I give the fins 24 to 48 hours to get fully dry. I want them to be completely dry so that they won't develop any slight warps after I remove them from the press. I only use white glue for this, since it shrinks much less than wood glue. The plastic side of the freezer paper is primer-ready without any further preparation.

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SAM # 0011

Yes, that Dap/Red Devil grainy stuff in the can/tube which is powdered cellulose in a paste form mixed with Acetone and Toluene.
If you add some of that to the Talc dissolved in the clear dope, it fills even better.
Just don't add too much; like Cayenne Pepper, a little goes a LONG way.

ANY process that takes even a WEEK (let alone a month) to dry, I immediately dismiss as taking WAAAAYYYY too stinkin' long.
I'd sooner shoot Imron out of a NON-HVLP paint gun WITHOUT a fresh-air breathing supply before I would use any finishing materials that have any step resembling "wait a month for drying"

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

Well, I did say that I usually took my time when I build. But occasionally even I think that some of my waiting times are excessive. Minwax Wood Hardener does seem to need the time, though and I put up with it because it really really toughens up the balsa. I pay enough for balsa nose cones, so I want to make sure that they are reasonably durable. I have a 9.7" long, 2.34" dia. balsa nose cone that has survived more drops and falls (from up to 5 feet in height tip first onto a hard floor) than you can whip a launch rod at, and yet the worst damage that it has sustained are a couple of very small and superficial dings. So yeah, the long cure time can be a pain, but the ultimate results are amazing. I should point out that smaller nose cones don't take anywhere near as long to fully cure after the treatment. The really long cure times (on the scale of weeks) are for very large balsa nose cones. They are more costly to replace, though, so they are the ones that you really want to protect.

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SAM # 0011

Soaking the cones with a good penetrating coat of 30+ minute pot-life epoxy would do the same though, dontcha think ??
It would fully cure in a DAY, not a month.
If I let a project sit for a month, I lose interest in it usually.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

As I wrote earlier, I do in fact use laminating epoxy on many of my nose cones. I tend to use the wood hardener mostly on the really big ones. They are the most expensive, and they need all the hardening that I can give them, so I pull out all of the stops when I build with them. Needless to say, these are for my big projects, which are only a small portion of what I build. And as I have also already mentioned twice now, the cure time for wood hardener on smaller nose cones is much shorter than that.

The laminating epoxy that I use does indeed soak easily, at least for a little way, into the wood. I usually give it as many as three coatings, sanding it down after each one. It cures hard in several hours, but I usually wait until the next day to sand it. It certainly helps, but it doesn't make them totally bomb-proof. I've had things puncture through the epoxy a couple of times. The coating can only do so much when the wood underneath it is soft. So far I have only used BSI 20 Minute Finish Cure epoxy on nose cones. If I did it with West Systems or Aeropoxy laminating epoxy, the coating might be even harder. I do use long-cure epoxy for structural adhesion, but I'd be afraid that it would be too hard to sand if I coated a nose cone with it.

I'm not saying that my method is the only way or necessarily the best way; I posted about it because it is my own way. I have used a number of other methods for filling and sealing nose cones before this, so I know how they go. One that I haven't, though, is the dope augmented with talc and a little plastic wood method that you described above. It looks interesting and is one that I'll have to investigate sometime.

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SAM # 0011