Seems that 3 coats are the Charm regardless of the "filler material" being used.

Sigs30 used sanding sealer, some use (myself included) have or are using Balsa filler containing much higher solids, other are using waterbased sealer/fillers.
I've all but stopped using these "fillers" long ago.

Since i'm going to be priming and sanding the model anyway thats were i've learned to start.
Indstead of wasting a bunch of time with fillers I Start with whatever el-cheap-O rattle can primer I can find on the raw wood and bodytubes. As with all the other methods... open grain balsa fins, cones and transitions generally takes 3 coats to fill the grain. Basswood I've found can generally get away with two coats. DRY sand with 120 to 320girt papers to a babies but smooth surface ready for whatever base or color I choose. Recently I've been using a Walmart .89 grey auto primer with excellant results under Krylon (old formula) and rustoleum color coats .

Drawbacks: * Sometimes takes an entire can to fill a large model (like the E-interceptor).
*Should use a spraybooth or box to contain a bit of overspary.
* if spraying indoors you'll want to exhaust the smell outside with a blower.

Advantages: * Less smell than Pactra or other brand Lacquer based fillers.
* No brushing or trowel applying messy fillers.
* Much Quicker filling.
* generally less expensive (depending on primer used).
* Fills Bodytube seams and grain at the same time.
* Fewer steps to the completed model.
Hope this helps.

Those reasons are part of why I use Fill-n-Finish. The biggest reason is that I can sand the stuff in 10 minutes. The only primer that comes that close is lacquer primer, and the only lacquer I can get here is very expensive, so I only use it after slicking up all the balsa with F-n-F.

I hate sanding, so when I finally get in the mood, I need to get on it quick and get it over with.

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I love sanding.

I'm with you there.

How will you, or how did you fix the warped fin? It looks like it would need to be sanded, wet down and clamped in between two flat pieces of wood or metal...

I can't argue with your results, Micromeister, but I'm a bit squeamish about sanding raw balsa nose cones, even if they have a coat or two of primer on them. I used to do that, but too many times I ended up with misshaped nose cones!

Your method is exactly what I used to do when I started building rockets again a few years ago. Eventually I started using fillers and sealers before priming because they gave me much better results!

A bottle of Delta Ceramcoat All-Purpose Sealer also lasts a whole lot longer than many cans of spray primer. Two years ago, I bought two 8 oz. bottles of it at Walmart. I'm still on the first bottle.

I do agree that the extra steps are a bit of a pain, though. I'm always in favor of finding, simpler, easier methods to accomplish the same thing.

Also, as I mentioned in a thread awhile ago on finishing techniques (or was it on Krylon paint?), I suspect that what methods work best for an individual builder may depend, in part, on what part of the country (or world) that he or she lives in, and what the predominant climate is like in the area. I don't know that this is true, but I suspect that it might play some role.

I do all of my spraying outdoors and out in the open on warm, dry days when there is little or no wind. (Where I live, that limits me to doing all of my painting during a few weeks in high summer.) To avoid blushing the paint, I do not do the spraying out in my yard, because the area over the grass, and in the vicinity of shrubs, etc., has higher humidity than elsewhere. I take my rockets down to the end of my driveway, or even out to the street in front of my house, to lay on coats of spray paint. The air is always drier in those places. (In addition to the general climate of a local area, there are little micro-climates over and around everything, especially living things like plant foliage.) If I had a large slab of concrete (not asphalt) to go to that was out in the sun for part of the day (and would therefore be well-dried) and that was free of dust and wind, that's where I would do all of my spray painting.

Or else a well-designed and well-ventilated spray booth...

Mark \\.

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SAM # 0011

I just moistened spots here and there and let it warp itself back straight on its own.

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I love sanding.

Absolutely with you there !!! I hate sanding as well. but if we're going to get a decent finish we have to bite the bullet and sand on something. I've just eliminated most of the in between stuff.
Depending on were you live and the humidity level at the time your priming one can be sanding in less then an hour. I usually try to let each of the three coats set up for about 5 to 10 minutes, then wait about a half hour after the 3rd coat is applied. If the primer starts building up to quickly on the papers, I let it set awhile longer, or even let it go overnight if the humidity is high in the house

I'm not sure I follow you Mark? sanding on RAW balsa??? it's got at least 3 heavy coats of sandable primer... Not hard as nails but at least as hard as balsa filler/ sanding sealer and surely harder then f-N-f.
I can't remember the last time I really screwed up a nosecone or transition during sanding. If you start to see wood ya just add another coat before continuing.
yeah! I guess i'm pretty lucky I live in a Very high humidity area but have outfitted the rocket lab with two spray booths so I can spary anytime I want.
I will give the Delta ceramcoat a try in the future, I'm always looking for products and techniques to update my Tech-tip articles series.

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Keep em flyin Micronized
John

OK, maybe I misunderstood - I thought that you were talking about sanding in between each of those first coats of primer. Also, were you talking about using high-build primer?

Maybe I have gotten gun-shy from my earlier experiences, but I am very reluctant to touch sandpaper to a nose cone until I have, at a minimum, sealed the surface. I want to be sure that I am just sanding the surface grain, and not the cone itself. It may just be me, but ever since I started taking that precaution, I haven't messed up any more nose cones.

When I sand the filler/sealer coat, I wet-sand with 400 to 600 grit sandpaper. I am not really sanding the stuff off, but rather, it is more like I am smoothing it out. I try whenever possible to use the approach of building up a smooth surface through the application of many thin layers, rather than flooding the surface of the object and then sanding it down to something smooth.

As for sanding in general, I don't mind it at all myself, as long as it is producing good results. I like the look of a smooth paint job better than a rough one, and so I will do the work that is needed to get that look. I get great satisfaction when I can see that the surface is looking better and better as I sand it. But I haven't shown very many of my builds to anyone else yet; the reason I put so much care into the finish of them is purely for personal satisfaction.

Mark \\.

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SAM # 0011

Use what works for you. That's the beauty of reading all the different methods and materials. It all ends up looking good in the end, but different techniques and materials work better for different folks.

One thing I haven't done, but have read about here and thought it had merit is to use a different color primer for the first coat so that you see when you are getting down near the wood. You could then use a different color primer over it, or Fill-n-Finish, or any other type of filler. That might be what you are doing when you use a sealer first.

There's one thing I have figured out over the years, and believe me, I've tried to prove it wrong. No matter what method or materials I use, I'm gonna have to do a lot of sanding to get a good looking finish.

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I love sanding.

I have experimented with Aerogloss sealer and filler. Multiple coats of primer no sealer. Ceramcote and FNF. I will agree they all worked but each had advantages and disadvantages. For me Aerogloss sealer fits my building style so that is what I use. Also all the above techniques still require proper application and sanding technique. If you are sloppy with sanding, well the finished product will look sloppy. With Aerogloss sealer, I am able to sand after 1/2 hour and 3 to 4 coats is plenty. I am using old balsa wood from vintage kits. I apply the sealer the same way I apply filler when building wood projects. I make a conscious effort to brush the sealer into the grain using a stiff brush. I noticed in the beginning when I just half hazardly brushed the sealer on, the grain would not fill. But now that I am using a stiffer brush the sealer makes it into the grain. So basically it is 2 coats of sealer, sand, one coat sand and possibly one last coat and sand. I sand with 320 to 400 gritt. If I was unable to use Aerogloss, I would probably use Ceramcote. There is no oder and clean up is easy. I did find it tougher to sand, almost like sanding Elmers glue.

I recently got some Aerogloss Balsa Filler, so I'll give it a try. As for the Ceramcoat being hard to sand, that's why I wet-sand it. Dry-sanding quickly heats up the surface of the filler too much, making it soft and gummy, and the sanded dust melts and reforms into gummy crumbs that quickly load up the sandpaper. Sanding it with an aluminum oxide sandpaper (the black stuff) that has been run under the faucet for a couple of seconds right before you sand, and then periodically re-wetted, helps to avoid this problem. The water helps to keep the surface cooler and it helps to float the sanded particles away, preventing them from building up and melting right under your pressure point. Aluminum oxide paper seems to shed fewer grit particles during use, which also helps to lessen the build-up. Finally, as you re-wet the paper, you rinse off some of the slurry that is accumulating on it, which helps to delay the eventual load-up of the paper.

I usually start with 400-grit aluminum oxide paper. This grade (grit count) of paper is usually reserved for the final stages of sanding, but I find that it works really well for this particular purpose too. The idea is not to really sand the coating down, but more to smooth it off. I find that I get the best results when there is enough water on the paper to create a bit of very loose slurry on the surface as I sand. After anywhere from 30 seconds to a minute of sanding, I stop and wipe the cone dry with a paper towel, and check my progress. Usually, two or three coats of Ceramcoat, with wet-sanding between coats, is enough. Since I am usually going for a mirror finish, though, I tend to keep on applying thin coats and wet-sanding until I reach a point of diminishing returns. This extra work is a bit of a pain, but I am almost always pleased with the results, so for me it is worth the additional effort. Your mileage and your priorities may vary, though. One thing that I learned from reading Micromeister's Tech Tips a long time ago was that the smoother you get the base layer, the smoother your topcoat will be.

Better than Delta Ceramcoat APS by a mile is Pine-Pro Sanding Sealer, as I mentioned in an earlier post. It looks similar, but it is thicker and it fills the grain faster, it dries harder, and it wet-sands smoother than the Delta product. The only size that I can find it in is a 2 oz. bottle at my "local" hobby shop, which is 52 miles away. The LHS usually has only one bottle in stock (sometimes two), so that's all I can get per trip. Sadly, a single 2 oz. bottle doesn't last long. If only I could stock up on the stuff, I would be using it for all of my wood surface prep.

Mark \\.

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SAM # 0011