I am a long time Aerogloss sealer user since the 70s, and the formula has changed over the years. Out of all the products I have tried nothing beat Aerogloss sealer until I found Brodak balsa sealer. I was skeptical of Brodak sealer when I got my first small can last month to try, it was thin and brushed on easier than Aerogloss. I for sure thought it would not have any filler properties since it was so smooth and easy to sand. After four coats the balsa was as smooth as can be. I then painted the balsa and no grain. The secret to Brodak sealer is to brush it on pretty heavy when compared to Aerogloss. With Aerogloss if you brushed it on too thick it would be a pain to sand and take longer to dry. The sanding qualities are the best I have ever seen, even easier to sand than Aerogloss. I would never have found out about Brodak if Midwest did not stop making their sealer. So give it a try and let me know what you think. Also when you order it, let Brodak know you are using it for rocketry. I posted my last three builds using Brodak and I just ordered the 16oz can. I transfer the product into 4oz jars for easy use.