Sanding sealer or balsa fillercoat

[STRMan]

What do you thin is better for use on rocket fins, sanding sealer or balsa fillercoat. Is one preferable over the other for use on rocket fins?

Thoughts?

[ScaleNut]

depends on what you want to do, seal the wood or ,fill the grain.

[STRMan]

I have always used both products for the same basic purpose. I would put three coats on, sanding between each coat, to get a smooth fin with no wood grain showing when I painted them. The only difference I see is that sanding sealer is clear while balsa fiillercoat is white.

I have had good success using both of these products, but I was just wondering if anyone had opinions as to why one might be preferable over the other. They both seem to do the same thing in my eyes.

[ghrocketman]

Balsa fillercoat is much better at filling grain than sanding sealer.
I typically use 3 coats of Balsa Fillercoat on all balsa surfaces with sanding after each coat, followed up with 2 coats of sanding sealer for a smooth base for the topcoat.

For basswood or ply, skip the fillercoat and use sanding sealer only.

[scigs30]

For me Aerogloss sealer works the best. I have tried the balsa filler and the results were not as good as the sealer. I don't have a reason for this, but that has been by experience. I like the sealer because it is real easy to sand. I apply one coat and sand the fuzzies off. Then I apply 3 coats with no sanding in between 15 min apart. I then sand smooth and repeat the 3 coat process one more time. I then spray a coat of primer. After sanding the coat of primer there is no more grain showing. I normally do all this in one day. This has worked great for me, you can look at my post and see my rockets and fins. Once again I don't know why I don't have good luck with the balsa filler.

[STRMan]

I never used one on top of the other before. I'll give that a try this build. Thanks!

[ghrocketman]

The Balsa Fillercoat needs to dry much longer than the Sanding Sealer...that is probably why it does not work for you.
Give it at LEAST and hour between coats....for the sealer 15min is fine.

[Rocketking]

The only problem I have encountered with this is that it shrinks... Over a long period of time.

I made the mistake of applying it over the fin fillets one time, and it shrunk and pulled right up off the fillet!

Just a word of warning for those not familiar with it's peculiarities!

[ghrocketman]

The shrinkage of sanding sealer is a much larger problem if it is put on in coats that are too thick or if recoated without allowing the previous coat to COMPLETELY dry.
Several thin properly dried coats are MUCH better than 2 thick coats.
I have been using Pactra Aero Gloss and Sig Sanding Sealer and Balsa Fillercoat dopes for over 30 years to finish balsa parts and the only time I have had problems with shrinkage is if it is applied too thick or not allowed adequate drying time between coats. Basically this is the same as with any color butyrate dope finish as well.

[foose4string]

For me Aerogloss sealer works the best. I have tried the balsa filler and the results were not as good as the sealer. I don't have a reason for this, but that has been by experience. I like the sealer because it is real easy to sand. I apply one coat and sand the fuzzies off. Then I apply 3 coats with no sanding in between 15 min apart. I then sand smooth and repeat the 3 coat process one more time. I then spray a coat of primer. After sanding the coat of primer there is no more grain showing. I normally do all this in one day. This has worked great for me, you can look at my post and see my rockets and fins. Once again I don't know why I don't have good luck with the balsa filler.

My experience too. I've got a whole quart of the Aerogloss balsa filler, and I don't know if I'll ever use it. I prefer the sealer also. I stopped using sealer a long time ago, I prefer Fill n finish and primer, or papering now.

[ghrocketman]

I'd take the quart of Aero Gloss Balsa Fillercoat if you want to sell/ship it.

[foose4string]

I went down to the basement to try and add some semblance of organization this weekend. Looks like a pint sized can....not quart. Just barely used. Found it at a LHS a couple years ago. Availability of Fill N Finish can be spotty at best, so I may just hang on to the Aerogloss filler as a backup. I did a brief online search to find the price and availability of pint sized cans, but all I could come up with was the 3.5 oz size. :confused:

[ghrocketman]

New pints and quarts of Aero Gloss Balsa Fillercoat have not been available for at least 10 years....all that is ever found is new "old stock".

[mrhemi1971]

Thank god my LHS found 2 pint cans of sealer for me, and that was the last that his supplier had. Throwing my 2 cents in, I prefer the sanding sealer over the balsa fillercoat, I've tried both methods, and the sanding sealer just seemed to give me the best results. My Black Brant II fins came out so smooth that you can actually see your reflection in the paint!