Finishing tips

[cjc979]

Does anyone have a recommendation on some kind of wood filler or sandable epoxy? I'm trying to prevent as many imperfections as possible such as: spiral lines, fellets on fins/LL etc. I was at the hobby shop and found some white powder thats supposed to be mixed with water. Sounds like a mess so I steered clear of that one.

 

[SSenesy]

Here's a good place to start:

https://www.rocketryforum.com/showthread.php?40256-Balsa-to-Super-Smooth-Putty-vs-Sanding-Sealer-vs

 

[Micromeister]

Building Micro to Mid-power models using balsa and basswood I haven't used a single bit of wood filler or sealer in more the 12 years.

I've found it is more efficent for me (as I have a couple spray booths in the basement) to find and use the Cheapest Automotive grey sandable primer I can. Currently I'm using Wal-Marts 1.05 12oz can's.

Applied three wet coats spaced about 1-3 minutes apart, then wait about 10minutes for them to flash off. Check the body tube seams and wood grain. If needed apply another 3 coat application. then let the model sit at least 24hours. Dry sand with 240-320 sandpapers. if you reach bare wood or paper before the grain and seams are completely filled repeat with another wet coat or two of cheapy primer. wait another 24 hours and finish sanding. I generally don't go any finer the 360 or 400 on primer as it just isn't necessary to obtain a babies butt smooth finsh after applying the base and color paint coats.

Lots of folks use Elmer's fill'n'finish or what-ever the lable reads these days. Thinned with a little water the filler is troweled on & into body tube and balsa grain. It's messy, it can wet and delaminate body tubes but lots and lot of folks love the stuff. It's an option.

A much more smelly option is what used to be Pactra (now Mid-West) Balsa Filler, not the sanding sealer. Sanding sealer is just that a sealer it doesn't contain the heavy solids need to fill open balsa grain. Mix very well and apply in a well ventilated area. My better 2/3rds is most happy I've gotten mostly away from this stuff only using it on Exceptionally Deep balsa grain once in a blue moon. ps it's generally done outside these days

Lightweight Ceiling spackling compound has been used a few times with mixed results.

 

[Reddwarf]

I too just got reintroduced into rockets. I read this tip https://www.nar.org/HowToBuildAModelRocket/FillingSeamsAndBalsaPage4.html on using wood filler for the body seams. I did this on the baby Bertha I just finished. It worked well. I also applied to the fins but did not do enough work there as the finished product shows wood grain. Anyway, this works well but is very time consuming. I'm curious if the same results could be achieved with a primer coat, sanding, primer coat, sanding, etc.? Is the effect better to start with the wood filler or skip to primer?

 

[hornet driver]

My technique pretty much mirrors micro's . I use rustos primer filler --for really bad areas or areas I want to build up I use bondo glazing putty---warning --let it cure out all the way or it could crack--also use it in thin layers---but for basic rockets I fillet with yellow wood glue and then prime the whole darn thing !

 

[rbeckey]

Prior to attaching the fins to the rocket I rub Fill n Finish into the grain. After it is completely dry I sand it and use sanding sealer then sanding again. Primer usually takes care of any tiny flaws left. BT spirals are taken care of with Fill n Finish.