Fixing Ragged Fillets

[cerving]

I inherited a 7.5" Polecat Thumper that was built but not quite finished, one of the things that needs to be done is to clean us some very ragged fillets. It looks like they were done with epoxy, structurally they're fine but they look pretty bad. Normally I would just get out the RocketPoxy and clean them up, but I don't want to add any more weight to the back of this rocket than I have to. I don't want to sand them, either. What's a good way to fill up the ragged fillets so they look better?

 

[Banzai88]

West or equivalent epoxy with filler, light weight and easy to apply and easy to sand to a final smooth finish.

 

[James Keller]

Bondo is always an option. Way easier to sand then epoxy so you can add a thick coat and sand down until they fill all of the low spots. That'd what I would do.

 

[David_Stack]

Super Fil... It's what the control line stunt folks use for fillets between fuselage and wing

https://www.aircraftspruce.com/catalog/cmpages/superfil.php

 

[cwbullet]

Super Fil... It's what the control line stunt folks use for fillets between fuselage and wing

https://www.aircraftspruce.com/catalog/cmpages/superfil.php

Worth the price x 1000%

 

[Rschub]

I second epoxy with micro balloons. Super fil is kinda heavy for lightweight filler.

https://www.amazon.com/System-Three...ords=microballoons&qid=1697561589&sr=8-3&th=1
A trick you can use is to mix it up with a lot of balloons until it is really thick, then add some alcohol to thin it up, then add more filler. I would do a test mix or 2 to get a feel for how much alcohol you want to use. Rubbing alcohol is ok.

 

[waltr]

I may first use a Round file to remove some of the high spots.
Then epoxy with Micro-ballons to form a paste. This is fairly light weight and easy to sand.