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Building Tips and technical articles. => Paint and finishing => Topic started by: James Mills on April 10, 2014, 11:22:36 PM
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I'm slowly trying to finish my Junar for this summer and I'm close to being ready for the fillets. I'm going to put carbon veil on the fuse. Can I put the fillets down first and then on to dope and carbon or do they need to be last (I've seen pic's of planes being built both ways)?
Thanks,
James
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James,
You can apply superfil anytime. But it is better to apply after some finish and/or carbon is on. Done properly there is very little sanding, but having something over the bare wood is the better way to go.
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Thanks Tom.
James
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James,
I always put the fillets on after the carbon/covering. I want the fillet to cover the covering/carbon at the wing fuse joint and stab fuse joint. If not you could case a stress riser and crack the wing or stab. I have seen it where the carbon was put on after the wing was installed and fillet put in place. A few flights in and outboard wing blew off in a hard corner. Yes it blew off and let go from the flap horn and floated to the ground. The model was flown out level and the drive train was saved. It was not cool.
For me the fillet is the last thing that goes on the model. The very next item will be the dope and filler or primer or whatever the filer is for the finish. I guess the fillet is either the actual end of the build or the beginning of the finish. It is the final transition from building board to paint stand.
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My Super Fil is still under test. I used it to put wing in the fuselages. The first was the S-1 Ringmasters. They don't have the nice fillets like Bobby Hunt and a few others do. Also the S-1's have Rustoleum paint on them with Monokote on the wings.
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I always do the fillets last, over the covering, always, always, always... y1
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James,
I always put the fillets on after the carbon/covering. I want the fillet to cover the covering/carbon at the wing fuse joint and stab fuse joint. If not you could case a stress riser and crack the wing or stab. I have seen it where the carbon was put on after the wing was installed and fillet put in place. A few flights in and outboard wing blew off in a hard corner. Yes it blew off and let go from the flap horn and floated to the ground. The model was flown out level and the drive train was saved. It was not cool.
I would go further than that, you want to cover the wing (with either silkspan, polyspan, or carbon) before you install it in the airplane. For the very same reason, just putting it up to the fuse creates an additional stress concentration right at the fuse side, which is loaded anyway. The New Jersey guys blew airplanes apart regularly when they started using St60s (and creating heavy cornering forces for the first time ever). They ended up with all sorts of strange reinforcement like Windy's elliptical patches on foam wings, but still applied the silkspan to the completed airplane.
Brett
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I would go further than that, you want to cover the wing (with either silkspan, polyspan, or carbon) before you install it in the airplane.
Yep, that too, always. ;D
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I would go further than that, you want to cover the wing (with either silkspan, polyspan, or carbon) before you install it in the airplane.
Brett
Yes I do the same thing. Cover before installation with a little overlap in the middle.
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The first fillet I install is a fillet is on the inside of the fuse then apply top and bottom block finish sanding and tissue of fuse then the outside fillet is applied over the top of everything.
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The first fillet I install is a fillet is on the inside of the fuse then apply top and bottom block finish sanding and tissue of fuse then the outside fillet is applied over the top of everything.
...and it all happens in about 7 minutes. :##
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I would go further than that, you want to cover the wing (with either silkspan, polyspan, or carbon) before you install it in the airplane. For the very same reason, just putting it up to the fuse creates an additional stress concentration right at the fuse side, which is loaded anyway. The New Jersey guys blew airplanes apart regularly when they started using St60s (and creating heavy cornering forces for the first time ever). They ended up with all sorts of strange reinforcement like Windy's elliptical patches on foam wings, but still applied the silkspan to the completed airplane.
Brett
I do cover the wing in that manner.
Thanks,
James