Airtronics Olympic II electric sailplane build

[GliderFlyer]

Is there a better way to sand epoxy?

 

[rockyboy]

Is there a better way to sand epoxy?

And that's why I try to use an aliphatic type wood glue for joints like this...

Try grabbing a small file to take down larger amounts of epoxy blobs, and use masking tape to protect the balsa near the epoxy so the wood doesn't get sanded down too far while trying to smooth out the glue.

 

[GliderFlyer]

And that's why I try to use an aliphatic type wood glue for joints like this...

Try grabbing a small file to take down larger amounts of epoxy blobs, and use masking tape to protect the balsa near the epoxy so the wood doesn't get sanded down too far while trying to smooth out the glue.

Can I use an razor blade and try to slice it off?

 

[danskis]

I like the 2 fuselage option - build one and fly and build the other when you get to it. I'm no expert but there are a lot of dedicated glider guiders at my field. Having flown with them for about a year I can tell you that for a pure thermal machine - the lighter you can get it the better its going to thermal. I believe the local guys shoot for around 14 oz. AUW for a bungee launch plane. Bungee is a great alternative to a winch - you can get a lot of flights in. If the thermals are booming you can even just hand toss it.

 

[GliderFlyer]

Can I use an razor blade and try to slice it off?

yes.

 

[GliderFlyer]

yes.
View attachment 190724

I should have taken a before picture. Oh well. I was able to carve out the epoxy that was left all over the seam, then sand it all flat. It looks pretty nice (except for the gap) All's well that ends well!

 

[rockyboy]

Whew! Excellent news!

 

[GliderFlyer]

The microballoons arrived in the mail today. That stuff is so light, I though they sent me an empty bottle!
I opened the lid and saw that it was filled to the top. That powder is so fine, I better take precautions not to breathe it in.

 

[speedbirdted]

You can also use talcum powder. I've used both and while talcum powder is cheaper it doesn't sand as well as microballoon epoxy. (not like epoxy sands well anyway)

 

[Bricks]

Back in the day we would mix talc and Dope it worked so well and it was fun, it sure made putting on Silk span much easier.

 

[TooJung2Die]

Try to buy some talc today. Ever since it was linked to ovarian cancer it has become unobtainium. Everything on the store shelves is made from cornstarch. Maybe it works as well as talc for a filler.

 

[GliderFlyer]

yeah, well I've already got enough microballoons to last me a long while, but thanks!

 

[Born2bwire]

Try to buy some talc today. Ever since it was linked to ovarian cancer it has become unobtainium. Everything on the store shelves is made from cornstarch. Maybe it works as well as talc for a filler.

Both Sig and Brodak make a sanding sealer that is basically the same thing, butyrate dope and some kind of filler. The price per volume is the same as their dope. Technically, you lose some dope to the volume taken up by the filler but I figure it's close enough that I don't bother to mix up my own.

 

[GliderFlyer]

Sorry, its been a while. I am focusing on the nose right now and am having trouble getting it right. I started sanding last week but then realized that I wouldn't be able to access the motor once the firewall is glued in.

 

[GliderFlyer]

And then I realized that I had messed up on shaping the nose, so I decided to do it over.(At least the top part)

What had happened was I got carried away while sanding and sanded the top part too low so it ended up being not a circle shape. I think it would help if I had the hatch system figured out. I don't know how far forward the hatch should go.

 

[GliderFlyer]

It's more circular than it appears.

 

[GliderFlyer]

Does cooking spray work as a fiberglass mold release?

 

[GliderFlyer]

I am pretty satisfied with the result. The first attempt of fiber glassing did not go well. I was able to save the nose before the epoxy cured.
The second attempt was better because I used a better method, and only one layer this time.
I used the fiberglass cloth that I had laying around, which said 6/10 oz, which I know does not equal 2 (2ounce was recommended), but I can always put on another layer. But I did not remove as much epoxy probably as I should have ( there is a little puddle near the rear), so I think that the epoxy may have added a whole lot of reinforcement. I do notice it is stiffer, but should I still add another layer of 6/10 oz cloth?

Before cure


after cure


Cured &trimmed

 

[rockyboy]

I think that looks plenty strong as it is!

 

[GliderFlyer]

I decided to do another layer, but only where it was needed most, at the top . I used a balloon this time.