Jeddy

Suggestions please for covering an art hobby sierra. I like the idea of leaving the (beautiful) wood as it is, but am concerned about strength of it - especially the wing tips which are naked balsa and most exposed!
Someone suggested varnish (especially ship varnish), however I can't help feel that's going to add quite a bit of weight.
Can anyone suggest anything strong, light and transparent please. (If you have a picture I'd love to see it!).

Thanks,
Jeddy

averen

Strong + Light + Transparent = Fiberglass ... that is if you do the layup correctly.

This is probably your best bet. It will add more weight than a clear monokote or the like but it will also add some strength where the covering will add very little.

Unfortionately this isn't the cheapest method unless you or someone you know has a vacuum bagging system (vacuum bagging isn't necessary but it will give you a MUCH smoother finish! - I wouldn't do this if you don't have access to one!)

AcintSpec

Jeddy:

I have a Thermal Eagle that was done using the water based variety of Varathane. The wings are stained on the bottom with a dark color and finished off in natural wood on the top. As I understand it, use a sponge type brush and brush on a light coat of the material. Use paper towel and blot off the excess. Try to do both sides of the wing to avoid any distortion. Use a very fine steel wool or sandpaper when dry and apply another coat. You can weigh your wings before you start and after each coat to see how much weight you are adding.

Also have a Shadow that was done in Monokote. Someone else did an outstanding job as they turned out beautiful. White on top, deep red on the bottom.

Jeddy

Thanks for the replies, although I have to say I don't fancy glassing the wings, (not having access to a vac bag).
Now the nex problem is that I'm in the UK and we seem to have different names for things here!
What is varathane?
And what is Monokote?
Maybe once I know this I can look into these coverings. From the above comments, monokote sounds like a paint which I was hoping to avoid as I like the existing finish.

I think what I'm hoping to find is a light strong varnish which is fairly easy to apply.

Thanks again guys...

kingbee

"Varathane" is a brand name for polyurethane finishes. Look for a water based clear polyurethane product at a paint store or home center. The water based poly is about the lightest clear finish you can get. Oil based polyurethanes or traditional spar varnish will add more weight.

The water based is white in the can but dries clear, with very little darkening of the wood. It's also pretty thin so spraying it is easy if you have the equipment. Depending on the wood, it will take 2 or 3 coats to get a smooth finish. The first coat will raise the grain of the wood, so wet sand with 220 grit to knock down the fuzz. Wet sand as needed between subsequent coats. The stuff dries fast, so 2 or 3 coats in a day is possible depending on temp and humidity. And no strong fumes so you can use it inside.

Monokote is iron-on covering, similar to Solarfilm.

Cheers,
Dave

Jeddy

Thanks!

Gunnery Highway

What do you think of the $200 Sierra?
How's it fly? worth the money? or do you get what you pay for?

Jeddy

Not sure if that's directed at me, hope not! I don't think I'll be getting mine airborne for a month or two yet cause I'm still trying to finish a Blue Airlines, Blue Yorker I picked up at Dortmund last April!!!! Hoping to finish the Sierra this year though!! I'd be interested to hear of others comments though. I know the Sierra isn't going to be competition competitive, but then I don't tend to enter any, except for fun, I'm just looking for a model with which to be a slope hooligan