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getting clay to stick to balsa - tips?

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jf_reinhard

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I just flew my Semroc Hawk for the first time today. Both flights were a little nose heavy coming down, but the test glides were perfect and even implied that I might get a slight turn (without weight). Fortunately, nothing broke.

Anyway, I attempted to add a little modeling clay to the tail and one wing to balance it out, but the clay keeps falling off.

Any suggestions?

Thanks,
Jim

P.S. Also, if anyone know anything about the balance point for a Deltie B (where is it?), please let me know.
 

jflis

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What I do to get clay to stick (assuming you're talking a small amount) is to lay a thin layer of glue over the top of it and onto the balsa. Sorta like a "blister" of glue to hold it down. CA works well. You can also make a paper blister to hold it down with white glue.

As for the balance point, I am not familiar with that particular glider but most gliders want to be balanced about 1/3 the distance from the leading edge of the wing (general rule of thumb...)

hope that helps!
jim
 

Micromeister

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I just flew my Semroc Hawk for the first time today. Both flights were a little nose heavy coming down, but the test glides were perfect and even implied that I might get a slight turn (without weight). Fortunately, nothing broke.

Anyway, I attempted to add a little modeling clay to the tail and one wing to balance it out, but the clay keeps falling off.

Any suggestions?

Thanks,
Jim

P.S. Also, if anyone know anything about the balance point for a Deltie B (where is it?), please let me know.
What I do is work the clay in the hand for a short while to softens up, Most of the modeling clays out there these days seem to get a semi slick surface if exposed to the air. Working the clay softens it and makes it plyable enough to "Stick" on most balsa models be they raw wood or painted. I also keep my Clay stock wrapped in wax paper inside a small zip-Loc baggie...How did we ever live without Zip-loc bags????

It also helps to spread the clay into/onto the wood, rather then trying to just stick it. Sort of Whip to a side rather then pressing staight down. Generally I'll apply a clump sideways pressing and smear the clay to remove some of the excess in one motion. Then it's possible to add or subtract until you get the right amount in place. the stuff may roll off the first time or two...just keep at it, and it'll suddenly stick well. Since I started this "smearing/wiping" practice I haven't had to add any other material or glue to keep whatever type or brand of clay used. Some have been in place for years. Biggest thing is to get the clay worked to a soft point before you start;)
Not sure if you'll be able to see the clay globs on the model pics below but they are simply hand worked soft and applied, with the wiping/smear-in method first then add on an smooth a little more, or take of a little. this works fairly well on wing tips also if your trying to Add a little more turn to a model on the field.
Hope This helps a little.
 
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georgegassaway

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This may sound nutty, but.... use CA to glue some clay to the wood. The clay that is glued on with the CA will act as a good foundation for other clay to be stuck to it.

- George Gassaway
 

MarkII

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I agree with what John said. Work it in your hands for a little while to soften it up; your body heat will also warm it and make it stickier. I have been using the same 8 oz. block of Kleen Klay toy modeling clay for the past four years, and it isn't even half gone! It is non-hardening (it will not air-cure), and I have just kept the remainder in its little plastic wrapper, stuffed into its little cardboard carton. After all that time, it's still quite pliable and workable. I need so little for trim balance and for nose weight in small rockets, that the 8 oz. block is probably a lifetime supply. To adhere it to bare balsa, I just start with tiny bits of it and smear it into the wood. Be sure to wash your hands before you start to work with it, though, because anything that contaminates it will make it less tacky.

MarkII
 
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