correcting trailing edges
 

hi, i am working on a DF jet where the wings, stab & rudder have already been glassed:D

however, the "expert" left some small wawes in the trailing edges
thus i need a correct way to "true" these lines.... sanding one side and filling in the other side seems obvious to me, but how and what to use as a filler is my dilema ( to retain strenth & keep the weight to a minimum) [&o]

also, the rudder fin is slightly curved to one side, i would need to insert a rod (carbon fibre?)
to straighten & strengthen the tail fin

i was thinkink of rigging a temporary (straight) braces on each side, drilling the core and inserting a (?) rod, using epoxy to hold it place
not sure how exactly to do this...

otherwise the surfaces seem to be aligned OK

please help [:o]

thanx in advance, Vasek

RE: correcting trailing edges
 

Vasek,

Not sure what to tell you about the curved rudder (perhaps just build a new one?) but I normally laminate a piece of C/F in between the TE sheeting to get a sharp, strong, & straight surface. I've also used a dremel tool mounted in a dremel drill press attachment with a saw blade (or cutoff wheel if you want a thicker slot) to slot the TE 1/8" deep & then insert the C/F or 1/32" ply piece. That'll allow you to sand the TE down to a sharp edge.

Bob

RE: correcting trailing edges
 

bobman, thanks for helping,
there is already a C/F isert built in the surface, but it follows the slightly warped surface.... [&:]

RE: correcting trailing edges
 

can you laminate the whole thing in 1/64 ply and put it in a press with west sytems overnight?

RE: correcting trailing edges
 

seanreit, can u elaborate? u mean covering the whole stab with with ply? wouldn't that add a lot of weight? please explain...

RE: correcting trailing edges
 

Are you talking about a control surface? Or the whole stab? Call me at 512.259.0797, I'll try to help you out.

Sean

RE: correcting trailing edges
 

Sean, thanx 4 the offer (i just might take U up on it someday...) but for now problem solved!!!

i took a hard look again on the problem at hand, and it just hit me that it coud be the hinges poorly alligned causing the control surfaces to warp

the cores are BVM so i new tey were straight before the "expert" glassed them, but the problem wasn't in the glassing, it was the hinging! i cut the hinges and voila! the rudder sprung back, perfectly straight again!

i will have to correct some sanding that was done to correct the warps once the control surfaces were incorectly installed (what an expert![:'(]) but that will not be a big problem

i did the same for the elevators, the same "miracle" was produced... i weighted down all the control surfaces, am sure they will (gladly) go back to their initial shape overnight....

later i will re-hinge all moving surfaces to obtain the desired truness of the trailling edges

Sean thanx again for your help and your patience,
Vasek

P.S. i am sure some other issue will come up (this is my first jet) so i hope to see U on my future posts [sm=drowning.gif]

RE: correcting trailing edges
 

No problem, as you know the wealth of experiance here is incredible.

Sean

RE: correcting trailing edges
 

Sean BTW what filler du you use on glassed cores for correcting minor surface imperfections?

i will need to spread very thin layers over the sanded areas on those cores

i use car body putty (the lighter stuff) & finishing filler . if there is something better you know of, let me know

thanx, Vasek

RE: correcting trailing edges
 

The product I'm using right now is evercoat 100445 for the really thin stuff (it has no strength to speak of it's really for finishing pinholes etc). I used to use regular bondo for body stuff, but I'm using west systems with microballoons (easier to work with and sticks a whole lot better) but at a much higher cost per use IMO.