Author |
Message |
   
Al Kittleson
New member Username: Al38kit
Post Number: 31 Registered: 07-2007
| Posted on Sunday, October 26, 2008 - 05:37 pm: | |
I'm rebuilding the CT I bought last year. It had never been properly finished, so it's back to sandpaper and primer... All three "horns" forward of the hinge lines on the elevator and rudder surfaces had small cracks in the paint. I have not yet sanded down to the glass to investigate, but I expect there has been some flexing in this area to cause the cracks. It may just be superficial, but I need to find a fix. Anyone else have this problem? I'm considering sanding down to the glass and maybe applying a ply of BID carbon fiber to the area, and finishing with glass. Also, the elevator trim tab needs to be fixed. The servo does not align well with the tab actuator. It seems like overkill to me, as this tab is 38.5" X 5". I'm not interested in reinventing the wheel if this works OK, but the previous own had pitch issues...I found the elevator cables loose, which I believe will solve most of the problem, but have any of you had good luck with this HUGH tab? I've got a MAC 4A servo... Comments, ideas? Thanks, Al Kittleson Granbury, TX 817 326 1437} |
   
Reinhard Metz
New member Username: Reinhard_metz
Post Number: 87 Registered: 03-2003
| Posted on Monday, October 27, 2008 - 06:14 am: | |
I just completed my 10th year annual, and have no cracks on control surfaces. I do have some paint cracks in the thin wing-to-fuselage fairing, which is indicative of the need to use a softener (impact coat, as it is called) additive for the paint when used in a flexing area. That said, my extremely hard and brittle paint has no control surface cracks, so I would suspect some kind of signficantly inadequate construction in those areas - not a good idea, and a re-enforcement as you are suggesting may be called for. Also, the large trim tab - you don't need it, especially if you have the I/O 360 the plane was designed for. Reinhard Metz |
   
Al Kittleson
New member Username: Al38kit
Post Number: 32 Registered: 07-2007
| Posted on Monday, October 27, 2008 - 12:56 pm: | |
Thanks Reinhard...regarding the paint flex agent...is this used in all the stages or just the top coat and/or clear? I've taken your advice and bought the Spies Hecker...so far just the primer, and wonder if the areas need to be preped with the flex in the primer, also... I've got the IO-520...as long as the pitch trim works OK, I guess I'll stick with the big tab. Al |
   
Reinhard Metz
New member Username: Reinhard_metz
Post Number: 88 Registered: 03-2003
| Posted on Monday, January 19, 2009 - 05:58 am: | |
You can use the softener only in the top coat, specifically in flexing areas - no need to use anywhere else. |
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