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  #21  
Old 03-26-2021, 06:47 PM
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ronschreck ronschreck is offline
 
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Quote:
Originally Posted by BillL View Post
Hey, Ron, I have a box of these washers and never discovered the perfect use for them, but- just this week (first 'annual' since paint) got some paint turn-out with my screws (@#$%^&). Will these stick to the paint and prevent that post paint?
They may not stick to the paint but they will keep your screws from messing up the paint.
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  #22  
Old 03-30-2021, 08:44 AM
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I finally remembered to take some photos of my issues.. The photo where the spinner is visible shows the fine crack in the cowling..
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Last edited by jrock836 : 03-30-2021 at 08:46 AM.
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  #23  
Old 03-30-2021, 09:04 AM
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Looks like a paint problem rather than a fastener problem.
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  #24  
Old 03-30-2021, 09:35 AM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by gyoung View Post
Looks like a paint problem rather than a fastener problem.
I agree.

The paint is being extruded out from under the screws. Once the paint is moving on the cowl surface, the bond to the substrate is compromised and damage will continue.

One common cause is an excessively thick layer of paint that takes a long time to fully cure.

Add to that, reassembly only a few days after the paint was applied and this is often what happens.


BTW, the screws being used at the front of the cowl are not what is recommended. The plans call for washer head screws because they have some smooth / unthreaded shank where they pass through the cowl.
Using common truss head screws results in the threads baring on the edge of the screw holes which will accelerate elongation / wear in the holes.
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Last edited by rvbuilder2002 : 03-30-2021 at 09:39 AM.
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  #25  
Old 03-30-2021, 10:25 AM
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Quote:
Originally Posted by rvbuilder2002 View Post
I agree.

The paint is being extruded out from under the screws. Once the paint is moving on the cowl surface, the bond to the substrate is compromised and damage will continue.

One common cause is an excessively thick layer of paint that takes a long time to fully cure.

Add to that, reassembly only a few days after the paint was applied and this is often what happens.


BTW, the screws being used at the front of the cowl are not what is recommended. The plans call for washer head screws because they have some smooth / unthreaded shank where they pass through the cowl.
Using common truss head screws results in the threads baring on the edge of the screw holes which will accelerate elongation / wear in the holes.

Have a part number handy? I’ll add some to my next Van’s order.. Looking at KAI 38.07, I’m seeing a truss head screw listed, AN526C832R8. Not positive, but I believe that’s what I currently have..

The paint is what it is at this point. Looking to hide existing damage and reduce future damage until I can get the cowling re-painted.
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Last edited by jrock836 : 03-30-2021 at 10:42 AM.
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  #26  
Old 03-30-2021, 10:37 AM
funflying funflying is offline
 
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Iím with you Joe.
My 12, s/n120401, used truss screws all over the place to include the cowl, spinner, and was according to plans. But I noticed with the 12iS Iím helping with the cowl fasteners identified washer head screws. I immediately thought the plans were wrong and reverted to the truss screws.
Tomorrow when I go back to the 12iS build I will review the hardware call outs and replace the screws with what the plans call out. It will be an easy swap out since we are a long way from startup or paint.
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  #27  
Old 03-30-2021, 10:42 AM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by jrock836 View Post
Have a part number handy? Iíll add some to my next Vanís order.. Looking at KAI 38.07, Iím seeing a truss head screw listed, AN526C832R8. Not positive, but I believe thatís what I currently have..
It looks like the correction hasn't made its way through on the Legacy ULS plans yet, but the 12iS KAI DWG 37iS/U-12 shows AN525-832R8.

They are cad. plated instead of stainless, so don't look as pretty, but they will help minimize wear in the screw holes of time.
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  #28  
Old 03-30-2021, 11:07 AM
seagull seagull is offline
 
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  #29  
Old 08-28-2021, 08:24 PM
E. D. Eliot E. D. Eliot is offline
 
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Default Screws for cowling, etc.

Very interesting - I'm wondering if I should replace the 'old' screws on my vintage build with these - places life anywhere that the canopy plastic parts of the canopy are secured with the older stainless screws??? That would be approximately 100 replacement screws. And now I'm wondering about if it would be good to replace the screws in the gas inlet and spinner???
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  #30  
Old 08-28-2021, 10:22 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by E. D. Eliot View Post
Very interesting - I'm wondering if I should replace the 'old' screws on my vintage build with these - places life anywhere that the canopy plastic parts of the canopy are secured with the older stainless screws??? That would be approximately 100 replacement screws. And now I'm wondering about if it would be good to replace the screws in the gas inlet and spinner???
The locations specified on the cowl are because of experience with those locations. The other locations you mentioned havenít been a problem so the other screw type is used.
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