bruceh

bruceh

Well Known Member
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I'm done with rough fitting my cowling on the -9A. Now I want to sand down the edges for a perfect fit so I can start getting the hinge sections attached.

What sort of a gap between the top/bottom/sides should I leave for paint thickness?
 
A hacksaw blade or tongue depressor also work well. When I dropped off my RV-10 to get painted, there were several places that the painter wanted me to widen the gap a little more. I used a tongue depressor wrapped a sandpaper on my doors to get the proper gap.
 
As Reffeler stated, a hacksaw blade is the perfect thickness to allow for paint. Just see-saw it back and forth at the joint till it is an easy fit between the surfaces.
this method also assures a nice straight line between the upper and lower cowls.
 
further advise sought

If I use the hacksaw method, should I leave the hinges attached and run the hacksaw blade back and forth towards the face of the hinge below?

Should I do this before or after the hinges have been epoxied and riveted?
 
instructor_bill said:
If I use the hacksaw method, should I leave the hinges attached and run the hacksaw blade back and forth towards the face of the hinge below?

Should I do this before or after the hinges have been epoxied and riveted?
Click to expand...

Before. Use the hacksaw as a measuring device when you make you initial cuts. You can always put it back in later to re-measure
 
okay, before rivet/epoxy

Now, only as a feeler guage or have others used the hacksaw in-situ to get an exact assembled gap?

Are there pros and cons to doing either way?

If I protect the hinge with colored electrical tape, I think I should be able to run the blade in assembled, then there's no chance of over-doing it. Has anybody done it this way?
 
still need some clarification

I still need some clarification.

should I be using the blade as a feeler guage? I own feeler guages-- I could use them instead.

OR

should I be using the teeth of the hacksaw blade to create the clearance while the assembly is in place?
 
instructor_bill said:
I still need some clarification.

should I be using the blade as a feeler guage? I own feeler guages-- I could use them instead.

OR

should I be using the teeth of the hacksaw blade to create the clearance while the assembly is in place?
Click to expand...

The thickness of the blade is about the size of the gap you need.

I suspect you could use the teeth, but that may get a little tedious.:eek:
 
If you have your hinges clecoed in place and want to establish a even gap, here is what I do. It works great and is safe.
I use blue masking tape as guide to sand the edge back to. Place the tape carefully along the edge leaving the small amount of the fiberglass showing that you will sand off using a flat piece of wood or something to put the sandpaper on about 8-10 inches long. Remove the hinges to sand the edge if they are just clecoed in place. Be sure you have good lighting and carefully sand back to the edge of the tape. This is to ensure that you don't remove too much material.

I use this method even if I only need to trim very small amount because it gives you a guide. Take your time placing the tape straight. This also works for trimming aluminum edges. Take your time...
 
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Tried a short section

I tried a short blade 2 inches or so held in a razor blade scraper handle to miter the joint in... Like you might with a wood piece.

Garbage idea. Don't bother. Maybe with balsa.
 
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