Tbone

Tbone

Well Known Member
What procedures (that seem to work) on drilling the canopy holes for the #6 screws? I have read and seem to remember someone using a ceramic countersink and such. From start to finish what worked and drill bit sizes please?
 
I just completed this task for the windscreen/roll bar screws. I used a very dull #40 for the initial holes, countersunk with the microstop countersink, then enlarged to 5/32 with a unibit (long thin one) - 1/8" first, then 5/32". Drilled at low speeds and took my time. Worked really well in my 100 degree hangar. As for the sides of the canopy when installing the side skirts, the manual says to "pre-drill the canopy with a #30 drill through the canopy lower edges," then countersink and enlarge to 5/32". Why not the same #40 as the windscreen?
 
Just drilled my canopy holes three weeks ago. Used a 1/8" Plexi bit, then a plain ol' #30 countersink, then enlarged with a 5/32 Plexi bit. No troubles at all. BTW, I tried the standard #30 countersink a lot on scrap pieces before I followed friends' advice to do so. They told me not to fret over the pricey ceramic/stone countersinks. At least 4 local builder/friends had used a standard #30 countersink with no trouble.
 
Is 5/32 large enough for final size? Will that be enough clearance for expansion?
 
drilling canopy

Its not expansion that you have to worry about so much its the contraction of the plexi in the very cold winter temperatures especially in the skirt the plexi needs to be drilled oversized as the plexi shrinks more than the rivet through it,in the -30 to 40 that we get here in the northeast. Our canopy developed a crack from one of the skirt rivets but we were able to drill stop it.

cyril
 
My understanding (possibly wrong) is that the canopy, as a whole, expands and contracts. I don't think that the hole size does that? Is that what you are referring to? The reason I ask is that on my skirt I drilled to 3/16 and on the rollbar I used 5/32.
 
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