Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Old 03-16-2019, 01:00 AM
rv8gibbo rv8gibbo is offline
Join Date: May 2012
Location: Maitland, Australia
Posts: 90
Default Canopy Drilling

Hi Guys, I've just about got the canopy where it needs to be and Its time for the bit cut! My question and excuse my ignorance, is what is the best way of drilling? on or off the fuse? in a prefabbed frame?

Many thanks
Reply With Quote
Old 03-16-2019, 01:48 AM
rv8ch rv8ch is offline
Join Date: Feb 2005
Location: LSGG
Posts: 2,508
Default use glue

The way I did it was to not drill at all, but use a windscreen glue like Sikaflex. If you do a google search like this you will find lots of hints about how to do it.

If you have decided that you will drill, I'm sure that someone will chime in with some tips.
Mickey Coggins

Last edited by rv8ch : 03-16-2019 at 01:51 AM.
Reply With Quote
Old 03-16-2019, 05:54 AM
mike newall's Avatar
mike newall mike newall is offline
Join Date: Jan 2005
Location: Yorkshire, England
Posts: 1,761

Sikaflex !

Much, much easier and less fraught !

That is how your windshield is attached to your car
"I add a little excitement, a little spice to your lives, and all you do is complain!" - Q

Donated in 2018
Reply With Quote
Old 03-16-2019, 09:15 PM
Blain's Avatar
Blain Blain is offline
Join Date: Mar 2013
Location: El Dorado Hills, CA
Posts: 675

+1 Sika. Holes equal cracks.
R-22 sold.
RV-8 AW Cert 02-09-17
N82 Sierra Tango
Avatar courtesy of!
Dues gladly paid thru Nov. 2019(my reminder)
Reply With Quote
Old 03-17-2019, 06:59 AM
Carlos151's Avatar
Carlos151 Carlos151 is offline
Join Date: Jan 2008
Location: Lebanon, TN
Posts: 149
Default Don’t drill!

+1 for Sikaflex.
Drill = cracks = repair
Karl Richcreek
N151TK "La Otra Chica"
Flying as of August 14, 2015
Reply With Quote
Old 03-18-2019, 02:32 AM
rv8gibbo rv8gibbo is offline
Join Date: May 2012
Location: Maitland, Australia
Posts: 90

Thanks everyone, I'm going with Danny Kings Grommet idea, my engineer mate advised that I shouldn't use sika as it uses an acid cure and that it will accelerate any cracking, my question was more about wether or not it's recommended drilling and fasterning with frame off the fuse.
Reply With Quote
Old 03-24-2019, 08:40 AM
rkbrown819 rkbrown819 is offline
Join Date: May 2016
Location: Cape Cod, MA
Posts: 5
Default Danny Kings Grommet idea

Can you provide a link to this or share the information.
Sounds interesting, but I don't see this as part of this thread.
Rick Brown
RV-14A Flying
RV-8 Flying
RV-10 Empennage nearly complete
Reply With Quote
Old 03-24-2019, 12:28 PM
Tankerpilot75 Tankerpilot75 is offline
Join Date: Jan 2015
Location: Oklahoma City, OK
Posts: 427

Check the EAA website “Hints for Homebuilders.” If my memory serves me correct, their recommendation for drilling into plastics like the canopy was to use a “dulled bit” in that the heat generated will keep a crack from occurring. But please don’t follow this advice without first reviewing the video. My memory has been known to be a little suspect at times.
Jim Harris, RV7A, 2nd owner, N523RM
IO-360, Hartzel CS prop, Older Aerotronics built panel Dual GRT Horizon WS, GRT EIS, Garmin 340, 335, Dual 430s, TruTrak 385 A/P with auto level, FlightBox hard wired to WS, Dynon D10A with internal battery (backup EFIS), 406 MHz ELT.
Retired - Living the dream - And going broke!
Reply With Quote
Old 03-24-2019, 01:33 PM
Carl Froehlich's Avatar
Carl Froehlich Carl Froehlich is offline
Join Date: Dec 2007
Location: Dogwood Airpark (VA42)
Posts: 2,080

Addressing the orginal question, this process has worked well on several RV-8/8A over the last 15 years:
- Trim the glass do it fits as desired while clamped.
- Take the glass off and put a line of 1/2” wide or so masking tape on the frame - use just enough pressure so the tape does not fall off.
- Put the glass back on and clamp. You will see the tape now shows a perfect line where the glass is exactly tangent to the frame. This is where you want the rivets so you don’t stress the glass with side a side load. Remove the glass.
- Take your sharpie and draw in the line on the tape. Now space out your hole pattern.
- Drill #40 the holes in the frame without the glass installed.
- Remove the tape, replace the glass and clamp.
- Drill through the glass into the holes, cleko as you go.
- Once the glass is done, drill the skirt.
- Remonve the glass. Drill the holes in the frame out to #30.
- With the glass off, drill the #40 holes to #30 using a plexiglass bit. After that use a Unibit to open the holes to 3/16”.
- On the roll bar counter sink the glass to accept a #6 screw tinnerman. The rivet will go through the tinnerman - the tinnerman spreading out the force and teh rivet does not touch the glass.
- The fairing goes on per the instructions.

Reply With Quote
Old 03-24-2019, 02:02 PM
Breezy Breezy is offline
Join Date: Nov 2011
Location: Okeana, Ohio
Posts: 82
Default Canopy Drilling


I have installed canopies both new and replacement. All have been drilled and pop riveted or machine screw. I have never experienced a crack while installing. There are some simple precautions that will help with avoiding cracks.

Keep the plastic warm, about 80 deg.F works well. Warmer is not better, the material expands and contracts quite a bit in the normal temperature range. Fastening while too warm will cause stress after cooling.

I have used both plexiglass drill bits and dulled HSS bits. Either one works. Dull a HSS bit by running it in concrete for a few seconds. While drilling don't push very hard and have a hardwood block supporting to prevent pushing through.

If drilling over the steel canopy frame keep the bit aligned to the contact point of the tube and plastic. This will prevent glancing as the bit comes in contact with the frame. Use a bit that is slightly larger than the fastener, pop rivets expand while pulled and will cause pressure in the hole. Drill the frame with the correct size bit for the fastener.

An easy way to find the contact point of the frame to the plexiglass is lightly wet with water or window cleaner. Hand squeezing the two together will reveal a line at the contact point.

As I was typing, I recall mistakenly using steel mandrel pop rivets on one install. That aircraft has been flying for years with no cracks.

Take your time.

Also, I am not against SikaFlex. It looks like a good system, just never had the opportunity to use it.

First offense RV-8; N594WR; 80594 (time served)

Repeat Offender: 83137 (Flying 10/16)
N837DW; Superior IO 360; G3X Touch.
Exceptional Aircraft Award, Sun N Fun 2017; Best Homebuilt, Mid-Eastern Regional Fly-in 2017.

One More Time: 140359, -14 in process, IO-390 (Maybe)

KHAO (Hogan Field)
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 01:57 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.