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Canopy/Fiberglass Fun?

E. D. Eliot

Well Known Member
I will begin the fun of fiber glassing the front section of my canopy soon. I don't know enough to be afraid of this procedure and have decided to enjoy the ride. I will follow Vans instructions exactly and expect to have a good result.

I would like to explore a different manner of covering the front fuselage structure - you opinions are sought. Instead of placing layers of tape over the front top of the fuselage, waxing, etc., would it be ok to layer a few sheets of 6mil plastic there? I can't imagine that it isn't ok but as I said, I know nothing about fiber glassing. I look forward to this part of my RV-12 build.

Your thoughts on this possible alternate method please. Thanks.
 
Why exactly do you want to use 6 mil plastic instead of tape? Tape is the way to go - you put it exactly where it needs to go and it stays there. And, it's what the Vans instructions and guidance call for, so if you're following the plans...

Here's some pretty helpful video info. Granted, it's RV-14 focused -- but the principles and technique applies to any RV canopy fiberglass, really. Much of this directly applies to the process of glassing the RV-12 canopy, as well.

https://www.youtube.com/playlist?list=PLsHxidYW7eS2bmEfPh-zuZCXn5TXngVlY

The more fiberglass I've done the more I (crazy as it sounds) enjoy it. I know, I'm weird.
 
There is a pre-made fiberglass canopy trim for the RV-12 called the Viking Shield. You simply glue it to the canopy, although it does require some trimming to get a good fit. I bought one and got down to the last trim step when I decided I did not like the look of the tan glass color and black adhesive from inside the cockpit. I ended up doing all the glass work from scratch with gray colored epoxy to match the canopy frame and interior gray color.

PM me if you are interested in acquiring it.

John Salak
RV-12 N896HS
 
It is not as bad as most seem to make it out to be, just do it. I would use the scotch tape again. I used black dye in the glass, made the inside beautiful. Be sure and cover the panel and have a drop cloth inside. Mine ran down the panel face a bit.
 
The more fiberglass I've done the more I (crazy as it sounds) enjoy it. I know, I'm weird.

As been said before ... with fiberglass, nothing is "final".

I agree, it actually is easy to work with and I like the fact that I can never permanently dent it with misplaced bucking bar or mushroom head on my gun. Just keep a good supply of sandpaper and some good sanding blocks (Dura-blocks, also recommended here great; stick the paper on with some spray mount on the back of the paper) and you're golden. And, you'll be able to show off your Popeye arms, no spinach needed! ;-)

Likely you found DanH's posts here about how to glass ... super informative. I have them ALL bookmarked for easy reference. Thanks Dan!
 
It really isn't that difficult. The only advice....I found it better to use two or three more layers of tape (white electrics if you use black dye in epoxy) to give a thicker transition layer on plexiglass/mental.

You will use micro beads/epoxy paste as a/c bondo to fill in voids to effect a smooth transition in curves. Use socket over two attach bolts with a few wraps of tape to fill in voids where bolts go.
 
E.D. --- The canopy layup seems like a daunting task but it really is not bad ... if taken one step at a time. If you look at my DOGAviation Blog beginning around September 2015 you will see lots of photos of the process along with documentation.

Suggestions:

Like Don mentioned, mix black pigment (or your interior color of choice) in the resin for the first lay-up batch including wetting of the Plexiglas ? makes for a nice look from inside the cockpit.

Ric gave good advice about the micro beads and electrical tape ? I used high quality 3M red tape ? don?t use the thin cheep stuff for this task.

I used the thickest duct tape I could find and placed it onto the fuselage as suggested by Van?s then covered it with clear packaging tape, then smeared a thin film of Vaseline onto the packaging tape as the release agent ? worked great!

For cutting the fiberglass cloth suggest using a round fabric cutter (think pizza cutter with a sharp wheel) this is almost a must because the pieces deform almost by breathing on them and do not take well to being cut by scissors while being held.

Don?t pick up the cut pieces by hand as it can seriously distort the fabric ? I used thin metal rules slid under the fabric to move it from the cutting table onto a sheet of paper with the layup number written on it.

Get the cheep 1? bristle brushes from Harbor Freight and cut off about half of the length of the bristles to make it stiff and use it for stippling the resin into the dry cloth and also to work air bubbles out once the layer is on the airplane.

Place at least two layers of vinyl gloves on your hands ? at times I used three then peal off a layer when it gets too sticky.

When actually ready to do the lay-ups, have helpers ? it will go much smoother with extra help. I had two helpers for mixing the West Systems epoxy and wetting out the next cloth layer while I stippled the lay-up on the aircraft.

Place the cut cloth upside down on a piece of plastic wrap (I used plastic pallet wrap) and wet it out with resin then transfer to the canopy, position, and peal off the plastic.

Nothing wrong with cutting the cloth a little longer in the area of the canopy skirt ? it is easy to sand away the excess.

Do use peal ply to help wick up excess resin.

Go to an automotive paint shop and pick up a good sanding block with a rounded edge. I used one that is for self-adhesive sanding paper with good results. It will also come in handy for the cowling and tail cone fiberglass work.

Watch the video on Van?s site for lay-up and sanding tips.

Hope you find the posts covering the canopy lay-up on the DOGAviation Blog helpful.

Happy building,
 
My 2 cents

I did the layup process and thought it went pretty well based on my limited fiberglass experience. I had the paint shop finish the fiberglass work on the cowling and canopy. After a couple of years I noticed some separation between the fiberglass and plexiglass of the canopy.

This was on the area where the canopy curves on the front and was occurring on both sides. My first impression was this area takes some extra stress and twisting opening and closing from either side. Lifting or pull the canopy opening or closing will cause this stress. Just the nature of the design and not a bad thing, but take it easy up and down.

My fix started with cleaning and trying to expose this small area. Rough up and add epoxy to try and strengthen the bond. Then a little filler to smooth the repair. My concern is this repair adds a hardened material in this flexing area.

I noted some addition spots across the front also separating so this winter the canopy came home for repair. I again cleaned and opened up the areas the best I could and used tank sealant to fill this stripe about 3/16 wide across the front of the canopy where the fiberglass and plexiglass transition. It's paintable but I'm going to watch it into the summer to see how it holds up before any touch up.

The bottom line is to do the best prep job you can on this area to have the best chance at a good initial bond and maybe you will never have this issue!
 
The bottom line is to do the best prep job you can on this area to have the best chance at a good initial bond and maybe you will never have this issue!

Excellent advice.

people often don't do as good of a job fully scuffing the surface as they think they do.

80 grit sandpaper is recommended. That is pretty course so it is possible to leave a lot of area between the scratches that has not been scuffed.

Get close... and use an overhead light source to try and detect any amount of gloss. And don't just sand one direction. Make the sanding scratches go every witch way. <All detailed in the videos linked to earlier in this thread.>
 
I was also apprehensive prior to the glass work on the canopy. I found it to be one of the most rewarding parts of the build. It went pretty much as planned.

A couple of things to note:
When drilling the canopy frame front bow use the tape method to find the center of the bow you want to drill into. Search the forum for the method.

Use tape as described in the directions. Besides allowing the glass to separate from the sheet metal it also provides the correct gap between the parts.

Use a putty knife to gently release the glass from the tape. Epoxy sticks to everything no matter what the prep. Don't just try and lift the canopy.

When aligning the canopy bow to the panel don't get carried away - close is good enough. If you have filed the weld prior to bending the bow (if needed) that weld is where it will snap. Any good welder can patch it up if it does break though.

Enjoy it - you will be happy to have actually "created" a part where none existed before.
 
Practical experience gained by a mentor

+1 for having a helper. I had very little experience in fiberglass work before I did the layup. A friend which is highly skilled in this field came over and we did it together. Reading, understanding and following the plans is one thing. But practical experience is best achieved with someone who has the expertise on that. Especially for a part like the canopy fairing. I consider my layup session very rewarding and do no more panic when fiberglass comes into play. Thanks to the help and mentorship of my glass buddy.
 
I was fortunate (?) enough to have the experience of my first home built project, a WAR FW-190, when I went into the canopy. First, I was grateful for the progress in epoxy. In the old days the Hexcel system caused me quite an allergic reaction on my hands. Second I knew from experience that you always get a " do over" with fiberglass". Just cut/ grind it out and start over or add on. And you can always slap on a patch and add micro ballon slurry or flock.
 
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