The Good "Crack" HOBBS 1204.0 hrs

After 2 1/2 days of letting the SikaFlex set up, I finally removed the straps and "cracked" open the canopy as a fully intact unit. It was an exciting moment filled with anticipation. Well, I tried to crack it open I should say! When I first removed the straps and tried to lift the canopy on the co-pilot side it didn't budge!

Whoopsy, apparently I had inadvertently glued my canopy shut! Sean, John and I had discussed this possible scenario but I assured them it would be ok...hmm, maybe I was wrong?? ;) I moved over to the pilot side and tried again and it easily lifted a few inches, so I stopped to think it through before proceeding. I figured I would give it a little bit of extra force on that side and see if it broke loose...sure enough it did, whew! It turned out that some of the Sika had oozed out onto the tape protecting the roll bar. When I cracked it open it actually pulled the tape off the roll bar.

I was pretty impressed with how sturdy it already felt, even without the side skirts. This was pretty exciting to open and close it (even without the struts re-installed)...I kinda felt like a kid in a candy store...again. :) Check out the video...

Re-Energized! HOBBS 1200.0 hrs

Now that I am getting back into the groove with building, I can feel the momentum picking back up where I cant wait to get back out in the shop. This weekend, my friend Sean Blair (RV7, Fuse) and his friend, John Armstrong (RV9A, Fuse) drove up from Colorado Springs (60 miles south of Denver) to help me glue the main canopy. They also wanted to get a tutorial on Sika as they both plan to use it on their canopies.

Getting over this hump was huge for me on an emotional level. Not only did it go really smooth, but I was so relieved to have that plexi attached to the frame so it is more sturdy and less likely to crack. I took a big sigh of relief when we finished up and Sean treated John and I to lunch.

In addition, it was so nice to finally have some help (I've done most of this build solo), it was also refreshing to have two more sets of eyes looking at the project. John pointed out something I hadn't realized about my transponder antenna (I'll post on this in a follow up) that I'll need to fix. Its amazing how, you, as the builder don't see obvious things sometimes.

Big thanks to Sean and John...really enjoyed the company and conversation. Sean also brought his full CAD interior package that he just received so I could 'oooo' and 'aaaah' over it. CAD interior is expensive, but they do make a darn nice product, I was very impressed and cant wait to order mine.

Here is my setup for holding the canopy in place for gluing. Before John and Sean arrived at 9am, I had been working on the setup/prep since 6:30am. I must've put the canopy on and pulled it off 20 times in those couple hours. Checking, double checking, thinking it through, did I forget anything?...masking...etc. Notice the pink foam pad on the side of the canopy...this helps pull the sides of the canopy into the frame nicely when strapped down.

Masking for application of the SikaFlex system. Notice the duct tape to keep the canopy from having too much stress on it while it rests on its back like a turtle. I was nervous with it in this position for obvious reasons. Make sure you have all your edges dressed before even thinking about doing this...even then, be careful.

Another last minute fit check to see how my interior masking lined up...I think we are good to go!

While I had some extra hands in the shop, I wanted to knock out these fuse rivets I couldn't reach solo. Sean ran the gun and I crawled inside the fuse (that's a bitch!) to buck these bad boys. Nice to have that taken care of.

My helpers for the day, introducing Mr. Sean Blair...

...and Mr. John Armstrong. Thanks again guys! I owe ya. :)

Sean was playing photographer while I put on the Sika primer with my foam brush.

A shot of the canopy strapped in place to allow the Sika to dry. I left it this way for about 2 1/2 days before removing the straps. As you can see, I did this while the canopy was in place on the fuse..not on a table. I know the slider guys take it off and do it on a workbench but I wanted to ensure I had the exact alignment to the fuse and the rear canopy. Since I wasn't using any holes in my canopy...not even cleco holes, I figured this was the only way I could pull it off. There were some drawbacks to this since you can't get inside to clean up the excess Sika before it dries, but all in all it worked out well, I liked the fit.

Also, my process for doing Sika was two steps. First step is to do a "structural" bond with the Sika, i.e., don't worry about doing the cosmetic fillets. Second step, later after the first batch has set up good, remove spacers if used, and then do your cosmetics...you know, make it look nice. I had a 65 degree shop in a pretty dry climate and really had no problems with the Sika drying too fast. I might have been able to combine the steps into one...but why put the pressure on yourself. Two steps is a little extra work with extra taping/prep and such but it came out good.

By the way, when doing the second step, I reapplied the Sika activator...I think you technically have a 24 hr window (check the literature) but I just did it to be safe...figured it couldn't hurt.

All in all, Sika, like most of the stuff on this build wasn't nearly as bad as some make it out to be. I think sealing the tanks was worse..ProSeal is nastier to work with than Sika. With Sika, the worst component is the primer. My concerns for structural integrity are non-existent...I did a test piece and was very impressed that not only did the Sika stay flexible, but it was very strong (and this was only about 1 or 2 in^2 piece)...I'm confident this canopy isn't going anywhere in flight.

I was so pumped up after getting the canopy glued in place on Saturday, I was dying to start fairing in the front of the Plexi on Sunday. Here you can see I started using "fine line" tape for make my contour line (1" up from the edge of the plexi)...no bueno! Fine line tape works well if you have a good guide to follow or need to do sharp radii. Otherwise it is just too wavy for my taste, as you can see here. I switched to good ol' electrical tape and it worked much better.

Black dye for my fiberglass layups so you don't see it from the inside of the cockpit...not convinced you need this since I will probably paint the inside of the plexi, but it was only a few bucks at ACS. I also used this bondo spreader for the contour from the sheet metal to the plexi...because its flexible you can control the radius, worked really nice.

First layup...filling the gap with a cotton Flox mixture...since the canopy was still strapped down while the Sika dried, I could only go so far until I remove the straps later. Also note, I didn't add Sika to the front area of the plexi (although I did tape for it)...didn't see a need since the fiberglass fairing will structurally hold this in place and Van's doesnt have screws in this area either.

More filling....I added 1" strips of fiberglass tape over my first layer of Flox that I had left over from my emp tips. I have since ordered 3" and 4" fiberglass tape from ACS, which I will used extensively for the remainder of this fairing work, the side skirts and the targa strip.

And, another layer of Flox to smooth over the 1" strips...its looking good, larger strips and filler will be the last steps before plenty of sanding to make it look pretty.

Cracked Canopy!! HOBBS 1188.0 hrs

Yep, I cracked my canopy...you read that right, its not a typo and your eyes aren't deceiving you. I danced through the 'big cut', laughing it off as being a piece of cake, only to crack the canopy later! Ironic isn't it?? This actually happened about a month ago, before my Mexico trip and I'm just now getting around to posting about it.

When I started this blog, I told myself, as bad as it is to be in the spotlight...I wanted full disclosure about the build process...including my knucklehead mistakes. I know there will be readers that rightfully so, say, "what an idiot"...but that's ok, I can take the heat. I figure, if my posting about it here helps someone coming behind me to avoid this, its worth it to me. I like to "pay it forward"...like all the guys (Dan Checkoway, Bruce Swayze, Chad Jensen, Jason Beaver) who went before me and helped me get to this point. And to those builders out there that make no mistakes...good for you, you are far superior to me because I make plenty. There is no way you get through one of these builds without some frustrations...some bumps in the road, this just happens to be one of them for me.

So, when I first saw this crack, I thought it was just the black SikaFlex primer that had somehow managed to get under my tape so I was trying to clean it off...that's why the area is scuffed up. Upon further inspection with better lighting, it was pretty apparent that sure enough, it was cracked, but good! The feeling of dread cant be described in words...I felt like I had been gut punched and all the air had been knocked out of me. I was so proud of my new glued in place rear canopy only to find this...it was a long emotional fall. 

What happened, from what I can tell, is this. I had used Popsicle sticks as my spacers for the SikaFlex like many builders do. I then used several clamps, with rubber boots mind you, to secure the plexi to the roll bar over the spacers. I think, on this particular one, I didn't get the Popsicle stick inserted far enough so the edge of the stick caused a pressure point when I clamped it. The plexi didn't like that pressure point...and bam, crack! My advice...make sure you insert it far enough in or do like some builders and use 'O-rings' as your spacers which I would do if I did another one.

After gathering my composure, I did what any good builder or pilot does. Remove the emotion from the equation, take a deep breath, assess the situation and consider my alternatives. First thought was of course, its ruined and cant be fixed...I'm fu#$%ed! Which turned to, great...you cant just buy the rear half, so all of the work done on the canopy (like the big cut and all the trimming) so far would be out the window if I ordered another one. Beyond the fact that it would cost in excess of $1200 to replace it. This idea was making me rather nauseous, so I immediately changed my thought process. Yes, I was in denial. :) 

Ok, what else can I do?? There had to be a way around this without starting over? Right? Paul Dye, who is a NASA flight director, RV8 owner/builder, KitPlanes contributor and VAF stalwart said something in one of his VAF posts that I really liked. He said, and I'm going on memory... part of the build process, part of becoming a skilled builder is learning how to overcome your mistakes...sometimes buying a new part is just not going to happen, and you're not going to throw away the entire airplane and start over. You have to find a solution. It reminds me of a saying I always like to use that I stole from the Clint Eastwood Marine Corp movie, Heatbreak Ridge..."Improvise, Adapt, Overcome". And thats exactly what I shall do...

With that quote fresh in mind, I did a google search on repairing cracked plexiglass. First order of business...stop the crack from getting worse. Stop drill that baby immediately! That almost made me cry to drill several holes in my new plexi--but I knew it had to be done. During my search, I also found out there are special 'Weld-on" products for plexiglass. Ok, now I felt I was getting somewhere...I had alternatives. 

But...the problem is, filling the crack and stop drilled holes will leave it opaque and look like crap. Then I thought...well, how about I paint a black strip on the outside of the plexi, over the roll bar. The 'slider' guys do this and it looks nice...Chris Sands exquisite RV7 had something like this as well. Shoot...although I hadn't planned it, this could work...my spirits were lifting. In addition, I planned to do a 'targa strip' anyway so this would work well with that design scheme and still look nice...almost like I planned it that way. ;)

After a month of really having the wind taken out of my sails over this cracked canopy, I am finally getting past it and feeling much better about it as I move forward. It wasnt easy, anyone who has cracked their canopy will attest to that, its a tough hump to get over. But, get over the hump you must...and build on! I hope my experience will help you avoid a similar fate.

Here is the massive spider crack...ugh!

Stop drilling it...you can see I missed a couple...

This is Chris Sands' plane and the canopy scheme I am referring to...notice the black strip over the roll bar and the 'targa strip' on the canopy. My canopy will look just like this when I am done....it doesn't look too bad does it?? :)

Another Learning Curve HOBBS 1181.5 hrs

As I start down the path of using SikaFlex for the first time...another learning curve is in process. Gosh, there has been a lot of them so far...and more to come. Its not a particularly difficult system to work with but since its the first time being exposed to it, I am once again learning as I go. Reading posts from other builders definitely helps...but in the end, you wont really know what its all about until you dive in and get your hands dirty.

So, here I am getting everything prepped...tape, scuff, cleaner/activator and primer...in that order. The ink black primer is the one to be careful with...it is blacker than black and doesn't come off easy. So tape well and be careful with the application. I used the foam brushes for applying both the activator and primer...worked good, no brush marks. I also bought some expensive 3M fine line tape...a lot of guys use electrical tape with good results.

Applying primer to the roll bar...let the activator sit for 10 mins...primer for 30 mins.

Popsicle sticks for proper spacing...and now applying the goop...the 295UV SikaFlex.

My approach was to tackle this in two separate work sessions. First one is to glue the canopy in place. After its set, then go back and do your cosmetic fillets. First go 'round I tried to do this with my finger and it didn't work very well...I ended up taking it all off because I wasn't happy with how it turned out. In discussion with my friend and fellow RV7 builder, Sean Blair, he suggested trying a plastic spoon and that really worked great...definitely a good tip.

I recommend removing the tape soon after application unless you are really good about not getting any on the tape (which I wasn't). If you wait until it dries, it will try and peel away the good with the bad.

Here are a couple shots of me filling time with the empennage fairing...this thing has really turned out to be a pain in my rear...kinda tired of dealing with it. I know it looks like crap in these pics...but once I put a coat of filler primer on it, it will look much nicer. :)

Rear Canopy Prep HOBBS 1168.5 hrs

Most of my activity lately has been focused on getting the rear canopy ready to glue with SikaFlex 295 UV. Since this will be an easier task than the main canopy, I figure its a good place to familiarize myself with SikaFlex without too much pressure. Most reports I've read say you can do the rear window in a short work session by yourself.

My first step was to do any fine trimming needed for a good fit. This required putting the plexi on and off several times. Cutting and then polishing all edges, finally getting it just right. I will tell ya, this is easier (less stressful) if you are doing a 'targa' strip like I am because your edge doesn't have to be so perfect.

Starting to plan my 'spacer' strategy. I am using two popsicle sticks taped together to get a nominal 1/8" gap (~3mm). This seems to be the general target for RV guys, although SikaFlex recommends 4mm. The problem with my plane is I didnt factor this gap into the construction so I have, shall we say, "challenges" to this approach. I'm still undecided exactly how I plan to address this...but for initial fitting, I used 1/8".

A slight diversion from the rear canopy took me to the struts on the forward canopy. I got these babies installed and its looking good! Beyond the superior in-flight visibility, I love the look of a tip-up...not sure why, becaue a lot of guys like the sliders. Maybe it's because the fighter planes of my childhood were F-16's and F-14's...tip-ups, not sliders.

Even though I am doing one half at a time...I did want to do a sanity check with the forward canopy to see if I saw any problems before I glue the rear canopy in place. It will need to do some of the same minor trim work but its looks fine for now.

Now I set about trimming the protective plastic back and adding tape for my edges...i.e., make sure the SikaFlex doesnt get anywhere its not supposed to. Just like taping for paint.

I scuffed the inside skins, not only for the SikaFlex but also because I plan to paint them black later...these will be visible even with the full CAD interior package.

Scuff the SikaFlex surfaces on the Plexi with scotchbrite for good ahesion.

My SikaFlex materials...ready to rock and roll. This was about $100 worth of supplies and should do the entire canopy. I plan do a test piece to see how it all works before committing to the canopy...stay tuned.