Canopy (and its fairing) after engine installation?

[ymc9]

Hello guys,

While still waiting for warmer weather to drill the canopy plexiglass safely, I'm wondering if it's good idea to install the engine first. Potential problems I can think of are:

1. Need to get around the engine to fit the canopy. Probably not too bad.
2. Need to protect the engine inlets when sanding the fiberglass fairing.

Has anybody done this in this order? Any other issues that I missed here? If doable, is it good to even start the engine without the canopy on?

Thanks!

 

[N8DAV8R]

I don't see any major problems other than the mess. I think I'd rather have the engine packed away somewhere clean and protected during all that messy work, mainly the sanding. The engine mounting is such a quick and easy task that I personally would not see much benefit in getting ahead, thus not worth the risk or work to protect it from all the dust.

 

[ravenstar]

Maybe others are neater at fiberglassing and epoxying than I am, but it was quite a mess. I did take precautions and covered everything with paper, but I think it would have been a lot less pleasant if I had to worry about getting any of that on my engine. If it were me, I think it's worth waiting a little longer. Warm weather is on its way. According to my notes, it was 72°F when I drilled my canopy and it turned out to be a complete non-event. Beforehand I had done some tests on scraps I acquired from another builder, and even breaking every rule I could think of I didn't have any issues with cracking. (Things like drilling the initial hole #12 with a standard bit, drilling two holes next to each other nearly touching, drilling #30 within 1/16" of the edge with both standard and plexiglass bits.) So I doubt you'll have to wait long for good conditions.

Once my canopy was finished, I removed it and the avionics cover to make work on the avionics easier.

Maybe you've done these already, but some items you can do in the meantime are the initial trimming of the cowl in preparation for fitting it over the engine (Section 37), and final drilling the nose gear flange which involves removing the nose gear to deburr then reinstalling. As N8DAV8R said, the engine mounting itself is very quick in comparison.

 

[Baron71]

Maybe others are neater at fiberglassing and epoxying than I am, but it was quite a mess…

I totally agree. Just finished the canopy (did it in winter BTW, using gas heater to heat my garage to 80F before starting to drill or cut and also ground the corners of my drill bits as per EAA instructions to avoid cracks. It worked for me).
I you want to see the mess, just take a look at the photos in my blog (https://www.redloop.de/?p=961).
The good thing about fiber glass work is, if you are not satisfied with your work, most of the time you can grind your way back and re-do it. The bad thing is that grinding creates a lot of fiber dust that even after cleaning my garage thoroughly still pops up like everywhere.
Therefore, I can only adjunct to letting the engine packed and covered snug as long as you have to do any grinding of fiber glass. Of course, the same holds true of for thoroughly closing up your fuel lines.

 

[ymc9]

Thanks for the comments, guys. I’m absolutely nervous about fiberglass work even after taking the EAA course. Will put the engine installation on hold then. I can still find plenty of other tasks .

 

[N8DAV8R]

Thanks for the comments, guys. I’m absolutely nervous about fiberglass work even after taking the EAA course. Will put the engine installation on hold then. I can still find plenty of other tasks .

Don't be nervous about the work, it's a fun challenge once you get going. Read that section of the KAI multiple times. Follow the directions closely as you go through the tapes and sanding steps. Set aside the recommended time and just work through it.

Honestly the canopy frame alignment that comes before the glass work is "worse" than the fiberglass.

 

[ymc9]

Don't be nervous about the work, it's a fun challenge once you get going. Read that section of the KAI multiple times. Follow the directions closely as you go through the tapes and sanding steps. Set aside the recommended time and just work through it.

Honestly the canopy frame alignment that comes before the glass work is "worse" than the fiberglass.

I know it is "worse" because I broke the frame when wrestling with it. On the second one now and will be as gentle as I can be ...