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Here's a shot of the spar after trimming the previous layup
and removing peel ply from the spar troughs. It's amazing to me how
some of these layups can be so messy, then, after cure and trim they look
pristine. Not that they have to be, but, makes you feel better about
your work when they are. |
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Here's the spar, mounted top face up. The spar trough
has been sanded and checked for bumps. |
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You can see some 2x4 spacers I used to hold the center of
the spar off of the table. |
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Here's the top trough after adding the dam to hold the spar
cap as you lay it up. There's no good way to hold this on, I have some
triangular braces mounted to the jig table. This didn't work so well.
The plywood ended up pushing out just a tad at the top as the layup was
completed. |
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Another view. |
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Another view. I have one of those board holders down
at the far end ready to hang the roll of spar cap tape on it. |
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Close up of the dam. I used 1/2" OSB, with a bunch of
packing tape on it. |
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Here's a shot of the spar cap after starting on the layup.
I have a suggestion for you on large layups like this - do all the prep work
on day 1, then, do the layup on day 2. I think we ended up starting on
this after lunch, so, we didn't finish until way after dinner. |
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A couple layers of spar cap tape have gone in. These
are still full length. |
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Close up of the spar cap as the layup progresses. The
tape wets out different than BID or UNI, not quite sure why. Requires
a lot more squeegeeing. |
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I cut a rubber squeegee to 3" wide just for these layups.
I like a big, heavy squeegee for the spar cap tape. |
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Add a layer of spar cap tape. Add some epoxy. |
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Squeegee. |
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Add another layer of spar cap tape. |
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Add epoxy. Squeegee.
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Repeat until you can't stand up any more. |
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Yes, I'm smiling behind the mask. Only 10 more hours
to go! |
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My son James, pictured here donning his mask, helped with
this layup by mixing epoxy. |
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Layup is done and peel ply has been added. |
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All done! Finally! I think this puppy took us
about 9 hours to do. |
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I don't think there's gonna' be enough spar cap tape left
to do the bottom cap. I bought some leftover from Bob Peplinski who
lives about an hour from me. |
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One down, one to go. Flip the spar over, remove the
dam and build another one. Oh, and don't forget to sand the spar
trough dull with 36 grit, too. |
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All ready for the spar cap. I used screws this time
to hold the dam to the back of the spar. Yes, they make tiny holes.
However, once you do the outside layup any loss in strength at all will be
rectified. |
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I asked a fellow EAA chapter member, Dave McCormick, to
come over and help with this layup. Went a ton quicker, not to mention
this layup has less layers.
Thank you very much, Dave! |
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Once that layup was cured, it was time to remove the dam,
peel ply, hot melt glue and etc. from the aft face. |
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This required a little persuasion. I used tons of box
sealing tape, but the dam was sure stuck on there good. |
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Smaller pieces of dam might make it come off easier, but,
then it takes longer to install. Go figure. |
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Now it was time to remove the peel ply, hot melt glue and
etc. Some of the epoxy managed to get behind the dam, and, run down
between it and the aft face. This made it hard to remove the peel ply
as it have thus become completely wet out top and bottom. |
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Oops. Missed some peel ply. |
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More peel ply. |
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I tried using the Shurform plane to trim off the extra spar
cap where the dam pushed away from the aft face a tad. |
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Didn't work too well. It took care of the corners
alright, but, the bulk of it didn't come off this way. |
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Trimming the ends to length with a hacksaw. I think
the blade was done after cutting both ends. Man, that stuff is strong! |
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Here's a shot of the aft face after removing the peel ply.
You can see a marker line on the aft face used to center the layups as they
were installed. You can also see the small holes on the bottom half
where I used screws to hold the dam on. |
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I clamped the spar to the end of the jig table, like before
when carving the bevel, to clean up the aft face. |
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My belt sander did most of the work here. When I look
at this picture and type this text I get itchy just thinking about it.
Spar cap tape is might scratchy. |
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I then used my router, with a 3/16" roundover bit
installed, to radius the edge of both spar caps. |
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Worked great! Just be sure to pass the router in such
a direction that it doesn't dig in. All those spar cap tape fibers are
not absolutely parallel to the aft face and that makes the router grab. |
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Flip the spar over and radius the other side and we're
ready to move on. Look at the concentration on that face! |
| Chapter 15
Step 5
Chapter 14 Step 7 |
