Chapter 14 6/7/2015 spar ready for wings & fuselage

Building the wings will be next, then the holes get drilled in the hard points on the spar and wings with everything meticulously lined up.  For now this is wrapped in plastic and put up high out of the way.   I'll switch to the other project for now.    Had to be social and go visit relies, then been on call this week too so progress was slow.  

Found a lot of good info in this book.   Our tax dollars at work!


FAA handbook on composites

5/18/2015 Chapter 14 Step 7 & 8

Hard points floxed on.

Corners floxed and layups over hard points.

Wing bolt access hole cut.    Layup is done with peel ply on now.   We'll see what it looks like tomorrow.

5/11/2015 Chapter 14 Step 7

Had some delays....waiting on epoxy from AS and finally got it from Wicks.   Also had a week of vacation, a friend bought a Comanche so helped him with some minor details, hail punched some holes in one of the hangar skylights, several power outages during storms.   Anyway, good to be making progress again.   

There were some glitches in this step.    A little glob of epoxy came off my glove and was on the tare button, causing the scale to continuously zero once.   Fortunately I realized that something was amiss and put that batch aside.   I'd used full width patches of the UNI and now think it would be a lot easier to handle by one person if they were half the width of a roll.

My neighbor (works professionally with composites) inspected my work and he gave it a thumbs up. 

The table is working pretty good at containing the dust when sanding.

Fiberglass cutting station Rev 1.0

Here's a better photo of the fiberglass cutting station I made last fall.   All the wheels castor.   The work surface closes up to protect the opened rolls.   The bottom has almost enough storage to hold all of the wing core foam.   After using this for awhile, I want to add bearing to the rods so the glass rolls off easier.   A longer (and smooth) cutting surface is a must.   Although this is the same height as my work benches so I can roll up to one of three that are 4 x 8 to make a big cutting surface.

On the back side is a nice working surface for the M drawings.   Rolls of peel ply are laying on top.

3/29/2015 Chapter 14

Made a wing dolly yesterday and cut a dozen pieces of UNI for the next step.   Not sure if I have enough epoxy to finish the next step so will weigh the glass and see.   One supplier has been out so will check on it tomorrow.

  

3/22/2015 Chapter 14 Step 6

Bondo and epoxy drips are pretty well sanded off.   3/16 radius almost done.   The downdraft table works pretty good when sanding.   The vacuum keeps the mess localized to the table.   Velcro held the side panels on the table.   

Time to order more stuff!  

3/16" radius/router mess.

3/19/2015 Chapter 14 Step 6

Took about 7 hours to do the bottom spar tape.  Ran into a few minor issues like the thread in the tape snagging and knotting.  The dam and bondo is knocked off.   Still have some epoxy runs to sand off and radius the edges.   The 50:50 hardener mix has worked about right at 65-70 degrees.   

Worked on the down draft table and made some foam panels to close up the the sides.    Think I'll try Velcro since the magnets didn't work very well to hold the panels on.   They need to be easy to put on and take off.

3/12/2015 Chapter 14 Step 6 top spar

Top spar is done and....I'd thought I'd posted this earlier but we've had a couple power outages, so guess it didn't get posted.   The bottom spar dam is ready,   hope to have it done by this weekend.

Bottom dam in place.

A 50:50 mix of fast and slow hardener (pot life 1.5 hours) seemed to work fairly well.   I used bowls of 4 oz of resin and 1.52 oz of hardener.

Wains coating cut length wise was used for the top spar dam and worked fairly well.  There are some epoxy runs so wish I'd put peel ply next to the box tape.  The lumber I had laying around that I was going to use for the bottom spar dam was warped, so I followed the plans and used 1/4" plywood.   Serendipity hit and I ended up cutting strips with and against the grain.    Then I recalled seeing some wood working tips where they pointed out how to use plywood if you need to bend it around something....it almost bends to easily.

1.5" x 1/4" plywood strips cut with and against grain.  

The bottom strip conforms to the spar much better but is is also very flexible, so takes more dabs of  bondo to keep it from springing out when pushed against than if the top strip was used.

To help with dust (and flying insect) control, the Paulk work benches are about to be modified to become down draft tables.  I've made some magnetic attachable panels for the sides.    The weather has finally gotten warmer too.   Hopefully other distractions and commitments will stay at a minimum for a few more weeks.

3/8/2015 Chapter 14 Step 6

The spar dam is an interesting topic when searching what other builders have done.  I can see why some used dry wall screws to hold it on.  The Paulk workbenches have nice 3/4" peg or clamping holes that could be used for rigging the spar in place and providing extra support to keep the dam from flexing out when doing the lay ups, but all that rigging would probably get in the way.    Originally I used about a 4" wide strip but found it easily flexed back.   Cutting it down to about 1.5" reduced the amount of flex quite a lot.   Box tape is on the trough side of the dam.

Some builders filled the little corner gap with flox to keep the epoxy from running down the side, but I think I'll try a mix of mostly fast and a little slow hardener on the first tape so it will set up more quickly to seal the little crack and hopefully keep much epoxy from running down the side.

You can see where the original dam's edge was from the old bondo spots and how short it is now.

A power outage last night put a damper on doing much.   Maybe Wednesday night the top spar will get done.  Warmer weather is coming!

3/4/2015 Chapter 14 Step 5

Put in a long night to get the 4 UNI layup done.   Electric blankets are on keeping it warm.

3/3/2015 Chapter 14 Step 5

Electric blankets and tarps are on pre-heating the spar and pre-cut rolls of UNI.   Lamps are heating the epoxy.
A small exhaust fan and duct (upper right corner of photo) are ready to exhaust the fumes through the doggie door.    I think this will work out good to start using up the two quarts of fast epoxy I have on hand.   One of the previous builders mentioned several times that it was to hot in Texas to use the fast epoxy so this will be a good time to use it before winter is gone.  

 Its nice to be able to refer to other builder's web sites.  One builder posted it took two guys 5 hours just to do the UNI layups on this step.   I'm sure it will take me longer but I'll probably have a helper tomorrow.

The high tomorrow will be in the 50's, then into the 20's.   Ambient temp in the work area for now is 61 with the heater off.   The epoxy and micro will be at about 65.  

2/28/2015 Chapter 14 Step 5

Dremeled the foam out for the center spar hard points tonight.   There's snow and ice on the ground outside so the inside temp is still in the 50's with a propane heater on and shop is partially partitioned off from the hangar now.   Electric blankets will be here Monday so epoxy work will be less dependent on the weather.  Should have ordered the blankets last fall but thought the storage area was going to be sufficient - but there isn't any ventilation.   Also started working on a heated epoxy pump station that will integrate into the fiberglass cutting station.   I'm anxious to get this spar finished as this foam is really fragile.  The work bench needs to be cleared off so the rudders can be put on the wings of my other project.   I took some time to go look at a couple of Long EZ's that are for sale too.

2/1/2015 Chapter 14 Step 4

Cut the top and bottom troughs for the spar tape today.   Inside temp is in the 50's and 60's.   Should start getting warmer soon.

1/18/2015 Chapter 14 Step 4

Pulled the spar out of the jig and moved to the work bench.


It warmed up to 68 in the work area today.   Should soon be getting warm enough to do the rest of the epoxy work.   I cleaned the epoxy pump out as the hardener was getting waxy and smelly.