My Glasair III Construction Diary - Page 10
By
Roger Halstead

Last Updated: 18 December 2004

12 April 2004, 3 Hours

I did 4 more inside lay-ups on the lower engine mount attach point reinforcements. This was the last of the resin batch.

I haven't included a lot of photos on these as the reinforcements look pretty much the same, "before and after".  I will set the camera up to get the detail/procedure of the lay-ups.  As I'm working back against the firewall and in difficult positions, it's ... well... difficult to get the camera set up to show the actual work in progress.  It's also too close to set the camera up in front to just show the work while I'm doing it.

13 April 3 Hours

I trimmed the edges of the reinforcements and inserted the cloth for the final (8th) lay-up on the lower engine mount attach point reinforcements.

14 April --  

UPS (referred to as "The toy truck") delivered two more gallons of Vinyl Ester Resin (good timing)  Now to do that final lay-up tonight and hopefully get started on the upper engine mount attach point reinforcements.  That and decide what to do about the annual on the Debonair.

26 April 2 Hours

Well, I have the 8th lay-up finished (and trimmed) on the bottom pilot's side engine mount reinforcement. Of course I discovered a air bubble in the corner that needs fixing.  I just haven't gotten to doing the resin part of the other three.

08 May 4 Hours

I filled the air bubble in the previous lay-up and finished the three remaining bottom lay-ups.

09 May 2 Hours

I trimmed/sanded the edges of the lay-ups and my neighbor, Ryan, helped me turn the fuselage upside down so I can do the top lay-ups more easily.

11 May 12 Hours

I discovered the the upper engine mount attach point reinforcements were not quite centered "as well as I'd like" in the fire wall cut outs, so Bob Winchester came over and helped me turn the fuselage right side up... again. 

Bob Winchester and Bill Albe have both made alignment inserts that fit in the engine mount. These originally had holes drilled to take a 1/8th inch drill bit.  I opened these up to take a quarter inch bolt.  I carefully leveled the fuselage from front to back and side to side using a "water level" in conjunction with a digital level, a laser transit, and a plumb bob in the vertical stabilizer.   I have wood blocks clamped to the front of the fuselage with their upper surfaces aligning with the water line 100 marks on which the digital level may be positioned

A very careful alignment moved the upper holes slightly to the copilot's side while it moved the bottom holes slightly in the opposite direction.  The lower, center holes did not change.  Going to quarter inch holes completely covered the smaller holes while allowing the centers to be moved about one eighth inch

The engine mount was clamped in place and aligned with a spirit level on a drill rod fitted through the nose gear mount as according to the instructions in the manual.  The new holes were drilled using the alignment inserts as guides.  The engine mount was then bolted to the firewall using 1/4 X 3 1/2 inch bolts with the inserts left in place..

22 June 3 Hours

Using the 2 layer laminate created at the beginning of the project I cut 4 triangular forms that will serve as the guides for making the upper engine mount attach point reinforcements.  All 4 forms were clamped together and sanded to shape.

23 June 5 Hours

( NOTE - Links will be added to larger images...Eventually)

I purchased a surface mount light fixture to use as a "light box" for marking and cutting the cloth used for the inserts.

Using a tongue depressor and hot glue I fitted  a 2 inch wide wood form with a slot cut to fit tightly over the temporary bolt holding the engine mount in place, into the space for the engine mount attach point reinforcement (photo to follow)  This block is centered by the bolt fitting into the slot. It is a solid form against which the "forms" for the reinforcements can be held while being "glued" in place.  This eliminated the need for hot gluing the forms themselves.  The forms are held against the wood block using regular "Scotch" (TM) transparent tape.

Using a thick Q-cell mix I  "glued" the two forms in place on the copilot's side.

24 June 3 Hours

The hot glue holding the wood block in place was cut and the block removed.  The block was then installed on the pilot's side and the above procedure again repeated.  After the q-cell mix was applied to the out side of the forms on the pilot's side the inside of the forms on the copilot's side were radiused using the Q-cell mix.

25 June 2 Hours

The hot glue was cut and the wood block on the pilot's side was removed. Using a thick Q-cell mix I radiused the inside of  the forms on the pilot's side..

26 June 3 Hours

Upper Engine Mount Attach Point Reinforcements:  Marked, fitted, and did the first outside lay-ups on all 4 forms.

28 June 5 Hours

Upper Engine Mount Attach Point Reinforcements: Trimmed the edges of the previous lay-ups with a box cutter while still in the green state. I marked, cut the cloth, and did the last three outside lay-ups on all 4 forms.  Each was placed over the previous lay-up while the previous lay-up was still tacky.  Excess resin was worked out

29 June 3 Hours

Engine mount Upper attach point reinforcements:  Trimmed and sanded the outside lay-ups smooth and to shape.  I marked, cut, and installed two inner lay-ups (one each side).  I made the cuts in the end, folded them over and used a spring loaded clothes pin to hold them together.  This worked very well.  

As the resin tends to flow to the lower portion of the lay-ups I tried using a small paper shop towel to blot up excess resin.  It worked very well and did not move the lay-ups.  Why didn't I think of doing this 40 hours back?  One done and seven to go.

I readied two more pieces of cloth for the next lay-ups. 

30 June 5 Hours

Two more lay-ups for a total of three inner reinforcements on each side.  I managed to squeeze in one more on each side so I'm now half way through on these reinforcements. (4 on each side with 4 more  to go)

1 July 2 Hours

One more lay-up on each side. (5 one each side, 3 more to go)

2 July 4 Hours.

Purchased 2 48 inch kiln dried, freshly milled Yellow Popular 2 X 4s to use on fixture for horizontal stabilizer.

I trimmed and fitted two more lay-ups, but as I was cleaning up the vacuum cleaner ate one.  I had one more already cut so I trimmed and fitted it.  Then did the glass lay-ups.  Only two more to go on each side.

I cut six more pieces of glass cloth for the inside, upper engine mount attach point reinforcements. 

As long as I'm not quite ready to use the 2 X 4s I decided to play around with stain and finish. 

3 July 3 Hours

Mainly trimmed the previous lay-ups while they were still in the green state and filled a couple of air bubbles that had escaped detection. I drill, or use a Jeweler's screwdriver to put small holes at each end of the void and then use one of the syringes I use for measuring catalyst to inject the resin.  This leaves the spot looking just like the rest of the lay-up with no trace of the void visible. (They are very thin voids)

Have I mentioned I'm getting really tired of these lay-ups where I don't see any real change in appearance?  There are 96 individual lay-ups in the engine mount attach point reinforcements. That doesn't count fitting and potting in the 0.10 SS plates later on.

5 July 3 Hours

I fitted the cloth on the pilot's side and did some fill work on the copilot's side, then covered the fill with peel ply.  I then applied the resin to the cloth on the pilot's side. As this is the last lay-up I covered it with peel ply.

6 July 4 Hours

I removed the peel ply from the lay-up on the pilot's side, Then removed the peel ply from the fill work on the copilot's side.  A bit of sanding and I fitted the cloth on the copilot's side, applied the resin, and covered it with peel ply.

7 July 3 Hours

I pulled the peel ply off the inside of the reinforcement on the copilot's side and then trimmed the excess cloth on both sides.  After a good cure I sanded the tops of the reinforcements to match the original forms. 

All the engine mount reinforcements are done! Oh, there are a few bits of trimming and sanding and a couple of small voids to fill, but I can now start on the firewall reinforcement rib.  Finally something that can show visible progress.

8 July 4 Hours

I dug out the blueprints and a sheet of 4.5# foam, used carbon paper to transfer the firewall reinforcement rib outline to the foam to create the two halves of the rib. 

I double checked the fuselage level from side to side as well as fore and aft (water line 100), then using a spirit level and straight edge marked out the placement line for the bottom edge of the reinforcement rib.

I fitted the two halves of the rib, trimmed the small ends back so they just fit together, laid them out straight and hot glued them together.  Hopefully I'll get a chance to seal the foam tomorrow and possibly bond it into place. (IF the seal cures sufficiently to handle)

9 July 2 Hours

Sanded the top edge of the rib to a 1/4 inch radius and then coated with a thin Q-cell mix.  Went back over it with another thin mix to catch some areas and irregularities.  I'm going to have to let it get a hard cure so I can sand off a few bumps.  It's a nice calm sunshiny day with temps supposed to reach the mid 80s F, so I think I'll just set it on the south shop apron.

10 July 4 Hours.

Sanded the sides of the reinforcement rib smooth and trimmed the bottom edge flat. Also sanded the firewall in the area where the reinforcement rib lay-up will be done.  Hot glued two wood wedges so their top edges were even with the placement line drawn on the firewall. Then put the rib in place and used just two dabs of hot glue to keep it from moving. 

The next step was making a thick 12 gram mix of resin and Q-cells, which was just enough to radius the top of the rib.

11 July 2 hours

Removed the wedges and radiused the bottom of the reinforcement rib against the firewall and fuselage sides.

17 July 3 Hours

I cut four pieces of cloth for the firewall reinforcement rib.

18 July 3 Hours

I re-sanded the area above and below the rib where the cloth lay-ups would be bonded and then fit one piece to the pilot's side of the rib.

19 July 8 Hours

I cut two pieces of cloth and redid the top two lay-ups on the Pilot's side, front wing attach point.  I used peel ply (Dacron) over the first lay-up in the morning.  By late afternoon it had cured and I did the second lay-up using  a coarse peel ply.  Now if I could have only done it this well when I started two years ago.

Although the manual says the cloth for the firewall reinforcement rib will have to be cut as it did the one for the front belly pan reinforcement, I was able to do the belly pan reinforcement without having to cut the cloth at the end. I decided to sacrifice one piece of cloth to a trial to see if I could do the same on the firewall reinforcement.

I already had the cloth positioned and held in place with spring loaded clothes pins.  I started at the end and worked into the corner.  I first thoroughly wet the fuselage side wall, the corner, and about 6 inches of the firewall and pushed the cloth into place while liberally applying resin on the top horizontal surfaces and then under the cloth out to the end.  Then I moved to the underside using much the same technique.  I made judicious use of stippling and resin to get the cloth to conform to the surfaces without wrinkles.

Holding the resin cup under the edge of the rib to catch the drips, I started at the centerline marked on the cloth and applied lots of resin, brushing it toward the firewall. This kept the cloth smooth and forced air bubbles out the other edge of the cloth.  I used this technique, moving slowly toward the center of the firewall.  The cloth is long enough to extend about 3 inches past the center.

I started with 70 grams of resin and had to mix an extra 30 grams to finish.  Using smaller batches extends the pot life and starting with fresh resin is no problem with the wet cloth as long as the resin has not gone beyond the jell state. In this case it was still wet.  (You do have to work rather quickly)  Mixing a fresh batch while wearing sticky gloves is a rather interesting exercise as well.  I use a fresh brush and mixing cup. The cup I've been using gets a dose of Acetone and the sticky brush is put into that.  That keeps the resin from curing so I can clean both later.

All drips (that I found) were cleaned up with Acetone.  I was able to properly fit and bond the cloth to the rib, fuselage, and firewall contours without having to cut it.  I didn't have to sacrifice the sacrificial piece of cloth.  Now, I only have to repeat this operation nine more times.  (five lay-ups on each side with a 6 inch overlap in the middle.

3 Hours 22 July

I fitted the cloth on the copilot's side and then applied the resin.  I spent too much time trying to make the lay-up perfect at the end of the reinforcement rip and the resin started to gel. Once it does that all you do is move the cloth around, so I minimized the air bubbles and moved them into spots where they would be the least problem and easiest to fill.  It actually looked pretty good and there were only a few bubbles that needed to be filled.

1 Hour 23 July