Trailer floor plywood epoxying (part 1)

Day 1 of sealing the trailer floor with epoxy started sketchy.  It was below freezing to start the morning.  Even with the epoxy warm from being inside all night, it immediately turned to gel goo when poured onto the cold plywood.  That would have been a disaster.  A heat gun directly on the plywood surface and epoxy started to lower the viscosity enough to let the brush spread the epoxy around.  I'm sure the plywood could have absorbed the epoxy better if it were warmer.  We'll see how it turns out.  One side each of the 4x4ft and 4x8ft plywood are sealed and have to cure overnight (or a couple of days).

West Systems 105 resin and fast hardener.  I always write down the opened date on the jug and usually write out the mix ratio for myself while mixing.  100g is a HUGE amount for me, relative to smaller RC airplane parts.  The 4x4ft piece took 130g of resin (before hardener) and the 4x8ft piece tool 250g of resin (before hardener).  That was roughly a half-quart of resin for a third through the sealing.  I have another quart in the basement, but will have to pick up more hardener.

First 4x4ft plywood floor (the bottom) is coated.  Only after doing this did I realize this one doesn't have holes.  The "real" part is a different 4x4ft piece.  Fortunately, I can just transfer over the holes and trim to the same dimensions.  Crisis averted.

Mid process of coating the 4x8ft piece shows the change in color.  Using furniture grade plywood for a trailer floor is wayyyy overkill.  If these pieces hadn't been sitting on my basement floor for about a decade, I would have used something less expensive.  With lumber prices still quite high after the pandemic, the price for this furniture grade piece was the same as I'd pay for crappy plywood today.

One related note is the epoxy is not UV stabilized, so the top of the floor will need another coat of something on top to stay protected from the sunlight.  I'm looking at Total Boat Wet Edge 1-part polyurethane (because they sponsor so many home-built boat channels) and a friend recommended Awlgrip 2-part polyester urethane.  Both of these are marine grade and meant for constant UV exposure.  It seems plausible either would survive plenty for a first flight this summer.  

I may be able to paint the floor after the floor is bolted in place.  I do have more welding on the inside of the frame, so bolting now would be premature anyway.

Floor:

• 4x4 epoxy bottom
• 4x4 epoxy top
• 4x8 epoxy #1 bottom
• 4x8 epoxy #1 top
• 4x8 epoxy #2 bottom
• 4x8 epoxy #2 top
• 4x4 UV paint 
• 4x8 UV paint #1
• 4x8 UV paint #2
• 4x4 bolted
• 4x8 bolted #1
• 4x8 bolted #2

 Trailer to do's are now:

• build three lid trusses
• weld in six backer blocks for the lid trusses
• seal the ply decking
• finish weld the upper rail to the vertical supports
• figure out how Goat parts sit in the trailer
  
• take all of Goat for its first trip around the neighborhood 

Optional trailer to-do's:

• install and wire running lights on the sides
• add reflective tape on the sides
• figure out front/side/back walls 
• create a rear door that can be quick-pinned in place
  

For the first-flight:

• backyard final assembly and thorough pre-flight check, including weight & balance
• re-weld the tow hitch release (I'm now doubtful it had good penetration) 
  
• buy tow rope, weak-links, and end rings
  
• buy/borrow radios (1x airborne, 1x car)
  
• find a place to fly
• travel
• fly

After the first-flight:

• add leather patch to wing tips where will rub the ground
• install leather patch guides for elevator control lines
• paint trim color
• install wing root kiss seal
• build a wing tip dolly
• build a wing wheel
• jury strut fairings
  
• main strut fairings (after flying to figure out the right angles)
• emergency parachute
  
• real variometer (LXNav with a TEK probe is my intention, if it is sensitive at low speed...)
• dogue chute