Bottom spar cap

This is pretty much a repeat of the top spar cap - so I won't go into too much detail here. If this is your first time reading about spar caps, make sure to read the top spar cap first since it includes much more detail.

Here I am prepping the bottom spar trough surface... getting it ready for bonding..

Plenty of UNI tape on hand...

Cutting all the UNI strips... using the jig as a cutting table made things move pretty quick...

Covered the foam shelf with tape to protect it from epoxy spillage... and marked the UNI tape lengths (not buttlines)...

Prepped the foam dam wall with duct tape to act as a quick release...

Since I was going to hot glue gun the dam instead of using Bondo, I lined the aft face of the spar with clear tape..

This is the spar aft face...

Notice the rounded corner between the trough and dam.. this later gets filled with flox..

I added a piece of duct tape where the center dam wall meets with the outer dam wall...

Adding flox along the corner...

Applied plain epoxy onto the trough surface...

First ply of UNI tape...

Removing the red thread....

Removing the cross thread... (Elle held the card in place while I pulled the cross thread away)...

Cross thread comes out in a single continuous strand...

Beginning to wet it out..

Gently spreading the epoxy... and letting it sit for a minute for the strands to soak up the epoxy...

Everything wetted out..

Showing the "steps" between the staggered plies...

Looking real smoooooooth...

Showing the bend around BL23 (again, the numbers on the tape is the length of the UNI tape, not the BL).

Notice the end foam 'shelf' so that the overhang would not droop while curing...

Here's a better shot... the shelf was hot glue gunned on just like the foam dam on the aft face... tape is underneath it to protect the spar's end bulkhead...

 

Trimming the ends...

I then removed the foam 'dam'.. the duct tape acted as a good release...

I then used the router to flush trim everything up...

And there you have it... bottom spar cap complete!

Next up will be installing the wood spruce blocks and prepping the surfaces to receive the outside layup!