[FLexpat]

Since I’m doing vacuum bagging, I need a good resin trap in case I screw up on how much epoxy resin I use. Made this out of a pressure cooker. I know it is too big but this is the best cheap solution I could come up with. It holds a vacuum but I haven’t gotten any resin in it yet. I sprayed the inside with silicone spray to make chipping resin out easier.

Went ahead and cut out the scupper blocks – Starboard was dry and port was mush.

I leveled the edge gaps with thickened epoxy and covered it with peel ply to minimize blush.
Cut 1.5” Coosa to fit with the template I made from pegboard – made the tolerances much closer that the 1+” gap that the original plywood had on the edges. I did a fit check after leveling the edge gaps too. The problem with this approach thumped me later…

Scarfed the top edge of the Coosa to tie in the glass to the transom on the top edge – used a power planer. I drilled through where the stern light goes and put in a lift loop of ¼” nylon. That made moving it much easier with a lift.

Drilled 36 1” diameter holes in the Coosa and cut matching plugs out of 1” fiberglass rod. I was amazed at how well that worked – they all fit perfectly and were flush on both sides (within ~0.02”).
Cut out a section in the center for a section of solid glass to go around the drive – that was a PITA to get right.

Epoxied in all the rod and plate inserts and vacuum bagged it – that worked pretty well.

In a couple of spots the absorber got epoxied to the Coosa where it slipped – I now make sure peel ply or release film separate the absorber material from the part. I intended to keep peel ply on and drill through it in a couple of places – the peel ply knotted up on the drill – I’ll show plan B when I do it next time.
Did a ‘final’ fit check with the Coosa – looked great – (I am such a sucker sometimes).
It was a BAD idea to stretch 6 mil plastic across a sheet of Coosa to make a layup table – the small wrinkles in the plastic meant that I didn’t get the layup I wanted. I will spend the $35 for a 4x8 sheet of melamine board before the next work session.
I used these measuring cups with a sloped measuring surface for the resin and hardener – they worked GREAT.

I cleaned them with denatured alcohol – I think acetone would wreck them. I also got a package of 4 silicone spatulas for $5 – used 1 for resin, 1 for hardener, and 1 for mixed epoxy application on the inside of the transom – they really helped in mixing and in getting the layer on the inside of the transom even (I followed up with a notched trowel). The 10” length of the handle helped me on the transom too.
Coosa core layup on the table was 2 layers of 10 oz cloth, the Coosa Core, then 1708, 1808, 1708.
Here it is before resin on the 1st layer of 1708.

Bagged it – the heavy glass on top of the Coosa came out great – my target was 40% glass (by weight) and I was pretty close – I calculated how much I would need to hit target and mixed about 5-10 oz extra for each batch and didn’t use all of the extra epoxy. I had the mix quantities for each layer up on my laptop screen in the shop to minimize mix screw-ups – it worked this time.
My intention was to put the Coosa core in the transom green but I didn’t notice that some of the 1708/1808 stuck out a little from the edge… and it gets pretty strong even if it isn’t cured. Didn’t get pictures of this UGLY part – the near disaster: I put a nice layer of thickened epoxy on the inside of the transom and lifted the core into place – almost… It was too wide by ~3/16” because of the glass on the edge (upper left corner of last pic). No problem – 15+” of vacuum will pull it in – WRONG. There was a ½” gap between the core and the transom skin because the core was hung up on the edges.
Managed to get it out before cure.
Now I get to re-grind the inside of the transom, cleanup the 10 oz side of the Coosa, and do this again.