Today was ‘Drill Five Holes Day’ as I’d done one yesterday… or it would have been drill 6 holes day. See the previous log for the drill bit details. OK maybe I will use a hole saw next time. I probably averaged around 1hr:15 mts per hole and used a lot of pressure and a very low drill speed.

Pic 1 shows drilling in action. Note the rings on the drill bit. I drew these on so I could see what sort of slow progress I was making. You can also see an air outlet. I had the compressor running and used this to keep the fiberglass cool while I was drilling. If its too hot to leave your finger on it… then you may have probably reached the TG of the resin… or if you like… it will go soft. So I’d stop every 30 seconds or so to clear the drill bit and check for how hot things were getting. This did nothing to speed up the process and if it felt hot I’d just stop and blast with air for a while.

I also roughed up the drill guides I’d made and used bondo and set this up as the outside guide to keep my drill straight. The stuff really sets fast with excess hardener and I used a lot of tape and bonded to that. It works really well and easy to get off later. I used a little drilling oil too but I’m not sure if it helped much.

Where my bit came through on the hard points I got a slight delam on the thin outside plies as I pushed through. I’ll clean it all up later, easy job.

Overall I have those 6 holes done. AND I am happy to have that ‘little’ job completed…. Next up the collars need to be trimmed and then floxed in place with the wings aligned correctly.

Drilling

More drilling

Access holes in spar