. . . in the airplane building world.
After cutting the ends of the spar cap even with each end of the CS spar & removing the peel ply, I flipped the spar onto its front face to remove the dam that was now not only bondo’d solidly to the CS spar, but epoxied, floxed and glassed as well (even though it’s covered with duct tape… thank God!) .
Well, when I flipped the CS spar onto its front face, I noticed a decent delam along the corner edge of the lower spar cap channel. The glass must have had issues with flowing around the corner from the rear face of the spar to the bottom spar cap channel. The delam was about 14″ long x ~0.5″ average on one side of the center line and about 8″ long with a few areas reaching 0.75″ in width on the other side.
I searched the blogs/Internet & then called Dale Martin to get a crosscheck from a seasoned EZ vet. My initial plan was to cut out the bad glass, recover with 2-plies UNI in the same orientation as called out for the original layup, overlapped onto the existing glass. I would then add a protective 1-ply BID over the entire repair.
I have to say I was feeling much better about it all after talking to Dale, especially when his recommended repair was EXACTLY what I had planned! Not to take anything away from Dale, because he really helped me through this builder’s crisis, but I was just glad that as a newb my decision-making was not too far off kilter. One of the issues that Dale honed in on was the build temps in my shop. The weather in Germany was getting much colder, and the temp swings were often distinct. Guessing on how many heaters to use & when was a constant challenge since even entering & exiting the garage by opening the one big door could keep the Mercury jumping up & down.
MGS is a German epoxy, so it’s good down to around 65° & scoffs in the face of humidity. But my personal minimums–if you will–for building was the normal 70° low end glassing ops temp target. Keeping an un-insulated detached garage, with no central air, heated during the German winter to say, 80-90° F constant, was cost prohibitive and simply wasn’t going to happen. My only other option was to stop building, which was going to happen in mid-October regardless, since I was deploying to Tampa for 6 months (the irony of having such a great Winter building location as Florida, with your entire project located in Germany!)
So I did some more research & then developed my plan of attack. I then cut out & removed the delam’d glass.
To get back on track & get back into a positive build groove, I cut the 3″ UNI tape for the lower spar cap.
I then went to the cutting table in my downstairs shop & cut the 2-plies of UNI and 1-ply of BID for the repair.
I refilled the hardener bottles & poured the last of the MGS from the large plastic container into a gallon jug.
I then went back to work removing some of the bigger chunks of the 1/4″ plywood dams. The thin ply wood worked well as a dam, but it was playing hell getting it off the CS spar because it would simple splinter & shatter when I tried to remove it since it just didn’t have the strength to stay together.