After doing the first practice lay-up in Chapter 3 we decided to just move forward and start Chapter 4. We skipped the confidence builder and the bookend. Ok, it's called a bookend but really!
Oh yeah, the seatback. The seat back is the red part in the picture below.
The first challenge is learning what tools to use and when. At this point we've 5 minute epoxied the two pieces of foam together to make the seatback. The 3" added width wasn't an issue but the height was, hence two pieces of foam. It doesn't really matter whether you glue the foam to the top or bottom, in the end you won't be able to tell.
In order to get the cut correct for the top of the seatback I tried several different approaches; tilting the head on my jig saw, hacksaw, etc. The picture below shows the basic setup. I use the masonite board on top to align the top line of the foam cut. The backside or bottom line is already cut to the prescribed length. The idea is to angle cut between the top line or masontite board and the bottom of the foam. I rough cut with the jig saw and will trim cut with another tool.
In the end Jan's idea worked the best. She went into the kitchen a grabbed her ceramic knife. This is about $80 at a good kitchen store but worth it. Of course I've promised to replace it...soon...honest! You can also see where my rough cut went off a little in the picture below. This was later patched.
The knife gives an amazing amount of control over the cut. While it has a sharp cutting edge you can actually grab the edge and use it as a guide without leaving red stains all over the foam.
Here's another shot showing my rough cut goof. Also notice the extremely fine slice of cut foam you can see on the blade of the knife. To say you can make paper thin cuts would not be accurate, cut paper thin in half and you'd get closer.
A close up of the fineness of the cut and the knife. Also notice the difference between my rough cut and Jan's knife cut.
After a careful handed knife cut you end up with something like this!
Ok, I'm really impressed with the knife cut!
Here we are back to my goof edge. I wish I had more pictures of the repair. Jan used the knife to cut a thin sliver of foam to attach into the goof spot. It worked great!
My first batch of micro. I forgot to do a 1:1 ratio of mixed epoxy to micro so out it went and I made another. I probably could have used it and just mixed more of one solution but since I had never made it before I had no idea what a good batch should look like. Better to be safe than sorry!
We've finished the cut and are getting ready to do our first real lay-up! Since we are going to use the Cozy Girrrls Lo-Vac system we lay down our plastic on the table first. We overlap the plastic rows by a couple of inches to ensure a good seal. Again, this is plastic on a roll we had left over from a move. We bought it at the U-Haul store.
After the plastic comes the foam. On the top, the fiberglass needs to hang over the edge of the foam. That's why the foam appears to hang over the edge of the table; because it does.
We've positioned the first layer of uni and are starting to spread the epoxy. We like to pour it on and squeege it out. (Rememeber this is our first crack at doing this - there may be better ways to do everything!) The squeeges we picked up at the auto parts store. There were 2 each of 3 sizes in the package for a couple of bucks. SOLD!
Another layer of UNI & epoxy. Then add a layer of peel ply, 3 layers of cheap paper towels, add the Lo-Vac hose and plastic on top. Make sure the top plastic forms a seal with the bottom plastic, turn on the vacuum pump, weigh it down and watch the clock.
Eventually I hope to get the garage better organized. At this point I'm searching for everything and almost nothing has it's place. However, I want to get started. I hope to organize as I go. Here's a picture of the Lo-Vac pump with the all important fan blowing up its...ah...open ended chassis.
The scratch test the next morning proved the layup should be done. We had peel-plyed the entire surface and when we took off the peel-ply and looked at the first side I saw some things I wasn't sure about. Some places in the surface looked like this.
Here's another shot. Was it too dry? Did I do something wrong?
I posted a question on the forum to see if I goofed and if I did how could I repair it. http://canardaviationforum.dmt.net/showthread.php?t=3074 It turns out and was later confirmed by Lloyd Gimple (my local down in Albq, guru, Cozy builder/flyer) that the area shown above was alright. Normally if you don't peel-ply the entire surface what doesn't get peel-plied ends up looking like that. Ok, I forgot to wet out the peel-ply. Next time I won't forget.
Here's Jan cutting away the excess fiberglass.
Now it was time to create a trough and fill it with flox for the glass to glass bond. Again it was trial and error on what tool to use. There are probably hundreds of methods that we didn't stumble across that would have been better, but here is how we did the job. Yelp, that's my FienMaster to the rescue!
Here's the result. I probably should have taken out more foam, but everything is a learning curve in Chapter 4.
We sanded the top, mostly with scraps of the foam we had cut off and rounded the corners per plans.
We akso tried the box cutter to cut away the foam from the fiberglass.
We laid up the back side, peel-lied, Lo-Vac'd and cured. When we pulled off the peel-ply there were a couple of areas we didn't like. This shows some of the flox that had run underneath the panel and now needed to be sanded off.
Here's a shot of an area that will need repair. I gues it's called a delamination, the glass is pulled away from the foam.
I saw a few more small places where the foam and glass weren't meeting on the edge. A few more repairs coming.
I sanded up the excess flox and took the seatback to the EAA Land of Enchanment Airshow that weekend to show to Lloyd Gimple for a master inspection.
Lloyd agreed that the side needed some repair but the seatback sides actually end up being taped into the fuse sides in a later chapter. I've seen comments on the forums that some folks feel the seatback side covering is nothing more than a training excercise.&nbs