So, a lot has moved on tank wise.
As ever, pictures speak louder than words. This is the tank now extracted from the car, and you can see it’s more or less like a model from StarWars. In the second picture you can see how it runs down the tunnel. The cut-outs in the top-left and top-right corners are to provide a recess for the sockets (as in socket set) so I can do up the diff mounting brackets. In order to fit the tank, the diff and brackets need to be dropped down to floor level (excluding the height of the the trolley jack it sits on) to get the tank in. What I needed to avoid was boxing myself in with the tank.
It’s important to get decent radius edges around the tank – if the carbon is just shoved into what’s more or less a 90 degree bend then it will bridge between the laminates, or between the laminates and the mould (filling the gap with resin). Not only does it weaken things, but you’re putting unnecessary amounts of resin in. Don’t forget this stuff is £20 per kg, you don’t waste it.
In my first attempt, I had started sanding around the curves and bogging in the gaps. I knew this wouldn’t be perfect because I’m not a sculptor. However, the tank wouldn’t be on display, so I thought I’d not be terribly worried. In retrospect, this clashes with the very pleasing OCD I’ve been brewing around neatness.
For another unrelated reason, I was in B&Q, and I had a revelation. They have 16mm quadrant beading. It’s cheap, and easy to put into the part. When I say easy, you cut a hole, stick it in, and have to start blending with bog when you go around the corners.
So, I went and cut out all the edges I had radiused (sp?) by hand, and put the beading in. Basically, you use your combination square to measure in 16mm from the corner in to each side, cut with an angle grinder and off you go.
There’s a bonus to this, which is the quadrant beading squares up the edges to the eye. The gaps between the edges and the poly sheet are made up with bog. So, it’s win-win.
I’ve tried a couple of ways to stick the beading in after cutting the raw part, and the main way is to use bog again. Hot glue is great for an instant stick, but you can’t sand it and it isn’t as strong a set as bog. The only downside of bog is that it takes about 15 minutes to go off so you find yourself doing all the work in batches, or alternating between one part of the tank and another. It’s fine and efficient until you have to join both bits together.
Myself, I’m chuffed. I think the tank will save me 5kg from the overall sprung weight.