Deburring, Deburring, and .... Deburring!

After Google blogger had a nervous breakdown yesterday and didn't allow anyone- including myself - to update their blogs, I am now going to pretend nothing had happened and I just did two days worth of work in one.

As the title implies, most of the work was really deburring. The fuel tank is a delicate piece of art and is therefore put as one of the last riveting jobs in the Van's work order. Probably assuming that by then the applicant had enough time to acquire build skills now desperately needed as well as an intrinsic understanding of the occasionally odd Oregonian instructions.
After reading through half of the instructions for the fuel tank in section 37, I can now honestly say that by then Van's also expects the builder to read between the lines and being capable of an almost telepathic understanding of build concepts. Which means that a lot of details in the instructions, you might have grown accustomed to, are now simply left out.
The exact moments when they require you to use sealant to avoid leakage of the tank are described in a generally entry note that is in bold font but in the actual step you can not expect to get another warning - although sometimes they choose to do it. This certainly does not imply that when they don't say it that you could leave out the sealant as this could lead to the previously described undesired leakage of the tank.
So, to shorten this up a bit, I needed a lot of time to think the whole thing through and understand where and how to apply sealant and how these steps could get combined to complete a series of tasks with one batch of tank sealant. I also peeked through every other available builder blog who already completed the tank and didn't complain about lost gallons of fuel.
After determining what to do and in what order, I came to the conclusion that the best way of doing this is to start by preparing all necessary parts. And this, as the title implied, is mainly done by extensive deburring, followed by deburring-style scuffing of the mating flanges and surfaces as well as scuffing the inside and outside of all rivet holes that penetrate the tank skin to allow the fuel sealant to get a good grip on the surfaces and not get washed away by fuel eventually.
For all this I was using the small 1" Scotchbrite wheel on a die grinder and a maroon SB pad for some manual action. To complete this step it took quite some time but I am now ready to build the forward part of the tank (and the other parts as soon as the goop, a.k.a. Pro-Seal, has cured enough).
This is the stack of prepared parts and skins:


Finally I also ended up doing the few riveting jobs that seem to not require gooping of the rivet shanks or anything else as these leakages will later be covered in a whole by a cover (which then will get gooped on).


The fit of the ring that got riveted onto that forward skin is horrible. I turned it endlessly and put it on when the deviation of the holes appeared to be minimal but I am still less than happy with it. Getting the screws through some of the slightly offset holes will require a lot of force. I hope I only have to do this once!
The ring has a got ring to skin fit on the inside of the large hole but it does show a 1/16" gap all around on the inside. I might fill that with Pro-Seal to reduce the chance of wash out around the screw seals.
I also finished the countersinking that was prep work for the forward tank mount bracket.


I also received and inventoried the wheel pants (my are they big compared to the ones for my RANS) and the Servo Kit (w/o AP74). And Stewart has also sent the third quart for completing the interior paint so I will be spraying some primer on the prepped tunnel panels that are sitting in the paint booth for some days.
Looks like this weekend is going to be a busy one...