Author Archives: Michael

Time: 6 Hours

Today started by finishing up the countersinking of the baffle access plate holes. That was followed up by deburring the edges of the baffle’s and every hole in them. I then scuffed all the surfaces that would eventually get ProSeal on them.

With all the surfaces treated and finished I clecko’d the reinforcement rings to be riveted with the nutplates. This went pretty fast once I set up the pneumatic squeezer.

I then deburred all the holes in the access plates and scuffed them so they would be ready for ProSeal. I grabbed half of the screws and attached the plates to the baffles for storage.

I’m going to go over all the plans and double check everything for the tanks but I think that I’m ready for some real fun, ProSeal!!! I set out and organized my supplies for that task. Hopefully this weekend I will start sealing! Pretty excited for this step to be done.

Time: 7 Hours

Today I started out by finishing up the deburring of the tank skin edges. So I broke out the bag of 1″ 3M wheels and my die grinder to accomplish this task.

I was able to finish both skins in an hour or so and moved on to the next task for the day, the tank baffle modifications. A brief history on why I’m going with the modification. It is said that it’s not “if” your Van’s fuel tanks will leak but more like “when”! These tanks are a “wet” design similar to the Lear I fly. That means that means all the tanks are built like any other part if the plane but just sealed with a product like caulk called ProSeal. This sealant is made to withstand chemicals like fuel. The problem is that it’s sometimes can be tough to get a “perfect” seal or one that lasts forever. Some tanks leak right away and you can fix while others can take days, weeks, months or years! So what do you do when you have sealed up your tanks and they start to leak down the road? Well the rear of the tanks there is a piece of aluminum called a baffle. This is just the rear piece that allows the tank to be sealed with the skin and ribs. Should you develop a leak (or when) Van’s has you empty the tank of fuel and drill a ~5″ hole in the baffle between the two ribs that would allow you access to the area that has the leak. Once you fix the said leak, whether it’s from a bad rivet or the seal between the baffle and skin, you cap off the hole you cut with a plate. This happens so often that Van’s has a tank repair kit that includes the required parts. The downside is you now have introduced metal shavings into your tank where you drilled plus the pain of doing this on a completed tank. So with that knowledge I have decided to be proactive with my tanks and prepare for my possible leaks, hoping that I never have any! There are 4 bays in the tank that would need access so I ordered 8 of each of the access plates and reinforcement rings that I used for the inboard ribs of the tanks. These will allow me to beef up the hole and add platenuts so that the in the future I would just have to break the ProSeal and unscrew the access plate to gain access to the bay that has the problem. So might say that I just introduced more placed for possible leaks and I would agree however fixing a leak at these areas would be very easy! So I spent a couple hours debuting the edges of the parts for the holes.

Then with several measurements I came up with the center of each bay on the baffles.

With the center marked I setup my hole cutter in the drill press to make the cuts.

The reinforcement rings have the platenut holes predrilled so I used them as a drill guide for the baffles. I found the center of the ring and drew lines on them. These lines will match up to the center lines on the baffles so that the access plates are lined up just right.

I started by drilling one hole and adding a clecko and then drilling another hole until I had all the holes done.

With all the #40 holes drilled for the platenut rivets I moved on to the #19 holes in the center of the platenuts for the #8 screws that will hold the access plates in place.

I took all the rings off the baffles and debured every hole on the baffles and the rings. I then grabbed my countersink cage with the #40 bit and set the depth so that the rivet would sit flush with the baffle web allowing the access plate to sit flush with the baffle.

I got all the holes countersunk on the right baffle and decided to call it a day, whew that was 7 hours of fun work. I will get back at it tomorrow and try to finish up this mod!!

Time: 6 Hours

I took Saturday off this weekend to let the mind rest. After a good visit with friends this morning I was able to get back into the Hangar. I needed to finish scuffing the rib flanges so that the ProSeal will adhere to them. I then loaded up the dimple dies into the pneumatic squeezer and dimpled all the rib holes.

the ribs are now all ready for assembly so I moved to the skins. First up was to debur all the inside holes. The punch process that is used to make the skins leaves a pretty big burr so before I used my debur bit I grabbed the die grinder with a 1″ 3M wheel and knocked down the edges.

Before I dimpled all the skin holes a scuffed the rivet hole lines first since it’s easier without the dimples.

I took care of both skins inside and outside deburring and scuffing. I then grabbed the DRDT machine to dimple all the skin holes. All the holes get dimpled except the row for the baffle as the are countersunk and the fuel drain holes. The perimeter holes get a #8 dimple for the screws that hold the tank to the spar. These holes are pretty big so I just took my time dimpling them so they didn’t crack the skin. They all came out perfect!

Here you can see a couple of the AN509-8R8 screws and how they sit flush with skin in their dimples.

Next up will be the baffles as I’m going to do some modifications to them, more on that later.

Time: 3 hours

I was able to get a little time in the Hangar today after working on my sons car. I got my new #40 countersink bit so first up was to finish the fuel filler cap flanges.

I also fabricated a couple of clips that hold the end of the fuel vent line right by the filler caps. I used a 1/4″ drill bit in my vise and shaped them. After several try’s I finally got two that I was happy with.

I also shaped the reinforcement plates for the last outboard ribs of the tanks and drilled them for the 6 rivets that hold them in place. I then used them as templates for match drilling the ribs.

I then had a visit by my friend Glen Vokac so that he could take a look at my anti-hang up guides for the flop tubes. He said all is well except that he would have waited to rivet them to the access plates until I had some ProSeal. So I took his advice and drilled out the 3 rivets that hold them in place. I’m getting pretty good at this task!

The other day I grabbed a couple of -6 rivets, they are pretty big, to plug the tooling holes in the last outboard rib.

I just placed the rivet in the hole for you to see, I will wait for ProSeal for these too! Not a long day but anytime in the Hangar is good!