Fuel Tank is COMPLETE

It is sure UGLY and should pass the leak test. I used more than enough sealant as it squeezed out of all of the joints and rivet heads and screws. Will let the tank sealant cure for at least 7-10 days before testing. No real problems. Ensure the clips holding the fuel return line are installed prior to installing the front cover and the fuel sender!!!

Will pressure test, probably try to clean it up a bit and then paint it with the stone finish. It should look a bit better then.

Took a couple of pictures of the interior of the tank thru the front opening.

If I ever build another, will use a bit less sealant.

Time Today - 4 hours

Fuel Filler Neck Pictures

A couple of more pictures showing how I bent the flange on the fuel filler neck to match the turtle deck skin.

Fuel Tank Continues

Yesterday, had a problem. Installed the fuel tank in the fuselage and then attempted to fit the filler neck. It was TOO long. After calling some of my fellow RV-12 builders and talking to Gus at Van's, it appears my fuel neck is about 1/4" longer than the others have received. Also, noticed the flange on the filler neck was perfectly flat. Others have received a fuel neck where the flange was pre-bent to the compound curve on the turtle deck skin. The joy of receiving one of the first finishing kits. Solving this issue took the most part of the day.

Today, shortened the filler neck a bit and then formed the flange on the filler neck to the turtle deck skin with a set of seaming pliers/visegrips. Ended up with a good fit, less than 1/32" all the way around.

Drilled the fuel neck flange to the turtle deck. I inserted the fuel cap to ensure I had alignment. Then, marked the flange on the top of the fuel tank. Match drilled the flange to the top and marked it with alignment marks before disassemling and deburring. Ensure you clean the fuel cap of all of the shavings.

Used a Unit-bit to drill a large hole in the center of the tank top flange, then tried a set of snips which cut a really rough cut. Cut a nice circle using a sanding drum in the Dremel. Looks pretty good!!

Fabricated the clips for the fuel return line using some scrap. Did not find a piece of Al in the parts list.

Time Today - 6 hours

Fuel Tank - 3rd Session

Yesterday, I prepped the fuel level sender and trial fitted it per the plans. No issues.

Prepped the parts for the fuel window today. Found out I did not have to drill the plexiglass to #27 as the holes were correctly sized. I did have to drill tank itself and the window backing plate to accept the #6 screw. This is not in the plans.

Roughed up the rivet hole area in the fuel window with some coarse grit sandpaper and scotchbrited the metal backing plate. Cleaned the metal mating surfaces with naptha. Did not use naptha on the window as I did not know if it would react badly. Was careful to avoid getting any oils on the plexiglass surface.

The window uses the tiny all metal locknuts. I ran the screws thru the locknut a couple of times before installation as they are very very tight.

Mixed a small batch of fuel tank sealant using the gram scale. Placed a thin layer on the window and then attached it to the top two screws (temporarily inserted). As I dipped each of the screws and tightened them just snugly, some of the sealant oozed to the view holes. It really just takes a THIN layer of sealant. I tried to clean one of them up a bit and made the situation worse. Nevertheless, it looks OK.

Used a small hemostat to install the 4 washers at the required locations, all at one time. Mess-free.

Finished by drilling the tank flange.

Time Today - 4 hours

Fuel Tank - 2nd Session

The 2nd session went a bit better than the first with regard to the mess.

I first attached the front brace. During riveting, several of the mandrels broke above the top head of manufactured head of the rivet. Each of the rivets snapped or popped and the shop head is the same as the others, but the mandrel snapped off at the wrong location. After finishing for the day, did a bit of research and found out that this is a common problem with these two types of rivets.

Here is what I found on the forum.

Broken Rivet Mandrel Thread #1
Broken Rivet Mandrel Thread #2
Broken Rivet Mandrel Thread #3

So will cut them off with the Dremel after the sealant cures.

Attached the baffles inside the tank ensuring all of the required passages remained open. Then, I deviated from the plans a bit and first attached the rear brace to the rear cover before installing the rear cover. Was much easier to set the AD4 rivets this way. Used a pair of tweezers to coat the head and stem of the AD4.

Three small batches of fuel tank sealant.

Time Today - 7 hours

Fuel Tank - Fuel Tank Sealant 1st Experience!!

UPDATE: Before starting the fuel tank ensure the fuel tank outlet strainer screws into its fitting. Found out during tank testing that my strainer would only screw into the fitting about 2 turns. See the picture on my May 17 entry. Going to have to find a way to correct this with it installed. 2 turns is NOT enough. Is EASIER to check it now!!

Started to assemble the fuel tank. Scotchbrited all of the mating surfaces with red scotchbrite. Section 5.0 tells you to score the mating pieces and do not be timid. So I did that. Cleaned the mating surfaces with naptha, per the instructions. Naptha can be found at Wal-Mart. It is COLEMAN stove fuel in the RV department. Its highly flammable - Be Careful! The plans tell you to hand pull all of the rivets.

Mixed the fuel sealant using a gram scale. 10:1 ratio. For this first batch I mixed 60 grams.

Lessons learned. A helper is useful here. Coat one of the surfaces with the goo. The pieces will slip around as you try to position them. The bottom slipped out of position on me. Had to disassemble and recoat the flanges with goo. Assemble with a few clecos. Dipping the rivets into the goo and then riveting the pieces is slow going. Get a helper to dip the rivets. And the stuff gets all over. Keep a supply of 6"x6" cloth pieces available and some lacquer thinner. You have to clean the HAND rivet puller and shake out the stem as you go.

I put some masking paper on the workbench, and I am so glad I did. Filled the holes in the corners with the goo and then ensured everything was sealed. Ran my gloved finger to smooth the outside.

Not the neatest, but should be OK. A helper, covering the workbench, gloves, and a lot of small cloth pieces are most beneficial.

My hands are only partially black. My clecos are soaking in lacquer thinner. Think I used about 15 pair of gloves for this session. Yuck.

Time Today - 4 hours

Response from Van's on the WH-RV12-OPTIONAL Harness

Q: Looking at the MAIN DB-25 pin connector on the WH-RV12-OPTIONAL harness. There is a white-black wire and a orange wire with female pins attached that are NOT inserted in the DB-25 connector. The wires are just hanging.

Received the following response from Gus at Van's.

"These wires are left unconnected, they may be needed for future changes to the Dynon. The wires are for Re-Dundant DSAB on future Dynon products. DSAB is Dynons own internal data tranfer protocol much like RS232. In the future both Data and Power etc will all be transferred on two wires between all Dynon units."

So I will leave them unconnected but have to extend at least one of them. This will allow be to heatshrink and then reach all of the locations in the DB-25. Will coil up the wires in the DB-25.