I'm building an older low wing kit where a hatch was not used and access to the tank area was through the opening in the bulkhead located at the wing leading edge. I prefer to install a hatch for complete access. I wanted to put the hatch on the bottom per the pics as the top has a rounded deck with canopy partially attached in what would be the hatch area. I have made a tongue in front and am looking for ideas to secure the rear. I don't mind a single nylon bolt in the rear or any other type arrangement. I'm just looking for ideas and wonder what others may have done.

I plan to have the tank sit on a platform so the hatch area would not be supporting any weight and wouild only need to hold itself in place.

Thank you,

Here is how I did mine on 4*60, its not the best but it works.
Its harder wood dwell with epoxy not to crush the balsa.
I covered it <u>all</u> and then used screws.
its sealed so there is no leaks in but there is not much access either - if I need to access the tank for some reason then cutting through the covering and apply covering again is minor.

What about magnets.. I was thinking of trying that but how does one keep them from pulling out of the fixed piecie (the fuse) and removable.. (the hatch)

The main problem with fuel tank hatches is the cr@p from the muffler creeping into the hatch crack and there is not much you can do about it.
its not that common to open this hatch at least for me its solve it and forget it and its been a year like that with the 4*60 and never opened it with the midstar.
on the other hand oil from the muffler is trying to creep in every time so not to solve one small problem by creating a much bigger one.

Alex

I have used a #2 wood screw in each corner (hit the holes with CA after setting and removing the screws once).

It's not something that comes off often. On my Contender I added a couple popsicle sticks to take up the pressure from the foam around the tank so it doesn't press on the hatch.

Mike,

Just some ideas:

1) Will the wing dowels interfere with the tank and foam wrap? If not, you could glue two triangular hard wood pieces to the corners of the former, to which screw the cover (the wood screws that hold my hatches keep getting loose with vibration and falling away, as well as crushing the balsa cover).

2) You could also hold the hatch cover with the dowels of the wing, by gluing a piece with two holes.

3) Four recessed micro magnets can also been epoxied to the cover and fuse at the rear end.

For any solution, the edges should be sealed with some foam or silicone, in order to avoid oil infiltration.

Most important: consider that your full tank will weight 10 times more during any 10 g maneuver; hence, a full 8 ounces tank may force against the hatch cover (or your platform) with a force as high as 5 pounds!

((0.79 x 8) oz nitro + 1.6 oz tank) x 10 g = 80 oz = 5 pounds

Regards!!

Don't think I'd rely on magnets. I bashed a Telemaster 40 and held the hatch on with two rather strong cabinet door magnets. Unfortunately, the engine vibration promptly shook the hatch loose. So much for that idea (:-).

As cool as magnets are I would not use them there. A high G loop and plop no tank or battery [X(]unless the tank and battery are positive attached in the compartment.

This is something you will probably open very seldom. On mine, I did what you did and used a metal screw. Then I cover it so there would be no leaks through the cover. When I need to open it, I just slit the covering and opened it up. Then used covering to reseal the seams. In 6 years it was opened only once.
Edwin

On my 12 year old Ugly Stik I built a solid front...

I've never touched it once. If the tank's set up right, and not in a position where the lines are rubbing against the firewall, or anything that might jeopardize them, or the tank....you really shouldn't have to mess with it ever.

If you're going to do a hatch though...use screws. Screw magnets.....ba-doom-ppsshhh!!

Yeah.. i was thinking about the rare earth type magnets which are very strong but having a hatch come off on the bottom side would not be good.

I think I decided on using two small nylon bolts, one in each rear corner similar to what I have used to hold on my DLG glider wings. They won't vibrate out, are very strong and easy to do...
Thanks for all the replies.. much appreciated..

About magnets:

http://www.tpbweb.com/media/catalog/264.pdf

Unless you plan on taking the tank out lots of times, use rare earth magnets and cover the entire hatch as well as the hatch gaps with a piece of covering so that there will not be any opening of any kind exposed to fuel residue. You can always slit the covering where the gaps are hidden and remove the hatch if it becomes necessary....Ron