Access panels in front skin

Hi All,

I'm not too far from putting on that last skin. I'm building a 7 tip up. I'm at the decision point of whether or not to put access panels in the front skin. I know several that have and they don't regret the decision. Others have said it is a waste of time.

If done like Dan Checkoway they are clean and unobtrusive. I'm leaning that direction but would like to get the thoughts of the collective wisdom of the those who have been doing this a while.

DArwin N. BArrie
P19

Can you reach everything?

Is there any doubt in your mind that you'd be able to reach absolutely everything from below? If you have no doubts, then leave 'em off. But if you have any doubt, they're so easy to make...

Also consider resale value. I consider access panels an "option" that a non-builder buyer...maybe somebody older and less flexible than myself...would appreciate.

)_( Dan
RV-7 N714D
http://www.rvproject.com

I love it

I bought my plane from a second owner and I considered it a plus!
I have done lots of changes behind the panel and rarely have to get under the panel. Most everything can be reached thru the top access panel...
I highly recommend it!!
Bob Martin
RV-6 Tip up.

They may leak in Wx

I own a '66 Mooney C model, which came from the factory with large rectangular avionics access panels on the fwd boot cowl just forward of the windshield. They were great for the few times I had to get in there. Beautifully made, great sheet metal work, looked tight with #10 countersunk screws.

But-ask any early Mooney owner what happens in rain and clouds. They leak no matter what. I remember my first flight on instruments with my new inst rating. I was in clouds for 2.5 hours, and the lower legs of my pants and socks were soaked. Not a good confidence builder for keeping the radios dry. The Mooney internet forums are ripe with ideas to try and seal them after being removed for annual or radio work. I finally got rid of mine by modifying and riveting them closed with metal and Pro Seal.

For this reason, in my RV-8, I put a generous hinged inspection panel in the fwd baggage compartment for behind panel repairs.

But that's just me, and I plan on flying weather in my RV. So, if you're planning VFR only, and the plane will never be out in the rain for long periods of time, you'll probably will not have a problem.

Just cuz your Mooney leaks...

atreff,

Just because your Mooney leaks doesn't mean diddly. We CAN do it better, and we do.

I used Tom Emery's custom-formed proseal gasket method on my access panels, and not a single drop in 530 hours -- with a fair amount of time flying through weather, plane left out in the rain from time to time, etc.

There are places where my plane does let in water (when sitting, not flying), such as the front of the tip-up canopy. The access panels do NOT leak.

Quality in areas like this is your responsibility, not perpetuating a precedent set by some leaky 40-year-old plane.

(this is coming from a person who has owned Mooneys before)

)_( Dan
RV-7 N714D
http://www.rvproject.com

Relax, Dan

Mea culpa, did not mean to offend. We're just building planes, here, not the Space Shuttle, I'm glad you like your panels. Relax. You've got avionics access panels, I don't. Have a nice life and fly safe.

dan said:

I used Tom Emery's custom-formed proseal gasket method on my access panels....................

Click to expand...

Sounds eerily similiar to a widely used technique on many access panels installed on the nations combat aircraft. It is known as FIPS.......or....... form in place sealing. Typically, an access panel (or cover) is treated with some non-stick parting agent, the structure to which the panel is affixed is prepared and slathered with a healthy layer of proseal, the access panel/cover is temporarily screwed into place with a number of fiber "donuts" between the structure and the cover. The donuts were essential in providing a uniform thickness to the proseal gasket. The squeeze-out of wet waste proseal was immediately wiped away. After cure, the cover was removed, it and the structure were cleaned up, the donuts removed and the result was a gasket like layer of proseal that provides lasting air-tight moisture protection. In practice, the slightest void or uneven thickness in the proseal formed gasket was cause for the inspection department to reject your FIPS work and make you do it all over again. It was labor intensive work and I suspect Mooney chose not to get involved with the time and expense of FIPSing.

Rick Galati RV-6A "Darla"

Parting agent

Rick said:

an access panel (or cover) is treated with some non-stick parting agent,

Click to expand...

What do you usually use as a parting agent?

Pro Seal parting agent

Mickey,

When I have made my own pro-seal gaskets on GA aircraft and bizjets, I've used DC-4 (Dow Corning silicone grease) as the parting agent.. I suppose you could try vaseline as well, but I have no experience with that.

Art

Silicon BAD

Not really, but I don't like silcon for possible contamination to surfaces that may be painted (fisheye). No doubt silicon works well, but it is hard to get rid of all traces of silicon. I like natural waxes which work fine. There is parting agent you can get from a boat fiberglass store which paints on and drys leaving film. Never tried the parting film, but non-silicon wax works fine. George

What a difference an E makes!

I agree silicone is bad.

Most of the time, words misspelled are understood...but please spell SILICONE right! The "e" is necessary to spell it right!

SILICON is "a nonmetallic element occurring extensively in the earth's crust in silica and silicates, used in glass, semiconducting devices, concrete, brick, refractories, pottery, and SILICONES..." from Webster's II New Riverside University Dictionary.

SILICONE is "any of a group of semi-inorganic polymers based on the structural unit R2SiO, where R is an organic group, used in adhesives, lubricants, protective coatings, paints, and electrical insulation." per Webster's II New Riverside University Dictionary.

SILICONE is made from the element SILICON.

SILICONE is a colorless, odorless oil that is used widely throughout industry.

1/20th of a drop of SILICONE per square foot can cause up to 85% strength reduction in the Space Shuttle bond systems which require over 4,000 psi tensile strength bonds.

Agreed...SILICONE is bad. But let's spell it right.

Don Hull

Make the gaskets after painting

Now that we not only know that silicone on the alum is bad prior to paint, and we know how to spell it, if you're making ProSeal gaskets and using a silicone-based parting agent, plan on making the gaskets after you paint.

Art

Wax paper as parting agent

If wax is ok, the I guess standard kitchen wax paper will probably work as well. I'll try it. Thanks for the hints!

Access panels

Thanks for the replies. I guess I'll take a day and make access panels. Anything I can do to avoid laying on my back under there will be done.

Darwin

I used clear plastic food wrap (Saran Wrap) on my empannage to lay up the VS-HS fairing for a better fit. Stretch it out & tape it down. Works Great.

Derrell

Derrell said:

I used clear plastic food wrap (Saran Wrap) on my empannage to lay up the VS-HS fairing for a better fit. Stretch it out & tape it down. Works Great.

Derrell

Click to expand...

A Lancair builder recommended I use ordinary clear packing tape stuck to the structure as the "parting agent" to do my empennage fairing and other fiberglass work using the West system with great success. On occasion, I would give the tape a very light coat of car wax just to be certain. When cured, the fiberglass always popped loose cleanly.

Rick Galati RV-6A "Darla"

I put in a single access panel in the center. About 6 inches x 18 inches.

Its not big enough. By the time you put 3/8 to 1/2 inch flanges to catch the nut plates it gets too narrow.

I waited until after I painted and put a little rtv on the bottom side of the lid.

Dan's idea of two, one on either side, is good.

If you are considering not installing to 'hinge pin puller' mechanism, I would recommend highly some type of access panel.

It would be very difficult to get pins or bolts in those spots from laying on the cockpit floor.

cary rhodes