How to seal most forward left panel aft of Cowling?

[Saira]

My customer, to help, removed the panel just forward of the windscreen that gives access to the avionics and now we need to reseal it. I was wondering if I could use a fuel tank seal. I am rather new to the Mooney world but have sealed other panels on Cessna's.  

[A64Pilot]

If you use fuel tank sealer it’s not unlikely that trying to remove the panel in the future will destroy it, that stuff is tenacious. Best luck I’ve had is using a heat gun and .020 safety wire to saw between the gap to remove it.

Now I’m not familiar with those panels, but back in the day for Huey floor panels we used zinc chromate putty, it never hardens fully and it very good at helping prevent corrosion and kept the water out, but as zinc chromate I’m sure causes cancer in California I’m not sure it’s available anymore.

‘We used butyl rubber on boats with good success, you can get it in strips like a thick tape.

[Shadrach]

On 12/20/2023 at 9:49 AM, Saira said:

My customer, to help, removed the panel just forward of the windscreen that gives access to the avionics and now we need to reseal it. I was wondering if I could use a fuel tank seal. I am rather new to the Mooney world but have sealed other panels on Cessna's.  

I will assume in this case you’re working on a vintage Mooney. The instrument access panels should be sealed with a soft weatherstripping material. Do not use fuel tank sealant. Do not use access panel sealant. Both of those are way too aggressive for this application. Instrument access panels are meant to be easily removed and reinstalled. 
 

the factory used a material very similar to caulk cord.

https://www.amazon.com/M-D-Building-Products-71548-Replaceable/dp/B000CSN69C/ref=asc_df_B000CSN69C/?tag=hyprod-20&linkCode=df0&hvadid=216530079730&hvpos=&hvnetw=g&hvrand=11459215495237251950&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9008066&hvtargid=pla-351421888303&psc=1&mcid=69a76529d3453c29a03b935763ea9fed&gclid=EAIaIQobChMI6LiWp7KegwMVRF5HAR1V7wNIEA0YASABEgILy_D_BwE

[N201MKTurbo]

I believe they were originally sealed with zinc chromate putty. I don’t think you can get it any more. I have used plumbers putty, but it dries out after a few years. I have used foam weather stripping and it worked well, didn’t leak and the panels came right off.

[PT20J]

I’ve used Rectorseal  81880 HVAC duct seal for a lot of things like sealing Wemac vents and plugging the hole where the cables run through the rear bulkhead into the tail. It’s easily mold to shape and doesn’t harden or dry out and is easily removed. 

[Shadrach]

43 minutes ago, N201MKTurbo said:

 I have used foam weather stripping and it worked well, didn’t leak and the panels came right off.

Can you remember which one?  I just cleaned all of the old stripping off mine and would be interested in making a change to something clean and easy.

[47U]

28 minutes ago, Shadrach said:

I would be interested in making a change to something clean and easy.

4 hours ago, Saira said:

My customer, to help, removed the panel just forward of the windscreen that gives access to the avionics and now we need to reseal it.

This is what I used… with the caveat, I NEVER use a garden hose, I clean the fuselage with Wash Wax All in a spray bottle.  And I use a canopy cover with extension over the avionics access panels if I’m parked on the ramp.

I ran two beads on the windscreen side, one bead on the firewall side.  Be sure to not cover up the channel to drain any water than might get past the bead.

[geoffb]

expanded PTFE flange seal tape works awesome for this, I had a partial roll left over from a turbine job

Sealed great, no mess, easy to remove panel next time.  You do have to replace it when you disturb the seal.

[A64Pilot]

Go to Amazon, search butyl rubber tape, pick a size and color you like, probably under $10.

Give it a try. It never hardens or cures and you can remove it, scrape the excess off with a plastic scraper, heat gun if cold and WD-40 is better than goof off, Acetone would probably be great but I don’t like it so much around paint.

[N201MKTurbo]

57 minutes ago, Shadrach said:

Can you remember which one?  I just cleaned all of the old stripping off mine and would be interested in making a change to something clean and easy.

I just used the adhesive backed foam. It has been a few years, but I think it was about 1/2 wide and 3/8 thick. It compressed down nicely and the panels fit well.

And I did test it with a hose and rain.

[67 m20F chump]

https://www.aircraftspruce.com/catalog/appages/windowsealant.php?clickkey=4115

 

3m strip caulk is sold at aircraft spruce.  Works great for this.  The product doesn’t harden.  

Edited December 20, 2023 by 67 m20F chump
Content

[Fly Boomer]

6 hours ago, Saira said:

My customer, to help, removed the panel just forward of the windscreen that gives access to the avionics and now we need to reseal it. I was wondering if I could use a fuel tank seal. I am rather new to the Mooney world but have sealed other panels on Cessna's.  

I would use this stuff, but the only reason is that I remember using it at least 60 years ago.

https://www.walmart.com/ip/Mortite-Weatherstrip-And-Caulking-Cord-45-GRAY-CAULKING-CORD/38480221?category=&customer_id_enc&parent_anchor_item_id=16879752&beacon_version=1.0.1

[Saira]

17 hours ago, Fly Boomer said:

I would use this stuff, but the only reason is that I remember using it at least 60 years ago.

https://www.walmart.com/ip/Mortite-Weatherstrip-And-Caulking-Cord-45-GRAY-CAULKING-CORD/38480221?category=&customer_id_enc&parent_anchor_item_id=16879752&beacon_version=1.0.1

Thanks for the help. I'll take your 60 years of experience... Seems legit...lol 

[haymak3r]

21 hours ago, PT20J said:

I’ve used Rectorseal  81880 HVAC duct seal for a lot of things like sealing Wemac vents and plugging the hole where the cables run through the rear bulkhead into the tail. It’s easily mold to shape and doesn’t harden or dry out and is easily removed. 

Sealing wemac vents? Do tell, as mine leak badly..

[PT20J]

58 minutes ago, haymak3r said:

Sealing wemac vents? Do tell, as mine leak badly..

My M20J has vents in each footwell sidewall that are attached to NACA scoops. I used the duct seal on the wemac flange to seal where it attaches to the scoop in place of the original sealant.

[haymak3r]

1 hour ago, PT20J said:

My M20J has vents in each footwell sidewall that are attached to NACA scoops. I used the duct seal on the wemac flange to seal where it attaches to the scoop in place of the original sealant.

Ah. I understand. Mine are with the overhead vents. It's almost like the tube has come off or something, as there is air coming around the vent even if the vent is closed. I need to pull the interior for multiple reasons, but not wanting to take that job on haha.

[0TreeLemur]

@Saira - Don't use goop!  Don't use tar!  Years ago @Hector clued me into this, and it works fantastically.  Before, I got water damage on my radio stack.  After installing this stuff, I flew my C through lots of heavy rain with no problems.  Replace it once a year and you'll not have problems.   Don't install it in the drainage channels.  You'll need to use an awl to poke holes for the screws to penetrate it.  This stuff is the shizzle.

 

[Shadrach]

On 12/20/2023 at 4:22 PM, Fly Boomer said:

I would use this stuff, but the only reason is that I remember using it at least 60 years ago.

https://www.walmart.com/ip/Mortite-Weatherstrip-And-Caulking-Cord-45-GRAY-CAULKING-CORD/38480221?category=&customer_id_enc&parent_anchor_item_id=16879752&beacon_version=1.0.1

It’s funny, one sort of develops a mental picture of forum members that they haven’t met. You keep throwing out statements that are in direct conflict with my mental picture. I would have assumed that if you were around to do anything “at least 60 years ago” it would have involved a pacifier or a teething ring.

[Fly Boomer]

14 hours ago, Shadrach said:

It’s funny, one sort of develops a mental picture of forum members that they haven’t met. You keep throwing out statements that are in direct conflict with my mental picture. I would have assumed that if you were around to do anything “at least 60 years ago” it would have involved a pacifier or a teething ring.

Ha!  That would be nice — I would be much younger.

[Gary0747]

I have the SWTA aircraft windshield smaller access panels with a simple solution that is reusable.    Put a bead of RTV Silicone and cover it with Saran Wrap before installing the cover then trim the excess.   

[Utah20Gflyer]

I have some sort of rubber gasket material that is semi permanent.  I’ve taken those panels off a bunch of times and no sign of any leaking. 

[RoundTwo]

3M strip caulk found in the Aviation aisle at auto parts store. It used to be dirt cheap, but not anymore.

3M Strip Caulk at Amazon