Door window crazed like crazy. How to replace?

[0TreeLemur]

@hmasing what size drill did you use for the window mounting holes?  I've read that oversized is good, some say 3/16", but I've also read 1/4".    Do those holes require a 100-degree countersink?   I haven't ordered plastic drill bits yet.

[0TreeLemur]

On 3/27/2019 at 2:37 PM, SheryLoewen said:

 DRILLING TIP

 

NOTE: Windshields installed with flush screws through dimpled holes in the skin need special attention. When drilling the Plexiglas being held in place, the windshield will be resting against the dimpled upset-holding it slightly out of position. To compensate for this, the pilot holes #40 should be drilled  to the outside edge of the existing holes.

They will lineup after the hole is drilled full size and countersink!

This prevents puckering of the metal on the finished job.

Shery/Paul thanks so much.  This is extremely important to know!

[0TreeLemur]

On 9/3/2018 at 3:56 PM, cliffy said:

Yes OK for owner maintenance, must be signed off correctly , by the owner doing the work, with name , pilot lic. number, date, hours and what was done and reference the proper section of 43.13 that lists what an owner can do.  You technically need the maintenance manual at hand while you do the work. Plexi drill bits can be bought or made by grinding the leading edge of the cutting point paralleled to the length of the drill so it doesn't dig into the plexi.  

Again, technically, if you use a thicker plexi for replacement you "technically" are making a change to the type design of the airplane that goes into a "minor alteration" of the airplane and that needs a real A&P for sign off-"TECHNICALLY"

 Any band saw blade used in cutting plexi should have a very fine tooth spacing. A wood cutting blade may/will crack and break the plexi. 

@cliffy  a search through the Mooney M20 maint. manual PDF for the words "window"and "windshield" turned up nothing about window replacement.  This weekend I'm going to replace the door window.  The old one is soooo bad it must be the '67 original.

[0TreeLemur]

On 3/27/2019 at 2:37 PM, SheryLoewen said:

 DRILLING TIP

 

NOTE: Windshields installed with flush screws through dimpled holes in the skin need special attention. When drilling the Plexiglas being held in place, the windshield will be resting against the dimpled upset-holding it slightly out of position. To compensate for this, the pilot holes #40 should be drilled  to the outside edge of the existing holes.

They will lineup after the hole is drilled full size and countersink!

This prevents puckering of the metal on the finished job.

Your recommendation worked out great!     I noticed after removing the old window that if you lay one on top of the other, they appear do be different sizes relative to each other depending upon which one is on top.   This means that using one to mark the hole locations in the other is not really possible.  Your technique eliminated that problem while accounting for the curvature issue.  I really appreciate your advice.

[0TreeLemur]

The end result - before and after photo.   There is a new window in the door, it is just so clear compared to the old one that it seems invisible

[carusoam]

Great details, Fred!

Thanks for sharing them.  

The old window appears to have changed colors a bit... comparing to the edges.

nice pic.

Best regards,

-a-

[0TreeLemur]

8 hours ago, carusoam said:

Great details, Fred!

Thanks for sharing them.  

The old window appears to have changed colors a bit... comparing to the edges.

nice pic.

Best regards,

-a-

Yes, the part that was exposed to the sun is badly crazed, while the edge is not nearly so.   The edge was inflexibly clamped, while the center probably experienced a lot of vibrational motion.    So, I leave it to you to say if it was UV exposure that weakened the material, vibration, or both that led to the changes in optical properties of the acrylic.

Mixing and applying that polysulphide sealant reminded me of that old Cheech & Chong comedy routine featuring the two Russians: "Look Like Dog $#!%?".  "Da.  Smell bad too."   We had a fun weekend.

[1964-M20E]

16 hours ago, Fred₂O said:

The end result - before and after photo.   There is a new window in the door, it is just so clear compared to the old one that it seems invisible

The only drawback is you will now need to use foggles when you ant to practice IMC flying. 

[cliffy]

At the airlines when we mixed that "stuff" up we did call it Dog S&^% !

[0TreeLemur]

Well we got the left-hand side window installed this past weekend.   At the pace my co-pilot and I work, it takes most of a weekend to replace one window.  I'll post our checklist items assembled from the advice received from MS members.  Thanks to all who helped us figure out how to do this!  As the photo shows, the new window (SG+UV) is reeeeealy nice.   Can't wait to take her for a test flight.

[flyboy0681]

21 minutes ago, Fred₂O said:

Well we got the left-hand side window installed this past weekend.   At the pace my co-pilot and I work, it takes most of a weekend to replace one window.  I'll post our checklist items assembled from the advice received from MS members.  Thanks to all who helped us figure out how to do this!  As the photo shows, the new window (SG+UV) is reeeeealy nice.   Can't wait to take her for a test flight.

May want to treat the rust spots in the tubing while you have the panels off.

[0TreeLemur]

Suggest a method?  CorrosionX?

[flyboy0681]

1 minute ago, Fred₂O said:

Suggest a method?  CorrosionX?

I meant fix the rust spots. Rust only worsens over time.

We've being using CorrosionX for years and when all of our panels were removed, there was nothing. And we are located in South Florida. Nuff said.

[Prior owner]

Just be careful scrapping the old sealant- it doesn’t take much pressure with a plastic scraper to distort the aluminum (bow it outwards permanently).

[0TreeLemur]

1 hour ago, PilotCoyote said:

Just be careful scrapping the old sealant- it doesn’t take much pressure with a plastic scraper to distort the aluminum (bow it outwards permanently).

We're done.  Mostly the old sealant came off by pulling at corners and scraping with fingernails.   That photo above shows the new window installed.

[0TreeLemur]

2 hours ago, flyboy0681 said:

I meant fix the rust spots. Rust only worsens over time.

We've being using CorrosionX for years and when all of our panels were removed, there was nothing. And we are located in South Florida. Nuff said.

Thanks-  you suggested that we "treat" the rust spots in the tubing, and I was asking about how you would do that.    My question was, should I just wipe on some CorrosionX and be done with it?

[Guest]

5 hours ago, Fred₂O said:

Suggest a method?  CorrosionX?

Mooney S/B M20-208 covers the subject.

Clarence

[0TreeLemur]

S/B M20-208 has been complied with.   We plan to tackle the interior next, that will be a good opportunity to inspect the tubing, remove the surface corrosion and apply some primer before continuing.  In the meanwhile, Corrosion-X it is.

[jaylw314]

17 minutes ago, Fred₂O said:

S/B M20-208 has been complied with.   We plan to tackle the interior next, that will be a good opportunity to inspect the tubing, remove the surface corrosion and apply some primer before continuing.  In the meanwhile, Corrosion-X it is.

There's some info in SB M20-208 that describes procedures for how to treat corrosion on the structural tubing

[0TreeLemur]

1 hour ago, jaylw314 said:

There's some info in SB M20-208 that describes procedures for how to treat corrosion on the structural tubing

Gonna do use that procedure.  Thx.