Side window replacement

[MikeOH]

Mine are pretty hazy...been thinking about DIY (I believe owners can replace; no A&P required)

How difficult is this?

How time consuming?

[Shadrach]

19 minutes ago, Robert Hicks said:

Windows are not an owner mx item. You could do it under supervision of an AP but will ultimately need a sign off.

You should familiarize yourself with Part 43 appendix A paragraph (c)

Look at line item 13.

 

[N201MKTurbo]

The F windows have a zillion screws. The later Mooneys had clips holding the windows in. 
 

It takes a bit of skill to do it right. I could tell you, but that is too much typing right now.

[Shadrach]

31 minutes ago, Robert Hicks said:

Pretty familiar with it. I confused this thread with another that was posted at the same time asking about 2 piece to one piece windscreen. So my apologies.

No worries. You seemed very confident that widows were not a preventative item. I just wanted to make the applicable regulations available.

[MikeOH]

28 minutes ago, N201MKTurbo said:

The F windows have a zillion screws. The later Mooneys had clips holding the windows in. 
 

It takes a bit of skill to do it right. I could tell you, but that is too much typing right now.

Yeah, I noticed the zillion screws

Tell me later, maybe?

[N201MKTurbo]

59 minutes ago, MikeOH said:

Yeah, I noticed the zillion screws

Tell me later, maybe?

Will do.

[pirate]

Side windows are not difficult to replace. 
Remove screws, mark / number  retaining clips if you have them, break old sealant and remove windows. Clean up old sealant, pre fit new windows, match drill holes with a high quality drill bit for plastics / acrylic's, cleco in place after each holes is match drilled, mask off exterior very close to window skin edge,  apply sealant ( I used fuel tank sealant ) to surrounding interior frame, set windows in place, install clips if you have them and screws. 
lightly snug screws then final torque. 
Labor times will vary depending on skill level, my side windows took about 20 hours with clean up. I would buy the best bits since there are many holes to match drill, don’t want to crack one. 

[MikeOH]

18 minutes ago, pirate said:

Side windows are not difficult to replace. 
Remove screws, mark / number  retaining clips if you have them, break old sealant and remove windows. Clean up old sealant, pre fit new windows, match drill holes with a high quality drill bit for plastics / acrylic's, cleco in place after each holes is match drilled, mask off exterior very close to window skin edge,  apply sealant ( I used fuel tank sealant ) to surrounding interior frame, set windows in place, install clips if you have them and screws. 
lightly snug screws then final torque. 
Labor times will vary depending on skill level, my side windows took about 20 hours with clean up. I would buy the best bits since there are many holes to match drill, don’t want to crack one. 

What chemical did you use to clean off the old sealant?

[FlyingDude]

7 hours ago, pirate said:

apply sealant ( I used fuel tank sealant )

Does cs3204 stick to plastics/acrylics?
 

I mix the compounds in plastic bowls and leave some of it to airdry. That helps me gauge cure time. Then I  can easily peel the sealant off of the plastic cups after a few days of during. The product is specified for application on metals, so I got curious and wanted to ask you. Does it also stick to acrylic? Do you have any specs/instructions I can read? Thanks.

[Echo]

The removal of the old sealant is a Slow time consuming process. Not difficult, just slow. I used razor blades.  Lots and lots of razor blades. Did a thread here years ago. Make sure and counter sink holes. Using old windows as template is key. 

[Echo]

20 minutes ago, FlyingDude said:

Does cs3204 stick to plastics/acrylics?
 

I mix the compounds in plastic bowls and leave some of it to airdry. That helps me gauge cure time. Then I  can easily peel the sealant off of the plastic cups after a few days of during. The product is specified for application on metals, so I got curious and wanted to ask you. Does it also stick to acrylic? Do you have any specs/instructions I can read? Thanks.

Yes. That is what Mooney used. Cure time is in minutes as I recall after mixed. We needed LESS sealant than we thought. 

[jetdriven]

On the early J models they use what appears to be CS3330 which is an access door sealant.  use the B2 so you have plenty of working time.

[MooneyMitch]

16 hours ago, MikeOH said:

Mine are pretty hazy...been thinking about DIY (I believe owners can replace; no A&P required)

How difficult is this?

How time consuming?

Mike, you haven't mentioned tinting color?  Clear, green, or smoke?  Either choice, you are going to really enjoy the fresh new look.

[N201MKTurbo]

You can use MEK to soften the sealant. It works the best, but it is getting hard to come by. Denatured alcohol works almost as good and is a lot easier to find.

The window you receive will probably need to be trimmed, use the old window as a template. Use a saber saw with a coarse blade to trim it and a belt sander to clean up the edges. 

As for the holes, there is the easy way and the right way. The easy way is to clamp the old and new windows together and drill through the old holes and then counter sink them. This is assuming the holes are correct and your countersink won't be properly supported when you countersink them. Over countersinking them is your best bet so the window sits flush with the sheetmetal and all the dimples go in. If some are not aligning quite right just countersink them a little more.

A little bit of theory about the window and the screws. To make sure there are no high stress points on the window, the dimples and the screws should not touch the windows. If more than 1 screw touches the window, they will be trying to push the window together or pull it apart when they are tightened. The same is true of the dimples. If they are not perfectly centered in the window countersink, they will be putting stress on the plastic when the screws are tightened. To achieve this, the screw holes in the plastic need to be bigger than the screws by about 0.010" and the countersink needs to be a bit larger than the dimple so when the screws are tightened they are just pulling the flat sheet metal flush against the flat window material. The small voids left are filled with sealant.

The right way isn't much harder if you have the proper tools. My step dad showed me a trick for doing this. He wasn't an airplane mechanic, but was the best carpenter that ever lived. Use the old window to drill holes in the four corner screw holes. Drill them the right size for your microstop countersink. Then screw the window in place using whatever screws will fit through the holes. you just have to hold it so it won't move. then using a door hinge center drilling tool as shown below (this is from the local hardware store, it isn't an aircraft tool), just make a tiny centering divot in the plastic at each screw hole. Next remove the window and drill all the marked holes with the correct drill for your microstop countersink and countersink all the holes. Check the fit of the window to verify the countersink depth. Erring on the deep side is better than erring on the shallow side. Next drill out all the holes to the size that is bigger than the screws. test fit the window by putting in a few screws at the corners and pay particular attention to the four initial holes you drilled to hold the window in place. You may need to open them up a bit if they are not centered.

Next, remove the window and clean the sheet metal with MEK or alcohol. Clean the window with clean water and clean rags. Mix up your sealant. I would suggest the A2 instead of the B2. It is thinner and brushable. If you have MEK you can thin the B2 with it to make it brushable. Using a new 1" chip chip brush, paint on a generous coating of sealant on the sheetmetal and the window, so that it has adhered everywhere where they mate. Put the window in place and start putting screws and nuts back on. Don't forget the interior mounting clips if there are any. They should be marked with a sharpie before you remove them along with the sheetmetal of the airplane that matches their position. And take a picture of the window and the clips before you take it apart as a backup if you cover some of your marks with sealant. Only put the screws and nuts together finger tight until you get them all in, then start tightening them from the horizontal and vertical center of the window and work your way to the corners. Do not wipe off the sealant and avoid touching it as much as possible. Let it cure and you can just peel the extruded bead of sealant off. If you smear it, you will need to use plastic scrapers and/or your fingernails to clean it off. 

 

 

[Bryan G]

I had a MSC install with the single piece back windows and new from side windows, they fit well and was worth the money. I went with dark gray for the back windows and solar gray for the front. I removed the old plastic trim and fabricated them together, you would never know it didn’t come like this.

Make sure you label all the metal tabs that the plastics attach to, the shop labeled them but installed some upside down which was a pain to fix.

[Shadrach]

1 hour ago, Bryan G said:

I had a MSC install with the single piece back windows and new from side windows, they fit well and was worth the money. I went with dark gray for the back windows and solar gray for the front. I removed the old plastic trim and fabricated them together, you would never know it didn’t come like this.

Make sure you label all the metal tabs that the plastics attach to, the shop labeled them but installed some upside down which was a pain to fix.

Where did the new interior trim pieces come from? Did they trim and join the old ones or is there an aftermarket source?

 

I took my curtains out for a few years. Passengers missed them a great deal. I have since reinstalled.

[Bryan G]

13 minutes ago, Shadrach said:

Where did the new interior trim pieces come from? Did they trim and join the old ones or is there an aftermarket source?

I did it myself, I used the remaining Jaeger Aviation spatial interior plastic repair kit.

3M Ez Sand Epoxy and aluminum/acrylic tape patch material, heat gun, dremel, and sand paper. I used the vertical piece that I cut away as a plastic piece to fill the void.

Edited January 14 by Bryan G

[Shadrach]

15 minutes ago, Bryan G said:

I did it myself, I used the remaining Jaeger Aviation spatial interior plastic repair kit.

3M Ez Sand Epoxy and aluminum/acrylic tape patch material, heat gun, dremel, and sand paper. I used the vertical piece that I cut away as a plastic piece to fill the void.

I figured as much. I’ve done a lot of interior plastic work over the years.  I had all of our window trim covered in ultra suede. Really upgraded the look and feel of the trim.

[Bryan G]

3 minutes ago, Shadrach said:

I figured as much. I’ve done a lot of interior plastic work over the years.  I had all of our window trim covered in ultra suede. Really upgraded the look and feel of the trim.

Who covered it for you, did you lose much UL?

[Echo]

Go! Pack Go!  

[pirate]

19 hours ago, MikeOH said:

What chemical did you use to clean off the old sealant?

I used MEK and scrapers, worked the best for me. 

[Shadrach]

4 hours ago, Bryan G said:

Who covered it for you, did you lose much UL?

I think it was so light as to be negligible. The stuff we used weighs something like 250g per Sq. Meter. I doubt we used that much to cover the window trim. IIRC the whole job (carpets, ceiling panels, window trim and cabin insulation was small net loss in empty weight.

I will post pics so you can see what I mean.

[Greg Ellis]

On 1/13/2024 at 10:23 PM, MikeOH said:

What chemical did you use to clean off the old sealant?

When I did mine myself I used denatured alcohol and it worked great.  I cannot answer anything else about the install because the windows on a 63 C model like mine are installed completely different than the F model in question.

[jetdriven]

On 1/14/2024 at 3:07 PM, N201MKTurbo said:

You can use MEK to soften the sealant. It works the best, but it is getting hard to come by. Denatured alcohol works almost as good and is a lot easier to find.

The window you receive will probably need to be trimmed, use the old window as a template. Use a saber saw with a coarse blade to trim it and a belt sander to clean up the edges. 

As for the holes, there is the easy way and the right way. The easy way is to clamp the old and new windows together and drill through the old holes and then counter sink them. This is assuming the holes are correct and your countersink won't be properly supported when you countersink them. Over countersinking them is your best bet so the window sits flush with the sheetmetal and all the dimples go in. If some are not aligning quite right just countersink them a little more.

A little bit of theory about the window and the screws. To make sure there are no high stress points on the window, the dimples and the screws should not touch the windows. If more than 1 screw touches the window, they will be trying to push the window together or pull it apart when they are tightened. The same is true of the dimples. If they are not perfectly centered in the window countersink, they will be putting stress on the plastic when the screws are tightened. To achieve this, the screw holes in the plastic need to be bigger than the screws by about 0.010" and the countersink needs to be a bit larger than the dimple so when the screws are tightened they are just pulling the flat sheet metal flush against the flat window material. The small voids left are filled with sealant.

The right way isn't much harder if you have the proper tools. My step dad showed me a trick for doing this. He wasn't an airplane mechanic, but was the best carpenter that ever lived. Use the old window to drill holes in the four corner screw holes. Drill them the right size for your microstop countersink. Then screw the window in place using whatever screws will fit through the holes. you just have to hold it so it won't move. then using a door hinge center drilling tool as shown below (this is from the local hardware store, it isn't an aircraft tool), just make a tiny centering divot in the plastic at each screw hole. Next remove the window and drill all the marked holes with the correct drill for your microstop countersink and countersink all the holes. Check the fit of the window to verify the countersink depth. Erring on the deep side is better than erring on the shallow side. Next drill out all the holes to the size that is bigger than the screws. test fit the window by putting in a few screws at the corners and pay particular attention to the four initial holes you drilled to hold the window in place. You may need to open them up a bit if they are not centered.

Next, remove the window and clean the sheet metal with MEK or alcohol. Clean the window with clean water and clean rags. Mix up your sealant. I would suggest the A2 instead of the B2. It is thinner and brushable. If you have MEK you can thin the B2 with it to make it brushable. Using a new 1" chip chip brush, paint on a generous coating of sealant on the sheetmetal and the window, so that it has adhered everywhere where they mate. Put the window in place and start putting screws and nuts back on. Don't forget the interior mounting clips if there are any. They should be marked with a sharpie before you remove them along with the sheetmetal of the airplane that matches their position. And take a picture of the window and the clips before you take it apart as a backup if you cover some of your marks with sealant. Only put the screws and nuts together finger tight until you get them all in, then start tightening them from the horizontal and vertical center of the window and work your way to the corners. Do not wipe off the sealant and avoid touching it as much as possible. Let it cure and you can just peel the extruded bead of sealant off. If you smear it, you will need to use plastic scrapers and/or your fingernails to clean it off.

LP Aero says not to use a sabre saw to cut the plastic windows.  We used a  band saw or a belt sander.

NOT RECOMMENDED: Trimming with a jig saw, saber saw, or a hand saw is not
advisable. If hand sawing is absolutely necessary, a coping saw with a bone cutting
blade with 30 teeth per inch may be used. Extreme care must be used to avoid the
blade hanging up and starting a crack. We recommend that the blade be inserted in the
saw backward so that the blade cuts when it is drawn towards you. Do not allow the
edges of the acrylic to pinch and bind the blade

[pirate]

A vibrating saw works really good too, pretty fool proof and  if you ever have to cut / trim  I highly recommend that one does NOT cut / trim in a cold environment. I heated my shop up to 72 for good part of the day. The picture below is after I cut (using a vibrating tool) the bubble for my RV separating the sliding canopy and windscreen portion, after trimming I highly recommend sanding and polishing edge's.