Side window replacement

[BaldEagle]

For those that have replaced their side windows, what do y'all recommend for measuring, mixing and applying this stuff?  I'm looking to do one window per weekend but might not have every weekend spare so not wanting to use the whole can all at once.

 

 

 

 

 

[BaldEagle]

  On 11/23/2020 at 2:22 AM, carusoam said:

Can’t get the link to work... 

-a-

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Apologies, I just moved the image so that it displays in-line.

[0TreeLemur]

We used a digital kitchen scale and a teflon cutting board.   Estimated the net weight of the product per container and used for calculations, put it on the cutting board and trowel together kind of like mixing paint.

Good luck.   Stuff is nasty.   To extend the cooking analogy, trowel it on the window frame like you are icing a cake.  

[Greg Ellis]

A while back I replaced all the side windows in my 63 C model.  I used this product.  It is the same product you have however it comes in a caulking type applicator that you just mix by pumping the plunger, albeit about 75 times.

Flamemaster CS3330 B2 Sealant - 6 oz. - SkyGeek.com

I was advised to use this by three different mechanics including the guys up at Wilmar, MN and Paul Beck at WeepNoMoreLLC (fuel tank reseal specialist).

The hardest part was mixing it which took about 75 pumps of the plunger.  It then fit in a traditional caulking gun.  I was advised to use one full tube for each window.  This produced quite a bit of excess which was easily removed after it cured but every single gap was completely filled and sealed.  It was a cleaner application because all the mixing was self contained in the caulking tube.

[N201MKTurbo]

I mix it in Dixie cups with popsicle sticks. A dollop of sealant on a 1 inch wide popsicle stick and a dollop of activator on a 1/4 inch stirrer stick gives the correct ratio.

Mix well in one Dixie cup then transfer to another Dixie cup and mix some more. The guy at the fiberglass store gave me this advice, that way you don’t have any unmixed stuff in the cracks and crevices. 

When you are done, just throw away the Dixie cup.

If you want it to be brushable, just thin it with a little MEK. I use the throw away Harbor Freight chip brushes to apply it. When I’m done I just set the cup and brush aside so I can see how it cured the next day. Then threw it away.

Don't mix too much, a little goes a long way.

I always wear gloves BTW.

[N201MKTurbo]

  On 11/23/2020 at 12:32 PM, Greg Ellis said:

A while back I replaced all the side windows in my 63 C model.  I used this product.  It is the same product you have however it comes in a caulking type applicator that you just mix by pumping the plunger, albeit about 75 times.

Flamemaster CS3330 B2 Sealant - 6 oz. - SkyGeek.com

I was advised to use this by three different mechanics including the guys up at Wilmar, MN and Paul Beck at WeepNoMoreLLC (fuel tank reseal specialist).

The hardest part was mixing it which took about 75 pumps of the plunger.  It then fit in a traditional caulking gun.  I was advised to use one full tube for each window.  This produced quite a bit of excess which was easily removed after it cured but every single gap was completely filled and sealed.  It was a cleaner application because all the mixing was self contained in the caulking tube.

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I second using the SEMKITS for windows. I have the pneumatic dispenser and It makes the whole job easier.

The only problem is once you mix one, you are committed to using it all up. I find I usually only use a fraction of it.
 

The instructions say 100 strokes, your arm will be sore before you are finished. If you have a few AMUs there is a machine that mixes them.

[MinneMooney]

I just replaced all 4 side windows in my ‘65 C and used the  CHEMSEAL B2 TANK SEALANT CS3204 3.5oz from Aircraft Spruce (also bought 3/16” & 1/4” “acrylic” drill bits from them). We did all 4 windows at the same time. It took 3 of the kits to complete the job (I bought 5 just to be sure). Even though the “B2” is supposed to have a 2 hour working time, it took almost 24 hours to cure in a 55F heated hangar. We eventually put a space heater in the cabin to warm things to 80F, which sped things up. I highly recommend the plastic scrapers with replaceable plastic blades for cleaning everything up. Windows came from LP Aero Plastics via Chief Aircraft. Only the pilot window required minor trimming to fit. The cleco’s were my A&P’s idea and worked out well.

Big job but it was definitely worthwhile. The old windows were almost opaque when the sunshine hit them.

[Greg Ellis]

@MinneMooney I suspect the J model of the original poster is more like your 65 C model.  On my 63 C model, the windows are held in place by clips on the inside.  No screws through the sheet metal or windows and no need for cleco's or acrylic drill bits.  The interior trim is removed and you remove the individual clips (numbering them to keep them in proper order), push the window into the inside of the airplane to remove it, clean the aluminum of old sealant, then you put the sealant on the inside of the aluminum and push the window into the sealant then put the clips back on.  Tightening the clips squeezes out the excess sealant outside the window and clean up is easy with a piece of old window cut and sharpened on the end.  It won't scratch when you clean the sealant.

[ArtVandelay]

  On 11/23/2020 at 2:22 PM, Greg Ellis said:

[mention=17631]MinneMooney[/mention] I suspect the J model of the original poster is more like your 65 C model.  On my 63 C model, the windows are held in place by clips on the inside.  No screws through the sheet metal or windows and no need for cleco's or acrylic drill bits.  The interior trim is removed and you remove the individual clips....

Nope, the J uses clips (retainers).

[BaldEagle]

 

  On 11/23/2020 at 2:30 PM, ArtVandelay said:

Nope, the J uses clips (retainers).

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I pulled the interior door panel off to take a look.  What's interesting is that the sealant that was applied at the factory (I'm assuming the windows are original as I don't see anything in the logbooks to suggest otherwise) is just pasted up against the side of the glass, which doesn't look ideal to me but I suppose it saves a lot of labor avoiding the cleanup.

[Greg Ellis]

If you are not already aware of this, number those retainers.  They have to go back in the position they came from. I bet you will find that when you remove the retainers, those windows will push in quite easily with that old sealant.  Denatured alcohol worked pretty good at removing the old sealant from the metal.

When I did mine, the new windows did not butt up tight to the aluminum skin of the airframe in all places.  There were gaps.  Nor did the old windows.  Excess sealant filled in the gaps to give a very good seal.  So you want excess sealant squeeze out, let it set then remove it with some type of tool that won't damage the window.  A great piece of advice from Paul Beck at WeepNoMore was to cut an old piece of window into the shape of scraper and sharpen the end of.  It will cut through the sealant and because it will be plexiglass on plexiglass it won't scratch the new window.  Just my 2 cents on having spent a weekend doing this.

Sorry that I don't have any photos to show you. 

[PT20J]

  On 11/23/2020 at 6:43 PM, BaldEagle said:

 

I pulled the interior door panel off to take a look.  What's interesting is that the sealant that was applied at the factory (I'm assuming the windows are original as I don't see anything in the logbooks to suggest otherwise) is just pasted up against the side of the glass, which doesn't look ideal to me but I suppose it saves a lot of labor avoiding the cleanup.

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Well, that’s interesting. What year is your airplane? I owned a 1978 M20J years ago and when we did the SB 208 inspection the windows leaked and I had to have a pitted tube replaced. I don’t remember how the sealant was applied but I do remember the pinkish color.

When I had the interior out of my 1994 J recently, I noticed that the sealant is brownish and completely covers the surface between the plexiglass and the skins. 

Perhaps the application practice at the factory changed over the years. This might also explain the effectivity note in SB 208B that says part B applies to all flush window aircraft. Per Stacey Ellis, flush window = clips. 

Skip

[carusoam]

65 Mooneys got significant window changes sort of...

I remember the clips and I have the drill bit... 

Its possible they used both the screws and the clips... (?)

As far as original windows goes...   they kinda look dark gray from the oxidized surface... but, if you cut them or look from a clean edge, you will easily see the coke bottle green color originally used as a sun block...  

Great mixing, spreading and keeping surfaces clean details, Gents!

Seams like anyone that has worked with fiberglass resins has learned the technique for measuring, stirring/mixing ‘doctor blade’ style... checking that your finished work has set properly by looking at the unused excess... and throwing away the stirring sticks and cups when done... 

Lots of high viscosity mixing technique involved... aka laminar mixing, when turbulent mixing is unavailable.... spreading the material thin on a board works really well to get things to blend down to the molecular level, when repeated...

Temperature is very important to cure fully... too cold will cure slowly, and may stop curing too soon...  too hot, things cure faster than you can work...

Science and MS, perfect together..! 
 

 

PP thoughts only, not a mechanic...

best regards,

-a-

[Immelman]

I don't know if you've already committed on the 3330.... but when we re-did our windows, I recall grey sealant which would have been the slightly tougher 3204.

I am not an A&P/IA, just going with what I remember my guy using.

And +1 for using the one where you mix with the plunger and dispense with the special caulking gun.

Edited November 23, 2020 by Immelman

[MARZ]

Two observations, 

Leave the protective plastic in place  on both sides of the window until all is glued, screwed and set.

Denatured Alcohol will safely remove small oops of sealant 

a

[TTaylor]

You might consider buying some disposable piping bags. Put what you want to use at one time in the bag. You can mix the two parts in the bag and then cut the end to pipe out the sealant like a caulk. 

[BaldEagle]

  On 11/23/2020 at 7:24 PM, PT20J said:

Well, that’s interesting. What year is your airplane? I owned a 1978 M20J years ago and when we did the SB 208 inspection the windows leaked and I had to have a pitted tube replaced. I don’t remember how the sealant was applied but I do remember the pinkish color.

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Mine is also a 1978 J.  I'll be doing SB 208 when the all the interior panels come off for refurbishment / replacement as it has spent some of it's life in Florida and PNW, but I'll certainly be looking for evidence of water ingress when I do the windows as well.

[MinneMooney]

The old sealant on my windows was very easy to remove and was like modeling clay. I did SB208 inspection last year and found no corrosion. My windows were held in with screws except the door had clips on the sides with screws across the top and bottom.

[carusoam]

Awesome Kim!

You helped my memory... screws and clips...

My 65C had the screws to hold the windows in place... the sheet metal clips were locations to screw the plastic interior to...

Thanks for the help!

Best regards,

-a-

[MARZ]

BTW -  don't forget to replicate the window label - "Do Not Open Above 150 MPH"

 

[MinneMooney]

Thanks. Fortunately, that warning label is on the on the trim piece that covers the window. There were labels on each side that warned it was “a violation of federal law to tamper with aircraft”. I chose not to reapply those.

[laytonl]

If you haven’t already seen this article, I suggest reading before doing the job.

http://www.knr-inc.com/shoptalk-articles/25-shoptalk/96-200711-side-window-replacement

 I replaced all my windows last year and this article was very helpful.  Ii took me about three days to remove the old windows (including removing the interior and only about three hours to install all four side windows.  And then a half day to put it back together.  
 

It is easier with two people as one can work the inside including installing Clecos and rivets while exterior person cleans and smooths the oozed out PRC.  Really not a difficult job except for removing the old windows.

i have a ‘92 J.

 

lee

 

 

 

 

 

 

[RobertGary1]

  On 11/23/2020 at 6:43 PM, BaldEagle said:

 

I pulled the interior door panel off to take a look.  What's interesting is that the sealant that was applied at the factory (I'm assuming the windows are original as I don't see anything in the logbooks to suggest otherwise) is just pasted up against the side of the glass, which doesn't look ideal to me but I suppose it saves a lot of labor avoiding the cleanup.

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Sounds exactly how they seller the tanks at the factory too.
 

-Robert  

[carusoam]

One sealant, a couple of different variations... one more permanent than the others...

Inspection panels use the thinner lighter version to ease removal...

The advantage to using this sealant... it stays flexible over a really wide range of temperatures...

Good for both fuel tanks and windows...

PP thoughts only, not a mechanic...

Best regards,

-a-

[BaldEagle]

Well that was fun.  I got the door window done in less than 3 hours.  It was original.  The pilot window... 8 hours.  Additional tools required included a jig saw, hammer chisel, drill, sheet metal seamers, rotary tool, and a bag of abrasive pads for it.  The pilot window had been replaced at some point in the distant past and whatever shop that did it either had not heard of a Mooney service manual, or decided that they knew better when it came to choosing the sealant.  It was impossible to remove without deforming the aluminum skin. Lots of evidence that the original sealant wasn’t cleaned up properly and I only had 2 rivets to drill out.  It was as if they drilled out the holes, with the wrong sized bit, but only had 1 size of blind rivet in their inventory, and was trying to get it wrapped up on a Friday afternoon.  2 rear windows to do next, and yeah, it’s the same sealant.  I can’t wait.