Replacing windshield

89 posts in this topic

Posted

Haha, Joey beat me to it. If you go this route, another neat trick is to paint a black edge on the inside of the window face maybe 1" or so in from the frame edge all around under where the frame tubing will mate. Also under the horizontal brace tube. This will literally make the tape disappear, provide a nice sharp outline and eliminate any aesthetic uglies like inadvertent wiggles due to less than straight tape application or other install difficulties. That tape gives you one shot at positioning the plastic, it is very sticky.

[edit] Or I suppose you could use white paint, dunno if the tape would show thru though.

Doug,  Is just any rattle-can paint OK for Lexan, or do you use something special for it?  EDMO

I know that you can buy cans that say "Plastic paint" too.  I painted some shutters with it and probably screwed up by cleaning with alcohol, and then used a self-etching gray primer before using the Plastic paint - Summer sun caused paint to peal in about 3 years.  I probably should not have used the primer? ??? EDMO

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Posted

Ed, I'm not 100% sure off hand. I think any old paint is ok if you prime plastic first. Not sure if sanding a bit of tooth is absolutely required though, the adhesion promoting spray primers avoid having to do that, i.e. self etching like you used. I have also seen rattle cans from Krylon and (ironically) Rustoleum that specifically say 'for plastics', so maybe you can use these directly without sanding or priming first. Of course the concern with sanding first is that it might be seen through the plastic when viewed from behind on clear sheet. Then again, maybe that would provide a desireable matt vs. gloss effect? Best to test on scrap first to see which paint/procedure provides the look you like.

One thing for sure, cleaning the Lexan will be critical. Never use ammonia based cleaners like 409 and Windex on polycarbonate, mild dish soap with warm water only. Cleaner/Polisher works on Plexiglass but not Lexan, so to make sure all surface contaminants were removed I would follow with a wiping of isopropyl alcohol, naphtha or mineral spirits only, taking care to avoid the edge face. Any other solvent will cloud or craze the poly. Then another immediate wash with mild dish soap and fresh warm water rinse. Dry with chamois or other clean non abrasive cloth.

I've never done this little trick on doors personally, but liked what I saw (might have been pics on TKF forum). Looked very clean with that sharp outline and completely eliminates that unsightly dirt and crud catch all between the window and tubing. That is a pet peeve of mine, no matter what I tried I couldn't get my KF doors totally clean and it really sticks out with the white door frames.

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Posted

I don't know if I would let anything petroleum based touch the lexan.  One drop of blue Loctite shattered my door in about 5 minutes.  I use plexus or pledge to clean my windows.

:BC:

 

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Posted

Oh ye of little faith. If you check the FAQs on the polycarbonate manufacturerswebsites, they actually recommend the items I mention. Again, other solvents including those in Loctite, will cloud, craze or shatter poly sheet. I posted links somewhere here onsite about cleaning, cutting and bending both polycarbonate and Plexiglass sheet. It lists all the solvent do's/don'ts for each.

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Posted (edited)

Vance,  Regarding the doors - I would use the same attachments you used on the windshield plus some of the other ideas the guys posted.  The bolts take more time and trouble to put in, but with the cushion I think they are less apt to make the Makrolon crack than rivets pulled too tight.  Possibly, you could drill bolt holes all the way through the tubes between the old rivet holes and the tape and/or paint should hide them.  I think most put too many rivets in the doors.  EDMO

Edited by EDMO

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Posted

Vance,  Regarding the doors - I would use the same attachments you used on the windshield plus some of the other ideas the guys posted.  The bolts take more time and trouble to put in, but with the cushion I think they are less apt to make the Makrolon crack than rivets pulled too tight.  Possibly, you could drill bolt holes all the way through the tubes between the old rivet holes and the tape and/or paint should hide them.  I think most put too many rivets in the doors.  EDMO

EDMO, you guys definitely have the creative juices flowing. I’m thinking about the white double sided foam or the 3M adhesive with a bolt like I did on the windscreen in the corners. I’m worried the foam thickness might expose the front edge of the lexan to the wing on the top edge. The lexan sets the doors frame depth on the bottom but the hinges set the top of the door frame depth. Does that make any sense? I guess a trip to the hardware store would tell me a lot more. 

 

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Posted (edited)

That new windshield looks damn good man!  Makes me want to do it too.  Thanks everyone for the tips.

But help me here... this is all new to me, difference between Lexan and Makrolon.  Which is best and why?

Thanks!

Edited by MN Kitfox 2

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Posted

Vance,  Regarding the doors - I would use the same attachments you used on the windshield plus some of the other ideas the guys posted.  The bolts take more time and trouble to put in, but with the cushion I think they are less apt to make the Makrolon crack than rivets pulled too tight.  Possibly, you could drill bolt holes all the way through the tubes between the old rivet holes and the tape and/or paint should hide them.  I think most put too many rivets in the doors.  EDMO

EDMO, you guys definitely have the creative juices flowing. I’m thinking about the white double sided foam or the 3M adhesive with a bolt like I did on the windscreen in the corners. I’m worried the foam thickness might expose the front edge of the lexan to the wing on the top edge. The lexan sets the doors frame depth on the bottom but the hinges set the top of the door frame depth. Does that make any sense? I guess a trip to the hardware store would tell me a lot more. 

 

I believe I would use a few more bolts on the front - a piece of lexan could do some major damage to fuselage, wings or the tail if it comes loose, not to mention the extreme discomfort to the pilot.  ???  EDMO

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Posted

Thanks, I know the answer to this.....Lexan and Makrolon are brands of Polycarbonate. Makrolon is more wear resistants than the Lexan brand. 

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Posted

The top picture is Joeys plane. I like how the doors look. 

The bottom picture is my plane. The lexan has a painted border on the outside. Some of the paint has chipped off and makes it look like hell.  I plan on cutting the painted border off and using the clear inside preice as a template. This time I will paint it on the inside. 

CC7788C9-FA81-4493-B882-36AEF4445012.jpeg

EDFD607F-9906-40BA-94EA-0D5FE66C35C9.jpeg

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Posted (edited)

The cowl, I think covers your windshield bottom and air pressure is pushing it towards the plane -  I was talking about the front of the doors, especially with some kind of tape underneath, might be in a high-pressure wind stream that could get under them, or suck them outward? - That is why I thought they should be more secure in the front.  "Anything that can come loose, will come loose, sooner or later."   Who knows what the tape will do in the future? - I trust bolts.   EDMO

Edited by EDMO
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Posted

The cowl, I think covers your windshield bottom and air pressure is pushing it towards the plane -  I was talking about the front of the doors, especially with some kind of tape underneath, might be in a high-pressure wind stream that could get under them, or suck them outward? - That is why I thought they should be more secure in the front.  "Anything that can come loose, will come loose, sooner or later."   Who knows what the tape will do in the future? - I trust bolts.   EDMO

If you read the link Joey posted about installing the KF bubble doors it says to install  fasteners (rivets) along the front edge. I assume they also believed it was nessesary to have a few fasteners tied into the frame.  I will look it over and install what I feel is appropriate. I have removed a lexan window that was installed using the 3M tape. I have to say that shit is serious. It really hold on good. I still don’t know that I’d soley trust the tape to hold the lexan to the frame. 

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Posted (edited)

So I went to cut out the doors yesterday and I don't have enough Polycarbonate left to make them one peice. If I make the tops and bottoms seperate then it will work. Has anyone done it this way? I hate to buy a whole sheet just to do one door. 

1511890831222114047849.jpg

Edited by NorthIdahoAvidflyer
Auto Correct

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Posted

If you try to make the windows in one piece, I don't think you will be able to attach it to the door.  I did top and bottom on my latest Avid rebuild.  JImChuk

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Posted

I kinda figured I might have trouble making it one piece. When I clecoed the two halves together it took a bowed form. 

This works better for me anyways as I don’t have to buy another piece of Poly. 

:BC:

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Posted

I’ve been working on the doors. I’d rather install the windshield. 

F4735F93-CECC-464B-9EAE-FC2F181C3370.jpeg

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Posted

did you 1 piece the lexan? Also don't final rivet the lexan till you fit the frame in the plane.

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Posted

TJay, No, i went with two piece at the direction of another builder and because I didn't have enough Lexan left over after making the windshield to make them one piece without buying a whole other sheet. I'm using the 3M tape with less rivets than the original doors had. After looking at the tape I went with more rivets that i had originally planned to because the tape was not at strong as I expected.

We have a guy in the local area who forms Lexan for various projects. I have been thinking about making a mold for bubble Lexan doors. I'm wondering if someone would be interested in a set of I had a few made??? Attached is a picture of a set of bubble doors on a Mark IV. I would love to know who made these and see if they had the molds. 

 

IMG_1468.thumb.JPG.81c75a3b2fbf91df931d4aa9f2869c67.JPG

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Posted (edited)

Wish the bubble doors you are thinking about would fit my KF!  I'd sure be interested.  The KF factory kit price is fine for guys with deep pockets building a new S7... but a little out of my aviation budget!

Vance, Dumb question:  If I were to do flat lexan door replacement, could I put 3m tape on the frame then slap an uncut sheet on it, stick it down, drill and screw it down, then trim the lexan to the frame?  Roto-Zip it or something? 

Kinda a quick and simple "for dummies" job that a guy with my talents could appreciate!  LOL 

Edited by Yamma-Fox
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Posted

Well.......I'm not sure but it sounds feasible.  When I was laying this out is was apparent that the lower section had a lot more compound curve than the top. I was going to try and make mine one piece but when I found out I did not have enough Poly it made me change directions. The 3M tape and a few rivets should work fine. It's not hard to drill through the Poly and hit the holes underneath once it is in place. I drill the rivet holes over one letter size for expansion and contraction. If you were to stick the Poly down you would not be able to adjust it or take it back off to enlarge the holes . You would have to make sure and leave sufficient material around the edges and there would be a lot of trimming and fitting to do after as each door opening is different. 

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Posted

With the door bowed out in the middle, I don't think you would ever get one piece to fasten down without it wanting to wrinkle somewhere.  And TJay is right about having the door in place when you drill and mount the lexan.  If the door is wracked, and you fasten the lexan to it, that's the shape the door will want to stay in, and it won't want to fit the door opening and close right.  Maybe if it's close it will still fit with no problems, but like my Avid where I widened the fuselage 3", the door had to be wracked quite a bit to fit the new door opening.   JImChuk 

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Posted

 

I already drilled a few rivet holes in the Lexan. I used the old panels to make the new parts so they should be close to fitting. I will mount them up and see how they look. If for some reason they need adjusted I should be able to cut or adjust it enough to make it work. There is a learning curve to this project for sure. Thank you for all the input. 

Does anyone know where or who made the bubble lexan??

 

 

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Posted

LP Aero Plastics, Inc. makes acrylic windshields, bubble doors and turtle decks for Avid and KF.

http://www.lpaero.com/stcpdf/cat.pdf see Pg. 35 & 81

If you call for a quote be prepared, they don't come cheap.

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Posted

That photo is a good friend of mine Paul Buss.

A while back he sent his door frames to LP Aeroplastics to prototype these doors.  They have the molds and will make them.  

The Kitfox IV windshield and skylight from LP is also a direct bolt in to an Avid.

 

Well worth the money.

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Posted

I sent LP Aero an email to see what the cost of those items are. I also asked for the prices of the Kitfox full windshield and Turtle deck. 

I will post their response. 

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