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jrthomas
07-09-2009, 05:41 PM
I'm sick. I recently ordered an acrylic windshield from LP. I took every precaution to read the material and handle it gently. I set it in place today, lined it up with the cowling an used some plastic clamps to hold everything in place. It was slightly over square, when it was right with the cowling it was a little foward at the top. I pressed it lightly to line it up the top and heard a pop. A crack had appeared at the front wing spar attach point. What a sick feeling. I drilled a small hole at the end of the crack but the damage is done. Has anyone tried glueing or repairing anything like this? At $520 I don't dare buy another one and possibly have the same again. I still have a sheet of lexan that came with the kit? Maybe my misfortune will forewarn someone else. Any suggestions?

prolab4
07-09-2009, 09:50 PM
Definitely a painful event. May I suggest you locate a plastics shop. There are many who fabricate display items like racks and such for retailers. They use acrylic and the appropriate cement daily. They know about capillary action and the best glue

I closed my hangar door on my windscreen and bought a lexan sheet but have not used it yet. A 4x8 sheet will make two windscreens. I will probably need to do it twice. best of luck to you

Cwehner
07-10-2009, 09:09 AM
Have the exact same crack in mine. Talked to a local plastic shop here and the told me to use this stuff http://www.ridoutplastics.com/ips4.html
It's water thin and a little slower drying. They told me to get a syringe with fine point needle. I drilled stop hole just as you did and carefully applied the weld-on #4 from the hole and the edge side of the crack. It wicked all the way up the crack very nicely. I was told it will get harder over a long period of time so I did it a few months ago and will hopefuly be installing it by the end of the summer. It seems by playing with it that it's done a pretty good job, so as long as I can get it on without recracking it it should suffice. most of the crack will be under the aluminum spar cuff. So we'll see....

Chris

jrthomas
07-10-2009, 11:10 AM
Thanks to all of you who responded. I just called and ordered the Weld-On #4 and talked to them.They were very helpful and said this is what I need. Your advice was a life saver. I'll let ya'll know how it works out. Thanks again. James Thomas

SkyPirate
07-11-2009, 10:03 AM
the more I hear about the acrylic windshield cracking the more I'm thinking lexan,..lexan now makes an X10 brand that is superior in they claim it is resilient moreso to scratching,..1/4" thich lexan can be worked with heat,..once a blank was cut out for the windshield attach it where you can with little effort..the areas that take some pressure to form it ..a heat gun can be used.

with any plastics..acrylic ..lexan ..etc..before trying to manipulate it to install it ..take some real fine sand paper and completely sand the edges to remove any burrs ..or sharp edges..if it's going to crack ..it will be where there is a nick or blemish of some sort on the edge,..lexan being the less likely to crack.

SkyPirate
07-13-2009, 06:56 PM
yeah it does seem thick ..how thick is the acrylic winshield?..I know that some have reported the .093 thick lexan caves in at speed,..the .125 probably would too,..not sure if they make a .1875 or 3/16's I know they make 1/4" .250,..I have not used the X-10 version of lexan yet,..but I have used regular ole lexan on my race car and my planes,..it's pretty maneuverable ..but it has a memory..so heat must be used ,.since there are no 90 degree bends in the application I think it could be manipulated for the purpose ,..I have rolled up a sheet of 1/4" lexan to about a 6"R and taped it for storage,..the compound bends would be the toughest ..

how much does an acrylic windshield weigh and what is it's thickness??

jrthomas
07-14-2009, 07:46 AM
Hey airhawg, .125 thickness as best as I can measure. It still has the protective coating. I e-mailed LP but no response yet. I explained how it happened, didn't blame anyone but just for their advise. I still don't think it should have cracked but I know once I take delivery it's my baby. I'll keep ya'll posted.

Agfoxflyer
07-14-2009, 08:24 AM
I did the exact same thing when fitting the windsheild on my 5. I lined it up on the top at the ribs and pulled the bottom forward slightly to match up at the cowl. CRACK! I ordered a new windsheild from LP. They gave me a good discount from the stated prices. Told me to match at the cowl and the top is what it is. As a result I cannot use the standard cuffs and will eventually have to make fiberglas ones. But I don't want to take the time now. Having too much fun flying. The second windsheild has worked fine, no cracks for two years. Live and learn. ($$$)

SkyPirate
07-14-2009, 09:26 AM
I just sent an inquiry to a lexan dealer,..asking him if he would do a rolling order in bulk,..basically giving him an approximate number of orders but not at one time and with different shipping addresses,..I have delt with this vendor for about 3 years..he is pretty good to deal with ,..my inquisition was concerning 3/16" lexan.
I'll post his answer,..might be able to save a few bucks,..he will do up to 5 cuts on 1 - 4'x8' sheet for free,..rect. or sq.
I know he is going to ask dimensions ..I can't remember what mine were on the model 2 ,..anyone have a lexan winshield handy for dimensions?

Chase

SkyPirate
07-14-2009, 10:38 AM
got a response

..quote"Yes I can supply 3/16" lexan 4' x 8' sheets
will need to ship truck line. will need a business address with a loading dock for ship quote. or ship to a local ups freight dock and you pick up there.
cost per sheet $192.00 per sheet"end quote

you can find this vendor on E bay under "popdisplays" he carry's all kinds of plastics lexan,..tools for working with it and adhesives,..like I mentioned I have done business with him for 3 years or so ..he is legit.

Chase

jrthomas
07-17-2009, 05:50 AM
I e-mailed LP about my windshield cracking, explained how it happened, didn't ask for anything except advise on repairs. That was on July 12 and as of the 17th I have had no response. I'm a little disapointed that they didn't answer a simple question from a customer. I'll let ya'll know if I do hear from them but I don't expect to after this long. Thanks, James Thomas

Gary Algate
07-20-2009, 07:49 PM
My first Kitfox was supplied with 1/8" Lexan for the windscreen. 1/8" is quite thick and won't cave in at speed (+110mph) Earlier models were supplied with 0.93" and this would. Only problem I found with Lexan is that it tends to crack near the Butt rib curve after time and also, if you spill gas onto it on a hot day it instantly crazes. I have replaced a few over the years because of this. A 4ft x 8ft sheet of lexan will actually make two complete windscreens if you plan out the sheet. On my latest fox I installed the LP Aero windscreen and I love it so far.

Gary Algate (Classic 4 Jab2200)

Gary Algate
07-22-2009, 06:34 PM
Unfortunately when I spilled gas on mine the lexan actually cracked (looked like a shattered windscreen) and had to be replaced. Funny thing was that it only cracked if it happened in the middle of summer, never in cooler months. (I lived in N.Ontario at the time)

Gary

Gary Algate
07-22-2009, 08:14 PM
This makes sense. On my first plane I had the 582 and had a filler on my panel tank as well as the wing. It was when filling the panel tank that I managed to splash the windscreen. I became reaaly good at changing windscreens and on one occasion, cut and fitted one in less than 2 hrs. (we had a funfly that day).

Anyway after the third one I removed the filler spout on the panel tank and only filled thru the wing.

I was really popular among the Kitfox group around Sudbury as my windscreen fitting talent was often called upon!

Gary

Gary Algate
07-23-2009, 03:46 PM
I always used a Jig saw with a fine metal blade. After marking out the pattern (using old windscreen) I would then stick masking tape each side of the line to prevent the motion of the jigsaw plate from marking the lexan. It cuts like butter and I have never had a problem.

Always do this in a reasonably warm environment (sunny day or heated garage). I have seen lexan crack when cutting on a really cold day.

Re Riveting - yes no problem just make sure you use soft Aluminum rivets (Hard rivets pull too much and will crack the lexan) and overdrill the rivet holes in the lexan by at least 1/3rd to allow for expansion.

Sand all edges to remove sharp edges and stress points.

prolab4
07-23-2009, 06:02 PM
The plastic shop from which I bought my 4x8 piece of Lexan for my model 3 also stocked and sold me a saber saw blade specifically for thin plastic.

megawatt
08-31-2009, 08:42 PM
Question? Can anyone tell me how to repair, install a new windshield that has a 3 inch chunk out of the left corner? Thanks, Dave

Mark
09-01-2009, 07:13 AM
Dave,
Is the piece out of the front or rear? I had a 1 1/2" piece break off near the front corner and repaired it with super glue gel. It (fortunately) is consealed behind the boot cowl but it is still holding after 150 hours. Does your broken piece have a screw hole in it? That might help support a glue bond.
Good luck,

megawatt
09-01-2009, 01:28 PM
Mark, The piece is the corner above the pilots head. It measures 5 inches into the top edge and 3 inches down the side edge, with a shallow arc between the two points. The guy I bought it from said he had been told it was still a usable windshield, but I have my doubts. I just got the fuselage and have not had time to look into the coverage of the windshield once installed. Thanks, Dave

Spook712
04-18-2010, 04:28 AM
Hey Guys,

i'm Marc from Germany.
Since i'm not in the states, getting spare parts is pretty expensive.

My Windscreen on my 4 Spaeedster just crackes and i'm afraid I can't glue it.
It was a Tinted acrylic one.

Some questions:
What company is LP that is reffered to at some places in the thread.

How can I manufacture a lexan one, can I bend and form it without heat?

Is there an alternative for the preformed one from Skystar ??

Thamx for the help,

Marc

SkyPirate
04-18-2010, 06:45 AM
Hi Marc,.. yes you can make one from lexan,..without a pattern it takes a little more time,..but can be done . get some measurements off your present wndshield so you'll know what size piece of lexan to get,..you do have some choices on grade of lexan,..I'm using M-5 bronze on my doors and turtle deck,..and clear on the front. (M-10 requires heating to form)

1/8" clear lexan,..leave the protective skin on the lexan until you have finished cutting the new windshield.

your going to have to have the wings folded back to start with when sizing the new screen. once the old windscreen is removed,duplicate the bottom arc on the old screen to the new lexan where it meets the cowl,.cut that piece but add an inch or so it can be trimmed later if need be.take the new lexan and place it in an arc where it meets your top leading edge of instrument panel and cowl, use some squeeze clamps at the door posts to hold it ..put the top nose cowl section on and put a rolled towel on top of instrument panel pushing the lexan out to meet the top section of your cowl,. now pull the lexan to the top of the door post / front wing attach point and clamp it there too,,swing your wing towards the lexan and trace the leading edge where the wing meets the lexan,..do both sides,.. and trace a line down each door post on the inside of the door opening.
remove the lexan,..you'll need a drill ..a hole saw I'm thinking its a 2.5 Inch hole saw,..and some good tin shears,..the straight edges you can cut with the tin shears..the section where the wing meets the lexan you'll need to use the hole saw,..once you've cut to this point ..put the windscreen back on the plane in the same manner,..and this time swing your wings to flight position and put the pins in,..you might have to manipulate the lexan a little ,,and or trim a little but once it fits well around your leading edges and you have the towel back in pushing the lexan out to the cowl ..,..you can fold the top part of the lexan down on top of the wing,..grab a bag of dog food or something to hold it down on top of the wing..do not cut this section yet.
Now once all of the front section looks good you can start your drilling,..start at the top just under each wing and work your way down.and then cut the top to fit,..in place or mark it remove it again and cut it ..once the cutting is done remove the protactive covering from the inside edges and where your attaching the wind screen,..
the top ,..ensure that your lexan is flat where it meets attach points,..once you know that it is,..start at the leading edge and work to the rear on each side about 3 inches from leading edge ..then go across the back where it meets the turtle deck,..then come back and finish from where you stopped at the 3 inch mark on each side of the top,,

sand all the sharp edges with fine sand paper peel the rest of the protective skin off ..and try her out :)

hope this helps

Chase

jrthomas
04-21-2010, 09:40 AM
I'll give y'all the final scoop on my cracked LP acrylic windshield. If you remember, mine cracked at the front spar attach point while setting it into place. I ordered a repair product and repaired it. I started back to work installing it and had it in place with all holes drilled and just minor trimming left to do. I had my buddy with me to help handle and we used extreme care to be extra gentle to do some final trimming on the bandsaw. We never made it to the bandsaw before it cracked again in a new spot, but also around the same wing attach point, under its own weight. I don't know how we could have handled it any more carefully. I don't know if I just got a lemon or if all are that fragile. The paperwork clearly states that there is no guarentee against cracking so I'm out if $500+ with nothing to show for it. I tried calling LP and left a message be they never returned my call. So I ended where I started with a sheet of Lexan. It's easy to work with and reasonably priced. Maybe I'm just too heavy handed for acrylic bit I don't know of anything I could have done differently. James Thomas

SkyPirate
04-21-2010, 07:46 PM
something I'm going to try,..on the top,.I'm going to put a piece of bronze M-5 right over my head under the clear lexan windshield,..basically layered one on top of the other so I end up with a little sun screen on top that will match my turtle deck and door's,..I'm hoping for no chafing between the layers ..might have to run a bead of adhesive to keep the dust out where the M-5 ends at the top of forward view area.

Chase

HighWing
04-22-2010, 08:15 PM
For what it's worth. I just checked my original 1993 Model IV windshield it is .060" I still have it to cut up and use on projects. The speedster came with the .093" and that is why the VNE was higher than the standard IV. I replaced it once in 9 years and 900 hours. I plan on using it again this time as well. It did sag a bit when in those steep fast descents, but I could cruise at 115 mph before repitching for climb and I had no problems with it. One issue with the .093 is that the crazing at the forward carry through was a bit more of an issue - guys complained a lot about it. I personally know of two instances where a Polycarbonate windshild actually split from to to bottom. Both were field repaired with tape while on fairly long cross country trips. I believe one was drilled and sewn together with safety wire as well. That one happened on the group Alaska trip some of you might remember.

My suggestion is to stay away from anything thicker than the .093" unless you can figure out how to aviod the tight bend at the wing. If you check the specs on Polycarbonate, the recommended minimum bend radius is thickness dependent and even the .060" is over stressed in our typical application - it is something like three inches, as I recall. It crazes as well. Regarding the abrasion resistent varieties available. These are designed for glazing applications in flat panels. The minimum bending radius is in feet as the abrasion resistant feature is a coating and it will crack it stretched around a bend.

If you plan on heating around the bends, keep in mind that Polycarbonate is hydrophilic - it absorbes moisture. When it is heat formed in production runs, it is heated at 250 degrees for a set time depending on thickness to avaporate absorbed water and heat formed soon thereafter to avoid the reintroduction of water. I have tried vacuum forming without drying and it look like a transparent sponge. The 250 degree drying cycle doesn't cause problems, so my susggestion is that would be the max temp.

The ultlimate benefit, in my opinion, is that not only being relatively enexpensive, that once fitted, you have a perfect pattern for the next one and it is lightweight for those that want to eventually get off the ground.