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#21
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David Koehler wrote:
Greetings All, I'm building a composite fuselage in South Texas, with out the aid of air conditioning. Does anyone have some suggestions on getting the resin setup time a little longer. I promote it for 85 degrees, I've tried a hotter temperature but it doesn't set well. The temp in the garage is 95+. I've put the resin container in a bucket of water and it helps a little. I need to do a large piece and the only option I can see is scheduling myself at 3am in the morning. It would be nicer if I could do it during the day. Thanks for any help you guys can give. david How well is your garage insulated? I put some of the silver bubble paper kind of insulation on the back of my garage door, that made a big difference. Since I don't have an a/c vent in my garage, I put a large fan in the doorway to the house to blow house air in there, that also makes a big difference. I've thought of adding ceiling insulation (in the garage attic) and blinds on the windows to help some more. |
#22
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Yellow is okay. I've felt the skin on yellow composites parked next to
white ones at airshows, and they feel about the same. On that same day, a dark navy blue or black painted plane would burn your hand if you touched it. |
#23
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On Wed, 13 Jul 2005 08:25:00 -0500, "MJC" wrote:
Any really light, bright color should be fine, but white is definitely the best for UV protection. Another question to ask yourself is if you'll be keeping it in an enclosed hangar most of the time. If so, then it's almost a non-issue. From what I've gathered, it's not the UV protection, it is heat absorption. Fiberglass composite gets "soft" when overheated, and white and several other colours do not heat up as much as black, red, and several other colours. MJC "Richard Riley" wrote in message news On Wed, 22 Jun 2005 20:34:32 -0400, "firstflight" wrote: :I have a composite kit aircraft, and it is time to paint! But I just hate :the idea of painting it WHITE (like most all the others). I understand that :HEAT is a big factor in this decision, and that white attracts the least :amount of heat which could disrupt the Epoxy over time. Since my plane is :held together with Epoxy, this seems like a valid concern. : :What do you think people? Does it have to be white?? Could one choose a :light yellow, light gray, silver,etc....... and not be pushing the envelop :too much? : :I happen to live in a very cool part of North America, so I am not too :worried about regular heat (like someone in Arizona might be). In Southern California I know of EZ's that are yellow, and Dick Rutan's in Mojave is light blue. There's a beautiful Berkut in England that's silver. So, yes, it can be done if you are very, very careful. But do be VERY VERY careful. Paint a sample panel, put it out at noon on one of the hottest days of the year. Find out how hot it gets, check that against the epoxy you're using AND the foam core - blue styrofoam swells up when it gets too hot. It's not a cumulative problem - 4 years at 140 degrees won't do anything bad. 30 minutes at 200 degrees and your airplane will be scrap. |
#24
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Both are important, and both are long term, not short term problems.
What's significant is that the same thing you do to achieve protection of one element (heat or UV) also, by happenstance, helps to protect from the other element. I have to say; if any composite resin gets "soft" when heated in direct sun (no matter what color it's painted), I'd say that's a good reason to never fly that aircraft again. A resin that gets soft in daytime sun is a resin that was not properly cured (mixed wrong?) and is not airworthy in any way and never will be. Makes me glad I'm building an RV :-) MJC wrote in message ... On Wed, 13 Jul 2005 08:25:00 -0500, "MJC" wrote: Any really light, bright color should be fine, but white is definitely the best for UV protection. Another question to ask yourself is if you'll be keeping it in an enclosed hangar most of the time. If so, then it's almost a non-issue. From what I've gathered, it's not the UV protection, it is heat absorption. Fiberglass composite gets "soft" when overheated, and white and several other colours do not heat up as much as black, red, and several other colours. MJC |
#25
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I feel your comments are rather alarmist! Epoxies do soften if exposed the
heat higher than the cure temperature. How ever then this higher temperature becomes the new softening temperature as the epoxy is now post cured. There is a limit to this post curing but it is much higher than the sun can generate. -- Cy Galley EAA Safety Programs Editor Always looking for ideas and articles for EAA Sport Pilot "MJC" wrote in message ... Both are important, and both are long term, not short term problems. What's significant is that the same thing you do to achieve protection of one element (heat or UV) also, by happenstance, helps to protect from the other element. I have to say; if any composite resin gets "soft" when heated in direct sun (no matter what color it's painted), I'd say that's a good reason to never fly that aircraft again. A resin that gets soft in daytime sun is a resin that was not properly cured (mixed wrong?) and is not airworthy in any way and never will be. Makes me glad I'm building an RV :-) MJC wrote in message ... On Wed, 13 Jul 2005 08:25:00 -0500, "MJC" wrote: Any really light, bright color should be fine, but white is definitely the best for UV protection. Another question to ask yourself is if you'll be keeping it in an enclosed hangar most of the time. If so, then it's almost a non-issue. From what I've gathered, it's not the UV protection, it is heat absorption. Fiberglass composite gets "soft" when overheated, and white and several other colours do not heat up as much as black, red, and several other colours. MJC |
#26
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On Fri, 15 Jul 2005 07:53:36 -0500, "MJC" wrote:
Both are important, and both are long term, not short term problems. What's significant is that the same thing you do to achieve protection of one element (heat or UV) also, by happenstance, helps to protect from the other element. I have to say; if any composite resin gets "soft" when heated in direct sun (no matter what color it's painted), I'd say that's a good reason to never fly that aircraft again. A resin that gets soft in daytime sun is a resin that was not properly cured (mixed wrong?) and is not airworthy in any way and never will be. Makes me glad I'm building an RV :-) MJC "post curing" raises the softening temperature, but virtually all common modern composites suffer some degree of softening at elevated temps. wrote in message .. . On Wed, 13 Jul 2005 08:25:00 -0500, "MJC" wrote: Any really light, bright color should be fine, but white is definitely the best for UV protection. Another question to ask yourself is if you'll be keeping it in an enclosed hangar most of the time. If so, then it's almost a non-issue. From what I've gathered, it's not the UV protection, it is heat absorption. Fiberglass composite gets "soft" when overheated, and white and several other colours do not heat up as much as black, red, and several other colours. MJC |
#27
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Yes it's vinyl ester resin, and regular glass lay-up. The first try was a mixture for 90 degrees and it didn't harden. I mixed another batch for 85 degrees and it hardened like the big boys do. I only promote 600 cc's at a time. We've had rather hot weather the past month, after 4 to 5 minutes I'm jellin, and I'm not talking about shoe soles. I did put the resin in the frig. and mix it cold, then do the glass, I had plenty of time and it looks like it harden. On the plus side, I read where it's advisable to have a heated room to cure the glass lays.... Would you believe I have a heated garage, right now anyway. Thank you for your time and consideration, david "......... :-))" wrote in message u... Would help if you told us what sort of resin ... sounds like a Vinyl Ester if you are promoting it but which one and what are you promoting it with and in what quantities ? Are you vacuum bagging or is it just a conventional wet layup ? "David Koehler" wrote in message ... Greetings All, I'm building a composite fuselage in South Texas, with out the aid of air conditioning. Does anyone have some suggestions on getting the resin setup time a little longer. I promote it for 85 degrees, I've tried a hotter temperature but it doesn't set well. The temp in the garage is 95+. I've put the resin container in a bucket of water and it helps a little. I need to do a large piece and the only option I can see is scheduling myself at 3am in the morning. It would be nicer if I could do it during the day. Thanks for any help you guys can give. david |
#28
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My garage is detached, and just a shell, no insulation. I've solved my
problem by doing what my eaa consular suggested, butting the resin in the frig. and cooling it off. I got the large piece of glass on with time to spare. He was concerned about groceries in the box, but the only thing I have in the one in the garage is beer.... It doesn't look like it affected the resin at all. Thanks to all for the help, David "Jim Carriere" wrote in message ... David Koehler wrote: Greetings All, I'm building a composite fuselage in South Texas, with out the aid of air conditioning. Does anyone have some suggestions on getting the resin setup time a little longer. I promote it for 85 degrees, I've tried a hotter temperature but it doesn't set well. The temp in the garage is 95+. I've put the resin container in a bucket of water and it helps a little. I need to do a large piece and the only option I can see is scheduling myself at 3am in the morning. It would be nicer if I could do it during the day. Thanks for any help you guys can give. david How well is your garage insulated? I put some of the silver bubble paper kind of insulation on the back of my garage door, that made a big difference. Since I don't have an a/c vent in my garage, I put a large fan in the doorway to the house to blow house air in there, that also makes a big difference. I've thought of adding ceiling insulation (in the garage attic) and blinds on the windows to help some more. |
#29
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"David Koehler" wrote in message ... snipped He was concerned about groceries in the box, but the only thing I have in the one in the garage is beer.... It doesn't look like it affected the resin at all. Have a couple beers and I bet it will affect the resin (and the rest of the job) :-) |
#30
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BarrenSands wrote:
"David Koehler" wrote in message ... snipped He was concerned about groceries in the box, but the only thing I have in the one in the garage is beer.... It doesn't look like it affected the resin at all. Have a couple beers and I bet it will affect the resin (and the rest of the job) :-) Temps are also a little high here in North Carolina lately. I'm about done welding. Just gotta be sure to clean the sweat off the steel, then add a little oil. But what will sweat do to a layup? -- This is by far the hardest lesson about freedom. It goes against instinct, and morality, to just sit back and watch people make mistakes. We want to help them, which means control them and their decisions, but in doing so we actually hurt them (and ourselves)." |
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