[VAC] Re: Structural loading / aircraft flooring
Hi Bill,
Have a '84-27'. Nice condition. Rear bed. It's 'ok', but not vintage.
Sold 65 globetrotter in immaculate condition that parents bought when it
was 4 years old. STUPID...STUPID...STUPID A salesman talked me out of
it, and charged $$ for the '84. Was sorry almost before I got off the
lot.
Want: '74 29' with side gaucho or queen ("full" whatever) bed.
Plan: Heck; we just thought it up a day ago. Got to get the wife to
agree first.
--== KIMM ==--
Always trying to reinvent a better wheel...
-Original Message-
From: Bill Scott [mailto:[EMAIL PROTECTED]]
Sent: Thursday, March 22, 2001 9:12 PM
To: Multiple recipients of VACList
Subject: [VAC] Re: Structural loading / aircraft flooring
Kimm, please tell us about your Airstream,model, year, etc, and what
you plan to do to get it ready for the big adventure.
Bill Scott
Charter Member and Membership Chairman
Washington DC Unit, WBCCI #3221
Our Homepage; http://www.servintfree.net/wbcci-dc/
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[VAC] Re: Structural loading / aircraft flooring
On a three piece beam, with steel on top and bottom and a spacer in between the bending load is carried by the top and bottom steel. The strength comes from the spacing. Loosing spacing causes a rapid loss of strength, as when a piece of tubing collapses in bending. Strength is proportional to the fourth power of the spacing. The channel is pretty well spaced by the web. In bending the flanges tend to bend in, so a good wood filler would gain a little strength. There is a strong tendency for the top and bottom to try to slip with respect to each other under a bending load. The filler has to handle that shear load. As flanges are strengthened that shear load on the filler gets greater. Pine/fir weighs 32 pounds per cubic foot. A 4x8x 3/4" sheet of plywood is 2 cubic feet, so about 64 +/- pounds a sheet. So the plywood floor deck in a 20 x 8' floor would weigh about 320 pounds. Aluminum can be light, but with two skins and spacers, the full skin probably weighs more. If you doubled the load carrying capacity of the frame by fitting more frame elements side by side to the original, and of the same size, and reduced the floor weight by going to honeycomb, you'd maybe come out even because the doubled frame would probably weigh as much as the improvement in floor. Then you still have to contend with axle, bearing, and tire load carrying capacity. Water is very heavy and some water beds have been known to crunch houses. Maybe there's the equivalent of an air mattress in a THIN waterbed. Gerald J. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Fresh water weighs 8.33 lbs per gallon. How much water will that waterbed hold? What will the weight of that bed do to your total weight-carrying allowance? When that stuff sloshes around (and it will, unless your bed is baffled) you will have some interesting side forces to contend with. Got a Hensley? You might need one. -- Roger Hightower 1975 31' SovereignWBCCI 4165VAC Mesa, AZ mailto:[EMAIL PROTECTED] To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Kimm Flatt wrote: I started this yesterday, then thought better not. But since it is still alive; HOW ABOUT FRAME: Replace the frame with Titanium. Very strong, extremely light weight. (You'll need to run your drills slower, because of excess heat.) What's wrong with a monoque body frame out of carbon fiber. Maybe need to make a sub frame (half the length of trailer) out of metal, just to spread the loads better though. FLOOR: Boeing 777 floors are a carbon fiber top/bottom with an aluminum honey comb inside. A 4x8 sheet is only $800. but it is SO SO light, and virtually unbreakable. I'm still of the mind to build my own flooring system with integrated heating tubes for radiant heating. OR there is a factory up here that makes plastic to replace wood. Decking, floors, whatever. It is stronger than wood, water proof (won't take on or soak up water at all) and won't mildew. Custom order to any size, so your floor could be 1 piece. And for cutouts and such, it 'works' just like wood. AXLES: I get my torsion axles in Phoenix or Sacramento. They come in #7,500 and #10,000 capacities each, and varied degrease of drop (straight, 2" or 4") and custom length, so you could raise or lower the ride height of your trailer too. 2@10k = 20,000 lb trailer. (double what most 29' are) Might have problems finding cheap 5K rated tires (at least of the size normally seen on trailers), better just go with three 7.5k axles and 3.7k rated tires. BED: Somewhere I saw a water bladder/air bed. It had hard sides, with a water bladder that sat on top of an air mattress. It is suppose to feel just like a water bed, but without all the weight. What kind of weight savings, we need numbers. So far we've doubled the capacity, and reduced the weight, eliminated floor rot, and have a water bed option. What next? Since we're designing our own, what about opposing slideouts. Costco now sells the smaller flat panel monitors, 42" In a year or 2 the rollable units will be on the open market. They come in virtually any size. So you can mount your 60" roll up monitor under the front overhead storage compartments, watch DVD movies (or TV) via your laptop, and lounge on your waterbed, all in your 4,000#, 32' AirDream. How about just getting a LCD/plasma video projector, then on the nice nights we can set up the outdoor screen and make some popcorn (jiffypop) over the camp fire. Any takers?? Right here! I'd certainly think this could be accomplished for less than one of those $150,000 units we saw last week. I'll tell you what, I'll do it for 100K, where do I sign? Cheaper by the dozen... bobb To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
"Dr. Gerald N. Johnson, electrical engineer" wrote: Strength is proportional to the fourth power of the spacing. Ah so that's why a 5" beam is so much stronger than a 3". The channel is pretty well spaced by the web. What web is this, you mean the cross-members in the frame? There is a strong tendency for the top and bottom to try to slip with respect to each other under a bending load. The filler has to handle that shear load. As flanges are strengthened that shear load on the filler gets greater. This all makes some kind of sense but wouldn't the main purpose of the filler be to spread the load and keep the steel from getting to the collapsing point in the first place? Once it's at that point I can't imagine a foam or honeycomb material that's going to stop it. I mean, noncompressible is all very well but the stuff is still going to be friable. And nothing fries you like an angry piece of moving steel! Aluminum can be light, but with two skins and spacers, the full skin probably weighs more. I was forgetting about the inner skin, just thinking of those photos of 2 guys holding up a full shell between them, looks like on 2 fingers but probably isn't. Hey! How about filling the space between the skins with HELIUM? They put argon gas in double-pane window assemblies for insulation; could helium serve a similar purpose? Or is it too small and leaks out? Yeah, I suppose if they could make skins that would never loosen around the rivets or leak, that would be something in itself. If you doubled the load carrying capacity of the frame by fitting more frame elements side by side to the original, and of the same size, and reduced the floor weight by going to honeycomb, you'd maybe come out even because the doubled frame would probably weigh as much as the improvement in floor. Then you still have to contend with axle, bearing, and tire load carrying capacity. I thought the idea was to fill in the spaces between existing members with some lightweight, solid material, instead of adding more frame members? And then also lighten the floor and maybe also make it stronger (?) with the aircraft flooring (is that stuff lighter AND stronger, or just lighter?). So then you have saved some amount of net weight AND your floor is stronger by "some" because of the filler and maybe some more because of the flooring. Probably not enough to add a waterbed but even a couple hundred pounds could be significant, if you are already pushing the tolerance. At the very least it's a better safety margin for the same amount of "stuff." Water is very heavy and some water beds have been known to crunch houses. Maybe there's the equivalent of an air mattress in a THIN waterbed. Collapsing houses, I thought that was just a myth landlords made up to keep from renting to hippies. At one point I remember figuring out that a waterbed doesn't load the floor any more than a full refrigerator, per square foot. And if a building is up to code it is supposed to be able to support a refrigerator. If it's not, that's another story. But, code for buildings doesn't appy to airstream floors anyway. Well hopefully this all isn't just totally a flight of fancy; for someone already doing a frame-up restoration who could locate some honeycomb or foam filler, it's not too much of a stretch to think about using these ideas to beef up the frame anyway, right? Especially for adding holding tanks and a battery of batteries to a unit that never had them, for example? As long as you placed them correctly and were careful about traveling with the tanks full, seems like it all only makes sense at least to consider it. Or, another option: boondock only near bodies of potable water, crap in the woods like all the other creatures, have all our little solar this and that, and forget all this bells whistles stuff! I mean, a little aluminum box to sleep in, some folding chairs, fire and maybe a little firewater, we're already way ahead on the deal, right?? all this, PLUS thumbs and the wheel? Hey, then all we need is to grow fur on our bodies and we're home free! --Sarah To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
The C channel has two flanges and the web that separates them. Its a poor cousin (structurally and cost wise) of an I beam. An I beam has three parts, that are two flanges and the web that separates the flanges. The shear connection from flange to web is critical and in rolled channel and I beam has extra metal. I envisioned house floor joists with two 2x6 flat for each flange, and one 2x6 as the separating web. So long as I ignored the shear at the connections it was a super strong beam. When I asked a structural engineer about it, he pointed out the flaw was in that flange to web connection. It could be made, but would require 16d spikes into the edge of the web ever 3/4". I believe most ordinary 2x6 would split on the dotted line into a pair of useless 1x6. Or else making a perfectly fitting glue joint and using a $25 a quart structural adhesive I've changed my house design, but I still have all those 2x6 on hand... It doesn't take a strong filler to hold the webs apart. Foam or honeycomb in aircraft floors and wings does well. Might not do so well if the flanges were 1/4" steel that would push a lot harder than .032 aluminum. Helium is hard to hold in without very good welded seams and then it leaks easily. Its often used to test welded seams in electronic components. Even if helium weighed nothing, it would only reduce the vehicle weight by the volume of air displaced, which in the Airstream walls, isn't much. The simplest concept in doubling frame strength would be to double the frame member thickness, increase the frame member height (both requiring wholesale replacement of the frame and lower skin), or most simple to add another channel the same size as the original to make a box or I beam. Scabbing another piece of the same sized channel to make a box or I beam is the most simple technique. When a bedroom floor moves when I walk across it, it might not like the total weight of the early water bed. I hear they make them lighter these days to solve many of those structural problems. It makes a big difference in the floor load whether the water is 18" or 4" deep. And it makes a big difference to the house floor structure whether the bed sits on four points or is a distributed load. A floor made to minimum HUD specifications can be kind of wimpy. The frame would benefit the most from added material near the middle at the axle(s). There's where the bending moment from distributed or point loads is the greatest. Its like a see-saw. I've never seen one break anywhere but at the pivot. That's because that's where the stresses are the greatest. A trailer frame is a see-saw. Doubling up the frame material out at the back or up close to the hitch isn't quite as an effective use of added material. Trouble with the body of potable water is that we make it less potable by crapping in the woods. Might not need the aluminum box, just a cover to keep the rain off and a sleeping bag, carry it all on our backs, sit on logs (if in a country side that has trees to cut into logs). Been there, tried that (at Uncle's orders, and a little on my own), I think I rather like parking the A/S and being ready for bed or supper in minutes instead of hours. Besides its hard to set up posts on a blacktop Walmart parking lot that might hold up the rain cover. And I don't grow fur on top my head well anymore. Gerald J. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
At 11:46 AM 3/22/01 -0800, Kimm Flatt wrote: .. FRAME: Replace the frame with Titanium. Very strong, extremely light weight. (You'll need to run your drills slower, because of excess heat.) I was (am) under the impression that Airstream frames were built of a stronger steel that most SOBs- I know that drilling my old '75 frame was quite a chore, whereas normal trailers drill fairly easily. IMHO- one of the best frames being built today is the Al-Ko frame, they have a website http://www.al-ko.com but it seems to be down at the moment. This is a galvanized frame with holes cut into the web (thanks, Dr. J), and seems to have a high strength to weight ratio- mI have a hunch that Wally would be using something like this (if not more advance) today. FLOOR: Boeing 777 floors are a carbon fiber top/bottom with an aluminum honey comb inside. A 4x8 sheet is only $800. but it is SO SO light, and virtually unbreakable. A couple of years ago, Shadow Cruise bought a patent for a composite carbon fiber construction method for building TTs- but shortly after that, they went bankrupt. I never did get any specifics about the technique, but it sounded fascinating. Chris Bryant Bryant RV Services DeLand, Florida mailto:[EMAIL PROTECTED] To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
McMaster-Carr (www.mcmaster.com) does show some round rods and flat sheets of titanium. No structural shapes. A 1' long swizzle stick is $22.50. A sheet .032" thick, 1 foot square is $231.71. The cost of a titanium frame probably would pay for the extra fuel to haul a steel frame at least 100,000 miles. Honeycomb or foam core floor would be poor above the radiant tubing. Poor for heat transfer, good structurally. It would be better to have embedded the radiant tubing in the floor deck and have only the top skin above the radiant tubing.. E.g. separate the two skins with foam or honeycomb blocks and run the tubing amongst those blocks. I think probably it would be most practical to make a lower skin of aluminum sheet or thin plywood, and the spacer of foam or honeycomb. There was an article in "ham radio" magazine (want a reference for interlibrary loan?) in the late 60s about using aluminum sheet, honeycomb, and a suitable epoxy to make a parabolic antenna dish. That same technique could still apply to making an RV floor. The Aircraft Spruce Company catalog offers materials and some instructions as well as detailed instruction books on precisely such construction techniques. Their catalog is free for the asking. Don't dream aircraft techniques without it. You can ask for it on their web page http://www.aircraft-spruce.com/. There are a lot of home built aircraft that have been built using foam or honeycomb covered with aluminum or fiberglass. Its a good technique and if the skin is fiberglass can be any conceivable shape. I doubt a radiant heat foam core floor can be built for the cost of 3/4" exterior grade plywood, but it sure could be a whole lot lighter and as strong. As long as we are tossing about wild ideas... Why not a two layered water bed. Start with one chamber (the top one) filled with clean water. Use that for domestic water (cooking, washing, drinking, etc) and dedicate the other chamber to gray water. Except for water spilled and drunk, the total water volume could be close to the same. One would have to monitor the clean water for leaks, and sanitary standards would require the separating membrane be double walled for safety. It probably would be practical to use two separate bags to get the double walled separation. Then monitoring the space between them for water would detect leaks in either bag. If the trip was long, might need to have a third air bag on top for extended sleeping comfort. Gerald J. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Bob, Interestingly, I read a fella's web site a year or 2 ago where he replaced his (non-A/S) trailer's furnace with a regular RV water heater, a pump, and an automotive heater core with a fan. He claimed that he used less gas and less electricity than he did with his conventional furnace. He also claimed that he got better heat distribution, even though he had only the single heat source; the heater core w/fan, mounted in a cardboard box. (IIRC) He was camped on the West Coast where there were steady, cold winds, temps down to about freezing, maybe a bit below. If you're going to replace the axles, look at going with Air Ride units. You don't need to reinvent the wheel, either, an outfit sells them complete. The ones they sell are meant to replace the Dexter, et. al. axles with leaf springs, but could no doubt be adapated to an A/S. This setup would also allow you to change the ride height of the trailer for serious back-country travel vs. expressway. They also sell an air hitch, but I think only for 5'ers. There IS an air-ride hitch for TTs, however. Jim bob basques wrote: - I'm still of the mind to build my own flooring system with integrated heating tubes for radiant heating. OR there is a factory up here that makes plastic to replace wood. Decking, floors, whatever. It is stronger than wood, water proof (won't take on or soak up water at all) and won't mildew. Custom order to any size, so your floor could be 1 piece. And for cutouts and such, it 'works' just like wood. AXLES: I get my torsion axles in Phoenix or Sacramento. They come in #7,500 and #10,000 capacities each, and varied degrease of drop (straight, 2" or 4") and custom length, so you could raise or lower the ride height of your trailer too. 2@10k = 20,000 lb trailer. (double what most 29' are) Might have problems finding cheap 5K rated tires (at least of the size normally seen on trailers), better just go with three 7.5k axles and 3.7k rated tires. - -- http://www.oldengine.org/members/jdunmyer [EMAIL PROTECTED] lower SE Michigan, USA mailto:[EMAIL PROTECTED] To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Sarah,
There isn't enough air volume between the inner and outer skins to be
worth replacing with helium.
Also, I've seen Insulated Glass (IE: Thermopane (tm, Libbey-Owens-Ford))
manufactured when I worked in a glass plant. Dunno about anyone elses,
but ours had plain ol' AIR between the panes. The spacers are a hollow
aluminum extrusion that's filled with a dessicant at assembly. This
sucks the water out of the air to prevent fogging. Fogging of an older
IG unit is caused by the seal failing; the seal is a 2-part goop that is
squirted around the edge of the assembly, covering the spacer and
sealing it all up. The stuff we used was then cooked in an oven to set
it up.
Another common myth is that IG units have a vacuum between the panes
("lites" is the term in the glass industry). You cannot have a vacuum
between the lites because they'd collapse, they're just not that strong.
Figure out the area of a closeby window of any size like your patio door
unit. Those are usually either 34" X 76" or 46" X 76", so there's LOTS
of square inches there. Atmospheric pressure is just under 15
pounds/square inch, so figure a vacuum of half that, or 7 PSI. Multiply
times the area of your patio door and you'll see what I mean.
Just an FYI:
Jim
Sarah Calhoun wrote:
-! How about filling the space between the skins with HELIUM? They
put argon gas in double-pane window assemblies for insulation; could helium
serve a similar purpose? Or is it too small and leaks out? Yeah, I suppose if
they could make skins that would never loosen around the rivets or leak, that
would be something in itself.
--
http://www.oldengine.org/members/jdunmyer
[EMAIL PROTECTED]
lower SE Michigan, USA
mailto:[EMAIL PROTECTED]
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[VAC] Re: Structural loading / aircraft flooring
Walmarts built in recent times generally have rest rooms near the front door. Older ones hide it half a mile to the rear accessible through the lay away department. Access even then is often better and the cleanliness better than the average gas station. The hair loss appears to be hereditary, came from my mother's grandfather. It started before the last session of graduate school. One could easily scab either steel or titanium, C channels back to back. Welding would probably work, though I don't know anything about welding titanium. My handy Marks Mechanical Engineer's Handbook doesn't say anything about fabricating titanium. It does say that its sometimes better than stainless steel for withstanding corrosion, and can give the same strength as steel while weighing only 60% as much and that its among the most abundant metals in the earth's crust, though its expensive to extract these days. Probably one could achieve a beneficial increase in frame strength by bolting the two channels back to back. Bolts in shear are strong, often stronger than the holes they are in. I'd use grade 5 or grade 8 bolts, probably at least 3/8" diameter in close fitting holes. I'd drill the holes with the scab in place so there'd be no need to drill the oversize to allow for errors in drill positioning. If scabbed back to back with adequate bolts, the two pieces will add their strengths. If one tried to stuff one channel inside the other without as much bolting through the web as for back to back, the inner channel may not begin to take load until the outer channel has bent. Fitting them tightly otherwise could be a problem. I prefer the back to back because that makes the combination into a better beam. One of the bad features of any channel is that it tends to twist when loaded as a beam. Further that loading should be not on the flange, but about one flange width beyond the web to prevent twisting. The advantage of channel over rectangular tube or I beam is that flat face for some mountings and the fact that its a lot cheaper to make than hollow welded or seamless tube. If the floor cross pieces are attached to each side of the original channel of the frame, then sticking in pieces of scab wouldn't be especially effective. The scab needs to be continuous past the axle to be of most benefit. It could go below the existing frame member and be angled to go below the axle but would then be below the belly skin and make the underside look like a SOB. Many SOB do have their frame exposed, and then the stairway at the entry is more like a ladder. Helium could displace fiberglass and mice, but would not be as effective at insulation. Fiberglass is not effective at insulation itself, but its effective in a wall space because it stops air motion. Helium without fiberglass would be warmed on the warm wall, would rise then the circulation would circle to the cooler wall where it would be cooled and it would sink. Air does the same thing without fiberglass to hold it in pockets. Vacuum does better as an insulator and takes no better sealing than helium containment. Gerald J. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
At 07:59 PM 3/22/2001 -0500, Jim Dunmyer wrote: Sarah, There isn't enough air volume between the inner and outer skins to be worth replacing with helium. Helium? Why would you want to put helium in there? Certainly not in a thermo-pane window. I'd think He would make convection even worse than air, and would also conduct heat better than air (which is an excellent insulator, if you can eliminate convection). Also, glass won't hold He very long - it leaks out, eventually (as in a He-Ne laser). - Dick (5368) To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Extrusion Titanium can be gotten as an extrusion. So, I'd either match the original frame and have the extra strength, or downsize it 50% and gain the space. C chanel most definately, or S. Webs can be either rivited or fastened with bolt type fasteners. .003 undersized holes gives a perfect crush fit, or 'worked' hole. Helps prevent cracks at the hole. IT is excellent against corrosion. Fastening the floor every 1.5 inches, with 1/4 inch fasteners, would make a structure so strong that it wouldn't warp, separate, twist or bend; I bet. I'd send pics of a monsterous floor done this way, but I'd be in heaps of trouble. The webs can have numerous holes in them for pipeing and whatever, without loosing strength. What about a blown in styerfoam for insulation in the walls? Easily conformable, easy to modify, and light weight. I prefer the s--tter in the trailer versus some public facilities. Glass; Regular glass, R-12 rating or higher, and automatic tinting like visionary glasses. (I forget what that is called.) --== KIMM ==-- Who really doesn't think this is all that outlandish. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Well at least someone is paying attention here. I guess there are people around who don't automatically think "balloon" when they hear the word helium. I hope you're taking notes on all this, Tuna, because you know we're expecting some pretty fancy stuff out of that rebuilt frame of yours! --Sarah Robert C Townsend wrote: Uh... i believe the helium is intended to provide 'lift', to reduce the weight on the suspension ;-). Tuna To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
So what is the source of this titanium extrusion material, if it's not a state secret? Kimm Flatt wrote: Extrusion Titanium can be gotten as an extrusion. So, I'd either match the original frame and have the extra strength, or downsize it 50% and gain the space. C chanel most definately, or S. Webs can be either rivited or fastened with bolt type fasteners. .003 undersized holes gives a perfect crush fit, or 'worked' hole. Helps prevent cracks at the hole. IT is excellent against corrosion. Fastening the floor every 1.5 inches, with 1/4 inch fasteners, would make a structure so strong that it wouldn't warp, separate, twist or bend; I bet. I'd send pics of a monsterous floor done this way, but I'd be in heaps of trouble. The webs can have numerous holes in them for pipeing and whatever, without loosing strength. What about a blown in styerfoam for insulation in the walls? Easily conformable, easy to modify, and light weight. I prefer the s--tter in the trailer versus some public facilities. Glass; Regular glass, R-12 rating or higher, and automatic tinting like visionary glasses. (I forget what that is called.) --== KIMM ==-- Who really doesn't think this is all that outlandish. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
I see many grades of titanium alloy from 14,000 psi yield strength to 160,000. The size reduction should depend on the alloy chosen. I'd prefer a box or rectangle or I to the channel, it will be stronger for the amount of material and will not have the tendency to twist under load. The webs do tend to have excess material and so can be drilled a lot for lightening. Foam in the walls works but makes wiring changes difficult. Fiberglass in the walls works too. Some public facilities and their users should be buried in the nearest landfill. I don't like the idea of automatic tinting glass. If I could control it, I might accept it. On a chilly day I don't want the glass to tint up and hold out the sun that I was planning to use for part of my heat. On a hot summer day, yes it would be nice to keep sun and subsequent heat out. Maybe some blown in foam beads ala Zomeworks between double paned glass would be handy. R-12 windows are a gleam, that I don't think have been achieved in any practical arrangement yet. Maybe with quadruple panes in vinyl clad foam sash. Otherwise the wooden sash isn't that good. And aluminum sash is about the same as an open window. The aluminum wall studs in the Airstream are not a help to its insulation. But they are far better for longevity than the wood the competition uses and used in the days of our vintage Airstreams. Gerald J. To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
[VAC] Re: Structural loading / aircraft flooring
Kimm, please tell us about your Airstream,model, year, etc, and what you plan to do to get it ready for the big adventure. Bill Scott Charter Member and Membership Chairman Washington DC Unit, WBCCI #3221 Our Homepage; http://www.servintfree.net/wbcci-dc/ To unsubscribe or to change to a daily Digest, please go to http://www.airstream.net/vaclist/listoffice.html If replying back to this message, please delete all the unnecessary original text from your reply.
