Bill,
My KR2S is made mostly from the Dow type of foam you have in your attachment, 2 pound per cubic foot density. It was pretty easy to find at the local Home Depot/Lowes, etc, at least it is in the Mid West. I concur with Colin's comments on the use of this type of foam. I did do a microslurry seal on my layups, but it did not take much due to the closed cells. Exception was the gas tank where I did use urethane foam because it won't dissolve in fuel. It was definitely harder to work with. I did not hot wire the Styrofoam, I used a wood plane to get the Styrofoam close to the template, then sanded to finish using an 8' long sanding board. Rob Schmitt N1852Z www.robert7721.com -----Original Message----- From: Bill Masquelier via KRnet <krnet at list.krnet.org> To: KR List <krnet at list.krnet.org> Cc: Bill Masquelier <billmasq at hotmail.com> Sent: Sat, Aug 22, 2015 10:29 pm Subject: Re: KR> Foam, peel ply and tank vents... Colin I was avoiding extruded polystyrene since I couldn't find it here in Southern California but since you brought it up again I have found that it is available near here (near French Valley) in Temecula at Whitecaps: http://www.whitecap.com/shop/wc/building-materials/insulation-materials/extruded-polystyrene-insulation so if anyone else here in SoCal needs it it does exist!! Thanks Colin and best on your trip over the Bearing Straits and beyond :) BillM > To: krnet at list.krnet.org > Date: Sat, 22 Aug 2015 23:23:19 +0100 > Subject: KR> Foam, peel ply and tank vents... > From: krnet at list.krnet.org > CC: colinhales at hotmail.com > > Several thoughts gents, > Bill, high there, I'll write soon, but continuing, unless you want to use wing tanks, remember that Styrofoam is a much better product than Urethane foam which I would NEVER ever use. > It crushes and has no rebound unlike polystyrene foams, so if you drop something on your wing skin or someone kneels on it, the Urethane foam crushes and a void is left behind the glass as it pulls away from the glass skin. Styrofoam has a bit of bounce and give and this doesn't happen. Also Urethane is open cell and you have to add the heavy layer of Micro balloon slurry to seal it before adding the glass cloth and trying to wet it out. > If you want to still use Urethane foam, you can now get a closed cell type. Any open cell foam can and will absorb water over time and you never know about it. Even white polystyrene foam is not water tight enough and water gets between the molecules over time, unless it is well sealed. > So personally open cell Urethane foam is just a bad idea all round. > I've squeezed water out of Urethane foam on a hovercraft, if you get water on your plane with open Urethane foam, it goes in and you will never get it back out. > If you want to use stub wing tanks, and have the outer panels dry, then by all means use Urethane foam for the stub wings but use Styrofoam for the outer wing panels. > Here is an article of other types of Styrofoam. The don't like the standard blue foam much but they are hot wiring it. We are not. > https://www.flyingfoam.com/content/why-we-hate-blue-foam > > A typical good supplier of blue foam I would say is, > http://building.dow.com/en-us/products/styrofoam-brand-residing-board-us-only/?sc_itemid=320ebb4f-f0ab-47e7-a5b6-334429f8dec8 > Next, peel ply. > A good cheap source of peel ply is called 'Ceconite', you know the stuff they stick on fabric aircraft? Go grab a load of off cuts from a fabric shop or buy some, its as good as the peel ply you can buy, no silicones obviously, and it comes in 6 foot wide strips in case you want to cover large areas. It comes in different grades of light or heavy that will give you different surface textures depending if you want to add on to the glass or simply have a smooth surface ready for applying fillers and top coat paints. > Fuel, > As for fuel sitting in vent pipes. If you can see the fuel sits in the pipe or presume it would do in the dip, that is fine . The air will bypass the fuel so don't worry about that, there is 'little' to 'no' head of pressure in the pipe, any slight difference in pressure will move the fuel along. My only comment on this is that you better make sure the vent pipe you are using or going to use is happy to have avgas or mogas or regular gasoline, whatever you intend to use sitting in it for long periods of time. Some nylon pipes go brittle when immersed in fuel for long periods. Just food for thought. > Sorry I'm going to miss the Kr gathering, I went through Mc.Minnville a week or two ago on my way up to Alaska. It is a brill place to visit, town is lovely, the puce Goose and the rest of the Museum is top rate and Graham, Northwest Air Repair is a great host, so please pass on my regards. > I'm now in Anchorage, eyeing up the Russians and seeing what can be done to continue. > Cheers Colin. > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options _______________________________________________ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
