X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-ma03.mx.aol.com ([64.12.206.41] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with ESMTP id 5268107 for flyrotary@lancaironline.net; Fri, 02 Dec 2011 13:21:22 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.206.41; envelope-from=CozyGirrrl@aol.com Received: from mtaomg-mb02.r1000.mx.aol.com (mtaomg-mb02.r1000.mx.aol.com [172.29.41.73]) by imr-ma03.mx.aol.com (8.14.1/8.14.1) with ESMTP id pB2IKfDf030859 for ; Fri, 2 Dec 2011 13:20:41 -0500 Received: from core-dsc002c.r1000.mail.aol.com (core-dsc002.r1000.mail.aol.com [172.29.253.69]) by mtaomg-mb02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 92ECCE000096 for ; Fri, 2 Dec 2011 13:20:41 -0500 (EST) From: CozyGirrrl@aol.com Message-ID: <1ddf0.20618834.3c0a70f9@aol.com> Date: Fri, 2 Dec 2011 13:20:41 -0500 (EST) Subject: Re: [FlyRotary] Re: Steve Brooks Cozy To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_1ddf0.20618834.3c0a70f9_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [70.242.146.38] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1322850041; bh=NfP4OpPruW+hfp2G2W1wPrqf8T+wgqsWqHI9YepI34o=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=o17J+0nXDm1tmf09VGXSRM047bAXCE1khDFAh4cP4m8ypGyRAttWd4PNkQjaqTkCe PCrOs+FaGKaQnfiSXHePHhUxwZdx3pj4Ua/eHKAmvDLLk4Igi4o8wojenV+uRahXMt N0lDcQ8eDLTngUBiPGbujlKUjrWSxDr8Mgg/b49g= X-AOL-SCOLL-SCORE: 0:2:466267904:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29494ed916f97c9c --part1_1ddf0.20618834.3c0a70f9_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit We just purchased to 30 gallon rotomolded tanks for our RV project, they are 1/4-3/8" wall and quite heavy. Chrissi & Randi _www.CozyGirrrl.com_ (http://www.cozygirrrl.com/) CG Products, Custom Aircraft Hardware Chairwomen, Sun-N-Fun Engine Workshop In a message dated 12/2/2011 11:47:09 A.M. Central Standard Time, echristley@att.net writes: My research lead me to "roto molding". You build a cheap, sheet metal form, that the molder fills with a calculated amount of powdered plastic, and then puts on the end of a rotating arm that goes in an oven. As the form is heated, it is rotated on all axis. I was willing to make the form, but couldn't find a molder. I ended up just welding the seems to make a tank. The number of Dyke Delta rotary builders is an even smaller subset than the Cozy rotary builders 8*). I used .050" for my tank since it has to actually hold the weight of the fuel. If I were going to be burying it in a wing where it would be supported on all sides, I would have used the thinnest material I could have reasonably worked with (.020" maybe?) Chad Robinson wrote: > I looked into what it would take to get these blow-molded, maybe with a > group buy from other builders. The complication is that the strakes are > a lifting body and are structural. The ribs are part of that structure. > They also serve as anti-slosh plates inside the tanks. Any solution > needs to include both of them. It's do-able: you just need a tank > blow-molded for each of the individual tank sections, then you > plastic-weld them together around the strake ribs. But it means you need > a bunch of molds... > > At the time, I had already bought a batch of ProSeal, so I went with > that. It looks pretty good - guess we'll see how it holds up (it sure > wasn't cheap.) So I never finished the research. > > The issue is there's a large group of rotary builders but a smaller > group of Cozy MKIV builders. Cozy builders with aircraft engines don't > need to deal with this - so it's an even smaller group. I'd be surprised > if you could get even 25 people together on an order, and you'd need > several hundred to make it economical to build the blow-molds. > > One alternate plan I had tinkered with involved making a very > rudimentary mold in the shop, then heating a standard 5-gallon red > plastic gas can and using compressed air to "inflate/reshape" it. A very > thin wall is just fine (preferable, even). The structure comes from the > Cozy's strake structure - you're just making a liner. But it's a lot of > work and finicky to get it right. I also looked into bladders, but there > are maintenance and reliability concerns with them filling/deflating > properly in odd-shaped spaces. > > Regards, > Chad > > On 12/2/2011 10:48 AM, Ernest Christley wrote: >> I reluctantly made a decision to not trust sealing a gas tank to any >> petrochemical that is shipped to me in a liquid >> form. You never know what all those petrochemical engineers in >> Congress will decide mandate to be put into our fuel >> next. So I welded a fuel tank and glassed that into the place that >> was designed for a fiberglass tank. I would have >> preferred buying a premade poly-ethylene or aluminum racing tank, but >> I couldn't find one that even came close to fitting. >> >> Aren't the Cozy tanks just big cubes sitting inside the wing roots? >> Would it be safer, and possibly easier, to buy a >> tank, sit it in the, and glass it into place? >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --part1_1ddf0.20618834.3c0a70f9_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
We just purchased to 30 gallon rotomolded tanks for our RV project, th= ey=20 are 1/4-3/8" wall and quite heavy.
 
Chrissi &=20 Randi
www.CozyGirrrl.com
C= G=20 Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop=
 
In a message dated 12/2/2011 11:47:09 A.M. Central Standard Time,=20 echristley@att.net writes:
= My=20 research lead me to "roto molding".  You build a cheap, sheet metal = form,=20 that the molder fills with a calculated
amount of powdered plastic, an= d=20 then puts on the end of a rotating arm that goes in an oven.  As the= form=20 is heated, it
is rotated on all axis.

I was willing to make the= =20 form, but couldn't find a molder.  I ended up just welding the seems= to=20 make a tank.  The
number of Dyke Delta rotary builders is an even= =20 smaller subset than the Cozy rotary builders 8*).  I used .050" for= =20 my
tank since it has to actually hold the weight of the fuel.  If= I=20 were going to be burying it in a wing where it would be
supported on a= ll=20 sides, I would have used the thinnest material I could have reasonably wo= rked=20 with (.020" maybe?)

Chad Robinson wrote:
> I looked into wha= t it=20 would take to get these blow-molded, maybe with a
> group buy from = other=20 builders. The complication is that the strakes are
> a lifting body= and=20 are structural. The ribs are part of that structure.
> They also se= rve=20 as anti-slosh plates inside the tanks. Any solution
> needs to incl= ude=20 both of them. It's do-able: you just need a tank
> blow-molded for = each=20 of the individual tank sections, then you
> plastic-weld them toget= her=20 around the strake ribs. But it means you need
> a bunch of=20 molds...
>
> At the time, I had already bought a batch of=20 ProSeal, so I went with
> that. It looks pretty good - guess we'll = see=20 how it holds up (it sure
> wasn't cheap.) So I never finished the= =20 research.
>
> The issue is there's a large group of rotary= =20 builders but a smaller
> group of Cozy MKIV builders. Cozy builders= with=20 aircraft engines don't
> need to deal with this - so it's an even= =20 smaller group. I'd be surprised
> if you could get even 25 people= =20 together on an order, and you'd need
> several hundred to make it= =20 economical to build the blow-molds.
>
> One alternate plan I= had=20 tinkered with involved making a very
> rudimentary mold in the shop= ,=20 then heating a standard 5-gallon red
> plastic gas can and using=20 compressed air to "inflate/reshape" it. A very
> thin wall is just = fine=20 (preferable, even). The structure comes from the
> Cozy's strake=20 structure - you're just making a liner. But it's a lot of
> work an= d=20 finicky to get it right. I also looked into bladders, but there
> a= re=20 maintenance and reliability concerns with them filling/deflating
>= =20 properly in odd-shaped spaces.
>
> Regards,
> Chad
= >=20
> On 12/2/2011 10:48 AM, Ernest Christley wrote:
>> I=20 reluctantly made a decision to not trust sealing a gas tank to any
>= ;>=20 petrochemical that is shipped to me in a liquid
>> form.  Y= ou=20 never know what all those petrochemical engineers in
>> Congress= will=20 decide mandate to be put into our fuel
>> next.  So I welde= d a=20 fuel tank and glassed that into the place that
>> was designed f= or a=20 fiberglass tank.  I would have
>> preferred buying a premad= e=20 poly-ethylene or aluminum racing tank, but
>> I couldn't find on= e=20 that even came close to fitting.
>>
>> Aren't the Cozy = tanks=20 just big cubes sitting inside the wing roots?
>> Would it be sa= fer,=20 and possibly easier, to buy a
>> tank, sit it in the, and glass = it=20 into place?
>>
>
>
> --
> Homepage:&n= bsp;=20 http://www.flyrotary.com/
> Archive and UnSub: 
>=20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
>=20


--
Homepage:  http://www.flyrotary.com/
Archive an= d=20 UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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