Aluminum Designs

On Thu, 29 Nov 2007 19:18:59 -0600, Brian Whatcott
<betwys1.DeleteThis@sbcglobal.net> wrote:

>Uh-oh: you said "aluminum boat" and "MIG welder" really, really,
>casually.
>Tell me you have MIG welded aluminum before - that you have the right
>mask screen, that you can not only stitch thick aluminum castings
>together, but you have seamed sheet as well....

Place I do my boating has lots of fifty year old aluminum boats, none
of which have ever had paint or maintainance of any kind. All are
riveted. Grumman canoes are riveted and they get bounced off the rocks
regularly, if they are used in white water. I don't think welding is
really suitable for anything under forty feet. Metal is too thin. Note
that all those airliners are riveted.

Casady
 >> Stay informed about: Aluminum Designs 

Any plywood design can be modified for aluminum. You need a design that
will be OK with some weight, as 1/8 aluminum weighs about the same as 3/4
ply. even 1/8 can be a bear to work with, I wouldn't be optimistic for the
chances of success with any thing lighter, unless you have a LOT of
experience.

I'm not sure what you mean by "semi tunnel" but I built an Atkin Rescue
Minor with fully protected prop and rudder. Or you can modify the transom
of any skiff to give you a bit of a tunnel effect with an outboard - at the
loss of some "lift".

Can you provide a link to pictures of the kind of boat (in wood or glass)
you are thinking of?

Sal's Dad


"Bob La Londe" <nospam RemoveThis @nospam.no> wrote in message
news:474cdab9$0$26010$88260bb3@free.teranews.com...
> Anybody know of any all aluminum designs (no wood composite or sandwich)
> available for sale for a shallow draft semi tunnel for river running? I
> can modify if need be, but I ain't gonna put no wood in it if I build it.
> Well, maybe for totally non structural stuff, but I doubt it.
>
> I'm trying to talk Mrs Santa into getting me a 60% duty cycle MIG w/ spool
> gun for Christmas.
>
>
> --
> Bob La Londe
> Fishing Arizona & The Colorado River
> Fishing Forums & Contests
> http://www.YumaBassMan.com
>
>
 >> Stay informed about: Aluminum Designs 

On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
<SalsDad.TakeThisOut@nospam--betts-hyphen-orourke.net> wrote:

>as 1/8 aluminum weighs about the same as 3/4
>ply.

If you divide 2.7, the density of aluminum, by 6, you get .45. I
thought plywood was heavier than that.

Casady
 >> Stay informed about: Aluminum Designs 

Richard Casady wrote:
> On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
> <SalsDad RemoveThis @nospam--betts-hyphen-orourke.net> wrote:
>
>
>>as 1/8 aluminum weighs about the same as 3/4
>>ply.
>
>
> If you divide 2.7, the density of aluminum, by 6, you get .45. I
> thought plywood was heavier than that.
>
> Casady


plywood floats.

Aluminum don't.

What am I missing here?
 >> Stay informed about: Aluminum Designs 

On Thu, 06 Dec 2007 23:22:23 GMT, richardcasady RemoveThis @earthlink.net (Richard
Casady) wrote:

>On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
><SalsDad RemoveThis @nospam--betts-hyphen-orourke.net> wrote:
>
>>as 1/8 aluminum weighs about the same as 3/4
>>ply.
>
>If you divide 2.7, the density of aluminum, by 6, you get .45. I
>thought plywood was heavier than that.
>
>Casady

It may be.
Black ash 0.54
Birch 0.67
red cedar 0.38 (!!)
see the table here...
http://woodsgood.ca/woodDensity.htm

Regards

Brian W
 >> Stay informed about: Aluminum Designs 

On Thu, 06 Dec 2007 18:32:10 -0600, cavelamb himself
<cavelamb.DeleteThis@Xearthlink.net> wrote:

>Richard Casady wrote:
>> On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
>> <SalsDad.DeleteThis@nospam--betts-hyphen-orourke.net> wrote:
>>
>>
>>>as 1/8 aluminum weighs about the same as 3/4
>>>ply.
>>
>>
>> If you divide 2.7, the density of aluminum, by 6, you get .45. I
>> thought plywood was heavier than that.
>>
>> Casady
>
>
>plywood floats.
>
>Aluminum don't.
>
>What am I missing here?

A clue.

Casady
 >> Stay informed about: Aluminum Designs 

Richard Casady wrote:

> On Thu, 06 Dec 2007 18:32:10 -0600, cavelamb himself
> <cavelamb RemoveThis @Xearthlink.net> wrote:
>
>
>>Richard Casady wrote:
>>
>>>On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
>>><SalsDad RemoveThis @nospam--betts-hyphen-orourke.net> wrote:
>>>
>>>
>>>
>>>>as 1/8 aluminum weighs about the same as 3/4
>>>>ply.
>>>
>>>
>>>If you divide 2.7, the density of aluminum, by 6, you get .45. I
>>>thought plywood was heavier than that.
>>>
>>>Casady
>>
>>
>>plywood floats.
>>
>>Aluminum don't.
>>
>>What am I missing here?
>
>
> A clue.
>
> Casady


I thought most aluminum alloys weighed in at .1 pound per cubic inch.
Except 6061 which is only .09 lbs/cu.in.

Ply was .025 to .033 lbs/cu.in.

So clue me in.
 >> Stay informed about: Aluminum Designs 

On Thu, 06 Dec 2007 19:29:19 -0600, cavelamb himself
<cavelamb.RemoveThis@Xearthlink.net> wrote:

>Richard Casady wrote:
>
>> On Thu, 06 Dec 2007 18:32:10 -0600, cavelamb himself
>> <cavelamb.RemoveThis@Xearthlink.net> wrote:
>>
>>
>>>Richard Casady wrote:
>>>
>>>>On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
>>>><SalsDad.RemoveThis@nospam--betts-hyphen-orourke.net> wrote:
>>>>
>>>>
>>>>
>>>>>as 1/8 aluminum weighs about the same as 3/4
>>>>>ply.
>>>>
>>>>
>>>>If you divide 2.7, the density of aluminum, by 6, you get .45. I
>>>>thought plywood was heavier than that.
>>>>
>>>>Casady
>>>
>>>
>>>plywood floats.
>>>
>>>Aluminum don't.
>>>
>>>What am I missing here?
>>
>>
>> A clue.
>>
>> Casady
>
>
>I thought most aluminum alloys weighed in at .1 pound per cubic inch.
>Except 6061 which is only .09 lbs/cu.in.
>
>Ply was .025 to .033 lbs/cu.in.
>
>So clue me in.

I simply questioned if aluminum was in fact exactly six times as dense
as plywood. That is what you get with sheets six times as thick
weighing the same. That would make the density of plywood .017.lb/cu.
According to you it isn't. I simply opined that most plywood does not
have that particular density. What don't you understand? And I am
sorry about the cheap shot. It isn't really my style. I have the
'calculator that takes no prisoners',HP-48, and it isn't a problem but
it is usual to express wood density as pounds per cubic foot, in the
US, at least. Density figures in general are usually with reference to
the density of water.

Casady
 >> Stay informed about: Aluminum Designs 

Richard Casady wrote:
> On Thu, 06 Dec 2007 19:29:19 -0600, cavelamb himself
> <cavelamb.DeleteThis@Xearthlink.net> wrote:
>
>
>>Richard Casady wrote:
>>
>>
>>>On Thu, 06 Dec 2007 18:32:10 -0600, cavelamb himself
>>><cavelamb.DeleteThis@Xearthlink.net> wrote:
>>>
>>>
>>>
>>>>Richard Casady wrote:
>>>>
>>>>
>>>>>On Wed, 5 Dec 2007 07:41:59 -0500, "Sal's Dad"
>>>>><SalsDad.DeleteThis@nospam--betts-hyphen-orourke.net> wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>as 1/8 aluminum weighs about the same as 3/4
>>>>>>ply.
>>>>>
>>>>>
>>>>>If you divide 2.7, the density of aluminum, by 6, you get .45. I
>>>>>thought plywood was heavier than that.
>>>>>
>>>>>Casady
>>>>
>>>>
>>>>plywood floats.
>>>>
>>>>Aluminum don't.
>>>>
>>>>What am I missing here?
>>>
>>>
>>>A clue.
>>>
>>>Casady
>>
>>
>>I thought most aluminum alloys weighed in at .1 pound per cubic inch.
>>Except 6061 which is only .09 lbs/cu.in.
>>
>>Ply was .025 to .033 lbs/cu.in.
>>
>>So clue me in.
>
>
> I simply questioned if aluminum was in fact exactly six times as dense
> as plywood. That is what you get with sheets six times as thick
> weighing the same. That would make the density of plywood .017.lb/cu.
> According to you it isn't. I simply opined that most plywood does not
> have that particular density. What don't you understand? And I am
> sorry about the cheap shot. It isn't really my style. I have the
> 'calculator that takes no prisoners',HP-48, and it isn't a problem but
> it is usual to express wood density as pounds per cubic foot, in the
> US, at least. Density figures in general are usually with reference to
> the density of water.
>
> Casady


Accepted, thanks.
 >> Stay informed about: Aluminum Designs 

There are lots of sources of materials density out there.

http://www.rfcafe.com/references/general/density_building_materials.htm
shows:

Aluminum at 171 lb/cu ft. Divide by (12* to get approx. 1.78 lb/SF for
0.125 aluminum.
Plywood (5/8 thickness construction grade) is 1.77 lb/SF (or 34 lb/cu ft)

So I stand corrected. 1/8 aluminum weighs about the same as 5/8 construction
grade ply. Maybe, when I calculated this a few years ago, I used a
different grade or species of plywood, or alloy of aluminum - I honestly
don't recall. But either way, it gets you into the ballpark. There are
relatively few elegant small boat designs using material this heavy.

Sal's Dad

--
>
>>as 1/8 aluminum weighs about the same as 3/4
>>ply.
>
> If you divide 2.7, the density of aluminum, by 6, you get .45. I
> thought plywood was heavier than that.
 >> Stay informed about: Aluminum Designs 

On Fri, 7 Dec 2007 15:33:51 -0500, "Sal's Dad"
<SalsDad.DeleteThis@nospam--betts-hyphen-orourke.net> wrote:

>Aluminum at 171 lb/cu ft. Divide by (12* to get approx. 1.78 lb/SF for
>0.125 aluminum.
>Plywood (5/8 thickness construction grade) is 1.77 lb/SF (or 34 lb/cu ft)
>
>So I stand corrected. 1/8 aluminum weighs about the same as 5/8 construction
>grade ply

I thought a figure was a bit high. It is, slightly, but had I known
the difference was a small as it is[I will take your figures] I don't
think I would have bother to post anything. It did smoke out some
interesting figures. Plywood tends to be about as dense as the wood it
is made from, it seems. The texts seem to give the density of woods in
pounds per cubic foot but with a modern calculator[HP48] any and all
units are convenient.

Casady
 >> Stay informed about: Aluminum Designs 

"Brian Whatcott" <betwys1.DeleteThis@sbcglobal.net> wrote in message
news:o1puk3tc67e3obvhn17tpa20ilvifqdnla@4ax.com...
> On Tue, 27 Nov 2007 20:54:32 -0700, "Bob La Londe" <nospam.DeleteThis@nospam.no>
> wrote:
>
>>Anybody know of any all aluminum designs (no wood composite or sandwich)
>>available for sale for a shallow draft semi tunnel for river running? I
>>can
>>modify if need be, but I ain't gonna put no wood in it if I build it.
>>Well,
>>maybe for totally non structural stuff, but I doubt it.
>>
>>I'm trying to talk Mrs Santa into getting me a 60% duty cycle MIG w/ spool
>>gun for Christmas.
>>
>>
>>--
>>Bob La Londe
>
> Uh-oh: you said "aluminum boat" and "MIG welder" really, really,
> casually.


There are some things about mig aluminum welding that a lot of people don't
realize...

1st - Its really hard to do a good job with a cheap welder like the 120V
20amp 10/20% duty cycle things with only two heat ranges like they sell at
Harbor Freight. I'm looking at a Hobart Ironman 250. I already got one of
those cheap ones. Figured I'ld use the push feed gun for steel and a spool
gun for aluminum so I wouldn't ever have to worry about gun/tip
contamination.

2nd - You have to burn some metal to get it dialed in just right. I got
scrap laying around from some other things I can burn up.

3rd - Use a clean stainless brush on all surfaces just before welding to
break up and remove the oxidation. Never use your brushes for aluminum on
ANYTHING else. Brushes are cheap insurance. USE THEM EVERYTIME even if you
brushed it yesterday.

4th - A spool gun is the way to go, but even with a push feed gun its
possible to push aluminum if you swap out the V groove feed wheel for a U
groove feed wheel. The V groove wheels shave the soft aluminum wire causing
it to plug up the feed tube and your gun.

5th - There is no 5th item.

6th - if for ANY REASON the wire doesn't feed STOP. Otherwise you will you
will have a wad of crammed up aluminum wire someplace in your rig.

7th - Practice and warm up for a few minutes on some scrap EVERYTIME before
you start on your cut pieces. (Thats a good idea on steel too.)


> Tell me you have MIG welded aluminum before - that you have the right
> mask screen, that you can not only stitch thick aluminum castings
> together, but you have seamed sheet as well.....

Nope, I'm not super experienced, but I got a pile of scrap aircraft aluminum
to practice on. I've played some with aluminum, and I don't plan on using a
cheap rig. I've used some of the torch alloy stuff too, but its really only
suitable for small work.

I have a variable shade autodarkening mask, and I use it for everything. I
even use it for cutting. I just lighten the shade up.

And worse comes to worse... I can alway learn to install blind rivets.
LOL.


--
Bob La Londe
Fishing Arizona & The Colorado River
Fishing Forums & Contests
http://www.YumaBassMan.com



--
Posted via a free Usenet account from http://www.teranews.com
 >> Stay informed about: Aluminum Designs 

"Sal's Dad" <SalsDad.RemoveThis@nospam--betts-hyphen-orourke.net> wrote in message
news:joqdneGVHrMEAcvanZ2dnUVZ_t2inZ2d@rcn.net...

> I'm not sure what you mean by "semi tunnel" but I built an Atkin Rescue
> Minor with fully protected prop and rudder. Or you can modify the transom
> of any skiff to give you a bit of a tunnel effect with an outboard - at
> the loss of some "lift".

There are some "tunnel" designs for running an outboard a few inches higher
that just have a small tunnel at the rear of the boat. When I was really
reading a lot about boat building a few years ago I recall reading about
some of them.


--
Bob La Londe
Fishing Arizona & The Colorado River
Fishing Forums & Contests
http://www.YumaBassMan.com



--
Posted via a free Usenet account from http://www.teranews.com
 >> Stay informed about: Aluminum Designs