"Brian Whatcott" wrote in message
news
On Tue, 27 Nov 2007 20:54:32 -0700, "Bob La Londe"
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

On Sun, 9 Dec 2007 19:16:34 -0700, "Bob La Londe"
wrote:

....
Uh-oh: you said "aluminum boat" and "MIG welder" really, really,
casually.


... I'm looking at a Hobart Ironman 250. I already got one of
those cheap ones.....
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....

5th - There is no 5th item

Bob La Londe

This seems like a plan to me: the story I hear quite often is that
the hot puddle will drop out given half a chance on thin stock.

A particular optical filter is said to be a big help in visualizing
the puddle's state.

Good luck!

Brian W

On Mon, 10 Dec 2007 02:38:44 GMT, Brian Whatcott
wrote:

On Sun, 9 Dec 2007 19:16:34 -0700, "Bob La Londe"
wrote:

...
Uh-oh: you said "aluminum boat" and "MIG welder" really, really,
casually.


... I'm looking at a Hobart Ironman 250. I already got one of
those cheap ones.....
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....

5th - There is no 5th item

Bob La Londe

This seems like a plan to me: the story I hear quite often is that
the hot puddle will drop out given half a chance on thin stock.

A particular optical filter is said to be a big help in visualizing
the puddle's state.

THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?

Casady

Jeff Burke wrote:

On Mon, 10 Dec 2007 03:36:36 GMT, (Richard Casady)
wrote:

On Mon, 10 Dec 2007 02:38:44 GMT, Brian Whatcott
wrote:


On Sun, 9 Dec 2007 19:16:34 -0700, "Bob La Londe"
wrote:

...

Uh-oh: you said "aluminum boat" and "MIG welder" really, really,
casually.


... I'm looking at a Hobart Ironman 250. I already got one of
those cheap ones.....
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....

5th - There is no 5th item

Bob La Londe

This seems like a plan to me: the story I hear quite often is that
the hot puddle will drop out given half a chance on thin stock.

A particular optical filter is said to be a big help in visualizing
the puddle's state.

THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?


Lowest bidder?


not hardly.

Best fastner for the material.

On Mon, 10 Dec 2007 00:14:16 -0600, cavelamb himself
wrote:


THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?


Lowest bidder?


not hardly.

Best fastener for the material.

Rivets were the best fastener for ships until they started welding
plates (then a few Liberty ships sank before the subs got 'em.)

Brian W

On Mon, 10 Dec 2007 20:48:04 GMT, Brian Whatcott
wrote:

On Mon, 10 Dec 2007 00:14:16 -0600, cavelamb himself
wrote:


THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?


Lowest bidder?


not hardly.

Best fastener for the material.

Rivets were the best fastener for ships until they started welding
plates (then a few Liberty ships sank before the subs got 'em.)

Brian W

Most of the high strength aluminum alloys are not weldable.

See Materials specification for 2024 - one of the more commonly used
aircraft alloys:

Welding

Welding may be done by use of resistance welding or inert gas
consumable electrode arc method. However it must be noted that, in
general, welding by any means is NOT recommended for this alloy
because of the degradation of corrosion resistance that occurs as a
result of weld heat. A repeat heat treatment should be done if welded.

Bruce-in-Bangkok
(Note:remove underscores
from address for reply)

On Tue, 11 Dec 2007 16:58:38 +0700, Bruce in Bangkok
wrote:


Rivets were the best fastener for ships until they started welding
plates (then a few Liberty ships sank before the subs got 'em.)

Brian W

Most of the high strength aluminum alloys are not weldable.

See Materials specification for 2024

Bruce-in-Bangkok

I marvel that people thinking about aluminum sheet invariably think of
2024. There are stronger materials now available, but weaker
materials are often useful. But one other factor mitigating against
welding is the top coat of soft aluminum which helps the sheet resist
corrosion.

Brian W

On Tue, 11 Dec 2007 16:58:38 +0700, Bruce in Bangkok
wrote:

THere have been at least a million aluminum airplanes produced. All
were riveted. Wonder why?


Lowest bidder?


not hardly.

Best fastener for the material.

Rivets were the best fastener for ships until they started welding
plates (then a few Liberty ships sank before the subs got 'em.)

Brian W

Most of the high strength aluminum alloys are not weldable.

Yes, of course. There are weldable alloys that make a very nice boat
and they are easily weldable if the plates are thick enough. Rozema in
Seattle makes a nice forty foot power boat. Yacht or oil skimmer, same
fittings and workmanship. The same good cabinet latches are on the
workboat. There are otters living under the building and you can watch
them from the breakroom.

Casady

For boatbuilding, you will want to use the 5000 and 6000 series alloys. See
Pollard's book, Boatbuilding with Aluminum
http://www.amazon.com/Boatbuilding-A.../dp/0070504261
.. NEVER use aircraft or other alloys, especially for use in salt water.

These alloys, down to about 3/16 thickness, can be welded. 1/8 is trickier,
and lighter gauge requires very specialized knowledge, experience, and
equipment, generally not appropriate for small-scale boatbuilding.


See Materials specification for 2024 - one of the more commonly used
aircraft alloys:

Bob La Londe wrote:

"Brian Whatcott" wrote in message
news
On Tue, 27 Nov 2007 20:54:32 -0700, "Bob La Londe"
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.



Trust me, you can't really push aluminum well enough to weld a decent
seam. I have the Ironman210, and even with the teflon liner, it balls
and birdsnests easily unless the gun is straight out from the welder.
Even then, it'll only skip once, and then you gotta get out the cutters.

Spoolgun is the way to go.

I don't care what they told you.

--
“TANSTAAFL”
__________________________________________________ __________________________

America: Ironically, the safest place to be anti-American.
__________________________________________________ __________________________
"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3