Anybody tried glueing cast aluminum parts together with epoxy?
 

My outboard, 20hp Honda, jumped off my transom yesterday and hit the
pavement at 20-25mph. No critical damage but knocked a gapping hole,
the size of a golf ball, in the cast aluminum lower pan, the one below
the power head, next to the tiller handle. Fortunately, I have the
knocked out piece and it fits back in the hole perfectly. My first
thought was to have it tig welded. But it's in a really tight place
and I doubt I'd get a good weld without removing the pan which means
taking the whole power head off. I could tack weld it but that'd leave
a crack that could leak splashing water, not to mention look kinda bad
(as if it doesn't look bad enough).
So now I'm thinking about just using epoxy to glue it in. Mind you,
it doesn't need to be terribly strong. On the other hand, I don't want
it to fall out by just jostling either.
Anybody ever tried epoxy to glue cast aluminum parts back together?
How well will it hold? And for how long?
Thanks in advance,
Phantman

Anybody tried glueing cast aluminum parts together with epoxy?
 

lid wrote:
My outboard, 20hp Honda, jumped off my transom yesterday and hit the
pavement at 20-25mph. No critical damage but knocked a gapping hole,
the size of a golf ball, in the cast aluminum lower pan, the one below
the power head, next to the tiller handle. Fortunately, I have the
knocked out piece and it fits back in the hole perfectly. My first
thought was to have it tig welded. But it's in a really tight place
and I doubt I'd get a good weld without removing the pan which means
taking the whole power head off. I could tack weld it but that'd leave
a crack that could leak splashing water, not to mention look kinda bad
(as if it doesn't look bad enough).
So now I'm thinking about just using epoxy to glue it in. Mind you,
it doesn't need to be terribly strong. On the other hand, I don't want
it to fall out by just jostling either.
Anybody ever tried epoxy to glue cast aluminum parts back together?
How well will it hold? And for how long?
Thanks in advance,
Phantman

Epoxy won't do it very well, but there are several urethanes and
acrylates which will.

Try www.loctite.com for more. Look at u50fl for a urethane. They have a
50 ml tube and mixing nozzle that might be the right size for what you need.

They have several acrylate type adhesives that work well also, but I
can't come up with any suggestions off the top of my head.


--
“No battle plan survives first contact with the enemy”
Sun Tzu

Anybody tried glueing cast aluminum parts together with epoxy?
 

PhantMan wrote:
Anybody ever tried epoxy to glue cast aluminum parts back together?

dazed and confuzzed wrote:
Try www.loctite.com for more. Look at u50fl for a urethane.

Thanks. Is that a transposition? I found u05fl. Says it can be used on
metal, wood, etc.

They have several acrylate type adhesives that work well also

I went through their selection process (nice website that) and it
pointed me to Depend 330, a no mix adhesive. The tech sheet says
"Technology = Acrylic" and under that it says "Chemical Type =
Urethane methacrylate ester". Soooo.... I guess it's an Acrylate,
huh? (obviously, the tech sheet is beyond me).
Also says it's good to bond metal, wood, ferrite, etc. then goes on to
talk about bond strength of grit blasted mild steel. Didn't mention
cast aluminum but I assume it'll work on that as well.

Anyhow, thanks for pointing me there.

PhantMan

Anybody tried glueing cast aluminum parts together with epoxy?
 

lid wrote:
PhantMan wrote:

Anybody ever tried epoxy to glue cast aluminum parts back together?


dazed and confuzzed wrote:

Try www.loctite.com for more. Look at u50fl for a urethane.


Thanks. Is that a transposition? I found u05fl. Says it can be used on
metal, wood, etc.
Yes, it was a trasposition.


They have several acrylate type adhesives that work well also


I went through their selection process (nice website that) and it
pointed me to Depend 330, a no mix adhesive. The tech sheet says
"Technology = Acrylic" and under that it says "Chemical Type =
Urethane methacrylate ester". Soooo.... I guess it's an Acrylate,
huh?
Yep

(obviously, the tech sheet is beyond me).
Also says it's good to bond metal, wood, ferrite, etc. then goes on to
talk about bond strength of grit blasted mild steel. Didn't mention
cast aluminum but I assume it'll work on that as well.

Keep looking. You'll find some that are excellent on aluminum.

Anyhow, thanks for pointing me there.

PhantMan



--
“No battle plan survives first contact with the enemy”
Sun Tzu

Anybody tried glueing cast aluminum parts together with epoxy?
 

Your simplest solution would be to grind a moderate bevel on the loose
piece, get it welded to the extent possible, and then caulk the whole seam
with 5200. Don't go hi tech. - Bill
wrote in message
...
My outboard, 20hp Honda, jumped off my transom yesterday and hit the
pavement at 20-25mph. No critical damage but knocked a gapping hole,
the size of a golf ball, in the cast aluminum lower pan, the one below
the power head, next to the tiller handle. Fortunately, I have the
knocked out piece and it fits back in the hole perfectly. My first
thought was to have it tig welded. But it's in a really tight place
and I doubt I'd get a good weld without removing the pan which means
taking the whole power head off. I could tack weld it but that'd leave
a crack that could leak splashing water, not to mention look kinda bad
(as if it doesn't look bad enough).
So now I'm thinking about just using epoxy to glue it in. Mind you,
it doesn't need to be terribly strong. On the other hand, I don't want
it to fall out by just jostling either.
Anybody ever tried epoxy to glue cast aluminum parts back together?
How well will it hold? And for how long?
Thanks in advance,
Phantman

Anybody tried glueing cast aluminum parts together with epoxy?
 

"Bill Kreamer" wrote:
Your simplest solution would be to grind a moderate bevel on the loose
piece

Actually, all the jagged edges match up perfectly and the piece fits
back together like a jig saw puzzle. Held in place, you can barely see
the seam where it fits together. I was thinking it'd be better to glue
it back just the way it is. Am I wrong for a reason I'm unaware?

get it welded to the extent possible, and then caulk the whole seam
with 5200.

In fact, I'd received that very advice at the coffee shop this
morning. Except in reverse order. Stick it together with 5200 (I was
told it's a Urethane based product) to bond and seal it, then
tack/spot weld it where possible for added strength.

Don't go hi tech

..... uh.... I dunno Bill, around here, 3M 5200 IS high tech lol!

Thanks :-)

PhantMan

Anybody tried glueing cast aluminum parts together with epoxy?
 

dazed and confuzzed wrote:
Try www.loctite.com for more. Look at u50fl for a urethane.


D&C,
What's your opinion of 3M's 5200 for this? (I already have a tube of
it).

PhantMan

Anybody tried glueing cast aluminum parts together with epoxy?
 

On Wed, 12 Oct 2005 20:04:34 -0500, lid wrote:

My outboard, 20hp Honda, jumped off my transom yesterday and hit the
pavement at 20-25mph. No critical damage but knocked a gapping hole,
the size of a golf ball, in the cast aluminum lower pan, the one below
the power head, next to the tiller handle. Fortunately, I have the
knocked out piece and it fits back in the hole perfectly. My first
thought was to have it tig welded. But it's in a really tight place
and I doubt I'd get a good weld without removing the pan which means
taking the whole power head off. I could tack weld it but that'd leave
a crack that could leak splashing water, not to mention look kinda bad
(as if it doesn't look bad enough).
So now I'm thinking about just using epoxy to glue it in.

Check out JB Weld. The stuff is absolutely phenominal. I've heard of
people bonding pieces of engine block back on with it and running the
engine for years.

Corky Scott

Anybody tried glueing cast aluminum parts together with epoxy?
 

lid wrote:
dazed and confuzzed wrote:

Try www.loctite.com for more. Look at u50fl for a urethane.



D&C,
What's your opinion of 3M's 5200 for this? (I already have a tube of
it).

PhantMan

never tried it with aluminum. HOWEVER:

THe issue with aluminum is that the bond is usually to the oxide layer
that forms rather than to the aluminum itself. Some folks have had good
luck with epoxy and some form of "brillo" type pad or sandpaper to break
this layer so that the epoxy can bond to the aluminum. With a cast part,
you might get enough"tooth" to make 5200 work.

I dunno, never having tried to bond aluminum with 5200.

Just because it is a urethane doesn't mean it will bond well to aluminum.

I'd stay away from welding after bonding though.

I think that the advice to TIG the parts is probably the best for a long
term solution. You can sand or grind the seam flat, and with a little
paint, no one will know.

--
“No battle plan survives first contact with the enemy”
Sun Tzu

Anybody tried glueing cast aluminum parts together with epoxy?
 

THe issue with aluminum is that the bond is usually to the oxide layer
that forms rather than to the aluminum itself. Some folks have had good
luck with epoxy and some form of "brillo" type pad or sandpaper to break
this layer so that the epoxy can bond to the aluminum. With a cast part,
you might get enough"tooth" to make 5200 work.

If it breaks and he puts it back a few days later there won't be
an oxide layer yet.


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Anybody tried glueing cast aluminum parts together with epoxy?
 

"dazed and confuzzed" wrote in message
...
THe issue with aluminum is that the bond is usually to the oxide layer
that forms rather than to the aluminum itself.

Indeed. And therefore an etching ALU primer must be used, prior to applying
epoxy. See www.westsystem.com for more info.

Meindert

Anybody tried glueing cast aluminum parts together with epoxy?
 

William R. Watt wrote:

THe issue with aluminum is that the bond is usually to the oxide layer
that forms rather than to the aluminum itself. Some folks have had good
luck with epoxy and some form of "brillo" type pad or sandpaper to break
this layer so that the epoxy can bond to the aluminum. With a cast part,
you might get enough"tooth" to make 5200 work.


If it breaks and he puts it back a few days later there won't be
an oxide layer yet.

THere will be an oxide layer thick enough to cause a poor bond in less
than a second after the part breaks again.




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--
“No battle plan survives first contact with the enemy”
Sun Tzu

Anybody tried glueing cast aluminum parts together with epoxy?
 

--For grins you might post this problem over at
sci.engr.joining.welding Maybe you'll get lucky and have a hotshot from
that group within driving distance..

--
"Steamboat Ed" Haas : A greasy donut, a cup of
Hacking the Trailing Edge! : coffee and thou...
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

Anybody tried glueing cast aluminum parts together with epoxy?
 

steamer wrote:
For grins you might post this problem over at
sci.engr.joining.welding

My news server doesn't carry it. I put in a request for it though.
We'll see what happens.
Thanks. Didn't know it even existed.

Anybody tried glueing cast aluminum parts together with epoxy?
 

"William R. Watt" wrote in message
...

THe issue with aluminum is that the bond is usually to the oxide layer
that forms rather than to the aluminum itself. Some folks have had good
luck with epoxy and some form of "brillo" type pad or sandpaper to break
this layer so that the epoxy can bond to the aluminum. With a cast part,
you might get enough"tooth" to make 5200 work.

If it breaks and he puts it back a few days later there won't be
an oxide layer yet.

Aluminum oxide forms within minutes....

Meindert

Anybody tried glueing cast aluminum parts together with epoxy?
 

West Systems 860 Aluminum Etch Kit
A two-part treatment for preparation of aluminum surfaces for bonding
with epoxy. Our research shows adhesion to aluminum is significantly
improved with this process. Also improves paint adhesion.
860-8 Two 1/4 pint bottles (treats about 50 sq. ft.)
860 Two 1-pint bottles (treats about 200 sq. ft.).

http://www.westsystem.com/

Anybody tried glueing cast aluminum parts together with epoxy?
 

I didn't know aluminum oxidized within minutes so I did a test.

Part of a piece of aluminum was scraped removing any oxidation and making
the scraped part bright and shiny. Two hours later the scraped part was
still just as bright and shiny. Eighteen hours later the scraped part was
not as bright and shiny. Part of the surface which had been scraped the
day before was rescraped and the difference was noticeable, the newly
scraped surface was brighter than the surface scraped the day before, but
both scraped surfaces were still a lot brighter than the part of the
surface which had not been scraped at all.

I would conclude that there is some oxidation in the first 24 hours.



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Anybody tried glueing cast aluminum parts together with epoxy?
 

On 15 Oct 2005 14:53:26 GMT, (William R.
Watt) wrote:


I didn't know aluminum oxidized within minutes so I did a test.

Part of a piece of aluminum was scraped removing any oxidation and making
the scraped part bright and shiny. Two hours later the scraped part was
still just as bright and shiny. Eighteen hours later the scraped part was
not as bright and shiny. Part of the surface which had been scraped the
day before was rescraped and the difference was noticeable, the newly
scraped surface was brighter than the surface scraped the day before, but
both scraped surfaces were still a lot brighter than the part of the
surface which had not been scraped at all.

I would conclude that there is some oxidation in the first 24 hours.


If you can't see the film, doesn't mean it's not there.
Astro mirrors are aluminized, these days.
In a vacuum chamber, a small aluminum sample is vaporized off a
filament onto the glass.
Then they let the air back in. That mirror surface looks good for
years. And if they hard coat it, it lasts even longer.

Brian W

Anybody tried glueing cast aluminum parts together with epoxy?
 

William R. Watt wrote:
I didn't know aluminum oxidized within minutes so I did a test.

Part of a piece of aluminum was scraped removing any oxidation and making
the scraped part bright and shiny. Two hours later the scraped part was
still just as bright and shiny. Eighteen hours later the scraped part was
not as bright and shiny. Part of the surface which had been scraped the
day before was rescraped and the difference was noticeable, the newly
scraped surface was brighter than the surface scraped the day before, but
both scraped surfaces were still a lot brighter than the part of the
surface which had not been scraped at all.

I would conclude that there is some oxidation in the first 24 hours.



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THe thin layer of oxide that forms in the first seconds is nearly
transparent. Try again, this time using a white piece of cloth. Polish
until the area seems as "bright and shiny" as you want. Notice the
black stuff on the cloth. That is aluminum oxide. Wait 30 seconds and
use a clean portion of the rag to polish the "bright and shiny" part you
just polished. Notice the black stuff? That is more aluminum oxide.

Aluminum is like silver. It oxidizes almost instantaneously.

It is this thin layer that fails when gluing parts. The adhesive bonds
to the oxide layer and the oxide fails, not the glue.



--
“The darkest places in hell are reserved for those who maintain their
neutrality in times of moral crisis.”

Anybody tried glueing cast aluminum parts together with epoxy?
 

dazed and confuzzed wrote:


Aluminum is like silver. It oxidizes almost instantaneously.

It is this thin layer that fails when gluing parts. The adhesive bonds
to the oxide layer and the oxide fails, not the glue.

I wonder how the Lotus Elise stays together then? It has an aluminium
tub-chassis, constructed from aluminium extrusions bonded together with
epoxy resin.

--

Geoff

Anybody tried glueing cast aluminum parts together with epoxy?
 

Regarding the corrosion of aluminum in bonding with epoxy..one of the
homebuilt aircraft was put together using the method of sanding the surface
through the still "wet" epoxy. The theory was the epoxy on the sanding
surface would minimize the corrosion.

Anybody tried glueing cast aluminum parts together with epoxy?
 

some of the homebuilt aircraft groups may be able to help. I know of one
company that designs and builds reduction gears for the homebuilt market and
they use a glue along with mechanical fasteners (bolts). I believe that
they use a locktite product.

Brian

Anybody tried glueing cast aluminum parts together with epoxy?
 

On Sun, 16 Oct 2005 13:35:55 +0200, GeoffC wrote:

dazed and confuzzed wrote:


Aluminum is like silver. It oxidizes almost instantaneously.

It is this thin layer that fails when gluing parts. The adhesive bonds
to the oxide layer and the oxide fails, not the glue.

I wonder how the Lotus Elise stays together then? It has an aluminium
tub-chassis, constructed from aluminium extrusions bonded together with
epoxy resin.

It's not that you can't epoxy aluminum. Of course you can. You just have
to do good surface preparation first.

There are products designed for this. Someone mentioned an etch sold by
West Systems or something like that. I think there is something called
Marine Tex that bonds well to aluminum.

But in the OP's case, I would just use JB-weld to stick the piece back in,
then put a single layer of fiberglass/epoxy over the outside of the broken
piece, then paint. I would sand the area in the immediate vicinity of the
break down to bare metal and clean with acetone or alcohol prior to
applying the epoxy.

Surface preparation is EVERYTHING in bonding applications.

--Mac

Anybody tried glueing cast aluminum parts together with epoxy?
 

On Sun, 16 Oct 2005 07:53:43 -0700, "patrick mitchel"
wrote:

Regarding the corrosion of aluminum in bonding with epoxy..one of the
homebuilt aircraft was put together using the method of sanding the surface
through the still "wet" epoxy. The theory was the epoxy on the sanding
surface would minimize the corrosion.



Reminds me of a sure fire stunt to pull on electronics technicians.

You ask them to bet you can't solder some aluminum alloy sheet strips
together with regular solder. They think it's a sure thing.

You prepare two strips, and scrape the surface with your pen-knife,

Then you place a blob of hot solder on the strip. (Of course it
doesn't tin) Then you scrape the strip through the melted solder.
It tins under the scrape, if its hot enough.
Soon you've scraped a good length of tinning on the strip, and you
prepare the other strip the same.

At that point, you sweat the two tinned strips together in the usual
way. Try pulling them apart. They will break away from the sweated
lap joint.

Brian Whatcott Altus OK