I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

--
*Why do we say something is out of whack? What is a whack?

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

Wouldn't be worth buying a roll of aluminium welding wire for one small job
like that but yes you could do it with a MIG with the right wire. If you
want it welded and it's small enough to post a mate of mine could TIG it for
you. I've got to get some other stuff to him soon anyway so it could go in
with that. Otherwise roughen the surfaces up a bit and araldite it. That'll
be as strong as you can get short of welding it.
--
Dave Baker

In article ,
Dave Baker wrote:

"Dave Plowman (News)" wrote in message
...
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but
there's little load on it. And I'm not sure I can be bothered finding
an aluminium welder. Unless I could do it myself with my MIG. Which
I'm not much good with on steel. ;-) Car body filler? Epoxy? Any
special precautions?

Wouldn't be worth buying a roll of aluminium welding wire for one small
job like that but yes you could do it with a MIG with the right wire.

I seem to be always buying stuff for that 'one small job' - given the
hassle of getting anything like that done round here. I have enough
materials to make the whole thing again a couple of times - so it wouldn't
be a disaster if I fooked it up.

If you want it welded and it's small enough to post a mate of mine could
TIG it for you. I've got to get some other stuff to him soon anyway so
it could go in with that.

Thanks - but I was hoping to get it finished tomorrow. ISTR seeing ally
welding wire in Halfords - might be worth having a go. I'm sure if
successful the rest would get used sooner or later.

Otherwise roughen the surfaces up a bit and
araldite it. That'll be as strong as you can get short of welding it.

It's only holding an air temp sensor. BTW, you were right about the thread
being M14 1.5. Got a set of taps off Ebay for pennies which did the job
just fine. Only carbon steel, but ok for ally.

--
*There's no place like www.home.com *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,

It's only holding an air temp sensor.

Araldite will be fine then. Build up a bit of a bead of it round the join
for added support and it'll be in there till doomsday. If the boss had a
little groove round it for the araldite to lock into so much the better but
some good deep scratches with a file or chisel edge should do.

BTW, you were right about the thread
being M14 1.5. Got a set of taps off Ebay for pennies which did the job
just fine. Only carbon steel, but ok for ally.

--
Dave Baker

"Dave Plowman (News)" wrote in message
...

It's only holding an air temp sensor. BTW, you were right about the thread
being M14 1.5. Got a set of taps off Ebay for pennies which did the job
just fine. Only carbon steel, but ok for ally.

Thread the tube, tap the hole?
Or are the taps/dies too small?

In article ,
dennis@home wrote:
It's only holding an air temp sensor. BTW, you were right about the
thread being M14 1.5. Got a set of taps off Ebay for pennies which did
the job just fine. Only carbon steel, but ok for ally.

Thread the tube, tap the hole?
Or are the taps/dies too small?

It needs to have a reasonable seal which means a flat surface. (the sensor
goes at right angles to the tube to measure the temperature of the air
passing through the tube) And a thread in thin walled tube wouldn't be
satisfactory.

--
*I'd kill for a Nobel Peace Prize *

Dave Plowman London SW
To e-mail, change noise into sound.

On 20 Aug, 23:33, "Dave Plowman (News)" wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

--
*Why do we say something is out of whack? *What is a whack?

* * Dave Plowman * * * * * * * * London SW
* * * * * * * * * To e-mail, change noise into sound.

Brazing if you've got a MAPP torch?

On 20 Aug, 23:49, Bolted wrote:
On 20 Aug, 23:33, "Dave Plowman (News)" wrote:

I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

--
*Why do we say something is out of whack? *What is a whack?

* * Dave Plowman * * * * * * * * London SW
* * * * * * * * * To e-mail, change noise into sound.

Brazing if you've got a MAPP torch?

Then again, maybe not...

http://www.twi.co.uk/content/brazing_al.html

In message , "Dave Plowman (News)"
writes
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?


Hi Dave,
I have never tried this, but a friend of mine had some success
with the following style of product. I thought of giving it a try just
to see how easy, or not, it would be. More like soldering/brazing than
welding.

Car body filler? Ugh!


http://cgi.ebay.co.uk/aluminium-weld...ow-temp-370C-_
W0QQitemZ160356193343QQcmdZViewItem

http://www.cupalloys.co.uk/joining-a...m-c100014.html

http://durafix.com/
--
Bill

"Dave Plowman (News)" wrote in message
...
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

Provided there is no peel stress, epoxy gives an extremely strong bond.
Araldite always used aluminium to aluminium bonds as the standard against
which other bonds with their adhesive were compared on their data sheets.

Colin Bignell

On Aug 20, 11:33*pm, "Dave Plowman (News)"
wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

If load really is low, PVA works well on ali


NT

Dave Plowman (News) brought next idea :
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

The slow setting epoxy, roughen then score the surfaces first.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Dave Plowman (News) wrote:

I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

http://www.weldguru.com/braze-aluminum.html

You can use Araldite, but you need to thoroughly de-grease and I find it
better to abrade away the surface oxide before applying the adhesive. I
once made a whole load of microscope slide racks from aluminium extruded
sections and glued them with araldite. It was obvious which ones were
not succesfully glued. A slight tap on the desk and they fell apart.

I was told when I worked with a group that developed composite structure
for aircraft that epoxy glued aluminium degrades fairly rapidly over
time and that over-the-counter epoxy gues really don't bond well to
aluminium. The preferred adhesives for aluminium are a hybrid epoxy
adhesive such as epoxy-nylon and specialist polyurethane glues. Some of
these glues require special primers or activators to be applied to the
surface before bonding.

If I wanted to make a permanent job I'd braze it, using the appropriate
aluminium brazing rod.

On 21 Aug, 01:33, (Steve Firth) wrote:
Dave Plowman (News) wrote:

I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

http://www.weldguru.com/braze-aluminum.html

You can use Araldite, but you need to thoroughly de-grease and I find it
better to abrade away the surface oxide before applying the adhesive. I
once made a whole load of microscope slide racks from aluminium extruded
sections and glued them with araldite. It was obvious which ones were
not succesfully glued. A slight tap on the desk and they fell apart.

I was told when I worked with a group that developed composite structure
for aircraft that epoxy glued aluminium degrades fairly rapidly over
time and that over-the-counter epoxy gues really don't bond well to
aluminium. The preferred adhesives for aluminium are a hybrid epoxy
adhesive such as epoxy-nylon and specialist polyurethane glues. Some of
these glues require special primers or activators to be applied to the
surface before bonding.

If I wanted to make a permanent job I'd braze it, using the appropriate
aluminium brazing rod.

I was building a control panel of Aluminium recently which had plywood
inserts and decided to try ordinary polurethane wood glue - 5 minute
setting gunable type . Totally successful. I then needed to attached
a small Al bracket to carry a connector and again used this PU glue,
finding it did the job perfectly for an Al to Al bond.

Now having read the above post about epoxy glued aluminium degrading
over time, I'll might remember to have a look in a year's time to see
if the bond is still OK.

Rob

Rob G wrote:

Now having read the above post about epoxy glued aluminium degrading
over time, I'll might remember to have a look in a year's time to see
if the bond is still OK.

I think the problem with epoxy is that the epoxy is porous to oxygen, so
the aluminium oxidises beneath the epoxy and that causes the strength of
the epoxy/aluminium bond to decrease.

Steve Firth wrote:
You can use Araldite, but you need to thoroughly de-grease and I find it
better to abrade away the surface oxide before applying the adhesive. I
once made a whole load of microscope slide racks from aluminium extruded
sections and glued them with araldite. It was obvious which ones were
not succesfully glued. A slight tap on the desk and they fell apart.

I was told when I worked with a group that developed composite structure
for aircraft that epoxy glued aluminium degrades fairly rapidly over
time and that over-the-counter epoxy gues really don't bond well to
aluminium. The preferred adhesives for aluminium are a hybrid epoxy
adhesive such as epoxy-nylon and specialist polyurethane glues. Some of
these glues require special primers or activators to be applied to the
surface before bonding.

Here's a nice article about the way that Lotus stick the Elise chassis
together from bits of aluminium - they use a specialised epoxy resin.

http://www.sandsmuseum.com/cars/elis...al/asauto.html

Apparently they still rivet each joint to stop a peel type failure.

Jim wrote:

Here's a nice article about the way that Lotus stick the Elise chassis
together from bits of aluminium - they use a specialised epoxy resin.

http://www.sandsmuseum.com/cars/elis...al/asauto.html

As it says for some reason the industry is very cagey about giving full
details of the types of epoxy used in different applications. The Lotus
glue is an odd one, a heat cured epoxy. That wouldn't work for large
aircraft. The Wings on most modern aircraft are bonded using an
epoxy-polysulphide adhesive (I think, but I'm not sure).

Apparently they still rivet each joint to stop a peel type failure.

Yes, called the "chicken rivet".

Steve Firth wrote:
Jim wrote:

Here's a nice article about the way that Lotus stick the Elise chassis
together from bits of aluminium - they use a specialised epoxy resin.

http://www.sandsmuseum.com/cars/elis...al/asauto.html

As it says for some reason the industry is very cagey about giving full
details of the types of epoxy used in different applications. The Lotus
glue is an odd one, a heat cured epoxy. That wouldn't work for large
aircraft. The Wings on most modern aircraft are bonded using an
epoxy-polysulphide adhesive (I think, but I'm not sure).

Apparently they still rivet each joint to stop a peel type failure.

Yes, called the "chicken rivet".
Fascinating article.

Most glues are good in shear, bad in peel..that's why tenoned joints are
used..

Steve Firth wrote:

As it says for some reason the industry is very cagey about giving full
details of the types of epoxy used in different applications. The Lotus
glue is an odd one, a heat cured epoxy. That wouldn't work for large
aircraft. The Wings on most modern aircraft are bonded using an
epoxy-polysulphide adhesive (I think, but I'm not sure).

The phrase epoxy-polysulphide doesn't hold up with me, though I could be
wrong, as I have been out of it for ten years now.

Epoxy suggests a 2 part mix, like Araldite.

Polysulphide suggests a 2 part mix that produces a synthetic rubber type
mix. A company that makes this is called Thiokol.

If an aircraft wing is not made of carbon fibre, then the aluminium is
joined using an interfay that is defined by the manufacturer. This can
be all sorts of things, but the cabin skins are usually interfayed with
one of the polysulphide compounds to prevent cabin pressure losses. This
is like joining the various skins with a water proof, air tight seal.

Take a close look at any aircraft and you will see that it is a
patchwork quilt of skins, rivetted to the cabin stringers and stations.
The stations being the frames that form the shape of the diam. of the
fusalage.

The size of the skins is down to the time that the interfay is applied,
to the final rivet goes in to that skin. Before the interfay goes beyond
workability.

Dave

Dave Plowman (News) wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?

Liquid metal/JBweld/Carbody..roughen and degrease..and clean.

Dave Plowman (News) wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?


If you have the right flux, you can soft solder it too.

I have some of that..its really odd to see ordinary solder wetting
'tinfoil'..

Dave Plowman (News) wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?


De-grease, abrade to remove oxidised layer, degrease again, then
Araldite.

They stick aeroplanes together with it, so maybe it's good enough for
sticking a sensor. ??? =-O
Cheers
Don

Donwill wrote:
Dave Plowman (News) wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an
aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?


De-grease, abrade to remove oxidised layer, degrease again, then
Araldite.

They stick aeroplanes together with it, so maybe it's good enough for
sticking a sensor. ??? =-O

Araldite went out of favour before 1978 when I transfered within the
aerospace industry. What followed was a product called hysol. This was
available as an adhesive and a liquid shim. Liqid shim had powdered
slate, or powdered aluminium mixed in, to give it more body.

Both Araldite and hysol depended on the same thing, they had to be used
on aluminium that had been anodised and epoxy primered. The bond to the
ally and paint was 100% and the weak point was the bonding agent itself.
I have seen many joints that have failed and it has always been the
bonding agent and not the paint. I think others have pointed out the
problems with a bare aluminium bonded joints.

(Just got back from 2 long drives, brain is about as much use as a bowl
of mashed potato at the moment)

So going back to Dave's problem, I would say weld, braze, or solder, for
a long joint life.

Dave

In article ,
Dave wrote:
So going back to Dave's problem, I would say weld, braze, or solder, for
a long joint life.

I've got the equipment to do any of these, but not the experience. I've
tried ally soldering ages ago - stuff bought from Maplin - without
success. Welding always has the danger of burning through with thin
material. Brazing sounds more like it - but what is used?

--
*It IS as bad as you think, and they ARE out to get you.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Dave wrote:
So going back to Dave's problem, I would say weld, braze, or solder, for
a long joint life.

I've got the equipment to do any of these, but not the experience. I've
tried ally soldering ages ago - stuff bought from Maplin - without
success. Welding always has the danger of burning through with thin
material. Brazing sounds more like it - but what is used?

I have had complete success with soft solder and Carrs aluminium flux. I
got it from a model train place in Raynes Park IIRC.

They also sold aluminium solder, but I never found it particularly good.
I used resin cored electrical lead/tin.

DO NOT inhale flux fumes. They are vile and lead to 2 days of cold//flue
like symptoms.

Do it outside.

Oh, here you go

http://www.chronos.ltd.uk/acatalog/C...etc_268 .html

You will need a solder gun or similar for big lumps, or possibly a
blowtorch.

It would be overkill for your purposes, but the one I have used is an
ITW Plexus epoxy-type resin specially formulated for aluminium
http://www.itwplexus.co.uk/

This was through the product reps that gave us a chance to try out
several of the products - and then test the joints to destruction.

Simple lap joint in aluminium sheet - the aluminium fails before the
joint.

Probably best bet for small quantities is a yacht chandler.