Alternative to welding aluminum frame of Komet?

On Oct 19, 7:32*pm, Bruno wrote:
On Oct 19, 3:49*pm, wrote:



On Oct 19, 5:23*pm, Udo wrote:

I agree with Tim, alu welds are much weaker.
Gussets and bolts are much stronger.
The most likely reason the weld broke, vibration.
Udo

On Oct 19, 3:48*pm, "Tim Mara" wrote:

if you're afraid of welding heat and don't want to remove the top (I would
dare to say they is a pretty big job, why not look at adding a few aluminum
sheet gussets where the cracks are...typically mechanical fasteners can be
as strong or stronger than the welded aluminum joints if properly done. Even
(good) high strength Pop-Rivets could be use easily to attached the gussets.
tim
Please visit the Wings & Wheels website atwww.wingsandwheels.com

"Bruno" wrote in message

...

I just noticed that a few of the welds on the top aluminum framework
of my Komet trailer have broken. *Maybe I am just lazy but I am
concerned about getting the welds redone with the fiberglass top right
next to it. *Does anyone have any suggestions for a good bonding agent
to use on the broken welds?

Thanks,
Bruno - B4- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

Agree with Udo
.060 aluminum gussets, Cherry Max rivets.
Good for life
UH

Thanks all for the replies. *I was hoping that someone would say JB-
Weld would work great but I think I am going to have to bite the
bullet and try my hand at doing a few rivets and aluminum gussets. *I
am glad I saw the broken welds when I did last night. *They are on
both sides of the bar that holds my stabilizer to the roof. *I only
had a few screws attached to the ceiling holding that half of the
stabilizer holder up into the roof. *Yikes! *I would recommend
everyone the next time they are in their trailer to look at the welds
up in the corners of their trailer roof for breaks.

Thanks,
Bruno - B4

Note that UH says Cherry-Max - these are not cheapo pop-rivets !

Dave Nadler wrote:

Thanks all for the replies. I was hoping that someone would say JB-
Weld would work great but I think I am going to have to bite the
bullet and try my hand at doing a few rivets and aluminum gussets. I
am glad I saw the broken welds when I did last night. They are on
both sides of the bar that holds my stabilizer to the roof. I only
had a few screws attached to the ceiling holding that half of the
stabilizer holder up into the roof. Yikes! I would recommend
everyone the next time they are in their trailer to look at the welds
up in the corners of their trailer roof for breaks.

Thanks,
Bruno - B4

Note that UH says Cherry-Max - these are not cheapo pop-rivets !

It's not an airplane - just use standard steel rivets, and put in few
more than you would need with the Cherry-max. They are in a place that's
easy to inspect. If you need strong rivets, the steel 5/32" are really
strong - and cheap (at least in the USA).

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Oct 19, 11:40*am, Bruno wrote:
I just noticed that a few of the welds on the top aluminum framework
of my Komet trailer have broken. *Maybe I am just lazy but I am
concerned about getting the welds redone with the fiberglass top right
next to it. *Does anyone have any suggestions for a good bonding agent
to use on the broken welds?

Thanks,
Bruno - B4

Bruno,

If you decide to go with gussets, suggest roughing up the area of
overlap with sandpaper, then acid etch with dilute phosphoric acid
(Jabsco Metal-Prep at Home Depot or AlumiPrep) wash with water and
dry. Then use Loctite Depend 330 adhesive (available from McMaster-
Carr on-line) along with mechanical fasteners if you wish, though
those won't really be needed using 330.

330 comes as a two part (gel and spray primer) almost instant setting
acrylic adhesive (actually one minute for bond - - 24 hours full
strength) that is ideal for lots of materials. It has a shear strengh
of 2,500 psi IIRC and, unlike most epoxies that cure brittle, retains
some elasticity so it accomodates dissimilar thermal expansion of
materials and shock loads etc.

Do not buy a lot more than you need, though, as it has only a 1 year
shelf life - - and they mean it! I think on day 366 the stuff stops
working. A little goes a long way and a medium size "kit" from MC
costs about $27.

bumper
zz

Don't mix steel and aluminium. They are too far apart on the electro-
chemical scale and will set up an electrolytic cell that will corode
the repair. Use aluminium or Monel-metal rivets and aluminium
brackets, gussets etc.

Note that UH says Cherry-Max - these are not cheapo pop-rivets !

It's not an airplane - just use standard steel rivets, and put in few
more than you would need with the Cherry-max. They are in a place that's
easy to inspect. If you need strong rivets, the steel 5/32" are really
strong - and cheap (at least in the USA).

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

.. wrote:

Note that UH says Cherry-Max - these are not cheapo pop-rivets !
It's not an airplane - just use standard steel rivets, and put in few
more than you would need with the Cherry-max. They are in a place that's
easy to inspect. If you need strong rivets, the steel 5/32" are really
strong - and cheap (at least in the USA).
Don't mix steel and aluminum. They are too far apart on the electro-
chemical scale and will set up an electrolytic cell that will corrode
the repair. Use aluminum or Monel-metal rivets and aluminium
brackets, gussets etc.

The steel rivets I use are plated - standard hardware store stuff - so
it's not steel on aluminum, but whatever the plating is (zinc, I
assume). I don't have any problems with corrosion, but it's not very
humid here, either.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

I believe stainless steel fasteners would be fine with aluminum in
this situation.

More info below quoted from http://www.bssa.org.uk/topics.php?article=89


"Aluminium and stainless steel together also appears to be a bi-
metallic corrosion risk, from the 'nobility' table.
With this combination the affect of relative surface area on corrosion
is important.

A large area of 'cathode' relative to 'anode' will accelerate the
anodic corrosion. Although aluminium is anodic to stainless steel,
large relative surface areas of aluminium to stainless steel can be
acceptable, dependant on local conditions.
Stainless steel fasteners in aluminium plates or sheets are normally considered safe, whereas aluminium rivets or bolts holding stainless steel parts together is an unwise combination, as there is a practical risk of corrosion.

An example of the safe use of stainless steel and aluminium together is where stainless steel fasteners and hold down bolts are used to secure aluminium roadway or bridge parapet guards.
Even with no insulation between the metals, there should be little
risk of corrosion.

In contrast, in a marine environment, severe localised pitting
corrosion to the aluminium treads has been observed where un-insulated
stainless steel bolts were used to secure the treads in place.
On the same ladder however, bolts with sound insulating washers did
not show any pitting on the surrounding aluminium."

tstock wrote:
I believe stainless steel fasteners would be fine with aluminum in
this situation.

More info below quoted from http://www.bssa.org.uk/topics.php?article=89

The table in this reference shows zinc much closer to aluminum than
stainless steel, thus a lower corrosion potential. That suggests the
common zinc plated steel rivets would be a better choice; however, I
must note all the rivets I checked, top to bottom, on my Cobra trailer
are aluminum!

As long as the joint doesn't get wet, the materials don't matter. The
joint will likely have condensation on it at times, so it is some concern.

For the intended application, size, quantity, cost, and weight of the
rivets provide no real restraints, so choosing a suitably strong
aluminum rivet should not be a problem. Put in a few extra and be done
with it. It's a trailer top, not an airplane. I'd skip the expensive
glue, too.

--
Eric Greenwell - Washington State, USA

I'd use a bunch of MD43BS 1/8" Monel pop rivets. They have a good
service history when used in aluminum and to join aluminum and steel.
I've got loads of them, contact me via email.

Thanks, Bob K.

"Bob Kuykendall" wrote in message
...
I'd use a bunch of MD43BS 1/8" Monel pop rivets. They have a good
service history when used in aluminum and to join aluminum and steel.
I've got loads of them, contact me via email.

Thanks, Bob K.

John Thorp (with no "e") recommended Monel pop rivets (From U.S. Shoe
manufacturing IIRC) for assembling the T-18 as an alternate to the aluminum
AN rivets.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

On Oct 22, 7:34*pm, "Capt. Geoffrey Thorpe" The Sea Hawk @See My
Sig.com wrote:
"Bob Kuykendall" wrote in message

...

I'd use a bunch of MD43BS 1/8" Monel pop rivets. They have a good
service history when used in aluminum and to join aluminum and steel.
I've got loads of them, contact me via email.

Thanks, Bob K.

John Thorp (with no "e") recommended Monel pop rivets (From U.S. Shoe
manufacturing IIRC) for assembling the T-18 as an alternate to the aluminum
AN rivets.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

I apologize up front for asking for advice and than ignoring all of it
and just doing my own thing...Thanks for the replies and help.

That said, I ended up reading the specs for JB Weld Puddy and decided
that if I wasn't going to jump on top of it or leave it out under 3
feet of snow that 10,000 pounds of shear strength might be enough to
repair the broken weld. Here is a pic of the break befo
http://www.taylormadeawning.com/imag...ailer_weld.jpg

Here is the fix while curing:
http://www.taylormadeawning.com/imag...iler_weld2.jpg

I am going to trailer up to Logan, Ut this weekend to hopefully fly
the ridges and will report back if the patch job fix has any problems.

Thanks,
Bruno - B4