Odd behaviour of brazed joint
 

Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer (I hope I am making myself clear, not too
sure about the correct terminology). The spot weld simply gave way.

I silver-soldered it back into place using Extra-Easy. On first
inspection a good joint, could not force it apart.

After several BBQ uses during which the grill is subjected to far less
stress than when I was testing the joint, the latter gave way.

I cleaned the whole thing with Dremel using a wire brush and sanding
drum. I re-soldered the joint. Same wire, same flux, both work fine
elsewhere. On testing the joint was fine but gave way again after 3 or
4 BBQ uses (the heaviest pressure on the grill is when cleaning it).

I had a good look this time with a magnifying glass: The joint gave
way on the bar, there seemed good adhesion on the stringer. I
re-cleaned etc. and re-soldered with particular attention on heating
the strut preferentially. I am waiting to see if I am third time
lucky.

What puzzles me that the joint would deteriorate with relatively light
use. The BBQ temp does not reach anywhere near the melting point of
Extra Easy (1150F). Is this a case of repeating heating and cooling
cycles which stress the joint? Has anyone seen this elsewhere?



Michael Koblic,
Campbell River, BC

Odd behaviour of brazed joint
 

wrote:

Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer (I hope I am making myself clear, not too
sure about the correct terminology). The spot weld simply gave way.

I silver-soldered it back into place using Extra-Easy. On first
inspection a good joint, could not force it apart.

After several BBQ uses during which the grill is subjected to far less
stress than when I was testing the joint, the latter gave way.

I cleaned the whole thing with Dremel using a wire brush and sanding
drum. I re-soldered the joint. Same wire, same flux, both work fine
elsewhere. On testing the joint was fine but gave way again after 3 or
4 BBQ uses (the heaviest pressure on the grill is when cleaning it).

I had a good look this time with a magnifying glass: The joint gave
way on the bar, there seemed good adhesion on the stringer. I
re-cleaned etc. and re-soldered with particular attention on heating
the strut preferentially. I am waiting to see if I am third time
lucky.

What puzzles me that the joint would deteriorate with relatively light
use. The BBQ temp does not reach anywhere near the melting point of
Extra Easy (1150F). Is this a case of repeating heating and cooling
cycles which stress the joint? Has anyone seen this elsewhere?

Michael Koblic,
Campbell River, BC

You don't specify what kind of BBQ, charcoal burns at around 1,200F, and
my IR gas grill burner at 1,100F.

Odd behaviour of brazed joint
 

Odd behaviour of brazed joint
 

On Wed, 31 Aug 2011 23:44:17 -0700, wrote:

Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer (I hope I am making myself clear, not too
sure about the correct terminology). The spot weld simply gave way.

I silver-soldered it back into place using Extra-Easy. On first
inspection a good joint, could not force it apart.

After several BBQ uses during which the grill is subjected to far less
stress than when I was testing the joint, the latter gave way.

I cleaned the whole thing with Dremel using a wire brush and sanding
drum. I re-soldered the joint. Same wire, same flux, both work fine
elsewhere. On testing the joint was fine but gave way again after 3 or
4 BBQ uses (the heaviest pressure on the grill is when cleaning it).

I had a good look this time with a magnifying glass: The joint gave
way on the bar, there seemed good adhesion on the stringer. I
re-cleaned etc. and re-soldered with particular attention on heating
the strut preferentially. I am waiting to see if I am third time
lucky.

What puzzles me that the joint would deteriorate with relatively light
use. The BBQ temp does not reach anywhere near the melting point of
Extra Easy (1150F). Is this a case of repeating heating and cooling
cycles which stress the joint? Has anyone seen this elsewhere?



It may not get hot enough to melt, but I bet it does get hot enough to
severely weaken the joint. Add in thermal stress 'cause I'm sure the
grill does not heat perfectly evenly and there you go.

Remove 333 to reply.
Randy

Odd behaviour of brazed joint
 

Are you getting interfacial corrosion?

wrote in message
...
Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer (I hope I am making myself clear, not too
sure about the correct terminology). The spot weld simply gave way.

I silver-soldered it back into place using Extra-Easy. On first
inspection a good joint, could not force it apart.

After several BBQ uses during which the grill is subjected to far less
stress than when I was testing the joint, the latter gave way.

I cleaned the whole thing with Dremel using a wire brush and sanding
drum. I re-soldered the joint. Same wire, same flux, both work fine
elsewhere. On testing the joint was fine but gave way again after 3 or
4 BBQ uses (the heaviest pressure on the grill is when cleaning it).

I had a good look this time with a magnifying glass: The joint gave
way on the bar, there seemed good adhesion on the stringer. I
re-cleaned etc. and re-soldered with particular attention on heating
the strut preferentially. I am waiting to see if I am third time
lucky.

What puzzles me that the joint would deteriorate with relatively light
use. The BBQ temp does not reach anywhere near the melting point of
Extra Easy (1150F). Is this a case of repeating heating and cooling
cycles which stress the joint? Has anyone seen this elsewhere?



Michael Koblic,
Campbell River, BC

Odd behaviour of brazed joint
 

On Wednesday, August 31, 2011 11:44:17 PM UTC-7, wrote:
Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer...
I silver-soldered it back into place ... the joint... gave way.

Brazing/silver-soldering is best when it has large contact
area with the right (about .005") gap for the filler material.
Perhaps your round/round wire joint just doesn't have
the right area; a suitable workaround would be to clean
and flux, then wrap thin wire around the joint (like a lashing
with string). When you apply heat and solder, this will make
a brazed joint with all the area of the thin wire, and with the
wire acting as a reinforcing fiber.

You might want to peen the working surface flat, using a block
of wood to back the grid, afterward.

Odd behaviour of brazed joint
 

On Fri, 2 Sep 2011 16:45:00 -0700 (PDT), whit3rd
wrote:

On Wednesday, August 31, 2011 11:44:17 PM UTC-7, wrote:
Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer...
I silver-soldered it back into place ... the joint... gave way.

Brazing/silver-soldering is best when it has large contact
area with the right (about .005") gap for the filler material.
Perhaps your round/round wire joint just doesn't have
the right area; a suitable workaround would be to clean
and flux, then wrap thin wire around the joint (like a lashing
with string). When you apply heat and solder, this will make
a brazed joint with all the area of the thin wire, and with the
wire acting as a reinforcing fiber.

You might want to peen the working surface flat, using a block
of wood to back the grid, afterward.
Why not just weld the sucker????

Odd behaviour of brazed joint
 

Odd behaviour of brazed joint
 

On Wed, 31 Aug 2011 23:44:17 -0700, wrote:

Silver-soldered to be precise.

One of the bars of the stainless steel BBQ grill detached itself at
one end from the stringer (I hope I am making myself clear, not too
sure about the correct terminology). The spot weld simply gave way.

I silver-soldered it back into place using Extra-Easy. On first
inspection a good joint, could not force it apart.

After several BBQ uses during which the grill is subjected to far less
stress than when I was testing the joint, the latter gave way.

I cleaned the whole thing with Dremel using a wire brush and sanding
drum. I re-soldered the joint. Same wire, same flux, both work fine
elsewhere. On testing the joint was fine but gave way again after 3 or
4 BBQ uses (the heaviest pressure on the grill is when cleaning it).

I had a good look this time with a magnifying glass: The joint gave
way on the bar, there seemed good adhesion on the stringer. I
re-cleaned etc. and re-soldered with particular attention on heating
the strut preferentially. I am waiting to see if I am third time
lucky.

What puzzles me that the joint would deteriorate with relatively light
use. The BBQ temp does not reach anywhere near the melting point of
Extra Easy (1150F). Is this a case of repeating heating and cooling
cycles which stress the joint? Has anyone seen this elsewhere?




I used the BBQ for the first time since the third repair. The
temperature of the joint did not exceed 320C (by IR), most of the time
it was below 300C. This was, however, considerably higher than the BBQ
thermometer indicated. The joint held.

This was a fairly light cooking session. It remains to be seen if the
temp stays that low when the BBQ is going all out for any length of
time. I am now inclined to believe that it will not.

I guess I shall have to shell out to have this welded or just put a
rivet in there or something.

Michael Koblic,
Campbell River, BC