OT: JB Weld Question

Jim Thompson

unread,

Jan 22, 2012, 12:19:43 PM1/22/12

to

Just used some JB Weld to make a steel-to-steel joint.

Amazing stuff, took overnight to fully harden, but it's so hard now
you can barely scratch it.

Only issue... runny during application. Any fixes for that... maybe
more hardener than 1:1 ??

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Oppie

unread,

Jan 22, 2012, 1:13:24 PM1/22/12

to

"Jim Thompson" <To-Email-Use-Th...@On-My-Web-Site.com> wrote in
message news:82hoh7dlg4ne9o47s...@4ax.com...

> Just used some JB Weld to make a steel-to-steel joint.
>
> Amazing stuff, took overnight to fully harden, but it's so hard now
> you can barely scratch it.
>
> Only issue... runny during application. Any fixes for that... maybe
> more hardener than 1:1 ??
>
> ...Jim Thompson

Been a while since I last used it but I don't recall it being runny. If you
can let it sit for a while before applying - towards the end of its working
time - and then apply, that might be better. Some epoxies get weaker if you
don't mix in the specified ratio. Depends on the chemistry.

Jim Thompson

unread,

Jan 22, 2012, 1:28:45 PM1/22/12

to

On Sun, 22 Jan 2012 13:13:24 -0500, "Oppie" <Op...@127.0.0.1> wrote:

>"Jim Thompson" <To-Email-Use-Th...@On-My-Web-Site.com> wrote in
>message news:82hoh7dlg4ne9o47s...@4ax.com...
>> Just used some JB Weld to make a steel-to-steel joint.
>>
>> Amazing stuff, took overnight to fully harden, but it's so hard now
>> you can barely scratch it.
>>
>> Only issue... runny during application. Any fixes for that... maybe
>> more hardener than 1:1 ??
>>
>> ...Jim Thompson
>
>Been a while since I last used it but I don't recall it being runny. If you
>can let it sit for a while before applying - towards the end of its working
>time - and then apply, that might be better.

I'll try that... could be because it's _warm_ here ;-)

>Some epoxies get weaker if you
>don't mix in the specified ratio. Depends on the chemistry.
>
>

Yep.

NT

unread,

Jan 22, 2012, 2:01:40 PM1/22/12

to

On Jan 22, 6:28 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-

Web-Site.com> wrote:
> On Sun, 22 Jan 2012 13:13:24 -0500, "Oppie" <Op...@127.0.0.1> wrote:

> >"Jim Thompson" <To-Email-Use-The-Envelope-I...@On-My-Web-Site.com> wrote in
> >messagenews:82hoh7dlg4ne9o47s...@4ax.com...

> >> Just used some JB Weld to make a steel-to-steel joint.
>
> >> Amazing stuff, took overnight to fully harden, but it's so hard now
> >> you can barely scratch it.
>
> >> Only issue... runny during application. Any fixes for that... maybe
> >> more hardener than 1:1 ??
>
> >> ...Jim Thompson
>
> >Been a while since I last used it but I don't recall it being runny. If you
> >can let it sit for a while before applying - towards the end of its working
> >time - and then apply, that might be better.
>
> I'll try that... could be because it's _warm_ here ;-)
>
> >Some epoxies get weaker if you
> >don't mix in the specified ratio. Depends on the chemistry.
>
> Yep.

Never deviate from the corect ratio with epoxies. Its a misnomer to
call one fo the tubes hardener anyway.

NT

Message has been deleted

qrk

unread,

Jan 22, 2012, 3:21:37 PM1/22/12

to

On Sun, 22 Jan 2012 11:01:40 -0800 (PST), NT <meow...@care2.com>
wrote:

JB Weld is pretty thick. We use it on vertical oriented parts.
There's a 5-minute version of JB Weld if that will help.

Les Cargill

unread,

Jan 22, 2012, 4:56:38 PM1/22/12

to

Jim Thompson wrote:
> Just used some JB Weld to make a steel-to-steel joint.
>
> Amazing stuff, took overnight to fully harden, but it's so hard now
> you can barely scratch it.
>
> Only issue... runny during application. Any fixes for that... maybe
> more hardener than 1:1 ??
>
> ...Jim Thompson

That doesn't sound right... should be the consistency of putty.

--
Les Cargill

Tim Wescott

unread,

Jan 22, 2012, 4:54:20 PM1/22/12

to

On Sun, 22 Jan 2012 10:19:43 -0700, Jim Thompson wrote:

> Just used some JB Weld to make a steel-to-steel joint.
>
> Amazing stuff, took overnight to fully harden, but it's so hard now you
> can barely scratch it.
>
> Only issue... runny during application. Any fixes for that... maybe
> more hardener than 1:1 ??

Don't you mess with the epoxy chemistry, Jim. You're an IC designer, not
an industrial chemist.

As pointed out, "hardener" is a misnomer. It's not quite "the other half
of the glue when finished", but it's pretty close. The Wikipedia entry
on epoxy is pretty educational.

Epoxies tend to be runny. They just aren't thixotropic by nature. Since
you want a thin glue layer anyway, the best way to deal with this issue
is to not use too much glue.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Ian Field

unread,

Jan 22, 2012, 5:13:27 PM1/22/12

to

"Les Cargill" <lcarg...@comcast.com> wrote in message
news:jfi0df$tin$1...@dont-email.me...

He bought the enema compatible version.

mpm

unread,

Jan 22, 2012, 11:43:16 PM1/22/12

to

On Jan 22, 12:19 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-

> | E-mail Icon athttp://www.analog-innovations.com| 1962 |

>
> I love to cook with wine. Sometimes I even put it in the food.

You might also try:
http://www.marinetex.com/marinetexepoxyputty.html

Used it once on a very difficult vertical repair of a hinge that was
under high stress.
Worked amazingly well, actually.
For all I know, it might be the same stuff as JB Weld. ?

Robert Baer

unread,

Jan 23, 2012, 12:17:19 AM1/23/12

to

Jim Thompson wrote:
> Just used some JB Weld to make a steel-to-steel joint.
>
> Amazing stuff, took overnight to fully harden, but it's so hard now
> you can barely scratch it.
>
> Only issue... runny during application. Any fixes for that... maybe
> more hardener than 1:1 ??
>
> ...Jim Thompson

They have a quickset version that may be less runny.
Never tried it, but have the suspicion that it is not quite as spiffy
in strength.

Robert Baer

unread,

Jan 23, 2012, 12:19:55 AM1/23/12

to

Well, yes, but..it flows quite a but during the "set" time, and so
seems to be runny; all relative (aunts, uncles, einstiens, etc).

Robert Baer

unread,

Jan 23, 2012, 12:21:41 AM1/23/12

to

Tim Wescott wrote:
> On Sun, 22 Jan 2012 10:19:43 -0700, Jim Thompson wrote:
>
>> Just used some JB Weld to make a steel-to-steel joint.
>>
>> Amazing stuff, took overnight to fully harden, but it's so hard now you
>> can barely scratch it.
>>
>> Only issue... runny during application. Any fixes for that... maybe
>> more hardener than 1:1 ??
>
> Don't you mess with the epoxy chemistry, Jim. You're an IC designer, not
> an industrial chemist.
>
> As pointed out, "hardener" is a misnomer. It's not quite "the other half
> of the glue when finished", but it's pretty close. The Wikipedia entry
> on epoxy is pretty educational.
>
> Epoxies tend to be runny. They just aren't thixotropic by nature. Since
> you want a thin glue layer anyway, the best way to deal with this issue
> is to not use too much glue.
>

Epoxies do not tend to be runny; there is a brand called CantSag if i
remember correctly, and that is but one of three i found without looking
too hard.

Jasen Betts

unread,

Jan 23, 2012, 3:39:32 AM1/23/12

to

Wikipedia the source of all ignorance has the same strength figures for
JB-kwik and JB-weld.

--
⚂⚃ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to ne...@netfront.net ---

Dave Platt

unread,

Jan 23, 2012, 2:46:19 PM1/23/12

to

In article <_e2dnR7LeqHmc4HS...@posted.localnet>,

Robert Baer <rober...@localnet.com> wrote:

>> Epoxies tend to be runny. They just aren't thixotropic by nature. Since
>> you want a thin glue layer anyway, the best way to deal with this issue
>> is to not use too much glue.
>>
> Epoxies do not tend to be runny; there is a brand called CantSag if i
>remember correctly, and that is but one of three i found without looking
>too hard.

I think it depends entirely on the specifics of the epoxy... the
resins and hardeners used, and any fillers or additives.

TAP Plastics makes a nice range of "marine-grade" epoxies... one
resin, three different hardeners. The mixed epoxies have significantly
different viscosities, wetting abilities, and hardening times. The
one I prefer as my "general utility infielder" bulk-mix epoxy is the
low-viscosity variety, and if I don't add any fillers it's *quite*
runny.

TAP sells a number of fillers that can be added to their epoxies, to
modify the characteristics. One which might be of interest is
"Cab-o-Sil", a very fine "fumed" silica that can make a liquid epoxy
into a non-runny thixotropic gel, or a peanut-butter or petroleum-
jelly-like paste.

Possibly, adding a few percent of a filler like this to JB Weld might
reduce its tendency to be runny during cure, without affecting its
strength and ruggedness. I would certainly want to try this
experimentally before depending on the result!

See http://www.tapplastics.com/uploads/pdf/pb14.pdf for details on
their various fillers.

--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Message has been deleted