Anti-Spatter Spray

By Lawrence (*****)

Date 09-30-2014 19:09

Three thoughts, (prolly not what you want to hear)

1) Anti-spatter spray is NOT intended/engineered to be placed in the weld zone, but rather on the adjacent base metal or fixturing.

2) If welding Ultra High Strength Steel it would be assumed that you are working with process controls and procedures that are so well thought out that spatter should not be an issue. Unless you are working with gage metal and short circuiting transfer, you ought to be able to develop a procedure to produce spatter free welds.

3) If you must use the stuff, find a hand pump delivery system rather than an aerosol can. Keeping compressed stuff near a weld circuit has always been stupid.

Now for opinion...... 95% of the time; Developing procedures or detailed work instructions to include anti-spat is like planning on making bad welds.
It's like keeping some rebar handy to slug bad fitups instead of planning an upstream process that provides materials that comply with established shop tolerances.

Example: Somebody requested I develop a downhill GMAW procedure to deal with large gaps on endplate connections.... I said NO Instead we took a walk upstream and discovered we had a problem with both calibrating the cutting equipment and a fitter that was willing to "make it work" instead of rejecting bad supply passed down to him.

Now having been all harsh... I fully expect you to tell me that this is indeed special work :)

By OBEWAN

Date 09-30-2014 20:00

They usually contain silicone...but I have not used them for a long time now.

Sorry, no hydrogen as far as I know.

And, they are used in MIG weld gun gas nozzles in most cases.

By Tyrone

Date 10-01-2014 11:08

We use them on robotic weld gun nozzles too.

Lawrence,
On this particular, highly specialized project ;) the weld procedure is set in stone. I can't change/optimize it to a spatter free process.

Production, in their never ending quest to reduce cycle time, is pushing to use anti-spatter to reduce cleaning time.
Hand pump (like!) or aerosol of the stuff will probably make its way to the weld joint. I'm planning on worse case (spray the whole joint), then do the usual gamut of mechanical tests.

I'm just paranoid about the steel's sensitivity.

Tyrone

By OBEWAN

Date 10-01-2014 12:45

You might want to consider looking into a nozzle cleaning station - or hiring a robotics technician to monitor the line and clean the nozzles.

And, spell checking is available in Word.

By ssbn727 (*****)

Date 10-02-2014 00:58

By Tyrone

Date 10-02-2014 10:33

Our robotic technician programmed the robots to self clean which includes dipping the nozzle into a jar of anti-spatter, followed by a quick blast of compressed air.
This is the only time that anti-spatter is used.

I ran spell checking in Word. Nothing lit up. Maybe it's the Canadian spelling of things that you see?
Tyrone

By Lawrence (*****)

Date 10-02-2014 11:50 Edited 10-02-2014 11:53

Now I'm confused.

If you are going to try to spray the anti-spat in the joint and go through the full range of mechanical tests (sounds like a PQR) Why can't you make some adjustments to things like
1) Gun angle
2) Travel speed
3) Voltage and WFS

In order minimize spatter?

Run trials prior to the mechanical testing to get the best spatter free result... Then you have a procedure you can qualify *without* the anti-spat.

If you have a budget/time to do mechanicals with the anti-spat... Why can't that resource be directed to a process control adjustment instead.

Seems like something that could be justified in a meeting with the decision makers (if you are not the decision maker)

Another negative about anti-spat spray testing is this: You will do your mechanical testing with welds made with spray... Ok... But in production will the amount of spray be the same? This is a little different than welding over sprayed primers that can be applied with at least some consistency. If that spray pools in a fillet root during production, the resulting weld will not likely have the properties of the welds from the PQR when the spray is carefully applied. Make sense?

Edit: After my last "Windows" update, the spell check function just miraculously started working in the forum !

Don't know if it's a Windows thing or a Forum thing... But I'm grateful :)

By OBEWAN

Date 10-02-2014 13:43

Yikes!!!

There is also copy/paste...

By Lawrence (*****)

Date 10-02-2014 14:08

Huh ?

By SCOTTN

Date 10-02-2014 14:47

Excellent points as usual, Lawrence. Proper adjustments can significantly reduce spatter. If you’re having a spatter issue, try some sample welds. If you’re seeing an excessive amount of spatter, you can make some adjustments to reduce the amount of spatter by trying several things… reducing the wire feed speed, reducing the volts, reducing the electrical stickout, making sure the weld area is clean, increasing the flow of the shielding gas, making sure the wire is clean and dry and that it’s not picking up anything from the feeder or the liner that may be contributing to the problem. Also, any time you use spatter spray, you don’t want to use it in a manner that will compromise the quality of the weld. Be sure to shake the can well before spraying the area, and don’t use it excessively. I’ve found that a lot of welders think that the more they use on the surface, the easier it will be to remove the spatter. Plus, they’re not paying for it, so using an excessive amount isn’t a problem for them. But if they end up spraying too much in the joint, it could result in weld defects that can weaken the joint and compromise the integrity of the weld. A consumables salesman has never once told me to be careful and not use too much, because, they’re salesmen. With regard to spell check, I personally think that using it is a crock of shut. My wife makes me so mad when she says I should always spell check my work. Sometimes she acts like I’m retraded.

By OBEWAN

Date 10-02-2014 13:39

Sounds like a process improvement might help or the creation of a preventive maintenance checklist -
Like cleaning every (insert time interval) minutes ....

It is hard to collaborate without knowing more details...

The robot tech might be able to get one of those multi-tools to use for cleaning...

There are many factors to consider - no one best fit answer...

Robots are not well suited to every welding application...not for me to say...depends on the production rate and product cost etc.

By Tyrone

Date 10-03-2014 11:17

I wish it were that simple. Tweak the parameters to avoid causing spatter. The weld process inherently causes spatter. Going outside the range of the WPS would mean requalification. I estimate $1.4M
Yes, it's my decision which direction to go, but I can't justify the cost of requal vs $50K of mechanical tests.

You've all made good points about the quantity of spray that might make its way into the joint. I plan on heavy application into the joint (worst case right?).

Tyrone

By Steven Obenour Date 10-03-2014 12:44 Edited 10-03-2014 12:50

1.) What is the code or contract obligation?

2.) Are impact tests required?

By lo-hi

Date 10-03-2014 16:20

I'm sure a shop of your size is on top of air quality and safety. Just thought I would mention the presence of methylene chloride in some of the anti-splatter and caution some of our fellow welders not to weld over puddles or cracks that could hold liquid. I remember a discussion earlier that went into more detail, maybe in safety.

By Steven Obenour Date 10-03-2014 12:50

Have you considered searching for an MDS or chemical data sheet? Sometimes they are listed online.

By Tyrone

Date 10-06-2014 10:43

Lo-Hi,
I'm planning on taking the MSDS sheets to Safety and the Union to get their buy-in. Thanks for the heads up on methylene chloride, I'll add that to my list for down selecting.

Steven,
I'm working to a military spec. Kenetic energy testing is required. That's were it gets expensive. Did you change your name because people were getting you mixed up with the Jedi Obewan? ;)
Tyrone