Remove the galvanized coating before welding. Just in the weld joints.
John Wright

Hi Hi
We might need alittle further info to better assist you. What is the material thickness you are welding? Maybe list current parameters...i.e volts, amps, wire type, gas...ect. Are these hand welds or is it on an automated system.
Is you setup capable of pulse? If so that would be something I would look into. Also check your torch angles. Most of the time I run into excessive spatter it is usually do to changes made to the torch angles for the automated systems anyway. I have all my parameters lock out. There are some products out there that are supposed to help reduce spatter (Like Spattershield system) but I havent tryed them...maybe they work maybe not.

regards

kam

Adjustment of power supply, wire diameter, and gas combine to provide extreme flexibility in GMAW process.

Your adjustments were restricted only to power supply settings?

Mask the slide with a piece of sheet-metal, copper strip, etc,

How about more specifics on the projection design?

I believe this problem was being interpreted as a GMAW process issue- projection welding is rather like a spot-weld process; remove the Zn at the weld and re-evaluate the adjustments which had tested unsatisfactory before scrapping out any parts. Early post by JW about ZN is accurate- it causes weld issues.

Is there any way to mask off the weld areas so that galvanizing doesn't bond to those locations? Epoxy paint will prevent zinc from bonding to the steel but I don't know if that would work for you. It sounds like you are working with pre-galvanized materials?

Other than taking another look at your welding parameters and seeing if you could make changes you might have missed (drag or push angle, electrode stick-out, shielding gasses, etc.) I would try an anti-spatter spray or something like that.

Chet Guilford

Splatter is not acceptable in any welding situation. It should be easily cured with proper welding parameters. While the zinc coating on galvanised may cause some spatter, due to the low zinc melting point-proper adjustment of welding voltage and wire speed (I'm assuming mig here) should give you a relatively splatter free zone.
Also, if you are migging these joints, be sure to use an E70S-3 wire instead of the standard S-6. You will have fewer metallurgical problems like cracking and the like.
Any questions, email direct.

Good Luck

brande

This is information that I had from a seminar I attended a while back.
I believe your problem might be in your slope adjustments.


SLOPE CONTROL, definition and info for RSW

Slope control is a form of automatic heat control. Up Slope is in increasing heat and Down Slope is a decreasing heat. The timing set for the slope functions determines the steepness of the rise or fall of the heat. The dial timing indicates the number of cycles to rise from minimum to maximum heat or visa versa. The trace of the rise or fall of the RMS voltage is a logorithmic curve which when translated to heat is an almost straight line change.

Slope control provides numerous little understood attributes for welding of many different metals and various different welding machines. The use of up slope takes the spit out of the start of welding current flow. Whether the spit would be caused by not enough pressure, oily or scaly stock, misfit parts or too small an electrode contact area, the chances are that no spit will occur. The successive half cycles of increasing voltage and current will gradually heat the stock, seat the electrode into the material, hotforge the misfit seperated parts together and complete a sound weld which otherwise might have been a hole burned through the parts. Sound spot welding never throws sparks. Sparks are molten metal which should have been part of the weld nugget.

Up slope contol was originally designed and built for cross wire welding where the wires cross at right angles and have just point contact at the start of the welding. Unless a very low power is used the wires will flash when the welding begins. The up slope control prevents this flash and it also increases the welding current progressively as the contact area grows. The net result is a good sound weld made quickly with a smooth fillet of metal around the weld area instead of a ragged rough edge as is often the casewithout slope control. Cross wire welding is classed as natural projection welding. The welds are usually made in multiple groups.

Up slope control is indicated for normal projection welding. It prevents the splattering of the material of the projections both from electrical flash at the start of the weld and by mechanical impact when the welding ram catches up to the heating of the projections. Unless the material of the projections is maintained in the proper place to form weld nuggets, the planned strength of the welded assembly may be destroyed.

Up and Down slope is widely used to prevent embrittlement caused by too rapidly cooling of many low alloy steels and the lower carbon steels, 1025 and lower. Down slope will not prevent embrittlement of the higher carbon steels. This group requires the use of quench and temper.


Hope this helps,

Brian J. Maas