MIG settings for gasless welding

[dhdev]

Hi, after scanning the forum for a few days doing my research, I bought my first welder this week, a Draper 70047 (160A Inverter multi-welder). I intend to use it for some work on a track car that I'm building at the moment. The stated range of current for MIG welding is 30-160A, so I thought this should be suitable for doing thin material like body panels etc. However with the mode selector set to "FLUX" and adjusting the dial the digital display will display 160 in it's maximum setting but 58 in it's lowest setting.
I installed some 0.8mm GeKa FCW and I had a practice at welding, having not welded before. I started on some thick steel (~4mm) with setting 120, then some thinner steel (~1mm) with setting 64, then some 2mm walled tube to 1mm steel sheet with setting 70 (my weld on the right) and I felt the results were OK (as shown in the photos). But when I went to transfer my "skills" to the car, I was unable to create a weld and was constantly blowing through and creating holes. I had prepped the areas back to shiny metal, so I'm wondering is it because I have too much current and is my welder therefore not suitable for the thin panels? Also is my welder faulty as I'd assume the display should show 30 in it's minimum setting?

 

[eddie49]

For gasless fluxcore welding, those welds are not bad. However, you do not show the burn-through on thin sheet....
The Draper 70047 is a synergic inverter MIG, which ( theoretically ) means that you only have to dial-in the material thickness and a microprocessor in the welder automagically does the rest. At the low end of product pricing, this type of machine only has one dial, and it is often calibrated in millimetres. This control actually varies the speed of the wirefeed motor, and wire speed affects Amps, which relates to material thickness at the rate of 30 to 40 Amps per millimetre ( or 1 Amp per thousandth of an inch ). The voltage delivered by the welder is adjusted automatically, in accordance with a map or algorithm programmed by the manufacturer. The single-dial machines rely on the accuracy of that map, which may not be suitable in all situations.
This model of Draper MIG has the advantage of a second dial labelled Volts, which allows fine-tuning or "trimming" of the preset voltage values. The calibration is zeroed in the centre, and offers a range from -2.5v to +2.5v. Have you tried using this control when welding thin sheet, e.g. reducing the voltage by the maximum of -2.5v ?

If this does not help, you can sometimes "fool" the program by setting a different wire thickness or type, e.g. select "0.6mm" or "0.8mm", or "gas" when you're actually using fluxcore.

The dataplate on this MIG states that it starts at 20 Amps. If none of the above suggestions and tricks help, the we would have to assume that the synergic map is just wrong, and maybe you should return the welder or persuade your supplier to swap it for a machine with simple manual controls for voltage and wirespeed.

Some more comments on this type of machine in this thread:

First Time Buyer £200 Budget

Hello All I'm a First time buyer! I'm looking for Something Cheap and easy to use as hobby welder for thin car body panels 0.5mm and up to 3mm plate... Could anyone help find a decent cheap welder for my purpose ! Should I go gasless or no? Pics of eBay welders.. under £200 Thanks

www.mig-welding.co.uk