Welding Question

[thidisbogus]

I purchased a Hobart Handler 125 MIG Welder for my welding efforts. I am going to be wleding over the incorrect taillight holes, welding in a new pioneer section and sump among other things. What setting should I use on the welder for the metal thickness in these areas? The machine has the following settings:

18-16 GA

16-12 GA

12-10 GA

10 GA -3/16"

[svt40]

For the Handler I'd use either 1 or 2 on the settings with .035 wire and then play with your wire speed till the weld sounds good. Usually around 40-50 for the speed. If yours takes gas I'd highly suggest using the 75/25 weld mix rather than flux core.

If you use flux core make sure to remove the nozzle as it's not needed and only causes problems with no gas.

Practice doing spot welds on a 2 spare pieces of scrap. A flat piece of copper also helps a lot when filling in holes. Clamp the copper behind the hole and you can weld directly onto the copper to fill in the hole.

[thidisbogus]

Hi Randy,

I purchased the 75/25 welding mix gas.

When you say 1 you mean 18-16 GA and 2 you mean 16-12 GA?

You mention 40-50 for the speed. How is that adjusted? I did not see that option in the owners manual?

[gearhead]

Good info here. www.instructables.com/id/How-to-Weld---MIG-Welding/
Always practice, practice, practice before welding your project.

Ed

[lt.luke]

The Hobart Handler 140 has two knobs, one for amperage and the other for wire speed. I think maybe the 125 is "simpler" and only has one knob?

Your machine has preset amperage and wirespeed values based on the thickness of metal it says you should weld.

I think the 16 - 18 gauge setting is the appropriate setting as that's the thickness of the tubs on these jeeps. Start there on your scrap peices and play with the settings. In addition to practice being important, YOUR comfort and your welding preparation play as much a role as practice.

Start by running stringers on a plain, clean sheet of metal. Visually inspect the top, then the bottom. Do this until you are good, then practice lap joints and some of the other type joints. When you get pretty good at them, try butt welding. This is the type of welding you'll need to do on the tub, but it is also generally ackowledged ast the most difficult joint to weld, so don't jump too fast into your actual project and don't get frustrated if you aren't good at it immediately. I recommend a general class at the local community college or VoTech school. You can self-teach, but that can lead to bad habbits when you weld.

Anything from not clipping the burned end of the wire can negatively affect your weld quality. Invest in a good small set of dykes and use them only for welding. I have a set that I use only for welding wire and plastic cable ties.

Remember that a clean surface is hugely important. any rust or contamination will likely ruin a weld.

[bazza46]

If you haven't done any welding before, or haven't welded thin sheet steel, you should definitely take Gearhead's advice and practice...lots and lots, on the same gauge scrap set up to simulate your job, before putting electrode to your jeep.

Although MIG is much easier to do than other types, it still is tricky to get a good bead on thin metal. Some people are satisfied to do very messy, porous welds and then grind them off smooth. I suppose this may be O.K., but they take a lot more cleaning up, and such welds are weak.

So give yourself plenty of practice till you are satisfied that your weld does not look like a string of pigeon droppings.

[Mike M]

Hopefully a simple follow-up question: If I plan on welding up typical bolt holes on my body, what size copper bar/plate (width & thickness) do I need? Thanks.

[F Bill]

A piece of half inch water pipe scrap, flattened on one end will work.. The heavier it is the better if you have a choice.

[ozm29c]

Hi Rodney,
Further to the constructive comments by other forum members. Here are some other thoughts to consider. BTw I have posted this before but I do think some of my thoughts below may be of some help to you.
1. Always check what lies behind your proposed patch panel ie will it burn!!!!! Is there a fuel line or electrical wiring looms.
2. Prepare the joints to ensure that you are welding clean metal, Any contaminants in the weld pool will either weaken the joint or blow out while you are welding like a mini volcano!
3. Keep the joint width between 0.5 to 1mm
4. Use 0.6/0.8mm dia wire with your smaller Mig welders. Having said that my thoughts on MIG welders are the bigger the better. Small MIG welders are fine but the bigger welders have more OOMPH!
5. If possible try to avoid using flux cored wire.
6. With patch panels don't try and weld in continuous seams, spot here then move away and place a spot there. Continue staggering your spotting until the join is filled-This takes more time but will help dissipate the heat and minimise your patch panel and parent metal from heat distortion. Remember HEAT is your enemy. A good cup of Coffee can be enjoyed many times
7. Use heavier gauge metal ie 1.2mm or at a pinch 1.6mm (than your parent metal)to make your patch from. This will help you to start your weld without blowing a hole in the joint. Once welded, the patch looks no different on the outside.
8. Use sunscreen on exposed parts of your skin as MIG welders have a tendency to burn your skin with excellent results. Better still try to cover all exposed parts of your body.
9. I know it is hard but try to weld with elbow length gauntlets (Leather gloves). I am sure experienced welders at some time in the past have grabbed a hot bit of metal with their bare hands by mistake. OUCH!
10. If you can borrow an auto darkening helmet, do so. Good for tak/spot welding.
11. Buy yourself an angle grinder but always use good quality cutting and grinding discs. Use the very thin section cutting discs to prepare patch panels and the parent metal that the patch panel is offered up to. As always use PPE (Eye protection and hearing defenders)
12. When grinding off the finished welds try not to use excessive force to speed up the removal of excess weld. All you will do is create heat with the end result being metal distortion. Once you have levelled the ground surface, get hold of a flapper disc to further smooth the surface.
13. Paint/prime the exposed metal as soon as possible to prevent corrosion.
14. The point of a screw driver is a very good tool for probing around the affected area to try and determine the extent of rust damage. Once you have cut the rust out of a particular area, then and only then is when you will know where to start your repairs.
Anyway I hope this will give you something to work with.
Don't rush the job
Good luck
Cheers
John Wilson

[thidisbogus]

Thank you John for taking the time to post such good advice in such detail!

[Steerman]

Listen to the sound of the weld when you're practicing. It should sound like sizzling bacon if the machine settings are correct. Welding 1/4" is easy with MIG. Welding sheet metal is very challenging and, as others have stated, requires a LOT of practice. I'm 6 units away from graduating (that's 4 years in the welding lab) with an AS in welding and I can tell you, welding sheet metal is very difficult. You will need backing plates of copper or aluminum and sheet metal clamps to maintain the gap. Sheet metal welding is basically all tack welds and the weld site must be cool to the touch before adding another tack or you will warp the metal. Keep your stick out at 3/8" or so. Follow the machine operating curves for preliminary settings. Adjust as needed. Make sure the metal is shiny bright prior to welding - MIG likes a clean surface. Wire speed controls the amperage - higher wire speed more amperage/heat.

Harbor Freight has autodarkening hoods for under $50. They also have very inexpensive sheet metal clamps (Eastwood has them also). Don't forget the backing plate 3/8" minimum 1/2" preferable - it has to be able to sink the heat. Wear dark clothes. Black Stallion has a nice welding jacket for $25 (Amazon). MIG gloves are a must and get a set of MIG pliers while you're on Amazon. I have to admit I have seen a lot of welders wear no gloves when MIGing - I guess my hands aren't as burn resistant. Eastwood has magnetic copper backing plates that come with the sheet metal clamp set.

You need a light touch with the grinder (or flap disk) as well or you'll distort the metal from grinding. Like others have stated, you can scrimp on the grinder and get one from Harbor Freight but buy high quality grinding and/or flap disks. Use PAM for a nozzle anti-spatter spray (don't get it on the weld surface).

Also MIG, with inert shielding gas, is an indoor process unless the air is really calm. If its windy you're done for the day.

Fluxcore is very useful for outdoors but is hotter and spatters a lot.

I use TIG now for sheet metal. The learning curve for TIG is the steepest of all the welding processes. It has the smallest HAZ (Heat Affected Zone)

Welding Tips & Tricks.com is a great reference site as well as Millers welding videos (and they have a smartphone app also).
http://www.weldingtipsandtricks.com/

Miller: http://www.millerwelds.com/resources/video_library/

[thidisbogus]

Thanks so much for posting! That Tips and Tricks site is the bomb.

[Steerman]

I love that site! Sign uo for his weekly videos - they're a blast. He's also on You Tube