Welding Machines

Wow!

I really appreciate the advice. I never thought about using an extension cord (duh!). I have started looking into classes at the local CC. Bit nervous about the time commitment (all their classes seem to be aimed at getting a state certificate), but no matter my intentions today, I can't convince myself that some time in the future I won't attempt a weld that affects someone's safety. I guess I better take that class.

Thanks again.

Check with an electrician or supply house and get the right wire that's heavy enough. No sense at having to buy it twice at today's prices. Mine is 10/3 for 100' on a Lincoln 175SP+ and I have no problems with it. I also weld only a short time within an hour. Also, watch yard sales and stuff, where you might pick up some cords, and there's nothing to say you can't have more than one. I have male/female on mine, so can use different cords or direct from the machine. Keep the shortie plugged in when doing bench work. The 25' when you only need to go a little, and the long one for long runs. You WILL have some voltage drop with the longer cord, so watch it if you're using the higher settings. If you're electrically inclined, it won't be hard to figure them out.

Steve

I'm making a scaffold section out of 1" pipe, steel you can buy any time locally in small pieces..

I am welding it with 7018 and will test the welds at >=3D 500 Lbs but I wonder if a 120V or 240V MIG would generally be capable of a strong weld on this common material. If you don't have a load cell, how would you test the joints?

Jim Wilkins

I'm making a scaffold section out of 1" pipe, steel you can buy any time locally in small pieces..

I am welding it with 7018 and will test the welds at >= 500 Lbs but I wonder if a 120V or 240V MIG would generally be capable of a strong weld on this common material. If you don't have a load cell, how would you test the joints?

Jim Wilkins

Shop crane (engine hoist) with a crane scale? That's what I would use since I have both.

In a pinch, you can use a sledgehammer, it is a not so bad test.

A 240 volt Mig would do nicely. Depending on the wall thickness so would a 120 volt unit. I suppose you could use a press to test some weld coupons. What do you have to stress welds? ERS

Having done a lot of rigging, here's what I'D do: Use come alongs, or dead weight to test them in actual conditions. Build a frame. Set it up. Make a hanging platform under where the boards and weight will rest. Load it up, either until it fails, or tests okay. Nothing like destructive or real life testing.

Hint: One of your failure modes is going to come from handling. You can jig and weld and build it right. But all the flexing from improper setting up, loading, or throwing them down from the third tier will crack more welds than if you use them right.

Why is it that owners and people who build this stuff (and/or pay for it) treat and handle it totally different than employees? What might last you or I five years can be destroyed by an employee in a pay period?

Never mind.

Steve

I collect second-hand measuring instruments and have some old mechanical force gauges similar to the Harbor Freight crane scale. There are plenty of inexpensive ways to pull, few to measure.

The question is what would you recommend to a newbie for non- destructive testing of large welded structures.

We went over destructive testing of weld coupons with a hydraulic press recently but you can buy a press pretty cheaply; these Dillon gauges were close to $1000 new. Bathroom scales don't go high enough. It looks like the high capacity weighing scales are mostly expensive commercial quality units that can be calibrated and certified.

One of my load cells is a 10,000 Lb pressure gauge screwed into a 1 square inch hydraulic cylinder. I think an import porta-power cylinder and a pressure gauge would be close enough for home shop use. YMMV, but I haven't ever needed to measure tension over 3500 Lbs and rarely over 1500. Naturally I don't risk the gauges to pull Billy-Bob's pickup out of the swamp.

Anyone else have any good ideas?

Jim Wilkins

If you need non descrutctive testing then you should consider x-rays. You will need to hire some company to come out and do this but x-rays will help you determine the qualities of the weld and the HAZ. You can also buy the dye penetrant inspection stuff in spray cans for less than 30 bucks. But if the structures that you, an admitted newbie, are making, could hurt someone by failing then you had better find out just exactly what needs testing. Maybe your insurance company, OSHA, or a testing lab can tell you what needs testing and what the methods of testing need to be. Eric