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DarrylF
13th Jan 2005, 10:55 PM
No, I'm not going over to the Other Side :)

I'm planning on getting a small welder. I'd like to be able to fabricate frames for extension tables for the table saw, other types of workshop frames/tables etc., wood racks maybe, brackets etc. Small stuff, mostly out of 1x1 or 1x2 RHS, smallish angle, up to 5mm thick at most I would think. No car panel or sheet metal work. No Al or stainless.

Not a lot of usage, nothing heavy duty required. I could go borrow a mate's MIG easily enough I guess - but I makes the job a pain to have to do that.

I've done a bit of stick welding, many moons ago but used to be reasonably good at it. I can deal with metal and understand the basics at least.

So I'm contemplating a small portable stick or MIG/gasless MIG perhaps. There's a GMC stick at Bunnies I think for around $100, or up to a CIG for $200 odd. Or maybe second hand - there always seem to be small units in hock shops, at markets etc.

I'll probably need a cutoff saw I guess - $100 GMC maybe?

Soooo, suggestions anyone? What's the best way to go?

Tankstand
14th Jan 2005, 12:22 AM
Darryl, I briefly saw the GMC welder at Bunnies but had no time to stop and examine it. It would be advisable to check its duty cycle (usually expressed as a percentage) anything under 20% may be a limiting factor. I.E. resting the machine 10 minutes after welding for 2 !

Maybe someone has already checked it out?

You can't go wrong with the CIG, mine has been brilliant. Just my biased opinion ;)

bsrlee
14th Jan 2005, 12:23 AM
Welder-wise, if you buy a stick welder in the 10amp plug range - get one with a fan - it drastically increases the duty cycle. I have a basic CIGweld unit with a fan, & it seems to have aout the same duty cycle as my old 15amp machine, just the variable amperage is in switched increments rather than continuously variable. A 15 amp unit is only a little bit more expensive than a 10amp unit, and if you are naughty you can either put a 10amp plug on it or make a 10>15 amp converter cord - most houses are now wired with 20amp rated wire, so the socket dies before the wiring catches fire.

I think the GMC cutoff saw will be fine, or anything with a 3 year warranty - mate of mine has not had a cutoff saw last much more than 2 years - and he buys Makita & Hitachi industrial grade tools - the gear box goes first.

Geoff Dean
14th Jan 2005, 07:11 AM
The GMC cutoff saw is not to bad for something in this price range. I bought one about 3 years ago to build some retainer walls and cut a lot of 100mm I beam with it. It still goes well today. the trick is not to try and cut to quickly, just let the saw do the work for you. :)

outback
14th Jan 2005, 10:57 AM
1. GMC CUtoff
2. CIG stick

or better yet, mig, the thin walls in the RHS is a shiiit to weld with a stick welder, but piiiis easy with a mig. For your requirements a wee little gasless, or small exchange bottle driven gas mig would be the ducks guts.

Dean
14th Jan 2005, 12:08 PM
The GMC model is rated at 25% duty cycle.
Here's my basic review - http://www.onlinetoolreviews.com/reviews/gmccen.htm

Hope that helps.

goat
14th Jan 2005, 01:34 PM
i have a cig gas/gasless mig and a cig stick and a cheap warrior cut off saw. my welds with the stick welder look like big blobs of chook poop but the migs welds look very presentable. so if ya havn't done much welding like me i'd go for the mig, i got mine (140 amp) out of the tradingpost $220 (cheap). the cut off saw ($120) is crap i should have gone the gmc platnium ,but it does the job don't try to force it just let it do the work .hope this helps

DarrylF
14th Jan 2005, 07:49 PM
Thanks guys :) Looks like my initial thoughts were about right. I'll pick up the GMC cutoff saw - and take it reasonably easy on it. For a welder I'll hunt for a second hand MIG or gasless MIG and failing that probably pick up a CIG stick welder. I'm reasonably comfortable I can pick up stick welding again, but MIG opens up more options I guess.

Any other thoughts would be helpful of course.

Glen Bridger
14th Jan 2005, 08:23 PM
Hi Guys,

For home use I wouldn't even bother worry about Duty Cycle. The Duty Cycle is the percentage of welding time per 5 minute blocks at maximum output current. (Its not the Workshop push-bike)

For example: If a welder has a Max output of 140 Amps and 25% Duty Cycle you can weld for a total of 1.25 minutes at 140 Amps per 5 minute block.

If you reduce the output Amps, the Duty Cycle increases. At 80 Amps it would be around 50%, which is quite a lot of actual welding time.

A hint with Gasless Migs, the wire/flux will absorb moisture and effect the weld quality. So if you only use it occassionally, remove the spool and store it in an air tight container with some dessicant gel.

Glen.

glenn k
16th Jan 2005, 03:04 PM
I bought a GMC cutoff saw and have had no problems with it. I have had an arc for years but recently bought a MIG off ebay new. I run it gasless but the spatter was bad so I went to gas. Now it sometimes looks like I can weld.

Glen Bridger
16th Jan 2005, 07:26 PM
Hi Glenn,

Most TAFEs run home handy-man welding courses which go for a few weeks. Might be worth looking at.

Glen.

DarrylF
23rd Jan 2005, 10:04 PM
Picked up a GMC cutoff saw and a CIG arc welder yesterday and got to play with them this afternoon. I learnt a few things.

The CIG is the second one up in their range. 25% duty cycle at 75amps. Fan cooled. $199 at Bunnies - good setup.

The cutoff saw is worth the $99 it cost. The cutting disc it came with is rubbish. Worked a lot better with a decent disc on it. The clamp/mitre setup is a little crappy, but I kinda expected that.

Main thing I learnt though is that it's a LONG time since I did any stick welding and I'm going to need a LOT of practice :)

Did a bunch of test welds on some flat bar and managed to make most of them look pretty good.

I cut the 4 sides for the frame for a new table saw side table - 40mm angle cut at 45 degrees on the corners. Cutting was interesting :) Trying to remember how best to measure & mark out steel for a start. The early attempts to use the GMC cutting disc left a couple of very rough cuts. As a result trying to use the magnets to hold the joint together to weld was not fun. I managed to tack it together reasonably square - though I had to break & re-do one tack weld.

Made a mess of most of the welds from there on I'm afraid :) Had every type of problem there is I think :) Got it basically done though. I did manage to flash myself twice, but not too bad.

Ground back all the welds and realised I still have a bunch of voids and I'd missed the outer edge of one joint completely :)

The mask that comes with the welder was rubbish - but I knew that. I bought the $19 CIG helment. Not too great. Lens in the wrong place (too high). Uncomfortable. Doesn't flip up easily. Worth the $19 I guess.

It was kinda fun to work with metal again :) Happy with my purchases for the money.

Tankstand
23rd Jan 2005, 11:09 PM
Darryl, practice makes perfect. I had to learn not to panick or hold my breath (Scared of those fumes at first). and learn to read the weld puddle (I.E. don't feed too fast.).

We look forward to the pics of the finished bench. :)

Glen Bridger
24th Jan 2005, 09:57 PM
Hi Darryl,

Mark's right, welding takes practice. Like all good hand skills a little bit of knowledge, the right equipment and practice and you'll get there. Years and years ago, I did 2 years and night school just so I could do general welding. I certainly couldn't make a living out of it, but for stuff around the home its OK.

One thing which may be worth a look is the type of electrodes you use. CIG/BOC make some real good "handyman" rods for their small welders. These are much easier to use then General Purpose rods. I think they are an Iron Powder rod. They cost a bit more but hey, if they do the job!!

One other tip, using an extension lead can reduce the input current slightly, so try to move the machine closer to the power point. (My second year teacher told me that.)

Hope this helps.

Glen.

DanP
24th Jan 2005, 10:13 PM
(Scared of those fumes at first).

Don't really worry about the fumes unless you're welding gal. Then try not to breathe too much of it. I had a big day welding lots of gal and felt like crap for a couple of days afterwards. Weld outdoors or set up a fan if you're welding gal.

I have used the most expensive rods you can buy and I have used the cheapest rubbish you can get. I'll be buggered if i can tell much difference, other than with the expensive ones, there is less spatter and it's easier to get a perfect weld.

Wait till you get your first good dose of 'sunburn' from the welding. Cover up when you plan on doing a fair bit of welding, full sleeves and long daks.

Dan

journeyman Mick
24th Jan 2005, 10:21 PM
Welding with damp rods makes things really hard. If you live in a high humidity area keeping the rods in a drying cabinet or giving them a few hours in a low oven will make for rods that are much easier to strike arcs with and give a much cleaner weld - less sputtering etc.

Mick

DarrylF
24th Jan 2005, 10:50 PM
Thanks guys :)

I'm using decent CIG rods out of a sealed pack - so that's OK. I've managed to get some really good welds, so I know the basics are correct. The big problem was putting this frame together yesterday. Just couldn't get it right.

I decided to finish off the job tonight and did a lot better.

Couple things I worked out. First is I don't think just leaning over the job is a good idea. I sat on a stool and made myself comfortable and had a steadier hand as a result.

I also actually read the manual from the welder last night :eek: It's pretty good really - nice, clear & simple instructions on how to weld.

I worked out the welding helment is adjustable too - sits much more comfortably now. Guess I should have at least looked before now :)

Much better result tonight. Pretty clean welds and not too much of a mess. Getting there.

Glen Bridger
24th Jan 2005, 10:50 PM
Very good point Mick,
I forgot to mention that. Some packets have drying instructions on them.
I keep my electrodes in PVC Storm Pipe. Just glue a push-on cap on one end and use one on the other end for a lid.

Glen.

By the way, if you want to cut some steel with them, soak them in water and crank the AMPS up to Max. When you strike the arc it will blow holes and cut thru. Its very rough but effective. Be careful handling wet electrodes. (You can buy special cutting electrodes too.)

Kiwibrucee
5th Feb 2005, 11:59 PM
Hi,My father used to keep his electrodes in an old fridge with a light bulb mounted in it to provide a little heat and keep them dry.It seemed to work well and we were in a fairly humid area.