OT- Question to Group on MMA equipment

I recently picked up an oldish Oxford welding kit, model RT-110.
It works fine, there are no problems I can see with it.
But buying it made me read a few of my books that contain generalised information on the gear used and most seem to suggest that DC equipment is generally the norm, but both AC or DC equipment can be used. I am wondering if any member of the group can put a bit more light on the subject and state when/where AC would be better over DC and visa versa.
I will be doing a bit of searching on the web tonight to see what I could fine out but any thoughts would be much appreciated.
I could have bought one of the SIP or MMart machines for the same price I purchased this one but decided the oil cooled welder would be able to weld for far greater times that the other models. I know that my Mig welder will over heat after a few minutes at higher currents when trying to do thicker steels.
If any one can help with any information such as user guides or circuits on the RT-110 it would be much appreciated. I guess that Oxford welders are not trading as I have not found them via google yet.
-- Cheers Adrian.
http://www.aphtrading.co.uk/pages/apage1.htm Weekend Workshop http://www.aphtrading.co.uk/pages/apage2.htm Home made propane Foundry http://www.aphtrading.co.uk/pages/apage3.htm Learning CNC on a Vertical Mill
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On Sun, 4 Jan 2004 22:12:35 -0000, "Adrian Hodgson"

Adrian
I use AC all the time, for most purposes it's just as good. Some rods you may find less easy to use, others possibly easier. Scrounge a few different ones to see what you get on with. I use Murex Zodian Universal a lot. For most 'everyday' welding, it shouldn't be a problem. I think the 'Oxford' people trade under the name of (G&T??) Young, somewhere in Oxfordshire (surprise?). they advertise (MIG sets, I think) now & then in MEW or Model Engineer Identical sets were/are made under the 'Pickhill' brand - quite possibly in the same factory?, also 'Planet Walsh', though they are less common.
Cheers Tim
Tim Leech Dutton Dry-Dock
Traditional & Modern canal craft repairs
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wrote:

is
wondering
state
weld
will
thicker
on
Its a long time ago but I seem to recall DC can occasionally give problems with "arc blow" this is where the arc is magnetically deflected and wanders around. I seem to remember DC was preferred for non ferrous work. Oxford oil cooled welding transformers had a very good reputation in the steel contracting industry as a low cost professional tool that would work continuously. CHris R
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wrote:

The Lincoln Welder Co in the USA published some very good (thick & heavy) books on welding, a couple of which I bought secondhand on the Internet for pennies. That sort of information is worth having.
I seem to think that 'Oxford' was the trade name/mark and not the manufacturer, the other name was Twickenham Transformers which I have a connection with in my mind for some reason.
Peter
-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info: http://www.oldengine.org/members/diesel
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Thanks to the replies from Tim, Chris and Peter.
I did a search on Pickhill and found these people http://www.pickhill-engineers.co.uk/aboutus.htm saying that they are now the only manufacturer of oil cooled welding sets in the UK having over the years bought out competitors and the right to manufacture all the well known makes of welding equipment such as:
OXFORD, MAX - ARC, TIC On there pages they list all the oiled cooled sets they do and there is an Oxford RT-110 giving specs.
Looks as though the same spec is now sold in a Pic-arc welder as well as the Oxford..
I also found this web site. http://www.ukwelder.com/wk_menu.php
I have started to print off the pages for future reference, seems to be very good to me and does mention this problem of magnetic problem as used by DC machines when the weld goes passed the clamp.
Any how thanks for the information passed, I now need to get down to practice some time. Even thinking of a course!
-- Cheers Adrian.
http://www.aphtrading.co.uk/pages/apage1.htm Weekend Workshop http://www.aphtrading.co.uk/pages/apage2.htm Home made propane Foundry http://www.aphtrading.co.uk/pages/apage3.htm Learning CNC on a Vertical Mill

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AC possibly has an advantage on alu but DC will keep a steadier arc the best place to ask sci.engr.joining.welding if you get a reply from Ernie Leimkuhler his advice is normally spot on

wondering
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on
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Thanks for that I will go through the messages in the group to see what I find first before jumping in and asking what many will see as a dumb question.
Cheers Adrian
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Assuming this is a stick welder - AC will work fine for 99% of what you are likely to do. DC lets you run some specialty rods, and you can change polarity for welding thin steel. It also lets you fit a TIG torch and argon bottle for steel/ stainless work. This is the biggest advantage IMO geoff
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On Fri, 16 Jan 2004 20:34:09 -0000, "Adrian Hodgson"

In the meantime... http://lametalsmiths.org/news/electric.htm http://www.ukwelder.com/wk_menu.php http://www.ytmag.com/articles/artint153.htm http://www.aussieweld.com.au/arcwelding/index.htm http://www.machinist.org/army_welding/ (thanks to the US taxpayer) http://www.metalwebnews.com/wc.html
It is hard to beat having someone show you the basics, then lots of practice. I learnt a lot by getting a holiday job welding frames for supermarket refrigerated displays... geoff
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Thanks Geoff.
All in favourites for further reading
-- Cheers Adrian.
http://www.aphtrading.co.uk/pages/apage1.htm Weekend Workshop http://www.aphtrading.co.uk/pages/apage2.htm Home made propane Foundry http://www.aphtrading.co.uk/pages/apage3.htm Learning CNC on a Vertical Mill
wrote:

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Manual Metal Arc (MMA) welding, is IMHO an art form, i have spent 3 years learning techniques, (flat, Vertical, Overhead.......OUCH!!!! lol), although these days i only use TIG some things to keep in mind.....
Always use dry rods (half an hour in the oven at a low temp should so the job, let them cool a little and off you go)
Keep the ark length as short as possible (about 3mm is ideal) , this will reduce porossity (holes) and spatter.
Keep the rod at approx 80 - 85 from vertical
Use the correct Amps for the rod (im sure these can be found on the murex web site somewhere)
Make sure the metal you are welding is "clean" (free from rust, scale, and oil)
After some practice you will be able to do a weld and the slag will peal off behind it (the sign of a good weld)
-- From the Keyboard of Tim Bird Home Page www.timbird.net
Photo Gallery http://timbird.fotopic.net /
Gravity is not just a good idea........ ITS THE LAW!!! How can I soar like an Eagle.... When I am surrounded by Turkeys!!!!
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[snip]l)

Strewth! I wish mine would do that! All I've ever seen is slag firmly welded to the job together with a small amount of weld metal!
My "technique" is to put lots of slag + metal onto the job, then grind 90% of it off, then repeat ad infinitum, occasionally chipping the slag out of the bigger holes it gets buried in!
This pocess is continued till theres enough metal in the slag to hold the job together for its lifetime, and then cover it well with filler and paint. Some of the results of this quaint process have survived quite a good number of years now without signs of disintegration.
Somehow though, I don't think its really up to Coded Welding standard........
Not only that - its incredibly tedious!
Dave.
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peal
welded
paint.
number
Well, I seem to have sourced a training course to suit me at least. An outfit in Blackburn called Training 2000.
Through the company I have just attended one of the Contractors Safety Passport courses and new they did other useful things as well. They seem to train most of the BAE systems apprentices in the area, nice workshop set up. Plenty of Lathes Mills, etc etc.
Got permission to pay for my welding course through work and then for me to pay the company the same back. Two days basically of Stick welding starting with safety aspects to start and if completed satisfactory will get some form of Cert, that although will not be to Industry standards is used by many places to show competence!!!!
Is costing me 220 plus the dreaded VAT. A price that I would consider to be an investment for same time and hassle in the future. If I learn a bad technique then I have to get rid of that before I start over.
I would like to be able to make small lifting platforms or even a go-Kart for the kids and want to at least ensure my work is up to the task.
-- Cheers Adrian.
http://www.aphtrading.co.uk/pages/apage1.htm Weekend Workshop http://www.aphtrading.co.uk/pages/apage2.htm Home made propane Foundry http://www.aphtrading.co.uk/pages/apage3.htm Learning CNC on a Vertical Mill
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On Thu, 22 Jan 2004 17:42:41 -0000, "Adrian Hodgson"

Those 2 days tuition will save you half a year of futzing around. Money well spent.

Can't comment ont eh price, other than it is a a lot cheaper her ein New Zealand. Come on down for a holiday :-)

Stick welding is good for reasonably heavy sections, but welding thin wall tube for a gokart would be hard work. Better suited to tig. gas or mig welding. Not to say it can't be done - IIRC the Manz Norton frames used to be stick welded, by better welders than me. Geoff
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for reasonably heavy sections, but welding thin
Can't comment ont eh price, other than it is a a lot cheaper her ein New Zealand. Come on down for a holiday :-)

Thanks Geoff I may take you up and visit on a holiday some day. I have just been looking at a thread on sci.engr.joining.welding where it looks as though there are others with similar views to me.
It is more of showing competence to be able to recognise what is a good weld and how to correct mistakes.
The college is talking about putting a test piece through at the end of it, I have not even been there yet for god's sake and already they want me to spend 70 on testing!!!
--
Cheers Adrian.



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wrote:

[snip]> Stick welding is good for reasonably heavy sections, but welding thin

Thin tube can also be brazed - bicycle frames were always brazed, and they have stood up to pretty hard knocks over the years!
I made the stand for my Myford by brazing (and some bolting), and stands for things like the pillar drill are brazed (carbon arc, not flame) from 1" square tubing. Even so, care is needed not to blow straight through the tube walls with the arc flame!
Dave. - can't afford/justify mig or tig :(
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On Sat, 31 Jan 2004 16:19:10 +0000 (UTC), speedy2 wrote:

For a socket joint, bike frames (including motorcycle) braze or silver solder rules. For butt joints welding rules.
VERY rough rule, but generally right.

You can when you blow holes in your work :)
--
Steve Blackmore

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they
for
tube
Nah! You just do it again, but more carefully the next time! All my joints in 1" square tube have been butt joints, and they haven't fallen apart yet. A few things I DID weld in it, were an "interesting" experience!
The Myford stand was made from some 6 foot high L-shaped ex-supermarket freezer supports made from industrial 3"x1" box speedframe. Great stuff, till I had to actually BUY a piece new - (mine had come from the local council metals bin in their yard!) and the "new" piece wasn't a patch on the older (free) stuff. That had been seam welded, the new was thinner metal and only "occasional" spot welded! It did the job, but at what a price...
Dave.
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On Sat, 17 Jan 2004 00:25:48 GMT, "Tim Bird"

overhead - ichy. Wear gloves and a hat with a flap on the back.

Arc length does depend on what you are welding and what rod. A rule of thumb is the rod diameter away from the work. There are some contact arc rods, where the rod flux is touching as it arcs. Mainly sheetmetal stuff. A useful trick somtimes for nice finishing work is not to watch the arc itself, but the back of the puddle. You can see how even it is as you are welding to get that nice even ripple finish.

This does depend on the rod you are using as well as your skill level. Cellulose coated electrodes (AW code 6011) are often used for welding dirty steel and pipeline welding. Mega splatter and a tenancious flux. Also have some stainless rods like that. The more general purpose rutile (6013 - very common) and iron powder coated rods (7014, 7018) are a lot easier.
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