cassidym
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| posted on 3/7/04 at 10:14 PM |
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MIG/TIG weld chassis
Hi all,
Apart from cosmetic appearance, speed of production, etc., which would be the preferred method to use?
I've got a Miller MigMatic 171 rated at 150 Amps and an EPS Exclusive 180M inverter rated at 180 Amps with all the TIG accessories.
My preference is the TIG as it has got a 100% duty cycle compared to the 35% of the MIG.
Before starting the build I plan to brush up my welding skills and would like to hear your opinions.
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Mark Allanson
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| posted on 3/7/04 at 11:16 PM |
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Go for the TIG, OK it will take you longer, about 50%. But as the chassis will probably only take you about 10 days, 5 extra days on a 18 month build
is bugger all - and TIG is sooo nice to do
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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Peteff
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| posted on 4/7/04 at 07:09 AM |
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You won't get anywhere near the limit on either machine. You could use the mig to tack it together quicker and then weld it up with the tig. On
the chassis most of the welds are only an inch long anyway.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Hugh Paterson
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| posted on 4/7/04 at 11:40 AM |
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Wots Mig, I aint used it since I discovered the delights of TIG Marks right its much better looking than blobs of Mig welds on yer pride n joy.
Shug.
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Jon Ison
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| posted on 4/7/04 at 12:06 PM |
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given the choice, id'e go tig on the chassis...... less distortion too
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spunky
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| posted on 4/7/04 at 01:09 PM |
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TIG is lovely to do and such a superior form of welding it would be my choice if I had the gear, however I think 50% longer is a little optomistic
IMHO.
Tack with MIG finish with TIG sounds ideal.
John
Oh yeah, at the risk of stating the obvious, beware of the UV rays from TIG. It's quite fierce and will give you sunburn
[Edited on 4/7/04 by spunky]
The reckless man may not live as long......
But the cautious man does not live at all.....
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Digger Barnes
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| posted on 4/7/04 at 02:54 PM |
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Is that true John that you get less distortion with TIG, I thought it was a hotter and slower weld hence more distortion?. P.S. I am using TIG on
stainless (now that is a whole can of distortion worms)
[Edited on 4/7/04 by Digger Barnes]
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Hugh Paterson
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| posted on 4/7/04 at 03:40 PM |
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Tigs hotter as well as slower, easier to control flow/penetration however, much better quality of finish
Shug.
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Jon Ison
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| posted on 4/7/04 at 06:56 PM |
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it is hotter but much more localised, look at the "rainbow" it dont run 1/2 as far..... like stated above you can see and control the weld
better, all IMHO of course......
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alainmengoli@hotmail.com
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| posted on 5/7/04 at 08:45 AM |
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why o why o why do I read threds in this forum??? Ended up buying a tig welder!! `oh well any one want a nearly new MIg welder SIP cost me nearly
£500?
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Digger Barnes
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| posted on 5/7/04 at 01:56 PM |
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I agree you can control the weld better John and the finished result looks soooo much nicer. The only thing with TIG is the need for a plenyfull
supply of welding clamps as a third hand.
P.S. Alain you wont regret buying the TIG, it can be very theraputic at times.
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alainmengoli@hotmail.com
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| posted on 5/7/04 at 03:44 PM |
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We'll see but I must admit mig is just like glueing. Not very reassuring. I love the row of coins tig creates. By the way hwo exactly do you
move the tig along is it a steady motion or do you stop then go?
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NS Dev
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| posted on 5/7/04 at 04:58 PM |
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For TIG welding I just use a steady motion, use the rod dips to give the finish (though for welding stainless steel tanks etc in my very limited
experience with TIG I have not used a filler rod at all, just seamed the corners together, seems to give the "stack of dimes" effect
automatically.
MIG welding done correctly is most certainly NOT like "glueing"!!! This is an incorrect setup problem, turn the wire feed down until you
progress nice and slowly and have plenty of time to watch the weld pool. Too many people let the welder run away with them and just "point and
squirt" (I know cos I used to!!). Don't, just slow it all right down to a TIG pace, set the MIG up for this then build up speed, not the
other way around. Doing it this way you will get perfect penetration with MIG and very neat welds (though not nearly as nice as TIG!!)
Given the choice I would use TIG for the chassis, but I don't have one at the minute so MIG has to do! Thinking about a TIG, you can now get a
decentish 140 amp inverter TIG from welderswarehouse for £350ish with all the accessories. However, it would be nice to be able to weld ally, and for
this you need an AC TIG which seem to start at £1500 for a single phase one, even s/h they are over a grand!!
For the minute I have a 230 amp single phase MIG which is nice and controllable at low settings for welding tanks up etc. (ironically, you tend to
find that big welders turned down are more controllable than small "diy" welders, don't know why but Mark Allanson might know? 3
phase welders are also so much smoother but then I don't have 3 phase!! doh!!)
[Edited on 5/7/04 by NS Dev]
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white130d
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| posted on 5/7/04 at 05:08 PM |
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TIG
TIG is (flame suit on) Simply glorified gas welding. You have a very focused heat source, and an inert/clean surrounding in which you feed a weld
stock into. Gas welding, you have an unprotected big damn uncontrollable heat source that is real dirty, that you feed a weld stock into.
TIG wins hands on for quality of weld in precision welding. MIG can be done well (I can lay a roll of dimes down any time on clean metal) and with
speed. Both methods take time, patience, practice and above all CLEAN METAL.
David
(will weld for beer)
PS, don't get a "Gasless" MIG if you want to weld well, although they work, you won't be happy with the quality
[Edited on 5/7/04 by white130d]
"There's only 2 things that money can't buy, and that's true love and home grown tomatos" Guy Clark
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DavidM
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| posted on 5/7/04 at 10:51 PM |
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MIG welding is cheaper, quicker, gives less distortion, and done correctly is just as strong and looks just as good. Looks different but just as
good.
Mind you it is also very easy to do it badly.
IMO
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alainmengoli@hotmail.com
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| posted on 5/7/04 at 10:52 PM |
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You said will weld for beer hmm.... should have said before I went out and bought a TIg. I own/run a pub and two bars will keep your email for future
services
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white130d
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| posted on 6/7/04 at 12:00 AM |
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Where!
Where in Derby are you, I will be in Matlock end of October (going to the Sodbury LR Sortout on the 23) will be in the Matlock are on the 24th -
28th
Peteff, you're in that are too aren't you?
David
"There's only 2 things that money can't buy, and that's true love and home grown tomatos" Guy Clark
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NS Dev
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| posted on 6/7/04 at 07:09 AM |
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quote:
Originally posted by DavidM
MIG welding is cheaper, quicker, gives less distortion, and done correctly is just as strong and looks just as good. Looks different but just as
good.
Mind you it is also very easy to do it badly.
IMO
pretty much hit the nail on the head there (though I would disagree about the distortion compared to TIG, but not gas) but as you say in the last bit,
very easy to MIG weld badly and get away with it and that's where the arguments against it mainly come from.
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David Jenkins
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| posted on 6/7/04 at 07:26 AM |
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quote:
Originally posted by DavidM
Mind you it is also very easy to do it badly.
It's also easy to do it badly and make a really nice looking weld at the same time! You can end up with a 'pretty' weld, which is
no use whatsoever.
It's been said may times on this forum - practice with scrap until you can make welds that look nice, but can survive being beaten senseless
with a 2lb hammer without breaking, and have full weld penetration when cut in half with a hacksaw. Aslo, be self-critical...if you're not sure
about a weld, grind it out and do it again.
rgds,
David
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Peteff
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| posted on 6/7/04 at 08:43 AM |
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Peteff, you're in that are too aren't you?
About 10 miles from Matlock in Clay Cross. It takes about 20 minutes to get there via the scenic route.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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NS Dev
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| posted on 6/7/04 at 01:21 PM |
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quote:
Originally posted by David Jenkins
quote:
Originally posted by DavidM
Mind you it is also very easy to do it badly.
It's also easy to do it badly and make a really nice looking weld at the same time! You can end up with a 'pretty' weld, which is
no use whatsoever.
It's been said may times on this forum - practice with scrap until you can make welds that look nice, but can survive being beaten senseless
with a 2lb hammer without breaking, and have full weld penetration when cut in half with a hacksaw. Aslo, be self-critical...if you're not sure
about a weld, grind it out and do it again.
rgds,
David
that's wht I was getting at really David, most MIG welds can appear ok but many can be just plopped on top if done wrong, as you say. With a bit
of experience you can usually tell good from bad, I work on the principle that I am trying to create a slightly concave fillet (this being the main
weld type on the locost chassis), rather than a convex one, and the concave fillet usually means good penetration as the "concaveness" is
usually due to the weld sinking into the workpiece.
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BradW
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| posted on 6/7/04 at 02:27 PM |
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Mig Tig
Hi,
Been following this with interest as I'm pretty close to starting the chassis, although still 'practising' MIG, do you ever stop
'practising' ??
The mention of the concave weld brought a question I have been pondering over, is it worth chamfering the edges of joints to form a shallow V to
'weld into', my thoughts are that this would help ensure penetration whilst keeping the surface pretty level, or at least leave some weld
there when it's ground (or should that be ginded) down.
Brad
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David Jenkins
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| posted on 6/7/04 at 02:31 PM |
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quote:
Originally posted by BradW
Been following this with interest as I'm pretty close to starting the chassis, although still 'practising' MIG, do you ever stop
'practising' ??
I don't know about that - but I do know that you can 'lose the art' if you don't weld for a month or two!
quote:
The mention of the concave weld brought a question I have been pondering over, is it worth chamfering the edges of joints to form a shallow V
to 'weld into', my thoughts are that this would help ensure penetration whilst keeping the surface pretty level, or at least leave some
weld there when it's ground (or should that be ginded) down.
It's not necessary to make a 'v' with the stuff we use - it's only 1.6mm thick so the weld pool goes right through. Your
biggest problem is trying to avoid blow-through!
David
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white130d
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| posted on 6/7/04 at 02:35 PM |
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chamfer
David J is right this is too thin. If you were welding 1/4" thick or more, then you want to bevel the ends.
David
"There's only 2 things that money can't buy, and that's true love and home grown tomatos" Guy Clark
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BradW
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| posted on 6/7/04 at 02:40 PM |
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Mig Tig
The blowthrough is one of the reason why I'm still practising, I am considering using 2mm rather than 1.6, I appreciate there is a weight cost,
but as I ma not planning on racing the extra strength (minimal) and easier welding do seem attractive, again any thoughts.
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