Following on from this tread.
I spent a couple of hours yesterday doing more practice and breaking to make sure the weld doesnt break and playing around with the settings (turns
out i had it on power setting 4 when i thought it was on power setting 5 
) and came up with this. (be as critical as you like. the last thing i want
is to get to SVA and fail on my welding )
Description
I think the wire feed may be a tad high
[Edited on 30-12-07 by speedyxjs]
If the power is set high, it looks as if you need less wire speed.
What material is that square tube. In particular the wall thickness.
Ronnie 
Yep, wire speed looks a tad too high, otherwise it looks plenty hot enough.
Looks pretty good to me!
You might want to turn to power up a bit and move the torch a bit faster as it gives a better looking weld Although If you're going to grind
it down I would bother.
As said above looks good but you need less wire speed and maybe more power.
You said, "be as critical as you like".
Well we all have to start somewhere but the chassis of a road going car is probably not the right place to begin. Skilled welders serve an recognised
apprenticeship and train for several years before being let loose on any work of significance, even then their work is subject to non destructive
testing. Looking at your weld I would suggest that it would fail any NDT. Initially it would fail on a visual inspection, if it had ultrasonics done
it would probably show a lack of fusion at the root. If you were to grind the cap off then bend the weld along the line of the weld it again would
probably fracture. I am sorry if I appear to be blunt but your life and other peoples lives could be at risk if any chassis welds fail. In the long
term if "home grown " chassis fail either because of poor design or poor build methods then someone in authority will begin to look at our
hobby and restrict our activities to sticking body kits to Corsas. Please get some instruction and help before fully welding your chassis.
Oh and a Happy new Year to you all
Cheers for the replys guys.
Bonzo - its 1 x 1 inch 2mm thick rhs. i wanted to go a bit bigger because of the engine i am using.
quote:
Originally posted by llionellis
You said, "be as critical as you like".
Well we all have to start somewhere but the chassis of a road going car is probably not the right place to begin. Skilled welders serve an recognised apprenticeship and train for several years before being let loose on any work of significance, even then their work is subject to non destructive testing. Looking at your weld I would suggest that it would fail any NDT. Initially it would fail on a visual inspection, if it had ultrasonics done it would probably show a lack of fusion at the root. If you were to grind the cap off then bend the weld along the line of the weld it again would probably fracture. I am sorry if I appear to be blunt but your life and other peoples lives could be at risk if any chassis welds fail. In the long term if "home grown " chassis fail either because of poor design or poor build methods then someone in authority will begin to look at our hobby and restrict our activities to sticking body kits to Corsas. Please get some instruction and help before fully welding your chassis.
Oh and a Happy new Year to you all
He may be bordering on rude (not my opinion) but he has a point ! Get some tuition, well worth the cost and will save you money/tears in the long run.
Try to let the weld in front of the torch.
looks as if you did not travel at the same speed.
We all needed to learn (and still do), so don't be bothered by critics.
As you use 2 mm 25x25 the tube won't be the trouble.
I noticed that welding 25x25 2mm at 140A or 160A with 380 Volts for me is the best.
Lower results in a weld which is "on top" off the rails and not welded really tru.
What you can do is grind it so can see if the weld is melted tru. If so the weld is more than strong enough.
It is also not nessary to be a proffesional welder. I've seen bad welds on fabricated chassis and wishbones from different manufactures.
The chassis design is really on the safe side. So it won't crack down the first ride.
Regular checking like MOT does the rest.
So go on and try to find your way to a nice weld.
Happy building.
Dont be disheartened, welding can be an arse to get the hang off initially.
Things that helped my MIG learning were:
Not using a hand held helmet.
Using a 9EW lens
Stopping practicing on joints, straight runs up the box section means I wasn't spending most of my time cutting up test pieces. If I did a
6" run up the length of box I could vary my speed/torch angle etc to see whats best. 1" runs are not long enough for that.
Turn the wire speed down as far as it will go, slow the torch speed down to compensate.
Destruction testing is a good idea to see what you have produced. If you are welding joints, weld one side of the box and wring it backwards and
forwards until it breaks off. This is what I did.
http://www.locostbuilders.co.uk/viewthread.php?tid=57862
Keep going but stop welding your chassis, you wont be happy with those welds once you do get the hang of it.
HTH
David
I think im getting the hang of it now
Image deleted by owner
This one looks much better. All the practice i have done have gone through to the other side and the weld hasnt broken when i break it. I had lessons
a couple of years ago but then went a year without welding and then obviously just tack welding while i was building the chassis. I have been trying
the arc technique as in the website mangogroove posted on the original thread which i think is why they look so wide.
[Edited on 30-12-07 by speedyxjs]
cool you getting it, not difficult really. Try resting you arm on something to stop any shaking. Oh and select macro on the camera to get close ups
[Edited on 30/12/07 by Mr Whippy]
quote:
Originally posted by Mr Whippy
cool you getting it, not difficult really. Try resting you harm on something to stop any shaking. Oh and select macro on the camera to get close ups
ah, the phones...a bit of card behind the tube might get the camera to focus better, unless its fixed
dont know if someone has already said this but a good start is to have the power on full, unless you have a particularly big welder. But on 2mm section i would have had my 135 on full, adjust the wire speed to match. You do have to be careful to avoid blowing holes, but thats almost the idea - you know you have full penetration if it blows a large hole! But do this on scrap, not your chassis. Once familiar with full power you can wind it down if you want.
sorry mate that looks very bad to me.
but i have been doing it for over 20 years .
turn the power up more then try it or grid the edges like this LIKE A V THEN WIELD IN IT TO FILL IT then try and brake it with a big hammer .
the best tip I was given when learning to weld was the pattern, ie lots of over lapping loops <5mm, rather than dragging the torch in a straight
line. It gets more heat into the weld as you hold the weld pool in one place for more time.
Hope this helps. I'd strongly suggest you stop welding the chassis now until after pracitising on off cuts you are comfortable producing a good
strong weld every time.
[Edited on 30/12/07 by gregs]
quote:
Originally posted by andyharding
quote:
Originally posted by llionellis
You said, "be as critical as you like".
Well we all have to start somewhere but the chassis of a road going car is probably not the right place to begin. Skilled welders serve an recognised apprenticeship and train for several years before being let loose on any work of significance, even then their work is subject to non destructive testing. Looking at your weld I would suggest that it would fail any NDT. Initially it would fail on a visual inspection, if it had ultrasonics done it would probably show a lack of fusion at the root. If you were to grind the cap off then bend the weld along the line of the weld it again would probably fracture. I am sorry if I appear to be blunt but your life and other peoples lives could be at risk if any chassis welds fail. In the long term if "home grown " chassis fail either because of poor design or poor build methods then someone in authority will begin to look at our hobby and restrict our activities to sticking body kits to Corsas. Please get some instruction and help before fully welding your chassis.
Oh and a Happy new Year to you all
There is critical and there is rude and your post borders the two. Perhaps more positive suggestions on improvement and less "you are going to die" drama would be more helpful?
Agree with both gregs and thunderace here, file or grind a v shape groove, then when welding push torch foward, if you feel you're not getting
enough weld pool into the groove then move tip side to side gently to fill the groove. this shouldn't be the case with 2mm though
but practice on scrap first, a jaguar engine will shove out a lot of power so i'd want everything to be as good as poss
you dont want to do all that hard work and then be disapointed if it fails
Good luck
I'd suggest making up lots of non structural bits first!!! Your welding is definately getting there (in fact, it's getting better than
mine!!) but a poorly welded chassis will not be fun. Even ignoring the safety issue for a little while, if its not rigid, it'll handle like
rubbish!!! Also, if you do find any failed joints once it's on the road it'll be a right PITA to re-weld them after its all painted, the
bodywork is on etc.... Better to do it right in the first place...
I do acknowledge the issue re our gorgeous nanny state regulating the hell out of anything. I can quite easily see a situation where they say any
amateur car builders have to have the welding assessed (rather like Part P for electrics)..... SVA is all well and good but when you compare it to the
build-up assesment for amateur built planes it's pretty mild...
Unfortunately, most people start at the beginning(!) which means starting with the chassis welding- possibly the most structurally important part (or
maybe that's suspension)....
Practice, practice, practice until your welds are 100% reliable and strong. Keep on posting pictures (welding porn )- the welding experts can give
advice and the welding muppets (me included) can learn from your mistakes and learnings!!!
It could also be the case that your welder is poorly set up to start with. I am assuming you are using a Clarke 150 amp.
My Clarke 105EN likes a fairly tight feed roller and a loose as possible wire holder. Loose as in just tighter than unwinding itself.
You have already said you are using amps setting 5, which on a 150 amp welder should be enough. Have a play with the wire feed, you should be able to
get a weld anywhere between 5 & 7, but you will have to radically alter your technique at these limits. There is a world of difference between 6
& 7 once you know what is going on.
There is a quote from someone on here, one of the more knowledgeable welders on here, that if you are blowing holes then you are just a fraction away
from a proper weld.
Blow those holes buddy.
Oh Dear!
Just got in, wished I had stayed out.
I am sorry if I caused any offense. I have seen some very poorly welded kit car components and chassis and I just feel that we should raise our game.
I am not in a position to instruct any one about welding, I will leave that to the experts.
My blood boiling rude comments where meant to help not hinder.
Please accept my apologies for any offense I may have caused.
Cheers guys. Been out doing more practice and got pretty good. Welds were much flatter and smoother and looking quite good. Then ran out of wire but i
will get some more and go for .6 rather than the .8 i was using. Thanks alot for your help.
Edit - cutting a V in the workpeice, brilliant advice.
[Edited on 30-12-07 by speedyxjs]
I found 0.6mm wire better suited to my slow style.
Seriously, try some 6" runs up a length of box - you will learn a lot more.
I wrote a really long reply about why it's a good thing to take a welding class, but the page refreshed and all that work went down the drain. To
summarize:
Take a welding class. It's worth WAY more than you could ever imagine. I'm going to a MIG class right now 4 days a week 4 hours a day. It is
some of the best money I've ever spent. I can't stress it enough, call your local junior college and find out if they offer welding classes.
Things might be different over there but my teacher is a car guy so we're allowed to build stuff in the shop as long as we keep out of the way
and don't leave a mess at night.
Also I have access to much nicer equipment than I could ever afford. I think the class came out to $175 with the $25 materials fee. With that I can
use any equipment in the shop including the tubing bender and TIG machines. It's actually a full service fabrication shop. Next door is the auto
shop and machine shop, where they not only have expensive CNC machines, but they teach you how to use them as well.
I've gotten a bit off my point, but learning how to weld properly is going to help you very much so down the road.