welding questions

[chenzo]

So I'm either brave, stupid or both and have now got a shiny new mig welder (clarke 151en gas/no gas) to do some work on the van.

the first and most pressing job is to weld new metal in to the rear side window holes as the small plastic windows the PO fitted are in fact bigger vertically than the triplex I've got hold of to fit (we want the proper full length windows).

I've kept the metal that I cut out from the door and RH side, so hoping as it is already the correct thickness and profile it will fit nicely.

Been practicing my welding on some scrap sheet (last did welding as an apprentice about 18/19 years ago and that was gas and arc) and although I can lay a decentish weld on to a flat sheet, when I try a butt weld with the stuff i cut out from the door, i end up with loads of blow through holes.

I'm using gasless 0.8mm wire at the moment and have tried various power settings but can't get a consistent weld that I would be happy attacking the van with so.....

What wire/gas do you use and any tips?

I'm thinking I need 0.6mm wire and a bottle of argon/co mix to get the best results with thin panels???

Also if I do mess it up is it recoverable?? ie can I then get someone with the skills to sort it out??

 

[ozziedog]

If you is a dab hand at welding,, I think it`s hard work without gas, if you ain`t done it for a bit I think it`s possible that you know what it should look like and therefor aren`t happy with what you`re seeing. It is hard without gas. A good pro will make it look easy whatever he / she uses. Recoverablity ,,,,,, that`s a toughy , on one hand anything can be done but on the other hand the last thing you want is to distort panels and large panels with flatish sections they`re the ones that want to do the twist (think Chubby Checker). Keep practicing and don`t go near a large flat panel until you`re happy, and try not to lay too much of a run down or your heading for distort city.

Ozziedog,,,,,,,,, Go on,, ask me how I know !!!! :lol: 8) :lol:

 

[tomedwar72]

I agree with Ozziedog, I think gasless 0.8mm wire isn't helping you here. For thin sheet work, it's much better to be able to see the weld pool which tends to be hidden under slag with gasless wire. Also 0.6mm wire would give a bit more fine range at lower power settings (used with Argosheild or similar welding shield gas).

Wire speed and power settings need to be fiddled with to find the best butt-weld option for your mig. Quite a few folk recommend this site for tips and advice:

http://www.mig-welding.co.uk/

There is a handy wire speed calculator and some good tutorials, the forums over there are a great place to find answers.

 

[Oslo_mark69]

agreeing with whats been said Argoshield and 0.6mm wire With panels small stitches and space the next weld as far away as you can so that you limit the amount of heat in one area. there is no rush in doing a good job. Remember you can always grind back .

 

[ronmidg]

I've given up trying to run a weld in body thickness steel, use tacks that eventually join up, 0.6 or0.8 wire is ok, tacking lets you turn the amps up a bit and then have less to grind off after, as soon as the arc stabilises its done, I can hear it quicker than my eyes adjust to see it, watch a few episodes of American Hotrod on Quest.

 

[dubs and classics]

In my opinion, when butt welding thin exterior panels, trying to run a weld will either distort the panel or blow through. The amount of heat required to penetrate properly when doing a run will distort 0.8mm metal in a second.

If you want to avoid a shit load of filling afterwards use a similar method to ronmidgs suggestion above. I would go for slightly bigger than a tack but not much.. do 1 to 3 spots at a time spaced away from each other at a reasonably high heat and lowish wire speed to ensure penetration and then let them cool for a minute or two before repeating. When it looks like you have filled all the spaces, carefully sand off the weld with flappy wheel, again only do a bit at a time to avoid heat build up and be carefull not to make the metal too thin. You will probably find a few gaps need filling once its all cleaned up. When butt welding like this its very important that the two mating edges are totally clean and no big gaps to fill. Its worth taking ages to do this, if you take your time you will need very little filler afterwards which saves time and makes a much better job.

Well, thats what I would do anyway..

 

[chenzo]

Thanks guys, hybrid tack welding it is then, with 0.6mm wire and some argonmix -- think I'll be doing plenty of practice first though

 

[67 BAY]

0.6 wire is best to use on bodysteel using argon mix will give you a hotter weld but it tends to be cleaner than pub gas/Co2 but its personal choice.Leave about 1mm gap and tack every 8-10 inches working round the panel,then tack middle of the tacks until you've welded it fully.Don't let the heat build up,same applies when grinding down let the grinder with a soft pad do the work too much pressure and heat can make the panel distort as much as welding can.


Steve

 

[bluebay]

Hi,as others have said ditch the gasless wire.Use 0.6 and argoshield,when doing verticle weld you generate a lot of heat just by the process.You will be better off with small tacks.Think about the heat your generating and ty and spread it around the work,work slowly and you`ll be fine.

 

[chenzo]

so should I have a small gap between the panels or not?

looking at the restoration guide book (can't remember the authors name, but the most popular one) he uses clamps which leave a small gap between the panels.

Also when it comes to gas - I'm waiting for either BOC or my local GEM hire to open tomorrow, GEM do air products gas bottles and are much more local - I take it that if the gas mix ratios are the same then there should be no difference between BOC and Air Products gasses???

any opinions before i go and get a bottle?

I am tending to favour GEM because they are nearer and also BOC are not open at the weekends - I am not near home during the week so could have problems getting gas from BOC unless I'm off work (although I see they do deliver)

and can anyone recommend a decent place to get steel sheet from for practicing - i did have some from my local homebase kicking about but have used that and they don't seem to stock it any more

 

[ozziedog]

I got an account with BOC but you`re right gas is gas and the independants have just the same gas and being open on the weekend is a huge bonus. The disposables are not cheap, but if it`s only a small amount , will probably work out cheaper for you. With my account ,,, I have to rent the bottles and pay annually (read that with one n ) :lol: So if you`re doing a bit,, this works out the best way, now that I`ve slowed down on the welding, I may look at one of the different ways that the independants do the big bottles, because I`m renting bottles at the mo and not useing the gas, :shock:
I wonder if anybods has worked out a rough formula ???? When to rent and when it`s not worth it ??

Ozziedog,,,,,,,, I don`t want to be a rent boy !!!!! :lol: :lol:

 

[chenzo]

I had thought about disposable bottles, but the people over on that welding forum hate them and reckon that you struggle to get good results due to problems with the regulators not pressing the valve in far enough.

But as it looks like I will be doing small tacks I'm wondering if this will be such a problem for me??

at the moment i've just got the filling patches on the rear window holes to do - but once i get started I know there will probably be more - i'm just going to try and repair the small piece of tin ware behind the pulley for example.

disposables are readily available at my local halfrauds and i do have a trade card which might give me some discount

any thoughts on disposables versus boc/ap??

 

[chenzo]

Got a disposable argon/co mix yesterday and some 0.6 wire - much better

I can see the weld pool and have already repaired some old tin ware I had as a practice piece

bit more practice and I'll attack the van :evil:

 

[ozziedog]

Well done,, but don`t forget that when you`re practising on a nice bench, it`s not quite the same under the bus with a shocker in your ear and a cv up your ass and you can`t quite get in here and there. Mainly when your practising,, do a bit of vertical as well, and try and make it a little confined,, just for realism. :lol:

Ozziedog,,,,,,,,, :mrgreen:

 

[chenzo]

yeah I'll probably end up setting fire to the hi-top :shock: :lol:

 

[ozziedog]

Just remember when welding near fibreglass,, it`s really hard to get a good earth for your mig !

Ozziedog,,,,,,,,,,,Seen it done ! :lol: :shock: :lol:

 

[chenzo]

:roll: that's where I'm going wrong arty0009:

 

[ProfessorWheeto]

DON'T RUSH IT! It's a large pre-stressed panel, if you rush it'll distort and then its buggered. As I was taught on my apprentiship, "if its too hot to flop your old chap out onto, its too hot to start welding it again"

But yeah, 0.6 and 5% argoshield. Not a fan of pub gas at all. Personally I wouldn't bother trying to lash in old steel either, just start with fresh clean steel. It's only a gentle curve to easy to replicate by hand. Just remember that your weld has to be solid, if you end up leaving holes or gaps you'll have problems later on down the line with moisture pushing through.

The regulators on those disposible bottles are total trash, if your doing a lot of welding it's going to make more sense to get some proper bottles and a decent regulator.

With regards to your welding gap, 0.5 to 1mm would be good, however if your not going to see the inside of the panel (due to lining etc) I'd be temped to joggle the repair patches to help with preventing distortion.

 

[chenzo]

yeah i had thought of joggling, i'll see what it is like when the window comes out again and i've got some time to get on with it

 

[ProfessorWheeto]

If you do go down that route, do yourself a favour and get a rolastep.
http://www.lb-restoration.co.uk/cgi-bin/store/commerce.cgi?cart_id=1295799591.7315&product=RESTORATION&pid=377" onclick="window.open(this.href);return false;
Brilliant piece of kit, much nicer finish than a regular joggler, and it does curves, and its quicker and its eaiser to keep in a straight line and it doesn't make your hand ache! Easily one of the best pieces of kit in my tool box.