Some questions from a new learner

[geoffsurf]

Hi everyone,

I've got a secondhand Sealey Supermig 185 welder that I'm learning to weld with. I just have a few questions that I'm unsure about.

1. After welding for a while I'm not sure whether I should leave the welder on so that the fan keeps running and cools the welder, if so for how long? Or whether its wearing the welder by leaving it on.

2. A professional car body welder taught me the basics last year, but I have been following useful guides on this website and realised that I have not been doing any zig zag movement. With thin car body work is it normal to be doing zig zag movement as you go along?

3. On a lap joint is it normal that the top sheet lip will melt back quite a bit or does that mean that the amp setting is possibly too high.

4. I have to cut and weld in three pieces of about 6 x 40cm sheet into the floor of my van, is the best approach to use a cardboard template and then use this to cut the panel out of the sheet of steel? I also wondered whether 'intergrips' are a good idea to hold the panels while I weld them in (although I'm worried as these seem to require a gap between the butt weld and I find that I manage to blow holes when there is any gap in the butt weld).

4. I seem to have a lot of black soot around my weld and wasn't sure whether this is just same paint around the weld or whether something else might be wrong.

Sorry for the large amount of questions just so much to learn.
thanks
Geoff

 

[Wozzaaah]

1. After welding for a while I'm not sure whether I should leave the welder on so that the fan keeps running and cools the welder, if so for how long? Or whether its wearing the welder by leaving it on.

If doing lots of welding then leave it on unless there is a lot of prep to do between runs in which case turn it off, as long as the machine is on it's using electricity.

2. A professional car body welder taught me the basics last year, but I have been following useful guides on this website and realised that I have not been doing any zig zag movement. With thin car body work is it normal to be doing zig zag movement as you go along?

Some like a weave, some don't. If the joint is sound without it then in my opinion there's no need.

3. On a lap joint is it normal that the top sheet lip will melt back quite a bit or does that mean that the amp setting is possibly too high.

Yes, that's completely normal, you have to bias the heat toward the lower metal to try to alleviate it.

4. I have to cut and weld in three pieces of about 6 x 40cm sheet into the floor of my van, is the best approach to use a cardboard template and then use this to cut the panel out of the sheet of steel? I also wondered whether 'intergrips' are a good idea to hold the panels while I weld them in (although I'm worried as these seem to require a gap between the butt weld and I find that I manage to blow holes when there is any gap in the butt weld).

cardboard templates are a very good idea, they save a lot of hassle caused by trial and error. Intergrips are good for butt welds, if you're burning through then maybe your parameters are wrong, wire size, type, gas, current etc

4. I seem to have a lot of black soot around my weld and wasn't sure whether this is just same paint around the weld or whether something else might be wrong.

Looks like a major lack of shielding gas. Are you using disposables cylinders? If so then you pretty much have to open the reg right up to get a reasonable flow.

Sorry for the large amount of questions just so much to learn.
thanks
Geoff

Don't worry about asking questions, that's what the forum is all about .

 

[geoffsurf]

What I'm not sure about is whether if I turn the machine off after heavy use it will overheat and damage it, whether it needs to be left on so the fan cools it or would it be fine to turn it straight off with the fan only being necessary when actually running?

I haven't tried intergrips but I have been reading about them and that they require a slight gap between the two pieces of metal. Do you have any experience with them, are they harder to weld with on a butt joint? I have found that I blow holes in the metal when there is a slight gap between metal with either a lap or butt joint, but if right up close together no problem.

I'm using a big Argo sheild BOC bottle with brand new regulator, it has plenty of gas but I only realised after the welding in the picture that I had it flowing at 10 on the dial. I'm not quite sure how to learn the correct amount of gas flow. Can you suggest any way of learning how to get the correct flow?

thanks

I'm not

 

[Wozzaaah]

I always turn mine off as soon as I'm finished, as long as there's no power to the machine it will be cooling, not heating up. If using a small mig at high power for extended periods then i suppose it might be a good idea to let it idle for a couple of mins but I don't really see it's necessary. I've never used intergrips myself but on a butt weld you should have a slight gap to help with penetration.
Is your reg calibrated in cfm or l/min? You definitely haven't got enough gas flowing so either it's being blown away (welding outside or in a draughty area?) or you simply don't have the reg set properly. You should have it set at 10 l/min or about 21 cfm.

 

[geoffsurf]

Ok, I have just ordered some intergrips so hopefully that will help with the floor panels that I want to put in. I didn't realise on a butt weld that there should be a small gap, so I better start practicing with a slight gap.

I'm welding on the flor just inside my garage with the big front door open, but I don't think there has been much wind. I have just checked and my regulator is calibrated in l/min, I think it was flowing at 10 l/min on the guage but I will give it anothe try and see if it's the same. If it is should I try turning it up a little to 15?

 

[Wozzaaah]

Yep, turn it up a bit and/or set up a windbreak, I'm sure that's the problem, it also may be that you're holding the torch too far from the workpiece and losing gas coverage that way, as a rule the contact tip should be about 8mm or so from the workpiece.

Just as a by the way, that sheet looks like it's zinc coated (zintec) but I can see you've ground the coating off so it should be ok, just be careful though, zinc fumes aren't good to breathe in and if you get any sign of that white/yellow fluff coming off then stop, get some fresh air and clean the metal more .

 

[geoffsurf]

Cool, thanks. I didn't get a chance today but tomorrow I'll have another good go and practice more. I guess the answer is just to carry on and keep practicing so that you can do the same good quality weld 7 times in a row, and after a break do the same again. Other than that it's hard to know what the next step to getting better is.

Ahh right they are bits of metal shelving, sounds silly but I thought it was just painted. I did notice smoke coming off which I didn't think was too good, possibly from the back. I read the other day on this site about how bad the fumes are, think I will clean the metal a little better.

On the subject of fumes I have some POR15 paint which I need to apply to some surface rust on my van and I've heard that the fumes are not good, don't suppose you've heard of this paint and know where to buy breathing equipment that would do but also not too pricey, I'm not sure what I need.

 

[Robotstar5]

On the subject of fumes I have some POR15 paint which I need to apply to some surface rust on my van and I've heard that the fumes are not good, don't suppose you've heard of this paint and know where to buy breathing equipment that would do but also not too pricey, I'm not sure what I need.

I've used POR15 to paint my Land Rover chassis (outside) and did not notice the fumes from it

 

[bigbadbugga]

I have just used por15 on my bug, the fumes are quite strong but as long as you use it in a well ventilated area and dont hang around brething the fumes for too long you will be ok.

However I would not spray it if I where you, I tried to spray it in a small touch up gun last week and was coughing and vomiting for an hour after a couple of minuites spraying even with a mask on. I would only ever advise spraying it with a pro setup and air fed mask. Also the overspray is inpossible to remove, as is any spillage on hands etc

 

[geoffsurf]

Cool thanks both of you. I rang up a shop that sells spraying equipment and they said exactly that. That your safe brushing it on but not spraying. Wow quite shocked that the air fed mask still wasn't good enough.

 

[geoffsurf]

I have been practicing over the last few days straight lines on a piece of metal and also doing butt welds. I seem to have issues with penetration, I think that my tack welds aren't penetrating properly and so the area around them isn't good?

 

[geoffsurf]

With my Sealey 185 Supermig I have 6 settings and keep changing between setting 2 and 3 on 0.9mm sheet metal. I also keep fiddling ever so slightly with the wire speed. I'm not sure if my welding is getting better or worse. When doing short bursts in order to keep heat down do you move while actually welding or move between the pulses?