How many amps ?

[JD7710]

Hello all

I'm needing to weld 15mm plate onto the ends of 254x146x31 I beam for a portal frame shed, current setup is a 10yr old sealey supermig 220 running 0.8 wire on argoshield universal. Now I'm thinking the old sealey won't be man enough for this job so what welder would be upto the task ?, only have single phase until this new shed is built will then be putting 3 phase into it.

 

[SiPMerlin150]

Even with that mig maxed out, you will run the risk of a cold joint. You be better off using an arc welder with some quality 7018 electrodes, like 3.2mm and around 130 amps. I have heard that any steel over 18mm thick will require a preheat with some burning gear like a torch. This is my 2 cents, other more experienced people will be along soon

 

[shenion]

According to the miller weld calculator, 12mm is 315 amps; 1.1mm wire and spray transfer. That is as high as it goes.

I'd say you would want a 600A machine to do it in one pass.

Multi-pass you would want to be high enough to reach spray transfer to use MIG, 200A at least and the appropriate gas (universal would be for short arc.)

Arc would be easier to achieve multi-pass.

 

[Jim_gsxr1000]

Id stick weld structureal work, much less chance of geting a cold joint, 4mm 7018 (Vacume packed) if u want to be ubber fancy

 

[Drains]

Turn up the Sealey and do multi pass welds. It's not ideal, it's not in spray transfer and it's not like doing stick 7018, but it will work. You might get some cold laps on stops and starts. So don't stop and start. Nae bother.

I'm really not sure about the Miller calculator suggestion. I've had 300A machines that would utterly destroy 15mm steel on full blast.

 

[matt1978]

^^^^^^^^

Agree with Signor Drains.

That a larger machine would be ideal, about 350 amps would weld 15mm on a 1.0mm wire but that's not realistic because you would have a WFS of around 19m/min and it would be totally uncontrollable.

Just have your exisiting machine flat out and do 3 runs.

A 12mm Leg Length fillet is about the absolute maximum that you can do in one pass and that requires a lot of skill and usually with the Aid of some sort of special welding process, such as Lorch SpeedArc or ForceArc from EWM.

A 8mm fillet is much easier to acheive as your root then do a split cap either side of it to get the required leg length.

 

[JD7710]

Just to update this a little, I'm gonna get rid of the old sealey and get either a technical arc or an oxford in the 350/400 amp range. I can get either of those machines for around a grand including vat (I can claim vat back aswell) is there any other machines worth looking at ?.

 

[lshigham]

Just to update this a little, I'm gonna get rid of the old sealey and get either a technical arc or an oxford in the 350/400 amp range. I can get either of those machines for around a grand including vat (I can claim vat back aswell) is there any other machines worth looking at ?.

Portamig are worth a look for sure (also available in 230v)

http://www.weldequip.com/portamig-hd-400v-mig-welders.htm

 

[tlovatt]

Tech arc, portamig, oxford and MTA are all built by the same company, and other than the extra capacitors in the oxford there is little difference in them

 

[Jim Davey]

Spread the net further afield, I just picked up a very tidy used EWM Phoenix 400 pulse mig with cooler, torch reg and earth for a grand. And frankly that machine will take any welding machine mentioned so far and rudely smash it's back doors in. Good bargains out there if you know where to look.

 

[driftkingireland]

i agree with drains too, your welder will do it just fine. turn it up full blast and just keep welding untill its filled. ive welded bigger with similar welders with no problem.

 

[dannyp]

well to give the welder the right wire and it'll do a much better job.

0.8mm just isn't going to cut it but with 220A it'll be right at the machenes top end but it should be abel to carry 1.0mm wire, you'll proably have to root and cap but it will do it

 

[JD7710]

well to give the welder the right wire and it'll do a much better job.

0.8mm just isn't going to cut it but with 220A it'll be right at the machenes top end but it should be abel to carry 1.0mm wire, you'll proably have to root and cap but it will do it

The sealey won't take 1mm wire, 0.8 is the largest size I can have in it because of the feed roller that's fitted. I have asked in the past at my local welding supply shop about getting a larger roller and running 1mm they say no other rollers available and the machine won't stand 1mm wire !.

 

[Lawnmowerboy]

It will work with that feed roller. Many others get by with it.

 

[dannyp]

feed rollers, apparently you should use the right size rollers ......... my 0.8 rollers have been feeding 1.0 for so long they cant grip 0.8 any more lol

 

[Ed.]

Don't want to denigrate your welder, but if your going to max out your unit you will have a big issue with the duty cycle! When I built my shed I ran a 6mm extension cable from the house circuit box to the shed to power the 235A Unimig, when it came to do the 12mm footplates I run mine almost at full amps for quite a while and ended up with a fried circuit board.

Personally I would not use your machine for the plate and beam size, especially with 0.8mm wire. I "googled" your machine and I am not 100% sure if yours is exactly the same as the specs I found but if it is, then the duty cycle is woefull, these are the specs I found.


http://www.toolstop.co.uk/sealey-su...-mig-welder-220amp-230v-with-euro-torch-p7755

Seriously it is not up to the job.

It's Duty Cycle is: 100% @ 70A, 60% @ 85A, 15% 160A, 10% @ 170A. Your unit may be listed as a "220" but it doesn't run at 220A. It will start to run out of juice almost from the start at full amps. Incidently the duty cycle on mine was about 40% at 200A even though it was listed as a 235A model and even then it was barely up to the job and that was with 12mm plates.

If your house? is already 3 phase wired, I would get a sparky to connect an external 3 phase outlet and then go and hire a decent welder about the 300+ amps @40% run 1.2mm, run a 6mm extension lead to the shed area or wherever you are welding the plates, this is assuming that the welding area is reasonably close to the house or where the power supply is. That way you will have the amperage to weld it properly and you will sleep at nights when a storm comes.

Just my 2 cents worth

Cheers

Ed.

P.S. Oops I didn't see your post #7 where you said that you were going to upgrade your machine, but will leave this post as it will inform other members here that you need the right sized welder to tackle medium to heavy fabrication and that model numbers don't mean a whole lot.

 

[JD7710]

Don't want to denigrate your welder, but if your going to max out your unit you will have a big issue with the duty cycle! When I built my shed I ran a 6mm extension cable from the house circuit box to the shed to power the 235A Unimig, when it came to do the 12mm footplates I run mine almost at full amps for quite a while and ended up with a fried circuit board.

Personally I would not use your machine for the plate and beam size, especially with 0.8mm wire. I "googled" your machine and I am not 100% sure if yours is exactly the same as the specs I found but if it is, then the duty cycle is woefull, these are the specs I found.


http://www.toolstop.co.uk/sealey-su...-mig-welder-220amp-230v-with-euro-torch-p7755

Seriously it is not up to the job.

It's Duty Cycle is: 100% @ 70A, 60% @ 85A, 15% 160A, 10% @ 170A. Your unit may be listed as a "220" but it doesn't run at 220A. It will start to run out of juice almost from the start at full amps. Incidently the duty cycle on mine was about 40% at 200A even though it was listed as a 235A model and even then it was barely up to the job and that was with 12mm plates.

If your house? is already 3 phase wired, I would get a sparky to connect an external 3 phase outlet and then go and hire a decent welder about the 300+ amps @40% run 1.2mm, run a 6mm extension lead to the shed area or wherever you are welding the plates, this is assuming that the welding area is reasonably close to the house or where the power supply is. That way you will have the amperage to weld it properly and you will sleep at nights when a storm comes.

Just my 2 cents worth

Cheers

Ed.

P.S. Oops I didn't see your post #7 where you said that you were going to upgrade your machine, but will leave this post as it will inform other members here that you need the right sized welder to tackle medium to heavy fabrication and that model numbers don't mean a whole lot.

I fully agree with what you say about my sealey it was bought for car body work. I will get a much larger 3phase machine for building this portal frame there's 3phase at the farm workshop where I'll be working so no problem there.
The frame is 50 foot span and for my own premises so I finally have somewhere to run my agri contracting business from instead of renting space like I am at the moment so it needs to be done right.

 

[Ed.]

Hi JD7710, good to see your on the right path, a decent large machine will work wonders with heavy fabrication and you can always dial it down for the light welding. My Unimig was too light for the work I do and so when the Unimig fried the circuit board I decided to go the whole hog and install 3 phase, bought a used Miller Autovision 456, which is basically a unit for robotic welding, but with a bit of modifying and a remote wire feeder I can now use it as a basic MIG and haven't looked back since.

I also don't have to worry about duty cycles anymore as it's rated at 450A at 100% and 560A at 65%, not that I use those sort of amps as the max I have ever needed to use is 350A, but I can also dial it down to use 0.6mm wire and down to about 70A, so it does nearly everything I need.

If you get a decent MIG that does at least 350A-450A it should cover virtually everything that you will do. Plenty of good used, not to old, brand name machines out there ie; Miller, Lincoln, Kemppi, Ewm, Migatronic ect. I am partial to inverter types myself as they have better control of the welding parameters and very cheap to run. The right gas is also important, if you are going to do a lot of heavy fab stuff then Argoshield Heavy would be the way to go but if you do more light to medium fab stuff than Argo Universal or even a 93,5,2 mix. A thing to watch out for when running the high amps is heat distortion, heavy plate is not easy to straighten.

I don't think that anyone has mentioned it previously, but are you a ticketed welder? and if not, will you have any issues either with the engineering approvals, councils permit department or the insurance companies due to the size of the structure and or public liability?

Good luck building your shed.

Cheers

Ed.

 

[JD7710]

Hi JD7710, good to see your on the right path, a decent large machine will work wonders with heavy fabrication and you can always dial it down for the light welding. My Unimig was too light for the work I do and so when the Unimig fried the circuit board I decided to go the whole hog and install 3 phase, bought a used Miller Autovision 456, which is basically a unit for robotic welding, but with a bit of modifying and a remote wire feeder I can now use it as a basic MIG and haven't looked back since.

I also don't have to worry about duty cycles anymore as it's rated at 450A at 100% and 560A at 65%, not that I use those sort of amps as the max I have ever needed to use is 350A, but I can also dial it down to use 0.6mm wire and down to about 70A, so it does nearly everything I need.

If you get a decent MIG that does at least 350A-450A it should cover virtually everything that you will do. Plenty of good used, not to old, brand name machines out there ie; Miller, Lincoln, Kemppi, Ewm, Migatronic ect. I am partial to inverter types myself as they have better control of the welding parameters and very cheap to run. The right gas is also important, if you are going to do a lot of heavy fab stuff then Argoshield Heavy would be the way to go but if you do more light to medium fab stuff than Argo Universal or even a 93,5,2 mix. A thing to watch out for when running the high amps is heat distortion, heavy plate is not easy to straighten.

I don't think that anyone has mentioned it previously, but are you a ticketed welder? and if not, will you have any issues either with the engineering approvals, councils permit department or the insurance companies due to the size of the structure and or public liability?

Good luck building your shed.

Cheers

Ed.

Just getting back to this !, no not got tickets in mig but I have all of them for stick.

I now also have just purchased a Muxex Transmig353 with Transmatic 4x4 feeder so now have the required power to knock the frame up. Shouldn't take long all the cleats and stiffeners I've made already even tho I work alone a couple of weeks should see it done and painted.

 

[DrNik]

Don't forget you'll need plenty more than a 13amp supply whatever process you need