Welding 1/4 aluminium advice

[yorkie_chris]

Morning,

I'm looking at building a structure on my boat, potentially out of ally. Looking at using 6mm plate for the skin and 1/4 section box and angle for the framework.

I've done a small amount of TIG work with aluminium before but as this structure is going to be around 4m wide x 5m long x 2m high I want to investigate MIG for speed and ease of tacking etc.

Has anyone got any experience with spool guns they would care to share, what size machine (180A plus head room to give a decent duty cycle?) to look at etc.


I was looking at the R tech MTS255S and the RT-SG-250 spool gun, but I do have access to a couple of other welders with a euro fitting if I went for the more expensive push pull gun it would be slightly less cash outlay and probably save some money on wire not having to buy 0.5kg spools.

Absolute best would be if anyone has a similar setup anywhere in the NW (regularly travelling between Bradford, Bacup and Lancaster) that I could come and have a play with the kit and pick your brains.

Cheers

Chris

 

[Brad93]

180A isn't enough to weld 6mm aluminium. You want about 230A for that thickness

 

[Brad93]

@Hood might sell you his MTS which has built loads of boats

 

[Brad93]

A push pool torch needs to work with that exact machine you can't just pick something off the shelf.

 

[Hood]

Think I am just going to hang on to my MTS255s just in case the unthinkable happens to the EWM Phoenix

Regarding the MTS however, it surprised me in its capabilities. I was expecting it to be border line for 1/4" Alu but it breezed that no problem.
One thing is the synergic lines are useless, or for Alu at least, don't know about Stainless or Steel as I never Mig them.
Having said that using in manual mode was easy enough and worked well.
Drawbacks to the spool gun were the fixed straight neck and the relatively short length of the lead, 5m as opposed to the 8M I had previously been used to.
I altered my spool gun to accept the neck from my other spool gun and that way I could fit a swan neck and rotate to the required angle.

 

[Hood]

Regarding the other welders you say you have access to, if they are big enough then your other option would be to get a TecArc spool gun, they have the control electronics inline with the welding cable and thus no need to fit circuit boards inside the welder/wirefeed unit.
It was a TecArc SGS360 that I used when I had the Esab L401 Mig.

They may however have spool gun compatibility, if they do then the R-Tech spool gun may work but that would depend on things like motor voltage etc.

 

[yorkie_chris]

Regarding the other welders you say you have access to, if they are big enough then your other option would be to get a TecArc spool gun, they have the control electronics inline with the welding cable and thus no need to fit circuit boards inside the welder/wirefeed unit.
It was a TecArc SGS360 that I used when I had the Esab L401 Mig.

They may however have spool gun compatibility, if they do then the R-Tech spool gun may work but that would depend on things like motor voltage etc.

Cheers, that gun is the same as the one R tech sell but they offer an inline/no PCB spool gun as well. Looks pretty similar to be fair just no spool and an extra £200.

 

[yorkie_chris]

180A isn't enough to weld 6mm aluminium. You want about 230A for that thickness

Seems alright on thicker stuff with the 180 there, but I don't know what duty cycle you'd get.

 

[Hood]

Cheers, that gun is the same as the one R tech sell but they offer an inline/no PCB spool gun as well. Looks pretty similar to be fair just no spool and an extra £200.

Yes, that is the Technical Arc spool gun that they are selling, also the PushPull is the TecArc one. The PushPull will be more expensive (£100 roughly) likely because it has a torch liner the full length where the spool gun doesn't require that.

 

[Brad93]

Seems alright on thicker stuff with the 180 there, but I don't know what duty cycle you'd get.

Double boosts videos are great but that isn't what I would call a well wetted or good penetrating aluminium weld. It can stick two bits together but is it going to be strong?

I've used an ESAB rebel at 215A and made okay welds on 6mm. Nothing to write home about, but they were biting in there.

 

[yorkie_chris]

Cheers Brad will be looking more towards the 250A machine I think

 

[slim_boy_fat]

I've noticed that the latest version of R-Tech's 180A machine has a front connector for a spool gun, which mine [2 years old] doesn't.

Would fitting a Teflon liner to my existing Euro connector lead + U-groove rollers allow me to try alu welding?

Their website indicates it ought to be simple, "Fit the Teflon liner into torch, alloy U-Groove rollers (steel are v-groove) and aluminium welding tips, connect pure argon gas and you are ready to MIG weld aluminium". Is it really that straightforward?

With this for example, along with the appropriate tip size https://www.r-techwelding.co.uk/mig-wire-4043a-aluminium-1-0mm-0-5kg/

Could be a cheaper way to experiment with something I've wanted to try but been put off by the cost of the gun? I already have pure Argon.

 

[Brad93]

Yep it really is that simple. You will want 1.0mm 5356 wire.

4043 will be too soft for your simple rtech machine.
You'll need a 4 roller feed unit, short torch and a lot of patience to feed 1.0mm 4043.

5356 feeds much better as the wire is somewhat stiffer.

4/5mm thick Aluminium will be about the max you can do with 180A

 

[Brad93]

Also buy the best Aluminium wire you can afford.
Cheap wire doesn't make for good welds.

ESAB stuff is good. As is bohler.

That wire you linked is a small 0.5kg spool for a spool gun. You need a 5kg or 15kg spool for a normal mig.

 

[slim_boy_fat]

You'll need a 4 roller feed unit

Thanks, Brad. Would I be right in thinking that's likely to be the expensive part of the 'exercise'? I just wanted to give it a go as it might be a handy thing to master at some point in the future.

You need a 5kg or 15kg spool for a normal mig.

Presumably just because of the different centre fitting?

 

[Hood]

Thanks, Brad. Would I be right in thinking that's likely to be the expensive part of the 'exercise'? I just wanted to give it a go as it might be a handy thing to master at some point in the future.

That was with 4043 wire which is very soft, as Brad said 5356 will be fine, it is a magnesium alu alloy and is much stiffer although not so fluid in the welding.

Presumably just because of the different centre fitting?

Yes but if you can rig something up give me a PM with your address and I will send you a roll of 1mm 5356 to try, I have quite a few as I used to use them in the spool gun but now I have the PushPull gun I use full rolls.

 

[slim_boy_fat]

That was with 4043 wire which is very soft, as Brad said 5356 will be fine, it is a magnesium alu alloy and is much stiffer although not so fluid in the welding.


Yes but if you can rig something up give me a PM with your address and I will send you a roll of 1mm 5356 to try, I have quite a few as I used to use them in the spool gun but now I have the PushPull gun I use full rolls.

Very kind of you, can I just confirm the existing feed unit will be OK with the rollers swopped out for U ones, 1mm tip(s), and a Teflon liner? I'm sure I'll be able to rig up a holder of some sort to accept the small centred roll?

 

[Hood]

Very kind of you, can I just confirm the existing feed unit will be OK with the rollers swopped out for U ones, 1mm tip(s), and a Teflon liner? I'm sure I'll be able to rig up a holder of some sort to accept the small centred roll?

Yes, should be fine, I welded Alu for 10 plus years with single roll wire feed units and a normal mig torch before I got the first spool gun. You just have to try and keep the torch lead straight or with a long sweeping curve, no sharp bending.


Edit, when I said single roll of course I meant two roll

 

[Brad93]

Yep that's only for the 4043 wire you need a better feed unit.

 

[slim_boy_fat]

Excellent, lads! I'll order up the bits needed and send you [ @Hood ] my details by PM in due course.

Much appreciated, both