Ally welding help

[Lee Patterson]

 

[Lee Patterson]

 

[Lee Patterson]

 

[Richard.]

The balance is one setting I rarely touch once set. It's a % of how much of the AC wave is in which polarity.
By going more into the negative your putting heat in the work peace so penetration is high AC cleaning is low. Go more towards the positive and your putting heat in the tungsten which will start to melt it and create the ball on the end. Penetration is reduced and cleaning is increased. I keep mine set at about 65-70% in the negative half wave.

 

[Lee Patterson]

So is going more positive if you are welding up some nasty old ally? Is there a trick to fine tuning the balance it is it not a critical setting?
Thoughts on the cheap foot pedal?
Have you finished laughing at my test welds?! The first bit it's hard to see the bit I did as there are old welds either side.
Is there a good table or online source for giving a guide to weld current based on ally thickness and joint type? The one I found seems to give low values generally based on where I am now.
Cheers
Lee

 

[Richard.]

I would only go deeper into the positive wave if I was welding a cast Alu which is a different ball game all together.
The name "balance" says it all. You need enough ep cleaning so that your pool is clean and like a mirror when your welding but you need enough en penetration to ensure the tungsten stays stable. You need to first work out on your machine what the range is on your machine. Set it to around 70% en or 30%ep and you'll not be far off.

 

[Richard.]

Cold aluminium rough rule of thumb is 40amps per 1mm thickness.

 

[Richard.]

The run done in the vice is done far too hot far too slow and contamination is throughout.
Have you cleaned it after welding as I can't see any etched zone around the bead which is the white residue created by the ep% removing the oxide layer. I also see a very grainy looking bead quite similar to others I've seen with silicon based filler that's been run to hot/slow/bad balance settings.

 

[Lee Patterson]

Thanks for the feedback.. So my machine works on the ep by the look of it. I have the dial set around 30%.
I have wire brushed over the weld after doing it. There was some residue there before. this material is about 1.2mm thick so I may have had the machine a little high. About 55-60amps. Filler wise I am not sure what my rods are off hand. I remember they were were something for welding a wide range of ally's? I should be able to find out. The weld on the thicker bit came up shiner and cleaner for sure. I think the base metal is probably 5083 it feels pretty soft. It is of the shelf sheet.
You said silicone based rods as that was a bad thing?

 

[Leetig]

Hi lee. As Richard said 40 amps per mm is the rule of thumb but for cold ally! The idea is to use lots of amps to get the puddle going ASAP and get moving. Once the material gets heat soaked your amperage or travel speed will have to be adjusted. The silicon based rod will be a 4043 and does leave a grainy appearance as the silicon come to the surface. Your welds do look very dirty so I advise you clean material thoroughly but don't forget that the rod could be introducing contaminates into puddle so well worth a wipe with acetone. How clean are your tig glove,hand?

 

[Richard.]

4043- 5% Si and 4047-12% Si. These are renowned for the grainy finish. To hot and slow is a common cause as is not enough ep cleaning, contaminates, even inverter harsh square wave is a theory I've heard to elaborate it as it's not something that happens on transformers to my knowledge.

 

[Lee Patterson]

I can confirm my rods are 4043. Should I get different ones or is it more aesthetics? The welds are not structural and largely will be hidden from view. Would be nice to have good looking welds too! Should I try and turn the ep up a bit? I probably could clean the work piece more. Gloves are well used but not oily or anything. Wire brush is not a new one but appears clean. Maybe I should get a fresh one. Can you wipe with thinners or alcohol as well or will either of these have an adverse effect?
Thanks
Lee

 

[Richard.]

You Should not be limiting yourself . 4043 is a good rod and technique/settings should be the focus not filler change. You could try 5356 (5%mag) see how you get on but certainly don't dismiss the silicon based fillers

 

[Lee Patterson]

I agree.. I need to get techniques nailed first! Just wanted to be sure I had not set myself a more difficult task than needed. I will try lower current first as was having to move pretty quick. I will double check the thickness if the sheet.
In the instance that you are welding a thicker bit to a thinner bit do you go with suitable current for the thicker bit and try and concentrate the arc more to that side?

 

[Richard.]

I agree.. I need to get techniques nailed first! Just wanted to be sure I had not set myself a more difficult task than needed. I will try lower current first as was having to move pretty quick. I will double check the thickness if the sheet.
In the instance that you are welding a thicker bit to a thinner bit do you go with suitable current for the thicker bit and try and concentrate the arc more to that side?

Yes or you'll melt the thinner piece and not even break through the oxide layer on the thick bit. I would concentrate on perfecting your technique first with some straight runs on some 3mm Alu plate before trying to attack some joints. There is no point in trying an outside corner joint before you can lay down a clean run.

 

[Leetig]

Lee it's a good idea to have seperate brush and gloves for alluminium. Sounds ott but it has to be spotless! There is nothing wrong with using 4043 rods but I find a 5356 has a better look. Richard is right in saying to try and practice on some thicker material. Don't get too hung up on balance settings either unless it's a filthy piece of cast I always leave it around 70 percent en. Alluminium can be very frustrating to crack but like everything it's all practice.

 

[Leetig]

What size rod are you using?

 

[hotrodder]

Tiny practice coupons makes life sooooo much harder, some decent sized coupons will make a much bigger difference than worrying about cleaning this, a few % balance or difference flavours of filler wire

To avoid wasting a load material the easiest method is to get some 50mm wide strip, cut it into lengths of at least 200mm and then tack a bunch of them together to create a coupon say 400 x 200mm. Make two of them and swap bewteen them as a way of controlling heat soak. For practicing fillets and outside corners tack them up like /\/\/\/\/

 

[Lee Patterson]

I think I am making progress. I had something else to cut up and play with. Out of test material now though. So hope these pass as useable welds?! First run I did I felt it was maybe not quite hot enough or moving a little quick? So I went up a bit on the amps and tried another run. The last part to me looks about the right level of weld to surrounding material and hopefully not too bad on the clean front? There was a bit of something either end hence the black marks. I paused halfway to avoid heat soak as I could see the weld flowing I that little bit more. Did that on both to be fair. I wire brushed and then wipe with neat alcohol prior to starting fyi.
Picture in following posts as before as it won't let me post more than one at a time for some reason?
Thanks in advance for the feedback and for sure I will get some strip layout for corner joints as suggested above.
Thanks
Lee

 

[Lee Patterson]