Welding Plasma Cut Aluminum

[Bigrhamr]

With steel if I am going to weld a air plasma cut edge I hit the edge with a grinder to remove the oxide(?) layer before welding. Is there any concern with that when working on Aluminum cut with air plasma? 5052 sheet, wire feed with pure Argon if it makes any difference.

Thanks for any pointers.

[jimcolt]

Bigrhammer,

On steel there is a small oxide layer, but the biggest problem for welding is the nitride hardening. By running a grinder over the edge you likely are removing this case hardened (about .005" thick) layer.

On aluminum, there are some oxides that cause a rough porous edge. If you are tig welding, the edge definitely needs ginding and cleaning. For Mig, it will make your weld better if it is ground smooth, although usually a good weld can be done on the raw surface.

On industrial plasma systems we use oxygen instead of air as the plasma gas for cutting steel...which leaves a 100% weldable edge. We use nitrogen and argon/hydrogen mixes for cutting aluminum and stainless with industrial plasmas for better weldability. Don't try these gases with an air plasma!

Best regards, Jim Colt Hypertherm

With steel if I am going to weld a air plasma cut edge I hit the edge with a grinder to remove the oxide(?) layer before welding. Is there any concern with that when working on Aluminum cut with air plasma? 5052 sheet, wire feed with pure Argon if it makes any difference.

Thanks for any pointers.

[coupebuilder]

We cut all our aluminum radiator shrouds on the plasma and the edges definitely need cleaned off for tig welding, however I have found a 6" single cut file works great and takes less time (and less likely to catch an edge) than a grinder for the small amount we need to clean up.

[gtj]

Noobie here. Researching plasma cutters and CNC tables.
I do more aluminum (1/8 to 1/2”) work, TIG welding parts after cutting out.
Questions:
1) how much material (aluminum oxide) is required to be removed from the plasma cut edge on air plasma cut aluminum for high quality TIG welds? ( Jim Colt mentioned .005” of the nitride layer on steel; is it similar for aluminum?

2) what amp plasma cutter is recommended to enable air plasma cutting handheld or machine torch, the 1/2” aluminum to obtain a high quality cut minimizing the post cut clean up required for TIG welding?

I’m leaning toward the Hypertherm Sync 65 once they become available next year and couple it with Crossfire Pro.

[adbuch]

Noobie here. Researching plasma cutters and CNC tables.


2) what amp plasma cutter is recommended to enable air plasma cutting handheld or machine torch, the 1/2” aluminum to obtain a high quality cut minimizing the post cut clean up required for TIG welding?

I’m leaning toward the Hypertherm Sync 65 once they become available next year and couple it with Crossfire Pro.

The current requirement will depend on the material thickness you plan to cut. I would personally recommend purchasing the Hypertherm Powermax 65 or 85 . Here is the cut chart for the 85 for aluminum below. For the time being I would probably steer clear of the new "improved" Hypertherm models until we get a chance to review some of the feedback from new owners. As you are probably aware, the consumables are much more expensive ($50 to $60 each per cartridge) and you would need one or more of these cartridges for each cutting scenario.

I have heard nothing but good things about the Langmuir crossfire pro. This looks to be a very good entry level table at a really great price, and with terrific customer support to boot.

David

Hypertherm 85 cut chart for aluminum.jpg (79.79 KiB) Viewed 2492 times

Hypertherm 85 cut chart for aluminum.jpg (79.79 KiB) Viewed 2492 times

[weldguy]

In my experience on aluminum you will need to remove much more than the .005" that was suggested for steel. Just eliminating the porous plasma cut edge on aluminum will have you removing 2-3 times that before the edge is clean enough for a good weld and on thicker aluminum you may have a little bevel on your edge which will make the cleanup even more time consuming before its weld ready.

[adbuch]

I agree with weldguy - the sides of the aluminum parts will be much rougher than steel, so will require more material removal for welding. In the past I have also used various brands of aluminum deoxidizer plus scrubbing with stainless steel wire brush to prepare for welding.
David

[gtj]

Thanks adbuch for the information. Much Appreciated.
In my area the Hypertherm machines are basically sold out with availability in March 22, only on the Sync models, as I was told production of the straight up Powermax systems are discontinued.
I'll check into the aluminum deoxidizer method you mention.

[gtj]

Thanks weldguy for sharing your thoughts.
I'm quite leary on the plasma cutter route for aluminum because of the extensive clean up required before quality TIG welds can be achieved.
What aluminum cutting methods do you use/recommend for parts that will be TIG (GTAW) welded after cutting on thicker aluminum (1/2")?
I adapted a wood track saw for straight line cuts and use a jigsaw on thinner aluminum, but it's the thicker aluminum and shape cutting that is causing me to look into an alternate method.
Smaller parts can be shaped on the lathe/mill, but the larger shaped pieces are limiting me.
Thanks

[adbuch]

I would probably grab up one of the 45xp machines while you can still get one.
David

https://www.weldingsuppliesfromioc.com/ ... jIQAvD_BwE

[SRdesign]

Thanks weldguy for sharing your thoughts.
I'm quite leary on the plasma cutter route for aluminum because of the extensive clean up required before quality TIG welds can be achieved.
What aluminum cutting methods do you use/recommend for parts that will be TIG (GTAW) welded after cutting on thicker aluminum (1/2")?
I adapted a wood track saw for straight line cuts and use a jigsaw on thinner aluminum, but it's the thicker aluminum and shape cutting that is causing me to look into an alternate method.
Smaller parts can be shaped on the lathe/mill, but the larger shaped pieces are limiting me.
Thanks

Have you looked into good quality cnc routers? They won’t cut as fast as a plasma because of the multiple depths that it would have to cut, but the cut quality would be good. I have a cheap hobby grade cnc router that just holds a dewalt router and I cut 3/4 aluminum plate with it for my plasma table build.

[gtj]

Hey SRDesign.
That’s an interesting concept. I understand the cut with an endmill in a router would be a weldable edge with minimal cleanup, so big plus there.
For a CNC setup, I imagine the drag the router/endmill cutting process would cause, would likely necessitate a significantly “beefier” gantry and motor setup?
Or are you taking multiple passes with several thousands of a depth per pass?
What table do you have and would you recommend it?
Other recommendations?
I’ll do a search and see if it brings up anything.
Thanks

[SRdesign]

It would be best for you to look into commercial grade router tables if you were going to go that route. I have a “hobbyist” table that holds a router. You would want a table that would have a spindle. It would be capable of removing much more material per pass. It took me many hours to cut my gantry plates for my plasma table on my cnc router, but it was designed for light duty aluminum projects, not 3/4 aluminum plate. Adbuch is building a router table he purchased from avid cnc that has a tool changer. Something along those lines might suit you well. There are other companies out there that sell good quality tables, I’m just not too familiar with them because it’s not something I’ve ever shopped for. I think shop Sabre sells router tables too

[adbuch]

Any of the Avid CNC Pro series will work fine.
https://www.avidcnc.com/pro-cnc-machine ... 47_54.html

[adbuch]

Here is a recent thread where I posted some photos of my Avid cnc build. There are also some links to demo videos of the Avid cnc with 3hp spindle machining aluminum plate.

viewtopic.php?f=3&t=33136&p=203277&hili ... nc#p203277

Here is one showing the Avid cnc Pro 4848 cutting 1" thick aluminum plate. I own this exact machine, but use it for wood. I am putting together a smaller 4824 table for machining smaller aluminum parts.
David

https://www.youtube.com/watch?v=jHSfDhyhWgU