HELP. Small aluminum welds

Date 12-12-2008 21:57

Hello Gonzo, I believe you have been given one of those tasks that should be returned to sender for a rethink. Having said that, does this "part" end up being something like a spool? Could you apply the welds in an over-sized condition and have the extra material machined off afterwards? Or better yet, have the parts machined on a CNC lathe in one piece from 2" stock. Unless I'm missing something here, machining from a solid 2" stock would be the more economical and less technically challenging choice.
Having to pre-heat, messing with properly welding the thin end plates to the solid center part, dealing with warpage and distortion issues, and not losing tensile strength at the same time sounds like a nightmare to me. .090" and .100"+ fillets on something like this is a feat in itself and I would congratulate you on even accomplishing that. I'll be looking to learn something right along with you on this one. Best regards, Allan

By Lawrence (*****)

Date 12-12-2008 22:58

Agree with Allan,

Inch and a half thick aluminum is not going to accomodate small fillets with GTAW.

They could be reduced in size somewhat with technique or an inverter power supply with frequency control and asymmetric current control of the AC cycle.

GMAW or GMAWP on a turntable would be the best way to reduce fillet size and heat input if the thing must be welded.

By Milton Gravitt (***)

Date 12-13-2008 01:18

Do you think you could DC these parts (just a thought).
MG

By gonzo

Date 12-13-2008 01:55

I've tried DC with 99.99% helium and just can't get it
to the rigth dim .The puddle goes wideas soon as it starts ....
thanks ....MG

By gonzo

Date 12-13-2008 02:02

Good afternoon Mr Lawrence
thank you for your help I'm still trying to see if I
can tweek My miller enough to reduce the fillet size
I'm glad alot of you sir's and lady's.....
are willing to help out
thank you .......gonzo

By danny midlash Date 12-15-2008 02:42

everything that you did sounds right. Are you dipping the wire? try making your weld puddle and laying the wire in it.

By RonG

Date 12-16-2008 20:33

I am guessing by 1/6 welds you meant 1/16"

What are you using for filler wire (Dia.)?

By gonzo

Date 12-17-2008 17:40

Sorry my bad typing. Yes its 1/16".0625
I was able to pass the parts with .090 welds on them
but I still need to figure out how to make them smaller
I keep geting parts with 1/16" weld call outs thank you..
for the correction .........Gonzo

By RonG

Date 12-17-2008 22:55 Edited 12-17-2008 22:59

Okay, but I really was asking what OD filler wire are you useing .035"-045" 1/16"?

I have made welds that small with Aluminum (a long time ago) but I was using a Plasma machine and .045"wire. Pretty tough wire to work with manually.

By 803056

Date 12-18-2008 04:27

I would try using DCEN with helium gas. Try EWTh-2 tungsten, maybe 1/16 inch diameter ground to a point and then blunted on the end. Use 0.030 inch diameter filler metal.

I imagine one of the problems you are experiencing is that the thin material melts before the thick material does. Try starting your puddle away from the thin disk and work the puddle up to the thin material after the puddle is stable.

Cleaning has to be just before you start welding. Wire brush the parts with a dry stainless steel brush that has be cleaned with 90% isopropyl alcohol. Flush the parts (do not wipe with a rag) after wire brushing to remove all surface oxide. Let the parts air dry and then assemble for welding.

I would not normally recommend preheating aluminum and in this case I would attempt to weld the parts without preheat.

Let us know what does work for you.

Best regards - Al

By gonzo

Date 12-19-2008 02:34

Hello Mr Al I got those parts out ...I had 14 of them and they had to be within .002
parallel to each face and all there just a small bar clamp with some shields
I had them do all the boring and machining on the solid bar it help a lot
but i still didn't get .0625 weld on them I'll try on the next job what you sugest ...
and thank you for your time ........and thank all of you for taking the time to help out
and teach cause this place is like a school to me I've learned a lot in almost a year
that I've been here I really apriciate your help thank you...........gonzo

By 803056

Date 12-19-2008 15:19

We're all happy to offer our suggestions and I for one appreciate your feed back on the results of your efforts. It sounds like you were successful. A satisfying out come for all of us.

Have a Merry Christmas and a prosperous and Happy New Year.

Best regards - Al

By Tommyjoking (****)

Date 01-25-2009 20:14

This would be difficult to impossible to achieve even with tiny filler wires and machined joints simply because of the differential in material thickness between your roundstock and your flatstock. I agree with Allen, they need to do a rethink on what they are asking because its not ache viable. If they can stomach the welds being machined down to tolerance then that seems like the best option.