Subframe/Factory Finished Ali........ Welding difficulties

Has anyone any 'preparation for welding' recommendations?
I sent my Subframe for welding the other day and the guy that did it (Ex Aerospace Engineer) found it a pain.
His thoughts were that it had been anodised or coated in something.
Laquered to prevent weathering, perhaps?
Any ideas how to make it easier to weld?
Bead Basting or polishing?

While I'm on,
can anyone recommend a good 'How To' guide to frame polishing coz I aint got a clue where to start and best equipment to use.

Thanks Guys.

Fringe wrote:Has anyone any 'preparation for welding' recommendations?
I sent my Subframe for welding the other day and the guy that did it (Ex Aerospace Engineer) found it a pain.
His thoughts were that it had been anodised or coated in something.
Laquered to prevent weathering, perhaps?
Any ideas how to make it easier to weld?
Bead Basting or polishing?

While I'm on,
can anyone recommend a good 'How To' guide to frame polishing coz I aint got a clue where to start and best equipment to use.

Thanks Guys.

Um Not 100% sure mate, I would give any ali that your going to weld a bleedin good clean by sanding it down & then degrease it properly, I can't say I've got a good knowledge of prep work when it comes to ali. As for frame polishing I think you start off with a course sand paper & then start working your way up to really fine wet & dry, I think your not meant to jump more than 80 grit at each jump & then start using a ali compound polish of sorts.

I'm sure Cabbie will come on & tell you exactly how to go about both jobs as he's da man when it comes to all that kinda thing

Ta Griz

Fringe wrote:Ta Griz

Your welcome mate, sorry I can't give you more help, you might be better off getting a ali polishing kit that you could put on a drill as I think sanding the frame will take a lot of work!

My welder had no problem with the subframe, I just added bits and he welded them on!

As for polishing the frame, take it to a polishers end of.

Thanks for the replys

Fringe wrote:
His thoughts were that it had been anodised or coated in something.
Laquered to prevent weathering, perhaps?

cabbie wrote:My welder had no problem with the subframe, I just added bits and he welded them on!

The welding gear should burn through any coating easily enough, but whenever welding, you should key/grind the area very slightly before a new weld so it's raw as can be, so you get the strongest weld possible.

cabbie wrote:As for polishing the frame, take it to a polishers end of.

Oh dear are your fingers still sore?

Took like 3 days to recover never again!