Will it hold to weld…?

[sepani]

It would have been fun to see a picture from underneath of the flange that is screwed into the wooden deck in the first post..

this is how it looks

 

[Dan_Johansson]

Shouldn't be a problem for someone with a TIG welder and five minutes to spare to fuse that together...

If you lived closer, I could have done it...

 

[Stefan1972]

But it's practically set up to break... personally, I would have opened up the hole a bit so the pipe goes through maybe 5mm, and both welded around the pipe on the outside and bridged from the pipe to the mount on the underside with a piece of plate. Just a snippet on each side would be enough. That would make it significantly more stable, and a single weld won't be stressed.