On 16/04/2022, at 5:12 AM, Ian Park <parkianj@...> wrote:

Craig,

It is bolted on to the original pipe which is still welded to the bottom plate. If I took the bolts out it would probably slide off. 

Mine was moving from side to side. There was only one bolt holding the sleeve on (fore and aft) which suggests the white nylon insert is only at the top. I drilled a new hole across the bottom which locked everything in place. I’d tried tightening the bolts in the engine room before this. 

I guess at some stage I’ll have to address the rusting plate issue

Ian

On 15 Apr 2022, at 17:07, Craig Briggs <sangaris68@...> wrote:

Hi Ian,
     Your picture of the bottom looks exactly like mine. On top, though, I have only a single pipe going straight up to the seat. It seems pretty certain that a prior owner of your boat must have cut off the original pipe a few inches above the base and a few inches below the seat and then added the sleeve so it could be adjusted up or down, swiveled, or removed. A fine idea.
     In my case of not being able to tighten either bolt, the seat is rotating back and forth about maybe 3° or 4°. That causes it to hit the lazarette seat when you open that and to be quite wobbly when you sit in it.
     Short of cutting open the base, I suppose I could copy your sleeve idea but weld a small metal tab on either side at the bottom going down an inch or so over the base and bolt those tabs into the base to prevent any rotation.
     It would be great to know exactly how that pipe was fastened into the floor inside of the base - Joel or Olivier, any ideas?

Best regards,
Craig Briggs - s/v Sangaris / SN68  Tropic Isle Harbor, FL